'01111411111 Wireles,. rld FEBRUARY 1986 95p

Synchrodyne receiver Forth for control

Compact disc mastering Loop aerial

Australia A$ 3l5 Denmark DKr 38 00 Robot electronics interface, Germany Dm 7 50 Greece Dra 360 00 Netherlands DR 9 20 Italy L 4 /0 0 land NI$ 4 80 Sparn Pts 421) 00 Switzerland SFr 8 00 Remote-controlled timer Singapore . M$ J 00 USA $ 4 00

www.americanradiohistory.com 4i/ 1Â1401 IL :1G oiriTHE HIGH TECHNOLOGY TEST INSTRUMENTS OF THE FUTURE

GRUNDIG OSCILLOSCOPES

M020: 20MHz DUAL - CHANNEL M022: 20MHz DUAL- CHANNEL OSCILLOSCOPE OSCILLOSCOPE WITH AUTOMATIC TIME 20MHz Dual channel oscilloscope RANGE 2 mV /cm with full bandwidth 20MHz Dual channel oscilloscope Automatic peak-value trigger Automatic time base selection TV line and field triggering Soft tuning for fast manual adjustment Add and invert (Both channels invertable) Triggerable 2nd time -base, guarantees error Internal graticule and X -Y operation free 'zooming -in' This 20MHz dual -channel oscilloscope has Hold -off control and Z modulation advanced facilities, making it easy -to -use, with Plus all the advanced engineering of the M053: 50MHz DUAL- CHANNEL all the ruggedness and reliability to meet your M020 OSCILLOSCOPE go- anywhere testing needs. Included is a peak -value trigger to ensure stationary displays. 50MHz Dual channel oscilloscope Automatic Triggering facilities allow clear display of even time -base selection complex signal shapes. Alternating 2nd time -base for expanded traces £275 Digital display of time- bases, for unambiguous measurements Suits advanced applications in pulse, data and video technology A 50MHz dual -channel oscilloscope. Time -base range is automatically selected and shown on a digital display. Like the M022, it has a Now, the world's first low cost 'scope with triggerable 2nd time -base, guaranteeing error - automatic time -base selection. Dual -range free 'zoom -in' on a selected area of the trace. 20MHz capabilities also include'soft tuning' in Performance with TV signals is particularly manual mode, so the 'scope leaves you free to impressive. carry out the measurement. £395 £995 GRUNDIG TV/VIDEO TEST EQUIPMENT

COLOUR GENERATOR FG 7 VIDEO GENERATOR VG 1000 PAL pattern generator Professional video generator 15 test patterns Comprehensive range test patterns of Multiburst facility to measure frequency Includes VTR head adjustment signal response Excellent signal quality 8 memories for rapid station store /recall External sync. facility Suitable for TV sets, monitors or VTRs RGB output Compact and versatile for field or laboratory Aprofessional broadcast -quality pattern use generator to meet the highest professiónal standards. Its special test card allows full visual assessment of the video system, including a FIELD STRENGTH METER ME90 special output for Fully automated field strength measurement precision testing of VTRs. £1650 LF radio to UHF TV in a single unit vc®oIMwoe v310000 Versatile test result selection Storage of received signal frequencies, for , Mt I- , 41111110pmmir rapid testing '04 D- I -... _ .'."t . - -= Alpha numeric display for station checks ITIi -, .il''1 Versatile enough to check -out TV receivers, Unattended monitoring with built -in results i ;- r- ...°...t-G..i= - 1o22,' monitors and VTRs, this compact generator is at printer home in the field as it is in the lab or workshop. Stereo decoding -- In addition to 15 monochrome and colour image Fully portable: integral battery and charger signals, further picture patterns can be achieved Microprocessor controlled for push- button by superimposition. Eight station frequencies can operation in all transmitter checks. The ME90 be recalled from memory for rapid test capability allows fast and accurate measurements in radio - even for special bands and TV bands, long wave to UHF. Versatile print and the IF output. £545 capabilities provide hard -copy confidence, whether routine or For further information and a colour brochure contact our Sales Office. continuous monitoring. All prices exclusive of carnage and VAT. Prices correct at time of going to press. A copy of our trading conditions is available on request. £2695 r r r- o r- Electronic Brokers Ltd, 140 -146 Camden Street, Q-,1 r== >. o L- r o 0 I d D London NW1 9PB Telephone: 01-267 7070 o o D.I r Electronic Brokers D L D ==D Telex 298694 Fax 01 -267 7363 ' ;;;',z` .' www.americanradiohistory.com Editor ELECTRONICS 8 PHILIP DARRINGTON Deputy Editor GEOFFREY SHORTER, B.Sc. 01 -661 8639 Technical Editor MARTIN ECCLES ire ess wor 01 -661 8638 Projects Editor over 70 years in independent electronics publishing RICHARD LAMBLEY 01 -661 3039 or 8637 (lab.) February 1986 News Editor Volume 93 DAVID SCOBIE 01 -661 8632 Number 1600 Drawing Office Manager ROGER GOODMAN FEATURES 01 -661 8690 BETTY PALMER Advertisement Manager Naiad robot trainer -4 17 BOB NIBBS, A.C.I.I. by K.H. Becker Forth in control 59 01 -661 3130 Interfacing the robot arm with by David N. Sands MICHAEL DOWNING Apple, BBC, Commodore and IBM The computer language Forth is, 01 -661 8640 computers. argues D.N. Sands, particularly ASHLEY WALLIS suited to the control of machinery. 01 -661 8641 He explains how. Northern and Midland Sales BASIL McGOWAN Data conversion 27 021 -356 4838 by M.E. Eccles Classified Executive Listing, by manufacturers, of a -to -d Timing by remote control SUSAN PLATTS and d -to -a converter i.c.s and 63 01 -661 3033 modules. by Peter Ferris Advertising Production This versatile self-contained Z80 BRIAN BANNISTER timer controls eight appliances with (Make -up and copy) 100 on -off settings using coded r.f. 01 -661 8648 Short -wave loop aerial 4 1 bursts injected in the mains supply. by G. Wareham Using Mukherjee's April 1985 design with domestic receivers. 68000 board - 5 72 by K.F. Coates Compact disc mastering 47 Guided tour of the Kaybug monitor by J.K. Watkinson software's 26 system calls. Current issue price 95p, back issues (if The confusion about p.c.m. available) £1.06, at Retail and Trade Counter, Units 1 &2, Bankside Industrial adapters and video recorders is Centre, Hopton Street, London SEI. explained, together with the Tel. 01 -928 3567. formats. Available on microfilm; contact editor. D.b.s. - a plan in search of 75 By post, current issue £1.30, back issues some users (if available) £1.40, order and payments to EEP Sundry Sales Dept, Quadrant Synchrodyne a.m. receiver 53 by Tom Iva11 House, The Quadrant, Sutton, Surrey by J.L. Linsley Hood An element of confusion still SM2 5AS. Tel. 01 -661 3378. attends plans for satellite television, Editorial & Advertising offices: Circuit details and setting up Quadrant House, The Quadrant, Sutton, procedure for the phase -locked in spite of two international Surrey SM2 5AS. oscillator. conferences. Tom Ivall explains. Telephones: Editorial 01 -661 3614. Advertising 01- 661 3130. Telex: 892084 BISPRS G (EEP) Facsimile: 01 -661 2071 (Groups Ii & Ill) REGULARS Beeline (300 baud): 01 -661 8978, type EWW to start, NNNN to end. Subscription rates: 1 year £18 UK News commentary 6 Circuit ideas and £23 outside UK. 33 Wireless world Student rates: 1 year £11.40 UK and Alvey's flagship. Power watchdog. £14.10 outside UK. H.d.tv. Simple AA battery Distribution: Quadrant House, The Prize-winning aids charger. Quadrant, Sutton, Surrey SM2 5AS. for disabled. to Telephone 01 -661 3248. Newapproach ) Subscriptions: Oakfield House, instrumentation amplifier - Perrymount Road, Haywards Heath, Communications 2 5 design. Sussex RH16 3DH. Telephone: 04444 commentary Shaft encoder counting. 59188. Please notify a change of address. USA: $49.40 surface mail, $102.60 Antennas. Q Q airmail. Business Press International Philips embrace MAC. 83 , 87 (USA). Subscriptions Office, 205 E. 42nd Early radio. Street, NY 10117. New products svi,chroavne ic::e.;er Forth Mr control Overseas advertising agents: see Amateur awards. back page. mastering Super-fast floppy. Compact disc Mu d" dl USA mailing agents: Expediters of Feedback 42 Speech recognition. Robot elechunic <<; ., the Printed Word Ltd, 515 Madison Suite 917, New York, NY Add-on current dumps r. New 6800 with MMU. Remote- eostmuedtimer Avenue, Super -fast 16/32 -bit 10022, 2nd class postage paid at New Indoor loop aerial. York. Postmaster - send address to the Maxwell. processor. See p.56 for full description of this above. cover illustration. ©Business Press International Ltd 1986. ISBN 0043 6062

www.americanradiohistory.com RADIOCODE CLOCKS LTD SPECIALISTS IN ATOMIC TIME, FREQUENCY AND SYNCHRONISATION EQUIPMENT NEW PRODUCTS MINIATURE RUBIDIUM OSCILLATOR MODULE Lower power, fast warm up, optional output frequencies, programmable frequency offsets. RUBIDIUM FREQUENCY STANDARD High performance, compact and rugged instrument. 2U rack or' /, MR case options. INTELLIGENT OFF -AIR FREQUENCY STANDARDS Microcomputer controlled instruments, directly traceable to N.P.L., precision ovened local oscillator, comprehensive monitoring and status information, real time synchronisation. LOW COST MSF FREQUENCY STANDARD Instant operation, directly traceable to N.P.L., self- contained portable unit, no scheduled frequency changes, 24 hr transmission, real time synchronisation

Off -air frequency Time code generators /readers " R ad i ocode standards Record /replay systems Intelligent time systems Intelligent display systems Clocks Ltd* Caesium /Rubidium based Precision ovened oscillators Unit 19, Parkengue, clocks & oscillators Time /frequency distribution Kernick Road Industrial Estate, Penryn, Master/slave systems systems Falmouth, Cornwall. Tel: Falmouth (0326) 76007 ( "A Circuit Services Associate Co.) CIRCLE6O Ft)If FURTHER DETAILS. Z80 CONTROL Z80 CARDMASTER CPU 416 Mhz Z80 CPU Sowter CP /M compatible 111 User transparent MULTI -TASKING Up to 32K EPROM & 16K RAM Watchdog crash Transformers protection., in the design and manufacture of several RS232 & RS422 Comms With over 45 years' experience 2' Z80a PIO (one uncommitted) hundred thousand transformers we can supply: On board bus buttering Nv Power -on jump hardware AUDIO FREQUENCY Euro -card constuction TRANSFORMERS OF EVERY TYPE The CPU card is supplied with a powerful three -way operating system. MCP - The Mwlrlaskmg Control Program. MONITOR/DEBUG - An enhanced version of the MCV monitors Commands include Single-Step and ereakpoint setting. YOU NAME IT! WE MAKE IT! MIRROR - MIRROR connects the CPU card to your C /PM computer. via the link. in such a way as to give the illusion of Cr PM running on the CARDMASTER CPU card. MIRROR itself is a two part program which effectively glees CARDMASTER direct access to your disk drive. (DISCS WITHOUT DISCS!). OUR RANGE INCLUDES Microphone transformers (all types), Microphone Splitter /Combiner transformers. Only T178.00 built and tested including the software subsystem. Input and Output transformers, Direct Injection transformers for Guitars, Multi- Secon- dary output transformers, Bridging transformers, Line transformers, Line transformers CARDMASTER I/O to B.T. Isolating Test Specification, Tapped impedance matching transformers, Gramo- phone Pickup transformers, Audio Mixing Desk transformers (all types), Miniature 2 Z80 PLO's transformers, Microminiature transformers for PCB mounting, Experimental transfor- 32 110 lines ÿ # mers, Ultra low frequency transformers, Ultra linear and other transformers for Tran- + 50% PCB free for prototyping ( ` sistor and Valve Amplifiers up to 500 watts, Inductive Loop Transformers, Smoothing Onboard port mapping Chokes, Filter, Inductors, Amplifier to 100 volt line transformers (from a few watts up to t ¢t: Eurocard construction isiiî'iti É 1,000 watts), 100 volt line transformers to speakers, Speaker matching transformers Customising service available (all powers), Column Loudspeaker transformers up to 300 watts or more.

We can design for RECORDING QUALITY, STUDIO QUALITY, HI -FI QUALITY OR P.A. c.rsmm PO, inn CM l 0 boato s ..r ors and tloas, orcmis ar. QUALITY. OUR PRICES ARE HIGHLY COMPETITIVE AND WE SUPPLY LARGE OR SMALL QUANTITIESAND EVEN SINGLE TRANSFORMERS. Many standard types are in Only [54.95 - PCAE28.50 stock and normal dispatch times are short and sensible. OUR CLIENTS COVER A LARGE NUMBER OF BROADCASTING AUTHORITIES, MIXING CUB MICROCONTROLLER DESK MANUFACTURERS, RECORDING STUDIOS, HI -FI ENTHUSIASTS, BAND GROUPS, AND PUBLIC ADDRESS FIRMS. Export is a speciality and we have overseas 280 CPU clients in the COMMONWEALTH, E.E.C., USA, MIDDLE EAST, etc. Send for our ques-

4 x 1 0 lines) Z80a PLO's (64 tionnaire which, when completed, enables us to post quotations by return. Z80a CTC 4K Battery backed RAM 2K sup.) 4K EPROM (2K MCV2.0 sup.) Powerful monitor (MCV2.0) Eurocard construction Ltd. Tne E.A. rie very popular CUB microcontroller is the ideal solution wnere stand alone controller s requued CUB fully support. Sowter Manufacturers and Designers ii'e powerful Z80 mode 2 interrupt structure. Single. step 8 breakpoint commands le MCV2.0 provide excellent debuggi g tools, The CUB is available built A. tested or as a bare PCB. E.A. SOWTER LTD. (Established 1941): Reg.No. England 303990 PRICES: Built 8 Tested T104.95 Manual only E4 50 The Boat Yard, Cullingham Road, Ipswich IP1 2EG, Suffolk Prices include carriage Please add VAT eU 15% P.O. Box 36, Ipswich, IP1 2EL, England

WC ELECTRONICS Little Lodge. Hopton Road, Theinetham, Diss, Norfolk IP22 1 JN Phone: 0473 52794 and 0473 219390 Telephone: Diss (0379) 898313 Telex 987703G Sowter CIRCLE 48 FOR FURTHER DETAILS. CIRCLE 33 FOR FURTHER DETAILS. 2 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com COUNTERS & OSCILLATORS LEVELL OSCILLOSCOPES LEVELL COUNTERS MET100 /600/1000 (99/126/175 CROTECH SINGLE TRACE 20MHz 3031/36 £195/216 8 digit 0.5" LED display. 5Hz to 100'600-1000MHz. 2rnV-10V /div 4Ons- 0.2s /div. Component tester. Resolves 0.1Hz. Sensitivity 5mV up to 10MHz. Low pass for INSTRUMENTS 3031: CRT 1.5kV 5x7cm. 3036: CRT 2kV 8x10cm. filter. Mains /rechargeable battery powered.

CROTECH DUAL TRACE 20MHz 1 @2mV) 3132 29 LEVELL FUNCTION GENERATORS TG302/3 £156/236 2mV-10V /cm. Ch1 ±Ch2. X -Y mode. Cal 0.2V 1kHzf sq. 0.02Hz-2MHz in 7 ranges. Sine, square, triangle, pulse and 40ns -0.2s /cm. Auto, normal or TV trig. Component ramp 20mV to 20Vpp from 50C). DC offset 0/± 10V. TTL comparator. DC outputs. Z input. CRT 2kV 8x10cm. output. TG303 also has a CMOS output and 6 digit 10MHz counter with INT EXT switch. CROTECH DUAL TRACE 30MHz ( @5mV) 3337/39 £425/570 LEVELL RC OSCILLATORS TG152D/DM £95/120 5mV- 50V /cm. Ch1 ±Ch2. Signal delay. X-Y mode. 3Hz- 300kHz. 5 ranges, acc 2 %+ 0.1Hz up to 100kHz, 4Ons -1 s /cm. Auto, normal or single shot trigger. Cal 0.2V 3% at 300kHz. Sine or square <20Q V to 2.5Vrms. Distn. 1kHz square. Z input. CRT 10kV 8x10cm. <0.2% 50Hz- 50kHz. DM has an output meter. 3339: VDU mode. Component tester. DC outputs.

LEVELL RC OSCILLATORS TG200D /DMP £130/165 HAMEG DUAL TRACE 20MHz ( @2mVl HM203-5 f270 1Hz -1MHz. 12 ranges, acc 1.5 % +0.01Hz to 100kHz, 2mV-20Wcm. Ch2±Ch1. X -Y. Cal 0.2V -2V 1kHz sq. 2% at 1MHz. Sine or square outputs <20Q.V- 7Vrms. 2Ons -0.2s cm. Auto, normal or TV trig. Component test. Distortion <0.05% 50Hz -1 5kHz, Sync output >1V. DMP CRT 2kV 8x10cm. Long decay CRT f25 extra. has output meter and fine frequency control.

HAMEG DUAL TRACE 20MHz I @5mV) HM204-2 £365 LEVELL DECADE OSCILLATOR TG66A £330 1mV- 50V /cm. Ch2±Ch1. Sig delay. X -Y mode. Y out. 0.2Hz- 1.22MHz. 5 ranges. 4 digits, acc 0.3% 10ns- 1.25s /cm. Sweep delay 100ns -1s. Cal 0.2V /2V 6Hz- 100kHz. Sine output <34 V- 5Vrms. - 2d8! +4dB 1 kHz/ 1MHz. Z input. Comp. test. CRT 2kV 8x9 Ocm. and V scales. Distn.<0.15% 15Hz- 150kHz. Mains.battery.

HAMEG DUAL TRACE 60MHz ( @5mV) HM605 £515

1 mV -50V cm. Ch2± Chi . Sig delay. X -Y mode. Y out. ANALOGUE METERS 5ns- 2.5s. cm. Sweep delay 100ns -1s. Cal 0.2V 2V 1 kHz/1 MHz. Z input Comp. test. CRT 14kV 8x10cm. LEVELL AC MICROVOLTMETERS TM3A43 £150/170 HAMEG DIGITAL STORAGE 20MHz HM208 £1300 16 ranges 15pVfs /500Vfs, accuracy 1 %+ 1 %fs+ 11.V. 1mV50V1cm. Ch2 Chl. Single shot and X -Y modes. -- 20dB' + 6dB scale. ±3dB 1 Hz -3MHz. 150mVfs output. 2Ons-0.25s/cm. 20MHz sampling. Two 2K memories. TM3A: 83mm scale. TM3B: 123mm scale and LF filter. Plotter output 0.1V/cm, 10sicm. CRT 14kV 8x10cm. LEVELL BROADBAND VOLTMETERS TM6AB HITACHI BATTERY DUAL 20MHz ( V209 £680 £235/265 @5mV) 1mV- 12Vdiv. Ch1YCh2. X -Y mode: Cal 0.5V 1kHz. 16 LF ranges as TM3A /B + 8 HF ranges 1mVfs /3Vfs, 50ns- 0.5s 'cm. Auto, normal or TV trig. Internal accuracy 4% + 1 %fs at 30MHz. ±3dB 300kHz- 400MHz. rechargeable batt. or mains. CRT 1.5kV 5x6.3 cm. LEVELL DC MICROVOLTMETER TM8 £130 HITACHI DUAL 20MHz V212/22/23 £2991395/450 23 linear ranges ±3rV /±300V and ±3pA /-±300nA plus 2 1mV- 12V /cm. 20MHz@5mV. Ch1 ±Ch2. X -Y. Ch1 log ranges for nulling. Output ±300mV at fs. output. 100ns -0.5s /cm. Auto, normal or TV trigger. Cal 0.5V 1kHz square. Z input. CRT 2kV 8x10cm. LEVELL DC MULTIMETERS TM9ABP 199/235 f V222 V223: DC offset and alternate magnify. 18 voltage ranges 3pV /1kVfs. Current ranges 3pA to 1A V223 : Sweep delay 11.4s- 100ms. ITM9A 1mAl. Linear R ranges 31) to 1Gí1.

HITACHI DUAL 40MHz ( @5mV) V422/23 £580/650 LEVELL MULTITESTER TM11 £175 As V222N223 but 40MHz, 2Ons cm and 12kV on CRT. 5QN 500Vfs ac, 50pA /500mAfs ac, 15C}rV /500Vfs dc, 150pA /500mAfs dc, 0.20 to 100G0), linlog null. HITACHI QUAD 100MHz ( @5mV) V1050F £1095 Diode /LED test. Optional RF, HV and Temperature. Ch1 /Ch2: 0.5mV- 12V /cm. Trigger Ch3 Ch4: 0.2V /cm. Dual time bases 2ns -0.5s/cm and 2ns- 50ms'cm. Signal LEVELL TRANSISTOR TESTER TM 12 £195 and sweep delay. CRT 20kV 8x10cm. Transistor, diode and zener leakage to 0.5nA at 2V -150V.

Breakdown to 100V at 1 L A, 10Q A, 1 mA. Gain at HITACHI QUAD 100MHz V1070/1100A £1580/2390 1pA- 100mA. Vsat and Vbe at 1mA-100mA. Chi /Ch2: 1 mV- 12V /cm. CH3 /Ch4: 0.1 V- 0.5V /cm. Dual time bases 2ns -0.5s /cm and 2ns- 50msicm. LEVELL INSULATION TESTER TM14 £210 Digital display of set values. CRT 18kV 8x10cm. Log scale covers 6 decades 10MQ -10 T0) at 250V, V1100A: Digital display of ACV, DCV, frequency. 500V, 750V, 1kV; 1M -1TC) at 25V -100V; 100k- 100GC) LOGIC ANALYSERS at 2.5V -10V; 10k -1000 at 1V. Current 100pA-10QiA. HITACHI DIGITAL STORAGE 10MHz VC6015 £1350 5mV- 12V,cm. Chi ±Ch2. Single shot and X -Y modes. THURLBY LOGIC ANALYSERS LA160A /B £395/495 100ns -0.5s cm. 1MHz sampling. Two 1K memories. DIGITAL METERS 16 data channels. Clock DC -10MHz 120MHz for BI. Plotter output 1V /cm, 5- 10s /cm. CRT 2kV 8x10cm. Binary, octal, decimal, or hex. formats. 2K word acquisition memory. Non volatile ref. memory. HITACHI DIGITAL STORAGE 40MHz VC6041 £3850 LEVELL DIGITAL THERMOMETER DT1K £44 1mV -12V cm. Ch1 ±Ch2. Single shot and X -Y modes. 120 °C + 820 °C, acc 0.2 °/Q± 1 °C. 3 digit 8.5mm LCD. 2Ons -0.5s cm. 40MHz sampling. Two 4K memories. A standard Type K thermocouple socket is fitted. Bead Plotter output 1V cm. 2- 10s /cm. CRT 12kV 8x10cm. couple is supplied. Battery life >3000 hrs. BENCH POWER SUPPLIES THURLBY 8 CHANNEL MULTIPLEXER 0M358 £179 THURLBY DIGITAL CAPACITANCE METER CM200 £89 Increases any oscilloscope to 8 channels. Choice of trigger 1pF to 250(20F, acc 0.2 %. 41/2 digit 9mm LCD. Fast THURLBY SINGLES PL154/310/320 £159/125/155 from any channel. Response DC- 35MHz. settling. 3 readings per second. Mains /battery. LED digital displays with resolution 10mV, 1 mA. <0.01% change for 50% load change. Remote sense. THURLBY DMMs 1503/1503HA/1504 f169/185/199 154: 0 -15V 04A. 310: 0 -30V 0-1A. 320: 0 -30V 0 -2A. 4F0 digit LCD. Up to 1.2kVdc, 750Vac, 10A, 32MC). LEVELL DECADE BOXES 4MHz. Resoln. 14V, 10nA, 10mí). Mains battery. THURLBY DUALS P1310QMD /320QMD £269/339 1503: dcV 0.05 %. 1503HA: 0.03%. 1504: True rms ac. Two 0 -30V 0 -1A 12A on 3201 with isolated, series tracking, series or parallel modes of operation. C410 : 10pF to 111, 110pF, acc 1 %±2pF. f45 THURLBY INTELLIGENT MULTIMETER 1905a £349 R401 1410) : 4 decades. 111010 steps, acc 1 %, £45 5'a digit LED. Up to 1.1kVdc, 750Vac, 5A, 21MC). THURLBY TRIPLES PL310K/320K £275/345 R601 (610): 6 decades. 111010) steps, acc 1 °° £58 Resoln. 1pV, 1nA, 1mO. dcV 0.015 %. Computing and 310K: 0-30V at 0-1A, 0-30V at 4,A & 4V-6V at 31. A R601S : 6 decades. 10 steps, acc 0.3 °0 £69 storage functions. RS2321IEEE interface options. 320K: 0-30V at 0 2A, 030V at 1A & 4V-6V at 7A R701 : 7 decades. 10 steps, acc 1% £66 FREE DELIVERY IN UK. VAT EXTRA. QUANTITY DISCOUNTS AVAILABLE, Moxon Street, Barnet, LEVELL ELECTRONICS LTD, Herts., ENS 5SD, England Telephone:01 -440 8686 & 01 -449 5028

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com DAIWA TRIO pmr equipment swr /power meter 900 to 1300 MHz. NS 44

TK702R TK802R Frequency range 900 to 1300 MHz, impedance 50 ohms, power range Compact control head with remote mount transceiver for flexibility and forward 5/20W, reflected 1.6/6.6W, connections N type. ease of installation. Scan and priority channel scan, for either carrier or tone, utilizing NS448 cross needle power /swr meter £60 inc vat, carriage £2.50. microprocessor control. Up to 32 synthesised channels. Rugged die -cast chassis contruction. High performance receive /transmit circuitry. Large selection of accessories. High quality external speaker. Professional quality microphone. (TYPE APPROVAL PENDING.) LOWE ELECTRONICS Chesterfield Road, Matlock, Derbyshire DE4 5LE l Telephone 0629 2817, 2430, 4057, 4995 Telex 377482 LOWLEC G CIRCLE 68 FOR FURTHERl',Il UI:"I' \ I I S. AFFORDABLE ACCURACY NEW DISCO ELECTRONIC CENTRE 120 WATT DISCO Twin Decks Twin Speakers I3oacao 730 QUALITY MULTIMETERS FROM ARMON FAMOUS LOUDSPEAKERSSPECIAL PRICES 380 WATT Disco Twin Decks Twin speakers 7410 Larr 730 Console nog, 6145. 120 watt Powered Console 1199 .car, f 10 SIZE POWER SIPNYRIein 5 YOMIXAL MAX TRAME DIMFXBIOXI er e f APPLICATION PRICE PHI Warn PA CABINET SPEAKERS. 4 or 6 or 16 ohm 75 wall 24 17 t NI Sandsh 0r tern Cone full Range n0 f £5690 watt 32.17 11075. 150 watt E84. 200 wag er00. 400 cone fvs p rI150 l' watt E 150. 300 watt MID N TOP £125. cary 110 each m R

11 Ner.ne care e wer (1150 f I RCS SOUND LIGHT Ready Built Deluge 4 Channel 4,000 watt w to 20 Naafnl i ern Sange '5.05 n chaser - speed programme controls £69.P. C2 New Model Mkll 20 for Gums. PU Pn!fun ()50 fl withh special 16 programmes 4 channel 4.000 watt 084. Post C2 25 Gomm Woo. (750 fl Bin JO WAa i* caler 19 n xpf, WnwrAW 75 (I DELUXE STEREO DISCO MIXER /EQUALISER L E D. V U display 5 50 IAN f. R,AYN edrw Coe Noe. f'IB o band graphic equaliser. left right fader, serachxble inputs for phono OA. f2 line. mike Hne Recor ny.A.1r £129 DELUXE E145 Post 52 Sooty t a.n Can .11flnse III f2 Aone H,Lams r f2 PROJECT CASES Aluminium Base. Black Steel Top

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The price of entertainment

Possibly one or two well -heeled technical standards which can major change sometimes. In all will have to be thrown out. readers may have received by -pass the shortcomings of our Britain , the last occasion came And simultaneous transmission satellite dishes in their present system. In Japan, an with the introduction of u.h.f. tv of the new programmes on Christmas stockings. If so, they 1125 -line, 60 -field standard, and the closure of the v.h.f. existing channels will be will probably be too busy devised by Sony and adopted by stations. Though costly for the possible only via complex watching Mirrorvision, the Japanese broadcasting broadcasters, it went virtually standards converters (at a Teleclub, RAluno and the rest corporation NHK has already unnoticed by the public. quarter -of-a- million pounds a to worry much about the future been chosen for the d.b.s. But high -definition tv is a time, according to one source). of tv: no doubt they think they service to come into operation different matter all round. At a We can expect few viewers or already have it. there in 1988. stroke, the Sony system makes broadcasters to show much The mushrooming satellite tv The CCIR has so far shown no all existing equipment obsolete, enthusiasm. industry is installing small taste for this system. But there both in the studio and the Surely a much better solution 12GHz terminals as fast as it can will be pressure from other viewer's home. This would not is that proposed in Britain by the get them and already there are 60Hz countries, notably the US, necessarily matter but for the IBA and outlined elsewhere in many in private hands. But even to adopt it as a de -facto world enormous cost of its this issue. The IBA has charted though the high -street rental standard. replacement. a coherent hierarchy of chains can now offer you a This pressure ought to be The audience for the new improvements to the existing system on monthly instalments, resisted. For all its qualities - service will have to find standard, a ladder which satellite tv is likely to stay very and the pictures and sound it simultaneously the price of a viewers and broadcasters could much a rich man's toy. gives are all that could be satellite terminal (the wrong ascend each at their own pace. Of course, true d.b.s. desired - the Sony system is side of £1000 at current prices), The biggest step is still the television for all has yet to arrive quite unsuitable for a public the cost of a special tv set, plus a first one, the adoption of C -mac in Europe. But when it does, it is service. contribution, somehow or other, in place of Pal. But with the hard to believe that the price of For one thing, it breaches the to the huge expense of making move towards modular tv terminals will fall to the levels cardinal principle of technical the programmes. The special tv receivers and the development which the public is willing to pay innovation in broadcasting, set is perhaps the most daunting of special C -mac i.cs, there is no for conventional aerial which is that you launch a new part. Imagine the cost of a reason why it should add installations (which is to say, development only when you super -high resolution c.r.t. or significantly to the viewer's pratically nothing). have found a way of making it projection tv with a 5:3 aspect costs. And the EBU has already And now the prospect of still compatible with existing ratio, plus the special processor declared its support for C -mac. greater expense is on the equipment. This principle made needed to recover the The goal at the top of the horizon for satellite tv- possible stereo sound, colour tv, compressed video signal! IBA's ladder is just the same, watchers, with the introduction teletext and many other Costs at the transmission end true high- definition tv. But of high- definition tv. Satellite improvements of which the are just as dizzying. Camera, reached this way, it could be transmission gives the perfect casual viewer is unaware. telecines, v.t.rs, production affordable. opportunity to introduce new Certainly there has to be desks, distribution equipment,

Steve Webb developed a system for receiving data from the two UOSAT satellites to keep his daughter Jenny, and his two other children, amused. The system, known as Astrid (see WW New Products Oct. 1985), is now being marketed worldwide and has found many enthusiastic users in schools, receiving news and data from space as well as pictures of the earth and cloud formations; useful for amateur weather forecasters. World's largest satellite network Linking 93 locations in 52 and one over the Indian ocean. countries for Explo 85, an Similar channels have been international congress of 15 booked on the European million Christians, BT regional satellite and on International claim that this was domestic satellite systems over the biggest link-up of its type N. America and the Caribbean, ever. They have organized Brazil and the Indian sub- global satellite links before, for continent. The major satellites events such as the Olympics, the transmit signals between World Cup, and the recent Live continents; the signals were Aid concert. For the congress then retransmitted to local BT booked broadcast quality tv satellites for reception on channels on three Intelsat locally -sited small -dish vehicles, two over the Atlantic anntennae. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com were impressively realistic, market, which seemed likely to though they still looked like adopt the NHK standard, Enhanced C -mac television - in contrast to appeared to see it mainly as a In the wake of Sony's overnight. He said that Sony's, which have the medium for electronic demonstrations of the 1125 -line broadcasters would find it appearance of a superior kind of production for the cinema tv system chosen for the difficult to finance such a cinema picture. Even so, the rather than as a broadcast forthcoming d.b.s. service in changeover; a high- definition film grain on 35mm telecine was system in its own right. Japan, Britain's Independent service would be an expensive noticeable at close quarters. Yet Describing the IBA system in Broadcasting Authority has luxury in its early days and the option to enhance resolution more detail, Dr Gary Tonge been showing the results of its revenues would take a long time later on by increasing the outlined the changes which own work on improved to build up. number of lines still remains would take place, both at the television standards. In the IBA demonstration, open under the IBA's scheme. studio and in the viewer's home. 'Evolution not revolution' is live pictures came from a Link For comparison, two First, PAL pictures would give the slogan adopted by the IBA. Electronics 625 -line camera conventional colour monitors way to C -mac as d.b.s. For whilst the Sony -NHK modified to give the extra width showed the same pictures transmissions were introduced. system (December MAC had been issue, page 5) shown to fit well represents a major into a satellite break with existing channel, and C -mac transmission decoders (which systems, the IBA would use chips aims to reach a now at an advanced high- definition stage of standard gradually, development) through a series of would not add orderly greatly to the cost enhancements to of a receiving the present terminal. Then the European standard. system could be And in enhanced by stages demonstrations to give a wider staged at their image, more lines London displayed per field headquarters in and reduced flicker. December, IBA So enhanced C- engineers showed a mac would reach transitional high - the same targets as definition system Sony's h.d.t.v., but based on modified by an evolutionary 625 -line equipment route rather than and their C -mac transmission This off- screen photograph shows the 5:3 aspect direct. Viewers - and system. ratio of the IBA's system. When the camera moved broadcasters - could pay for Tom Robson, the IBA's closer, the Debussy arabesque on the music -stand whatever level of quality they director of engineering, while could be read clearly enough to be played. required. Dr Tonge added that saluting the achievement of the the quality of the present Japanese engineers, stressed demanded by the 5:3 picture through an ordinary C -mac demonstration system might be the drawbacks of their aspect ratio, and there were decoder and in PAL form after enough to satisfy many. approach. "The 1125/60 system inserts from video recordings transcoding. And it could be But in addition, enhanced C- is not satisfactory to Europe and and telecine. All signals, with seen that the double scan of the mac could offer features such as should not be accepted as a accompanying stereo sound, wide -screen monitor reduced high -quality stereo digital sound worldwide system ", he said. were coded in the enhanced C- field -rate flicker very (up to eight mono channels were A major problem was the mac system (by which the effectively, disposing of one of available), data transmission, 60Hz field rate, since three - analogue luminance and colour the major advantages claimed and scrambling of subscription quarters of the world used signals are combined by time - for the 60Hz system. tv programmes. 50Hz. And although standards division multiplexing, with a Mr Robson said that the Straightforward C -mac is conversion was possible, good separate time -slot given over to Japanese approach was based already recommended by the conversion was very expensive. data and digital sound). on 12- year -old technology and European Broadcasting Union According to another IBA Display equipment included a did not take account of recent as the standard for d.b.s. engineer, Sony's own h.d.t.v. fairly ordinary, though developments in tv equipment television services and it has the converter was rumoured to have modified, American -made design - such as the field -store support of major European cost over half a million pounds. projection tv (which cost, as the in the wide -screen monitor. electronics manufacturers, And standards conversion could engineers gleefully pointed out, (And indeed the charge -coupled including Philips; though at not cope with the 10Hz beat about a tenth of the price of delay -line i.cs recently present it is in active use by only which arose when 60Hz Sony's); and a Barco shadow - developed by Philips mean that one broadcaster, Norway. So equipment was used under mask monitor fitted with a field stores should be appearing how quickly could the enhanced 50Hz studio lights. Japanese tube and some special in 625 -line domestic sets very version be put into practice? "If But one of the most serious electronics, which gave a soon.) Yet it might take years the IBA was given the go-ahead objections, according to Mr sequential scan of all 625 lines at for domestic receiver to appoint franchise -holders for Robson, was that direct change a 50Hz repetition rate (twice the technology to match the quality a satellite channel, it would take to any new system such as normal rate) simulating the line - which had been shown in four years to get the channel Sony's would mean making all structure of a 1250 -line picture. h.d.t.v. demonstrations. ready ", said Mr Robson. "We existing equipment obsolete The large-format pictures And he indicated that the US could be ready then." ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 7

www.americanradiohistory.com As has been predicted for Prize - winning aids for the disabled some time, the compact disc can be used to store Cedric the computer allows the words and there is also a visual prizewinner was Cedric's computer data and used user to select words, letters or keyboard to "type" out letters inventor, Andrew Downing, like a rom. Hitachi have symbols from a video screen by and words. There is no senior lecturer in electrical and produced CD -Rom. Each sensing the direction of eye attachment to the user but a electronic engineering at disc has a read -only movement. It was designed for headrest is recommended for Adelaide University. memory capacity of use by those with high -level comfort and stability. Small The other prizewinner was 552Mbits and the data paralysis and loss of speech and head movements are allowed Peter Donaldson, chief engineer transfer rate is 176Kbit /s. was a winner of the IEE Prize for, as is eye blinking. If the eye at the MRC neurological for helping disabled people. The moves out of range the screen prosthesis unit. The bladder other joint winner was a device display tells the user and waits controller treats incontinence for bladder control for for realignment. Each time the by electrical stimulation of the paraplegics. computer is switched on, it is sacral anterior roots in the The Cedric computer uses automatically calibrated to the spine. A receiver unit is planted very low intensity red light to user's eye. The computer can beneath the ribs and is reflect off either eye and be linked through an RS232 controlled by a transmitter held detects the point on a video port to a printer or other adjacent to it outside the body. screen to which the user is peripheral and can be used as a Signals from the receiver are looking. Selection is remote control system for connected by implanted cables Dr David Wright was accomplished by eye fixation environmental control, to to the nerves in the spinal awarded an Honorary on the desired word or control switch lights or appliances on column. Fellowship of the Royal can contain more than 1,500 and off, for example. The joint Television Society. He is a specialist in colour and Robert Hum is about to test a v.l.s.i. telecommunications worked in optics when he circuit in a GenRAD GR 18 i.c. tester. The tester, claimed Alvey's Flagship became involved in the to be the most advanced in the world, is capable of early development of performing 11 520 000 000 tests per second. So it would Flagship is the major television. The colour have completed 170 billion in it demonstration model for the system adopted by the about tests the time NTSC was based largely on takes to read this paragraph. Mr Hum works for Bell - Alvey advanced computer Northern Research in Canada on the development of research programme. Much Dr Wright's researches. v.l.s.i. circuits for Northern Telecom. The manufacture accent is placed on the need for He was Professor of of reliable chips depends on the ability of the research parallel processing and also on Technical Optics at centre in understanding how and why chips fail and then `declarative' programming Imperial College, and has on the ability to prevent such occurances. languages which improve the published many papers computer interface and enable and a standard reference the user to tell the computer work: The measurement what to do in plain language. of colour. The project is the joint responsibility of Plessey, ICL, The next generation of Manchester University and mobile telephone systems Imperial College, London. in Europe is under Manchester University has consideration at Ericsson. developed a data -flow computer Basing their researches on and Imperial College are the existing Nordic cellular working on Alice, a graph - system and on experiences reduction machine which uses in other areas of the world, about 200 Inmos Tranputers. Ericsson will present the Plessey's contribution will be results of their in speech recognition and deliberations to the synthesis and in v.l.s.i. design, European under the leadership of Dr. Telecommunications Keith Warren. Administration during We suggested to Dr. Warren this year. that task -specific transputers would be the next logical step in A better deal for disabled speeding up the processing, and and elderly telephone he agreed but said that they users is called for by DIEL, were already progressing an independent advisory beyond the Transputer and committee on Open technology were looking at bit -slice telecommunications for A technical college equivalent of centres are located throughout the processors, some of which may the disabled and elderly. the Open University has been country so that students can have be task-specific. They are particularly launched by Telford College, expert guidance when needed. The computers produced by concerned that the Edinburgh, called Teltec. Each Tutors can also work under contract this research are not aimed at research into low data -rate course consists of practical kits, to individual companies to provide replacing existing systems but visual phone system audio and video tapes and texts and in -house training. at doing tasks not previously should continue at Essex covers such areas as control and If Teltec does not offer a course University and that such instrumentation, electronics, required they can trace and request possible on a computer, in the areas of users should be relieved microelectronics, pneumatics and a suitable package from another especially from paying vat on hydraulics, electrical skills and participant in the Open Tech artificial intelligence and in computer appreciation. Tutorial scheme. user /computer interfacing. equipment and services. 8 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com THE WAY TO CONTROL...... switching, relays, heat, temperature, flow, alarm systems, lift control systems, management systems, refrigeration plants, kilns, furnaces, boilers, spray driers, production lines, bakery control, banking systems, plant & machinery, analysis, data acquisition. THE BBC BASIC* INDUSTRIAL CONTROLLER MULTI BASI C THE REAL TIME MULTI -TASKING ROM. Robust INDUSTRIAL NETWORK. ENABLE EVERY. Single Eurocard -can stand alone and ENABLE WHENEVER. run BBC BASIC programs. Full MULTI -TASKING Program control applications in with up to 8 background tasks BBC BASIC, FORTH, PASCAL running concurrent with the or any other language ROM. main program. Adds I/O expansion to your BBC BBC BASIC CONTROL via the 6502 Bus connector. powerfully enhanced. Tube Interface for fast development. 19 Industrial Network Commands. Runs BASIC programs in ROM or Control of INPUT /OUTPUT. from battery backed up RAM. Five real -time COUNTER/TIMERS. Battery backed up Real Time calendar clock. The ability to run REAL TIME PROGRAMS. A full range of Eurocards for use in target applications. Eight real -time TASK INTERVAL TIMERS. Fully BUS compatible. Also available for the BBC Micro.

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ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 9

www.americanradiohistory.com RAEDEK ELECTRONICS Telex2N 312242 DISTRIBUTORS FOR RICHARDSON ELECTRONICS MIDTLX G. 102 PRIORY ROAD, SCRIBERS LANE, HALL GREEN, BIRMINGHAM, B28 OTB. ENGLAND. TRANSISTORS: VALVES:

TYPE LIST: TYPE: LIST TYPE: LIST: TYPE: LIST: TYPE LIST. TYPE: LIST TYPE: LIST: L f f f f f f 2N3375 10.90 2SC1978 6 40 AH211A 137.50 EF94 2.00 043 250 6AU5GT 3.70 813 30.00 2N3553 1.60 2SC2053 0.80 4112511 90.00 EF95 1.60 0B2 250 6428 3.80 934 18.00 2N3632 12.95 2SC2237 13.00 AH2532 31.50 EF183 1 90 0B3 250 6BA6 1.50 935 41.20 2N3733 12.95 2SC2287 9.60 BT5 52 50 EF184 1.80 0C3 250 68E6 1.95 2050 4.80 2N3866 1.20 2SC2290 24.00 BT5B 52.50 EK90 1.40 2C39A 39.90 68H6 215 2050A 4.80 2N4416 0.75 MRF240 20.70 8T17 142.00 EL34 3.90 2C39WA 42.00 61116 2.00 5544 81.00 2N4427 1.40 BT17A 130.00 EL36 230 2D21 200 68K4C 4.50 5545 95.00 MRF245 33.00 BT95 125.00 2N5090 10.90 MRF247 ELB4 1.60 2E26 7.50 6BN8 3.50 5557 24.50 33.30 C3J 30.00 EL86 2.10 2K25 114.00 2N5109 1.95 MRF433 9.00 6BZ6 2.50 5559 52.50 C3JA 30.00 EL519 7.70 3 -400Z 7800 6C4 1.95 5727 2.95 2N5160 3.00 MRF449A 10.15 E55L 56.00 EL803S 9.95 3 -500Z 85.00 6CB6A 1 80 5867A 140.00 2N5589 760 MRF450 14.95 E8OCC 14.00 EL821 13.75 3828 15.00 6CJ3 2.30 5879 6.15 2N5590 7.90 MRF450A 14.95 E8OL 2100 EN32 16.25 3C45 24 50 6CW4 6.30 5965 2.20 2N5591 9.50 MR F454 17.25 E88CC 3.90 EN91 2.00 3CX100A5 35.00 6DC6 2.45 5991 32.00 2N5641 6.95 M R F454A 17.25 E90CC 7.50 EZ80 1 60 4 -65A 52 50 6E5 4.20 6130 24.50 2N5642 9.30 MRF455 16.50 E13oL 21.25 EZ81 1.50 4 -125A 60.00 6EA8 225 6146A 9.00 2N5643 11.85 MRF458 17.20 EB91 1.35 EZ90 1.50 4 -2504 76.00 6GK6 2.50 61468 9.00 2N5913 2.50 MRF475 EBC91 1.10 FG17 24.50. 4 -400A 80.00 6HF5 4.25 6360A 4.95 2.30 EBF89 2N5944 7.85 MRF476 2.15 1.35 FG105 160.00 4 -400B 8000 6HS6 3.95 6550A 7.25 EC90 1.25 GXU1 15.00 2N5945 10.10 MRF644 4 -400C 80 00 6J86A 420 68838 8.70 22.50 ECC32 325 GXU4 45.00 4B32 30.50 2N5946 10.80 MRF646 27.00 6JE6C 6.25 6973 3.95 ECC81 1.60 GZ34 2.10 4C35A 13500 6JS6C 4.70 7027A 6 50 2N6080 6.65 MRF648 32.70 ECC82 1.60 KT66 900 4CX250B EK7 2.50 7199 4.20 2N6081 8.40 MRF901 2.75 ECC83 1.60 KT77 8.75 EIM /AMP 55.00 61(11 2.25 7247 3.20 2N6082 10.50 SD1013 9.75 ECC85 1.85 KT88 24.95 4CX250B 6K D6 5.90 7262A 26.00 2N6083 11.20 SD1019-STUD 23.10 ECC88 2.00 ML8536 275 00 NAT 48.00 61038 2.00 7360 12.20 2N6084 12.00 SD1019-5 22.80 ECC91 2.00 ML8741 265.00 4CX350A 8700 6L6GC 3.90 7586 11.50 2SC1729 15.50 SD1127 3.10 ECC189 2.00 NL SERIES 4X150A 33.70 6L06 6.25 7587 35 00 2SC1945 3.45 SD1134-1 2.25 ECF80 1.50 00V02 -6 22.00 5AR4 210 6011 2.25 7591A 4.65 2SC1946A 16.00 SD1136 11.90 ECF86 1.65 00V03-10 5.30 5AS4A 210 6SL7GT 225 7815AL GE 48.00 ECF801 0V03 12 7.00 2SC1947 8.50 SD1143 9.40 1.80 5R4GYA /8 3.50 6SN7GTB 305 7815R 53.00 ECH81 2.30 0Y3 -65 57 50 5U4GB 2.10 6U8A 2.00 8122 101.00 2SC1969 2.10 SD1219 14.70 ECL82 1.90 0Y3-125 6300 5V4GA 2.50 12AT6 2SC1970 140 SD1272 10.95 1.50 8906AL 55.00 ECL86 1 60 QY4-250 69.80 6AH6 230 12AU6 1.70 15082 2SC1971 3.50 SD1278 13.75 1180 1.70 RG 1 -240A 1000 6AK5W 2.50 12AV6 2.00 572B 2SC1972 52.00 9.50 EF85 3.00 RG4-3000 90.00 6ÁK6 1.95 12BA6 1.80 807 2.90 EF86 2.30 XG1-2500 52.50 6AL5W 1.80 128A7 2.35 Also available Camera Tubes, Cathode Ray Tubes. 810 75.00 EF89 2.30 XG5-500 2450 6AQ5A 1.75 128E6 200 812A 36.85 Igourons. Eimac Power Tubes and accessories. EF91 2.95 XR1 -3200 72 50 6A05W 1 80 12BY7A 2.70 EF92 2.20 XR1 6400 12000 6AS6 2 40 12BZ6 3 70 American tubes EF93 1.50 042 2 00 6AS7G 4 30 12DW7 3 75

Prices: Are correct al little 01 going to press and may be slibleCI lu nlleraholl

V.A.T.: All prices are excluding V A I , please add 15 to ordii And postage. Terms: C W O Guarantee: All goods are of current production and sold with manulacturer s warranty Postage Packing: Add E1 00 to order CIRCLE 70 FOR FURTHER DETAILS.' CROFTON ELECTRONICS Toroidal

YOU OF THE OF YOUR MONITOR? Transformers ARE SICK SIGHT as manufacturers we are able to offer a range of quality Toroidal Transformers at highly competitive prices and fast delivery. Mail Order Price List 15VA 6.92. 30VA 7.18. 50VA 8.86. 80VA 9.92. 120VA 10.59. 160VA 12.10. 22VA 13.69. 300VA 14.77. 500VA 19.20. 625VA 22.09. 750VA 26.17. 1 KVA 42.22. 1.2KVA 46.79. 1.5KVA 52.06. 2KVA 68.95. price includes p +p &vat Available from stock in the following voltages:- 6- 0- 6.9 -0- 9,12-0- 12,15 -0 -15. 18-0- 18,22 -0 -22. 25 -0 -25, 30-0- 30,35 -0- 35,40 -0- 40,45 -0- 45,50 -0- 50,110,220,240(max.10 amp). Primary 240 volt. Quantity Prices and delivery on request (we also manufacture conventional El type transformers) Airlink Transformers. Unit 6, The Maltings, Station Road, Sawbridgeworth, Herts. Tel: 0279 -724425. CIRCLE 25 FOR Ft'IZ'l'HER DETAILS. ATTENTION ALL CIRCUIT DESIGNERS!! Many are, for unless it displays the capability of your equipment, you are losing out. LOW COST ELECTRONICS C.A.D. Our range is comprehensive - both open frame and cased, I.B.M. PC /XT, BBC MODEL B and SPECTRUM 48K "ANALYSER" computes the A.C. FREQUENCY RESPONSE of linear /analogue/ circuits. GAIN as well as monochrome and colour -sizes from 5" upwards. and PHASE, INPUT IMPEDANCE, OUTPUT IMPEDANCE and GROUP DELAY (except Spectrum version/ are calculated over the frequency range required. The effects on performance of Ring or write for details. MODIFICATIONS to the circuit configuration and component values can be speedily evaluated. Pictured is Thomson 1 S1 professional above the CM3131 Circuits containing RESISTORS, CAPACITORS, INDUCTORS, TRANSFORMERS, BIPOLAR and 12" High resolution colour. FIELD EFFECT TRANSISTORS and OPERATIONAL AMPLIFIERS can be simulated - up to 150 components (IBM version/. Ideal for the analysis of ACTIVE and PASSIVE FILTER CIRCUITS, AUDIO AMPLIFIERS, Technical Sales and Service LOUDSPEAKER CROSS-OVER NETWORKS, WIDE -BAND AMPLIFIERS, TUNED R.F. AMPLIFIERS, AERIAL MATCHING NETWORKS, TV I.F. and CHROMA FILTER CIRCUITS, LINEAR P.O. Box 6, Kington, INTEGRATED CIRCUITS etc. etc.. "ANALYSER" can greatly reduce or even eliminate the need to breadboard new designs. Used by INDUSTRIAL R 8 D DEPARTMENTS and UNIVERSITIES worldwide. VERY EASY TO Herefordshire HR5 3SX USE Prices from E20 ex VAT. ACCESS or AMERICAN EXPRESS welcome. For further details and example computation or the details on our NEW DRAUGHTING Telephone: (05448) 557 PROGRAM, please write. phone or telex' also at: NUMBER ONE SYSTEMS LIMITED TELEPHONE: 0480 6I 778 DEPARTMENT WW TELEX: 32339 35 Grosvenor Road, Twickenham, Middlesex. TW1 4AD 9A CROWN STREET, ST IVES Telephone: 01 -891 1923 HUNTINGDON CAMBS. U.K. PEI74EB

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Electronic Brokers Test & Measurement Instrument Distribution Disvision AUTHORISED DISTRIBUYO For the Leading Brands of Electronic Test & Measurement Equipment Philips, Fluke, Hameg, ICE, Thandar, From Colin, Compact Instruments Thurlby, GP Industrial, Claude Lyons, OSCILLOSCOPES Fluke 8026B C172 I.C.E. 680G C25 MISCELLANEOUS 3'12 digit, LCD, eight functions include 48 measuring ranges, sensitivity 20Kn/V, DC conductance audible continuity, true RMS, DC accuracy 2 %, 10cm mirror scale overload PRODUCTS accuracy 0.1ó1n. all 20 series DMMs have 2 year protection. warranty. I.C.E. M80 £19 Fluke80208 C173 40 measuring ranges, sensitivity 20Kn/V, DC %, range extend 3112 digit, LCD, eight functions include accuracy 2 wide of accessories conductance diode test, audible continuity, OC measuring capabilities. accuracy 0.1(ío. extensive over -load protection. PULSE, Fluke 80218 C139 FUNCTION, 31h digit, LCD. seven functions include diode test PATTERN GENERATORS Thandar TH 302 C80 and high speed audible continuity, DC accuracy Philips PM 5503 £155 Thandar digital thermometer, LCD display of °C 0.25 %, safety test leads provided. °F. range 40 °C to 1100 °C, resolution Pattern generator, 5 testpatterns for mono and and - 0.1° and use with type K probes (bead C114 for monitors, RF 1', for Fluke8022B colour, video output CCTV and supplied). 3112 digit, LCD six functions include diode test, output in VHF and UHF range, 1 kHz tone for Philips PM 3206 C286 OC accuracy 0.25 %, optional accessories sound checks. 15MHz, compact portable. dual trace. 5mV available to enhance all DMM measuring Thandar TG 101 C110 sensitivity, auto and TV triggering, variable time capabilities. Function generator 0.02Hz to 200kHz, sine, base speed Z modulation. Fluke JF77 C110 square, triangle, variable DC offset, TTL output. sweep, 10Vpp output into variable 3112 digit, LCD with analogue bar graph, external auto /manual ranging, DC accuracy 0.3 %, touch 600n. and hold facility, supplied with carrying holster. Thandar TG 102 C160 Function generator 0.2Hz to 2MHz, sine. Fluke JF 75 C88 square, triangle, TTL output. variable DC offset, 3112 digit, LCD with analogue bar graph, external sweep, 20Vpp output into variable 500. auto /manual ranging, DC accuracy 0.5 %, seven Thandar TG 105 C105 functions include diode test and audible \ continuity. Pulse generator 5Hz to 5MHz, iOnS. amplitude 0.1V to 10V into 50n, free -run. gated or Thurlby OM 358 £179 Fluke JF73 £72 triggered modes. TTL output, pulse width Thurlby multiplexer expands any oscilloscope to 3112 digit, LCD with analogue bar graph, auto variable 100nS to 100mS. 8 channels, displays analogue or digital signals. ranging, DC accuracy_0.7%, six functions Thandar TG 501 C295 triggering from any channel, band width 35MHz, include diode test, all 70 series DMMs have 3 Function generator 0.005Hz to 5MHz, sine precision calibrated attenuator. year warranty. square. triangle. ramp, pulse, TTL, variable DC Fluke JF 25 C193 offset, variable start/stop phase, 20Vpp into variable 50n. 3112 digit, LCD with analogue bar graph, sealed Homey HM 203 -5 C270 ruggedized construction. auto ranging, DC COUNTERS & 20MHz. dual trace. add and invert, maximum accuracy 0.1%. touch -hold facility, extensive sensitivity 2mV automatic and normal overload protection. COUNTER /TIMER triggering, X -Y operation, component tester. Thandar SC 110A C175 10MHz, battery powered portable, bright line and economy triggering for battery conservation. TV frame and line triggering. Sensitivity 10mV to 50V. Thurlby CM 200 C89 BENCH & HANDHELD Thurlby digital capacitance meter 4112 digit LCD, DMMs 1pFto 2500AF range, accuracy 0.2%, fast Thandar TF 200 C175 settling, battery or mains operation. S Counter, 10Hz to 200MHz, 8 digit LCD, battery v powered. 10mV sensitivity, time average period. totalize and reset. TP 600 pre- scaler, 40MHz warm to 600MHz available at £45. Thandar PFM 200A C76 Fluke JF 27 C218 Counter, 20Hz to 200MHz, 8 digit bright LED. 3'12 digit, LCD with bar graph, ruggedized battery powered. 10mV sensitivity. resolution construction, auto ranging, DC accuracy 0.1 %. 0.1 Hz. selectable gate times. mains adaptor and touch -hold facility, min -max and relative mode TP 600 pre -scaler available. operation. Thandar TM 351 C115 POWER SUPPLIES Philips PM 2519/01 C299 3112 digit, LCD, 29 ranges of measurement. DC Thurlby PL 154 C159 Tachoprobe C70 4112 digit, LCO with analogue bar accuracy 0.1%, diode test, battery life typically 0 to 15V, 0 to 4A bench power supply, twin Compact tacho-probe for use with DMMs or graph, auto/manual ranging, 4000 hours, complete with batteries and test LED displays meter voltage and current. high frequency counters. 2 speed ranges from 100 frequency to 1 MHz, true RMS, dB, leads. stability and resolution. remote sense facility. to 280,,000 RPM, accuracy 1 %, non-contact relative reference. Thandar TM 451 C195 ran 1m. 4112 digit, LCD display with function legends. EB90 C7 Philips PM 2518X/11 £199 auto/manual ranging, DC accuracy 0.03 %, x 1 oscilloscope probe. 4 digit, LCD with electroluminescent sample /hold facility on all ranges. audible E881 £10 display, auto /manual ranging, true continuity. s 10 oscilloscope probe. RMS. dB, relative reference. current to 20A. PM 2518X/01 without Thandar TM 355 £85 EB95 C13 illumination £145. 3112 digit, 0.5" bright LED. 29 ranges of x 1 and x 10 oscilloscope probe. Fluke8010A C243 measurement, DC accuracy 0.25 %. battery or 3'12 digit, LCD, 10A current range, seven mains operation. diode check, supplied with test LINE CONDITIONERS functions include conductance, diode test, true leads. Claude Lyons LVC 250 C271 RMS, DC accuracy 0.1%. 8010A Ni -Cd battery 2.54, 600VA rating, line voltage conditioner. version 0279. fast response (typically 1112 cycles), isolated Fluke8060A £306 ANALOGUE 0kk input/output, compact and portable for easy 4112 digit, LCD. ten functions include installation. conductance, diode test continuity, dB, MULTIMETERS Claude Lyons LVC 65 C186 frequency, true RMS. DC accuracy 0.04 %. Thurlby PL 320 C155 0.65A. 156VA rating, line voltage conditioner. relative reference mode. Philips PM 2505 £165 0 to 30V. 0 to 2A. bench power supply. constant unaffected by frequency variations, transient Fluke8062A C245 62 measuring ranges. 10Mn input impedance. current or constant voltage, precise current limit and noise suppression All LVC units have 2 year 4112 digit, LCD, seven functions include diode linear resistance ranges, audible continuity, control and monitor system, ripple and noise warrantly. test and continuity, relative reference, DC automatic polarity indication, low power <1mV. consumption. accuracy 0.05 %. true RMS. self diagnosis test. Thurlby PL 310 £125 EPROM PROGRAMMERS Fluke 8024B £220 I.C.E. 68OR C32 0 to 30V, 0 to 1A, bench power supply, meter GP Electronics UV 141 C88 3'12 digit, LCD. eleven functions include peak hold 80 measuring ranges. sensitivity 20Kn/V, DC accuracy 0.1 %, resolution 0.01V and 0.001A. EPROM eraser, variable electronic timer, on voltage and current. audible and visual logic accuracy 1%. 12cm mirror scale, overload DC output switch, load regulation <0.01% for powerful UV source. up to 14 device capacity, level detection, DC accuracy 0.1%. protection. 50% load change. convenient tray loading with safety interlock.

Electronic Brokers are leading suppliers of electronic test & measure- Visitors are welcome to our showrooms where all products are on ment equipment. Our Distribution Division handles the major names in the display and demonstration. For customers wishing to order by phone. we industry and all products are stocked in depth in our spacious new premises offer a 24 hour answering service. at Camden Town. ready for prompt despatch to all parts of the country. All prices are exclusive of VAT and correct at time of going to press. Electronic Brokers offer full technical support and expert advice on all Carriage and packing charges extra on all items unless otherwise stated. aspects of electronic test and measuring. A copy of our trading conditions is available on request.

II r ° 1 ° Electronic Brokers Ltd r1 °l , r q -JI U r I o Ii r ° ° o( H 140 -146 Camden Street London NW1 9PB Electronic Brokers °1 7, ] 7, II r ' ;I Telephone 01 -267 7070 Telex 298694 CIRCLE 80 FOR FURTHER DETAILS. www.americanradiohistory.com CONGUIN SOFTWARE LTD Low Cost IBM PC Based CAD Systems VUTRAX smARTWORK The comprehensive PCB design system The PCB Artwork Editor for the engineer in a * Schematic capture hurry. It understands electrical connections and * Auto placement is therefore easier to use than AutoCad. * Auto routing * Auto routing * Technical drawing facilities * Plots artwork on Epson printers or HP * 32" by 32" drawing size and Houston plotters. Upto 10" by 16" * Upto 8 layers * artwork * Upto 8000 pads * Single or double sided * Supports various graphics options * Powerfull, but easy to use * Runs on IBM PC * Plots artwork on Epson printers or a range of pen plotters. * Can interface with AutoCad * Runs on Apricot, Sirius, IBM PC /AT /XT smARTWORK requires IBM PC. 192K RAM, dual and most compatiables. disk drives, COLOUR graphics card. Software from £1200. The smart buy at only £895.00 (+ £15 P &P) Demo system £70.00 Demo disk £25.00

AUTOCAD General 2D drafting package einne.M1 A range of three IBM tt IN IM, MOM C with auto -dimensioning. Will support a -"a === compatible machines, variety of graphic displays and output the PC, XT and AT. devices. PERSONAL COMPUTERS Prices from £1,599 Software from £1,000 Note: All prices exclude VAT and are subject to change without notice. Conguin Software Ltd, Freepost, Morden, Surrey SM4 1BR Phone: 01-640 9130 CIRCLE 50 FOR FURTHER DETAILS. RSD CONNECTIONS LTD MONITOR LEADS RIBBON CABLE (Price per ftl IDC SHROUDED HEADERS BBC to Microvuec E2.20 Grey Rainbow WITH EJECTING TV to Computer E1.25 9 -way .13 .24 Green Screen E2.95 10 way .15 .28 LOCKING ARMS BBC to Fidelity etc. E4.95 14 -way 18 .32 Straight Right R. WITHERS QL to Fidelity etc. £4.95 15 -way .20 .36 Angled COMMODORE to Fidelity etc. 16 -way .22 .40 10 way 85 90 E4.95 20 -way .30 .50 14 - w £1.00 C1.20 15 way E1.25 E1.45 Phono to Phono E 1.25 24.way 36 .60 20 way E1.40 E1.60 AGENT TO THE STARS! BBC to Ferguson E2.50 25'way 40 65 26 way £1.70 £1.95 QL to Microvnec £2.50 26 -way .45 .70 Ja way E2.00 £2.30 -way RWC are main agents /distributors for Yaesu, Icom, 0 to mono monitor E1.50 34 .60 .80 40 .0 £2.15 £2.45 BBC to Sony 'Kaga £5.95 37 -way .65 .85 .ay £2.30 E2.65 Kenwood, M.Modules, Jaybeam, Tonna, Revco BNC to BNC E2.95 40 way 70 .90 M way 1245 E285 COMMODORE to Ferguson £2.50 50 -way 95 E1.25 Antennas, Cleartone, Mutek, AKD, Drae, FDK, Welz, Tait BBC to Hitachi £2.50 60 -way E1.10 £1.40 DIP HEADERS SONY to Fidelity etc. E6.50 64 way E1.15 E1.50 DIP 14 90 and Neve Radiotelephones to name but a few! We also MSX to Ferguson E2.50 DIP 16 95 QL to Ferguson £2.50 DIP 21 £140 stock a wide range of B.T. approved cordless telephone EXPORT & HOME DIP 28 12.35 IDC AMPHENOL DM and telephone systems! TRADE ENQUIRIES Ju4mp made 36 -way plug £4.95 leads to order E5.95 INVITED 36 -way socket INLINE MALE HEADERS 36 way plug Isolden type) £4.95 D CONNECTORS E3 28 TUNE INTO OUR SPECIALIST DISK DRIVE LEADS Solder 26 way E3.63 Dual disk drive power lead E4.50 Bucket Male Female 34 way 1409 Dual disk drive lead 1R1 f 10.25 9 way .75 £1.00 40 way 1442 Single disk drive power lead E2.75 15 wav .95 £1 50 SERVICE! Single disk drive lead 1 m E7.25 25 way £1.50 £1.90 IDC D CONNECTORS We manufacture our own range of VHF 1 /UHF beam Disk drive exin. lead en £7.25 37 way £2.40 E3.25 Male Female AMSTRAD 2nd DRIVE £6.95 Hoods 95 9 way £2.70 E3.20 antennas 15 E3.20 E3 70 CASSETTE LEADS TELEPHONE CONNS 25 wav £3.80 (445 BBC to cassette E2.25 3 1590 E680 We're the only company in the UK that produces DRAGON to cassette £2.20 Surface master jack socket E3.75 i modular VHF /UHF Raycom power SPECTRUM to cassette El .25 SPECTRUM DRIVES amplifiers 115-50 BBC to Acorn cassette £2 25 Surface extn socket £2.50 Dual watts output) AMSTRAD to cassette £2.20 outlet adaptor E4.25 RS232 wAFA leao l m 110.50 Line jack cord 3mtr £1.85 CernroiirtswAFAm,,ntm E10.50 PRINTER LEADS 4 -core cable per metre 15p Mer.ra Etto lean 12" E6.00 We supply a large range of power transistors /modules BT plugs 48p ALL 1 METRE LENGTH SPECTRUM imported directly from Japan. BBC All surfac e units shuttered BY approved EXTENSION LEADS BBC serial E8.95 We supply /repair amateur radio AMSTRAD £16.75 CONNECTORS IDC eaññxer /business systems MEMOTECH £12.75 E10 50 EINSTEIN £12.75 Card Trans 2 Row 6 mat) Fto2Ms 11475 We check transceivers on our spectrum analyser - IBM PC E15.75 Edge PCB Socket 11 i, h rnSiOn cable ' E10 75 a SPECTRUM interface nl,F £12.50 for comprehensive report 10-way E1.20 £0.85 £080 One to RS 232 £9.75 EDGE CONNECTORS ATARI E15.25 14-way £0.90 Only supplier of modified Revco RS 2000 60- 520MHz MSX £13.95 16-way £1.60E1.20 E1.00 2323 way1ZX -181 E1.85 APRICOT E15.20 20 -way £1.90 E1.35 E1.20 2 - 28 way (Specleuml E2.10 extended coverage scanning receiver modified by RWC 26 -way £2.40 E1.60 El 45 DOUBLE SIDED PLUG BOARDS DRAGON £9.95 ZX -81 23 way E1.35 QL £10.75 34 -way £3.10(1.95 E1.60 Probably the UK's largest seller of used radio 40.way E3.40 £2.00 E1.85 Spectrum 28 -way E1.50 IDC ANY COMBINATION OF £3.85 £2.25 E2.00 ADDITIONAL equipment 50-way 56 way Card Edge for LEADS MADE TO ORDER 60 -way £4.80 E2.60 E2.25 Extension Lead £4.25 We offer the largest selection of radio allied services 75p P &P IN UK. Access & Visa accepted. Add 15% VAT to all orders under one roof Please contact us for details Cheques made payable to: R. WITHERS, 584, Bagley Rd West, Oldbury, RSD Connections Ltd, Dept WW 2 Warley, West Midlands PO Box 1, Ware, Herts. B68 OBS. Tel: 0920 5285/66284 Tel: 021 -421 8201 (24hrs) Telex: 334303 -TXAGWM -G CIRCLE 10 FOR FURTHER DET:VLS. 12 ELECTRONICS R WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Electronic Brokers Second User Test & Measurement Equipment Division THE SOURCE OFALL GOOD USED TEST EQUIPMENT;

This is just a sample of our Farnell Marconi SSG 520+ TF1245A 'O' Meter £1200 huge inventory - contact us TTS 520 Trans. Test Set £4250 TF1246 Oscillator £650 Hewlett Packard TF1247 Oscillator £650 with your requirements 214A Pulse Generator 100V £750 TF1313A LCR Bridge £775 801 1 A Pulse Generator £625 °TF2702 Inductor Analyser £1000 OSCILLOSCOPES 80076 Pulse Generator 100MHz £1650 Hewlett Packard 8015A Pulse Generator Dual 50MHz £1950 TV TEST EQUIPMENT 182T Scope Mainframe £1850 8018A Serial Word Generator £1650 Tektronix 1715Aopt.01.Storage Scope £2450 8601A Sweep Generator £1950 R148 PAL TV Generator £4400 1980B Scope System £4950 8600A Digital Marker £950 149A NTSC Generator £2950 Hitachi 8616A Signal Generator 1.8- 4.5GHz £4000 520A NTSC Vectorscope £3750 V1100 Scope £1050 Marconi 521A PAL Vectorscope £4400 Tektronix TF2002AS AM /FM Signal Generator £950 690SR TV Colour Monitor £1950 °465B/DM44 Scope 100MHz £2100 TF2002B AM /FM Signal Generator £950 1485R TV Waveform Monitor £3500 475A Scope 250MHz £2500 Scope 350MHz £4950 GENERAL PURPOSE T & M 634/1/20 Monitor (As New) £950 AF SOURCES Fluke Scope 100MHz £1650 Hewlett Packard 515A Calibrator £1450 4346 25MHz Storage Scope from £1950 4204A Decade Osc (New) £595 887A8 Diff. Voltmeter £1500 2445 150MHz Scope £2475 Wavetek 931 B Diff. Voltmeter £850 5223 Scope Mainframe £3600 185 Sweep Generator £650 Hewlett Packard 5403/041 Scope Mainframe £1950 184 Sweep /Function Generator 5MHz £750 *3437A DMM £1500 °166 Pulse /Function Generator 50MHz £1750 6A OMMms £1950 TEKTRONIX 7000 SERIES 3465A DMM £350 7603 Scope M/F £1950 DMM £495 R7603 Scope M/F (Mint) £2650 TEKTRONIX GP T & M EQUIPMENT 3468A AM501 Op Amp £300 3406A Sampling Voltmeter £1500 7623A Storage Scope M/F £3750 Data Aquisition Unit £1950 7633 Storage Scope M/F £7850 DC508A Counter 1.3GHz £995 3497A °DD501 Delay £300 69408 Multiprogrammer £1500 7704A Scope Mainframe £3200 Vector Voltmeter £2000 7904 Scope M/F £6850 DM 501/02 DMMI £200 8405A FG501 1 MHz Function Generator £325 8746B 'S' Parameter T /set £7650 7A11 FET P /In £1600 £725 7A19 600MHz Amp £1600 FG502 11 MHz Function Generator £565 467A Amplifer °FG503 3MHz Function Generator £300 641000A- 7A26 D T P /In £1650 M.D.S. Terminal £9000 7B50A Timebase £575 FG504 40MHz Function Generator £1650 041 PG502 Pulse Generator £1650 Marconi 7853A Timebase £585 -£985 RF Meter £1500 7685 Timebase £925 PG505 Pulse Generator £450 6460/1 Power PG506 Calibration Generator £1950 °TF2603 RF Millivoltmeter £550 °7D11 Digital Delay £1200 £750 Ditigal £850 PG508 Pulse Generator £1250 TF2905/8 TV Pulse Generator 7014 525MHz Counter TF2807A PCM Tester £1350 7M11 Delay Line £750 RG501 Ramp Generator £250 SC502 Scope £900 TF2809 Data Line Analyser £950 7S11 Sampling Plug In £1850 TF2828 Simulator £1250 7514 TOR Sampler £4500 SG502 Signal Generator £525 SG504 Signal Generator 245- 1050MHz £2100 TF2829 Digital Analyser £1250 7T11 Sampling Timebase £4000 TF2915 Data Monitor £1200 S1 Sampling Head £950 TG101 Time Mark Generator £1750 S54 Pulse Generator Head £600 TM501 Mainframe £275 Tektronix TM504 Mainframe £375 576 Curve Tracer £9000 ANALYSERS 178 Fixture £1500 Hewlett Packard COUNTERS & TIMERS A6901 Ground Isolation Monitor £275 332A Distortion Analyser £750 Fluke °16154 Logic Analyser £2200 HEWLETT PACKARD COMPUTERS 7220A Communications Counter 1.3GHz £595 2624B- °85588 Spectrum Analyser Plug -in £4000 1900A Counter 80MHz £150 °8559A Spectrum Analyser Plug -in £7500 005 -013 Terminal £1300 Hewlett Packard 26318 Printer £1250 8903A Modulation Analyser £4800 *5341A Microwave Counter 10Hz- 4.5GHz £1250 Tektronix 7221B Plotter £1200 *530013+ °9825A Desktop £2000 Data Analyser £2000 53058 Counter 1.3GHz £495 °3308 Spectrum Analyser 9862A Plotter £750 Marconi 9885S Disk Drive £500 10MHz -40GHz £7500 2437A 100MHz Counter/Timer £395 7001 /DF2 Logic Analyser £1900 2438 520MHz Counter /Timer £650 °TR502 Tracking Generator £2500 Systron Donner °7002 opt 01 Logic Analyser £2000 £6500 £500 60546 -05 Microwave Counter URGENT - We need to PM102 Personality Module purchase modern Tektronix and PM108 Personality Module £850 BRIDGES RF SIGNAL GENERATORS Hewlett Packard Hewlett Packard T & M Equipment E H Labs *427113 Digital LCR Meter £2950 - For the best price contact us. °1398 Pulse Generator 50MHz 10V £500 4342A 'O Meter £2100 Electronic Brokers are Europe's largest specialists in quality Electronic Brokers Guarantee second user test equipment. Established 17 years ago, we have Unless otherwise stated, all test equipment sold by us carries a 12 pioneered the second user concept in Britain, and many overseas month warranty. When you buy from Electronic Brokers you know the territories. To support our growth we have a skilled team. This includes equipment is in 'top notch' condition. It is refurbished in our own service trained sales staff, whose role is not only to sell, but provide a helpful laboratories and checked to meet the original manufacturer's sales information service to our many customers. Backing this team is our specifications. And it's serviced by our own highly qualified technicians. own service laboratory where technicians monitor each item of All prices exclusive of VAT. Carriage and packing charges extra on equipment we sell. Our maxim is service, and those who have dealt with all items unless otherwise stated. us will know that we endeavour to always live up to our reputation. A copy of our trading conditions is available on request.

i r -- ) h E Electronic Brokers Ltd

r : 140-14G Camden Street London NW1 9PB Electronic Brokers Telephone 01-267 7070 Telex 298694 CIRCLE 79 FOR FURTHER DETAILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 13

www.americanradiohistory.com O1 -208 1177 TECHNOMATIC LTD O1- 208 1177 BBC Computer & Econet Referral Centre DISC DRIVES TECHNOMATIC drives are fitted with high quality slimline mechanisms and are available with BBC B Plus with DFS £369(a) BBC B Plus with 1 28K kit or without integral mains power supply. The dual drive power supplies are switch mode type £389(a); BBC B Plus Econet (no DES) £360(a); and are generously rated. All drives with integral power supply are fitted with a mains indicator. All drives are supplied with all the necessary manual BBC B Plus cables, and a formatting disc. All drives Econet & DFS £399(a); BBC Dust Cover are capable of operating in single or double density modes. £450(d); Single Drives: PD800 2 x 400K 40/80T DS 1770 DFS Upgrade for Model B £43.50(d) 1 X 400K 40/80T DS: TS400 £99(b) £199(a) Acorn 2nd Processors: 6502: £169(a); Z80: £299(a) PS400 with psu £120 (b) Dual Drives: (with integral psu) 3.5" Drives TORCH UNICORN: Z80 Card: £199(a); Z80 Disc Pack: Stacked Versions: TS35 1 x 400K 80T DS £99 (b) £499(a) PD200 2 x 100K 40T SS f 195 (a) TD35 2 x 400K 80T OS £172 (b) TORCH Graduate G800/2 £699(a) META -ASSEMBLER. Both an editor and Macro-Assembler. Meta can assemble 3M FLOPPY DISCS most 65xx, 68xx, 6804, 6805/6305, 6809, 8048, 8080/8085, Z80, Industry Standard floppy discs with a lifetime guarantee Discs in packs of 10. 1802 and more. (Free updates due very soon - 68000 series, 8088/8086, 5' 4" DISCS 37," DISCS Z8000 etc.) Many advanced features including Macros, conditional assembly, 40 T SS DD £13(d) 40 T DS DD £181d) 80 T SS DD £30(d) /selective Global search etc. etc. Includes 16K Eprom, disc, function key card, 80 T SS DD £22(d) 80 T DS DD £241d) 80 T DS DD £38(d) and comprehensive manual. Please phone for comprehensive leaflet. Meta - Assembler £126(c) FLOPPICLENE DRIVEHEAD CLEANING KIT We stock the full range of ACORN hardware firmware and and a very wide FLOPPICLENE Disc Head Cleaning Kit with 28 disposable cleaning discs range of other peripherals for the BBC. For detailed specifications and pricing ensures please send for our leaflet. continued optimum performance of the drives. £14.50 (b) PRINTERS DRIVE ACCESSORIES EPSON: RX8OT £169(a); LX80 £210(a); FX80 £245(a); FX80 + £299(a); Single Disc Cable £6 (d) Dual Disc Cable £8.50 (d) NEW 10 Disc Library Case £1.80 (d) 30 Disc Storage Box £6 (c) FX105 +incl NLQ & IBM mode £449(x); JX80 4 colour printer £435(a); 30/40 Disc Lockable Box £14 (c) 100 Disc Lockable Box £16(c) LQ1 500 Printer £8991aí. TAXAN KAGA: KP81 0 80 Col NLQ £2291a); KP910 156 Col NLQ £339(a); MONITORS All 14" monitors now in plastic JUKI 6100 Daisy avilable or metal cases, please specify your Wheel £279(a). requirement. BROTHER: HR1 5(P( Daisy Wheel £285(a); HR15LX (Serial) £3651aí. 14" RGB 1431 Std Res £185 (a); 1451 Med Res £225 (a);1441 Hi Res £385 (a). PLOTTERS 14" RGB with PAL & Audio 1431 AP Std Res £199 (a) 1451 AP Med Res £275 (a) Epson H180: A4 4 colour Plotter £345(a): Hitachi 672: A3 4 colour Plotter Swivel Base for Plastic 14" Microvitecs £20 (c) £4651a) 20" RGB with PAL & Audio 2030CS Std Res £380 (a); 2040CS Hi Res £685 (a). ACCESSORIES KAGA TAXAN 12" RGB VISION II Hi Res £210 (a); VISION Ill Plus £330 (a) We hold a wide range of printer feeders, feeds etc) attachments (sheet tractor SUPERVISION Ill Plus £330 (a) in stock. Serial, parallel, IEEE and other interfaces also available. Ribbons MITSUBISHI 14" RGB Med RES IBM & BBC Compatible £229 (a) available for all above plotters. Pens with a variety of tips and colours also MONOCHROME MONITORS: available. Please for and phone details prices. SANYO DM8112CX Hi Res 1 2" Green Screen £86 (a) Plain Fanfold Paper with extra fine perforation (Clean Edge): KAGA KX1201G Hi Res 1 2" Etched Green Screen £92 (a) 2000 sheets 9.5" X 11" £13(b) 2000 sheets 14.5" X 11" £18.50(b) KAGA KX1203A Hi Res 1 2" Etched Amber screen £105 (a) Labels per 1000s: Single Row 3_" X 1 7/16" £5.25(d) Triple Row 2 -7/16" X 1 7/16" £5.00(d) PHILIPS BM7502 1 2" Hi Res Green Screen £75 (a) PHILIPS BM7522 12" Hi Res Amber Screen £79 (a) MODEMS BBC Leads RGB £51d) Microvitec £3.50m (d) Monochrome £3.50 (d) BUZZ BOX This pocket sized BT approved modem complies with V21 300/300 baud and UVERASERS PRINTER BUFFER uvi T Eraser with built -in timer and mains indicator. provides an ideal solution for communications between users, with mainframe The buffer offers a storage of 64K. Data from three Built -in safety interlock to avoid accidental exposure computers can be loaded into the butter which will computers and bulletin boards. Suitable for use with Open University computer. to the harmful UV rays. continue accepting data until it is full. The buffer will Battery/mains powered. It can handle up to 5 eproms at a time with an average automatically switch from one computer to next as erasing time of about 20 mins. £59 + £2 p &p. BUZZ BOX £55(c) mains Adaptor £10(d) BBC Data Lead £8(d) soon as that computer has dumped all its data. The UV1 as above but without the timer. £47 + £2 p &p. computer then is available for other uses. LED bar - MIRACLE WS 2000 For Industrial Users, we offer UV140 & UV 41 era- graph indicates memory usage. Simple push button sers with handling capacity of 14 eproms. UV141 has The world standard BT approved modem covering all standard CCITT and control provides. REPEAT, PAUSE and RESET a built in timer. Both offer full built in safety features functions. Integral power supply. £199 (a). BELL UV140 £69, UV141 £85, p &p £2.50. (outside UK only) standards upto 1200 baud. Allows communication with BBC Cable Set £30. virtually any computer system in the world. Expandability to Auto Dial and Auto Serial Test Cable Serial Mini Patch Box Serial Mini Test Answer with full software control enhance the considerable features already Serial Cable switchable at both ends Allows an easy method to Monitors RS232C and CCITT provided on the modem. Mains powered. WS 2000 £125 (c) Auto Dial Board/ allowing pin options to be re- routed or reconfigure pin functions V24 Transmissions, Auto Answer Board (awaiting BABT approved) £30 (d) Software Control Kit £10 linked at either end - making it possible without rewiring the cable indicating status with dual (d) to produce almost any cable assay. Jumpers can be used colour LEDs on 7 most configuration on site. and reused. £22 (d) significant lines. Connects in NEW WS -3000 RANGE - the new professional series. All are intelligent and Available as M/M or M/F £24.75 (d) Line. í22.50(d) 'Hayes' compatible, allowing simply 'English' commands to control its many features. All CONNECTOR SYSTEMS models feature Auto-Dial with 10 number AMPHENOL memory, Auto -Answer, Speed Buffering, I.D. CONNECTORS EDGE RIBBON CABLE CONNECTORS (grey /metre) (SONAblock TYP.) 36 way plug Centronics printer port, data security option etc. All CONNECTORS t0-way 40p 34 -way 160p No of Header Recep- Edge (solder 500p (IDC) 475p models 01" 0156 16-way 60p 40 -way 180p are factory upgradeable. ways Plug 'ac le Conn. 36 way skt Centronics 10 90p 65p 120p 2 6.way (commodore) 300p 20-way 85p 50 -way 200p WS3000 V2123 (V21 & V23 + Bell) £295 (a) 20 145p 125p 195p 2.< 10-way 150p (solder) 550p (IDC) 500p 26-way 120p 64 -way 280p 2 x 12-way (v¢ 201 . 355p WS3000 V22 (as above plus 1200 baud full 26 175p 1S0p 240p - 24 way plug IEEE (solder) 34 200p 160p 320p 2x 18-way 400 475p (IDC) 475p 2 x 23-way (ZX81) 1sp 220p duplex) £495 (a) 40 220p 190p 340p 24 way skt IEEE (solder) 50 235p 200p 390p 2 x 25-way 225p 220p DIL HEADERS WS3000 V22bis (as above plus 2400 baud 2 x 28-way (Spectrum) 200p 500p (IDC) 500p 2 x 36-way 250p PCB Mtg Skt Ang Pin Solder IDC full duplex) £650 (a) 1 x 43-way 260p 24 way 700p 36 way 750p 14 pin 40p 100p The WS3000 range all have BT approval. D CONNECTORS 2 x 22-way 190p 16 pin 50p 110p No Ways 2 x 43-way 395p 18 pin 60p of x 77 way 4000 500p GENDER CHANGERS - 9 15 25 20 pin 75p 37 2 x 50-way(S100conn, 6000 25 way D type - SOFTY II MALE: 24 pin 100p 150p Ang 28 This low cost intelligent eprom programmer can program 2716. 2516, Pins 120 180 230 350 EURO CONNECTORS Male to Male £10 pin 160p 200p 2532. 2732. and with an adaptor, 2564 and 2764. Displays 512 byte Solder 60 85 125 170 Male to Female £10 40 pin 200p 225p page on TV has a serial and par- IDC 175 DIN 41612 Plug Skt - 275 325 - Female to Female £10 allel I/O routines. Can be used as an emulator, cassette interface. FEMALE: 2 x 32 way St Pin 230p 275p Softy II í195.00(b) St Pin 100 140 210 380 2 X 32 way Ang Pin 275p 320p Adaptor for 2764/ Ang Pins 160 210 275 440 3 x 32 way St Pin 260p 300p RS 232 JUMPERS ATTENTION 2564 £25.00 Solder 90 130 195 3 x 32 way Ang Pin 375p 400p All prices in this double page 290 (25 way DI IDC SM A + B 400p IDC 195 325 375 - 24'' Single end Male £5.00 advertisment are subject to IDC Skt A +C 400p SPECIAL OFFER St Hood 90 95 100 120 24" Single end Female £5.25 change without notice. Screw 130 150 175 24" Female Female £10.00 2764 -25 £2:001d); - For 2 X 32 way please specify Lock 24" Male Male £9.50 ALL PRICES EXCLUDE VAT 27128 -25 £3:OO(d); spacing (A + B, A + CI. 24" Male Female £9.50 Please add carriage 50p 6264 LP -15 £4:001dí unless indicated as follows: TEXTOOL ZIF MISC CONNS DIL SWITCHES (a) £8 (b) £2.50 (c) £1.50 (d) INDUSTRIAL PROGRAMMER SOCKETS 24 -pin C7.50 21 pin Scarl Connector 200p 4 -way 90p 6 -way 105p ACORN IEEE INTERFACE £2781a1 £1.00 EP8000 £695 (a) 28-pin £9.00 40 -pin £12.00 8 pin Video Connector 200p 8 -way 120p 10 -way 150p Using `Preste)' type protocols. For information TECHNOLINE VIEWDATA SYSTEM, TEL: 01 450 9764 and orders - 24 hour service, 7 days a week

14 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com 74 SERIES 74C SERIES 74273 2.00 74LS273 1.25 4076 0.65 LINEAR ICs COMPUTER COMPONENTS 74276 1.40 7415279 0.70 4077 0.25 4078 0.25 7506416X1 4.00 PEV80AR0 7400 74278 1.70 7415280 1.90 AD7581 12.00 LM710 0.48 Cvu TMS4500 14.00 E PROMS 75154 1.20 4081 0.24 ADC0808 11.90 TBA231 1.20 ENCODE Rs 7401 74279 0.90 7415283 0.80 74C00 0.70 LM711 1.00 TMS9901 5.00 75159 2 20 4082 0.25 T8A800 7402 74283 1.05 7415290 0.80 74C04 0.50 4179100C 25.00 LM723 0.80 0.80 1802CE 6.50 TMS9902 5.00 2516 +5V 3.50 75160 5.00 4085 0.60 T84810 0.90 7403 74742 3.20 7415292 9.00 74008 0.70 AN-1-5050 1.00 LM725CN 3.00 2650A 10.50 TMS9911 18.00 2516 -35 5.50 75161 3.50 AY52376 11.50 7404 74290 0.90 7415293 0.80 74C10 0.70 4086 0.75 AY-3.1350 3.50 LM733 0.65 T8420 OM 6502 4.50 TMS9914 14.00 AY53600 7.50 4089 1.20 2532 4.50 75162 4.00 7405 74293 0.90 7415295 1.40 74C14 0.50 AY-3-8910 4.90 LM741 0.22 TBA820M 0.75 65CO2 -2MHz 2532 -30 5.50 75172 3.00 74C922 5.00 4093 0.35 TBA920 2.00 7406 74298 1.80 7415297 9.00 74C20 0.70 AY-3-8912 5.00 LM7747 0.70 12.00 280P10 2.50 2564 8.00 75182 0.90 74C923 6.00 4094 0.90 TBA950 2.25 7407 74351 2.00 7415298 1.00 74C32 1.00 CA3019A 1.00 LM748 0.30 65024 6.50 Z80APIO 2.75 75188 0.60 4095 0.95 TC9109 7408 74365A 0.80 74LS299 2.20 74C42 1.50 CA3020 3.50 LM1011 4.80 5.00 6502B 8.00 ZBOCTC 2.50 2708 4.50 75189 0.60 4096 0.90 TCA210 3.50 7409 74366A 0.80 7415321 3.70 74C48 1.50 CA3028A 1.10 LM1014 1.50 6800 2.50 Z80ACTC 2.75 2716 +5V 3.50 75365 1.50 A R 4097 2.70 TCA220 7410 74367A 0.80 74163224 3.90 74C73 1.00 CA3046 0.70 LM1801 3.00 3.50 6802 3.00 Z80DART 6.50 2716 -35 5.50 75450 ENUDERA RTES 4098 0.75 0.80 7411 74376 1.60 7415323 3.00 74C74 1.20 CA3059 3.25 LM1830 2.50 TCA270 3.50 6803 -2 12.00 Z8OADART 7.00 2732 4.50 75451 4099 0.99 0.50 7412 74390 1.10 74LS324 3.20 74C76 1.00 CA3060 3.50 LM1871 3.00 TCA940 1.75 6809 6.50 -2 MC14411 7.50 4501 0.36 2732A 9.50 75452 0.50 7413 74393 1.20 7415348 2.00 74C83 2.00 CA3080E 0.70 LM1872 3.00 TDA1004A 5.00 6809E 10.00 Z80DMA 7.00 75453 0.70 COM81166.50 4502 0.55 TDA1010 2.25 7414 74490 1.40 7415352 1 20 74C85 2.25 CA3085 1.50 LM1686 8.00 68809 10.00 Z80ADMA 7.50 2732A -30 6.00 75454 0.70 4072B 7.50 4503 0.36 TDA1022 4.50 7416 7415353 1.20 74C86 0.50 CA3086 0.80 LM1889 4.50 68809E 12.00 2732A -35 5.50 75480 1.50 4504 0.95 TDA1024 1.10 7417 7415356 2.10 74C90 1.90 CA3089E 2.50 LM2917 3.00 68000 -LB 36.00 Z804510 /0/2/9 2764 -25 2.00 75491 0.65 4505 3.60 TDAI170S 3.00 7420 7415363 1.80 74C93 1.50 06309060 3.75 LM3302 0.90 7.00 27C64 -25 10.00 75492 0.65 UARTs 7421 74LS SERIES 7415364 1.80 74C95 1.60 4506 0.90 CA3130E 0.90 LM3900 0.80 TDA2002 3.25 8035 3.50 Z80BP10 5.00 4507 0.35 1.30 TDA2003 1.90 7422 7415365 0.50 74C107 1.00 CA3130T LM3909 1.00 80C35 6.00 Z808CTC 5.00 27128-25 3.00 8T26 1.20 AY31015P 3.00 4508 1.20 TDA2004 2.40 7423 741500 0.24 7415366 0.50 74C 150 5.00 CA3140E 0.45 LM3911 1.80 8039 4.20 Z808DART 9.00 27128-25 7.50 8T28 1.20 AY51013P 3.0 4510 0.55 1.00 TDA2006 3.20 7425 741501 0.24 7415367 0.52 74C151 2.00 CA3140T LM3914 3.50 80C39 7.00 27256-25 20.00 8T95 1.20 COM8017 3.00 4511 0.55 TDA2020 3.20 7426 741502 0.24 74LS368 0.50 74C157 2.50 CA3146 2.25 LM3915 3.40 80804 4.20 27256-30 20.00 8T96 1.20 1M6402 4.50 4512 0.55 TDA2030 2.50 7427 741503 0.24 74LS373 0.90 74C 160 1.80 CA3160E 1.50 LM3916 3.40 8085A 3.00 MEMORIES 17268 12.00 8797 1.20 4513 1.50 TDA2593 5.00 7428 741504 0.24 7415374 0.90 74C 161 1.80 CA3161E 2.00 LM13600 1.50 800854 7.50 27512 P.O.A 8798 1.20 4514 1.10 TDA2653 7.00 7430 741505 0.24 7415375 0.75 74C 162 1.80 CA3162E 6.00 M51513L 2.30 8086 22.00 216 -150 4.00 TMS2716 5.00 811595 1.40 4515 1.10 TDA3560 7.50 7432 741508 0.24 74LS377 1.30 74C163 1.50 CA3189E 2.70 M51516L 4.50 8088 17.50 2101 4.00 811596 1.40 MODULATORS 4516 0.55 TDA3810 7.50 7433 741509 0.24 7415378 0.95 740173 1.00 CA3240E 1.50 MB3712 2.00 2102 2.50 811597 1.40 4517 2.20 TDA7000 7437 741510 0.24 74LS379 1.30 74C 174 1.50 CA32800 3.00 MC1310P 1.50 3.50 8741 15.00 2107B 5.00 CONTROLLER 811598 1.40 6MHz 3.75 4518 0.48 7E41002 7.00 4.50 7438 741511 0.24 7415381 4.50 74C175 1.50 D7002 8.00 1413 0.75 8748 16.00 21114-35 4.00 8815120 3.00 8MHz 7439 741513 0.34 7415385 3.25 74C193 1.50 4519 0.32 DAC1408-8 3.00 MC1458 0.45 TL061CP 0.40 2114 2.50 CRT5027 18.00 7440 741514 0.50 7415390 0.80 74C194 1.50 4520 0.60 DAC0800 3.00 MC1495 3.00 TL062 0.60 TMS1601 12.00 2114 -2 3.50 CRT5037 12.00 4521 1.15 9602 3.00 7441 741515 0.24 74LS393 1.00 74C195 1.50 DAC0808 3.00 MC1496 0.70 TL064 0.90 TMS9980 14.50 CRT6545 9.00 SOUND 8 4522 0.80 9636A 1.60 7442A 741520 0.24 74153954 1.00 740221 2.50 DG308 3.00 MC3340P 2.00 TL071 0.40 TMS9995 12.00 2147 4.00 EF9364 8.00 9637AP 160 VISION 7443A 741521 0.24 7415399 1.40 74C244 2.00 4526 0.70 HA1366 1.90 MC3401 0.70 TL072 0.70 EF9365 25.00 4527 0.80 TL074 1.10 7444 741522 0.24 7415445 1.80 74C245 2.25 CL7106 6.75 MC3403 0.65 Z80 2.50 4116 2.00 EF9366 25.00 9638 1.90 12MHz 12.00 7445 741524 0.50 7415465 1.20 740373 2.25 4528 0.85 CL7611 0.95 MF1OCN 4.10 TL081 0.35 Z80Á 2.90 4116 -20 1.50 EF9367 36.00 7446A 741526 0.26 7415467 1.20 74C374 2.25 4529 1.00 CL7650 4.00 MK502409.00 TL082 0.55 Z80B 5.50 MC6845 6.50 4531 0.75 TL083 7447A 74LS27 0.24 7415490 1.50 74C 902 1.20 CL7660 2.50 MK50398 11.00 0.75 Z80H 7.50 41256 -207 0.50 MC6845SP 6.50 CRYSTALS 7448 74LS28 0.24 7415540 1.00 74C911 9.00 4532 0.65 CL8038 4.00 ML902 5.00 TL084 1.00 41256 -157 0.50 MC6847 6.50 DISC 4534 3.80 TL094 2.00 SUPPORT 7450 741530 0.24 7415541 1.00 74C912 4.50 CM72166 22.00 ML922 4.00 DEVICES SFF96364 8.00 CONTROLLER 32.768KHZ 1.00 7451 74LS32 0.24 7415608 7.00 74C922 6.00 4536 2.50 CM7217 7.50 M1462214 3.00 TL170 0.50 4164 -15T1 3.00 TMS9918 15.00 1.00MHz 2.70 4538 0.75 TL430C 1.20 7453 74LS32 0.24 741561019.00 74C923 6.50 CM7555 0.90 NE529 2.20 2651 12.00 4164 2.00 TMS9928 1060 16432MHz 2.25 4539 0.75 7454 74LS33 0.24 7415612 19.00 740925 8.50 CM7556 1.40 NE531 1.20 U441003-3 9.35 3242 8.00 4164 -20 2.00 TMS9929 10.00 765A 13.00 2.00MHz 2.25 7460 74LS37 0.24 7415624 3.50 74C926 7.50 4541 0.90 LC7120 3.00 NE544 1.90 UA759 3.20 4416 -15 3.50 6843 8.00 2.45760MHZ(L) 4543 0.70 3245 4.50 7470 741538 0.24 7415626 2.25 LC7130 3.00 NE555 0.22 UA2240 1.20 6520 3.00 4532 -20 2.50 INTERFACE 8271 P.O.A 2.00 4551 1.00 7472 741540 0.24 7415628 2.25 LC7131 3.50 NE556 0.60 UAA170 1.70 ICs 2.45760MHz(S) 4553 2.40 6522 3.50 7473 74LS42 0.50 7415629 1.25 LC7137 3.50 NE564 4.00 UCN48014 4.00 6522A 5.50 4816AP/3 2.00 FD1771 20.00 2.50 4555 0.36 7474 741543 1.50 7415640 2.00 LF347 1.20 NE565 1.20 ULN2001A 0.75 6532 4,80 5101/5501 4.00 AD7581 15.00 FD1791 20.00 2.5MHz 2.50 74ALS SERIES 4556 0.50 7475 741548 0.90 7415640 -1 3.00 1E351 0.60 NE566 1.50 ULN2002A 0.75 65514 6.00 5514/5114 4.00 4000808 11.90 FD1793 20.00 2.662MHz 1.75 7476 74LS49 1.00 7415641 1.50 4557 2.40 LF353 0.90 NE567 1.25 ULN2003A 0.75 5516 6.00 AD561J 20.00 FD1797 22.00 3.276MH1 1.50 74ALSOO 0.45 4560 1.40 7480 741551 0.24 74LS642 2.50 LF355 0.90 NE570 4.00 ULN2004A 0.75 6821 1.50 5517AP 6.00 AM25510 3.50 15795MHz 1.00 74ALS02 0.45 1.40 7481 74LS54 0.24 74LS642 -1 3.00 4566 LF356N 1.10 NE571 3.00 ULN2068 2.90 AM25L525213.50 WD169115.00 4.00MHz 1.50 74ALSO4 0.50 4568 2.40 68821 2.50 7483A 74L555 0.24 7415643 2.50 LF357 1.00 NE592 0.90 ULN2802 1.90 6829 12.50 6116P -3 3.50 A4251525383.50 W0214312.00 4.194MHz 2.00 7401508 0.50 4569 1.70 7484A 7415730 0.30 7415643.1 3.00 1E398 4.00 NE5532P 1.50 ULN2803 1.80 6840 3.75 6116LP-3 3.50 AM26LS31 1.20 W02793 27.00 4.43MHz 1.00 7401510 0.45 4572 0.45 7485 74LS74A 0.35 7415644 3.50 7441520 LM10CLH 4.50 NE5533P 1.60 ULN2804 1.90 68840 6.00 6264 -12 12.00 AM26LS32 1.20 WD2797 27.00 4.9152MHz 2.50 0.45 4583 0.90 0.30 UPC575 2.75 7486 741575 0.45 74LS645 2.00 7441532 0.45 LM301A NE5534P 1.20 6850 1.60 6264P- 157.50 AM7910DC 25.00 5.00MHz 1.50 4584 0.48 LM307 0.45 UPC592H 2.00 -15 7489 7415764 0.36 74LS645 -1 4.00 74ALS74 0.70 NE5534AP 1.50 68850 2.50 6264LP 4.150 DAC80C81-V 5068MHz 1.75 4585 0.60 LM308CN 0.75 UPC1156H 3.00 7490A 741578 0.42 7415668 0.90 74415138 1.50 OP-07EP 3.50 6852 2.50 28.00 6.00MHz 1.40 4724 1.50 LM310 2.25 UPC1185H 5.00 7491 74LS83A 0.70 7415669 0.90 744L5139 1.50 PLL02A 5.00 6854 6.50 6514 -45 4.00 DM8131 6.00 CHARACTER 6.144MHZ1.40 14411 7.50 XR210 4.00 GENERATORS 74924 741585 0.75 7415670 1.70 744L5244 4.00 LM311 0.60 RC4136 0.55 68B54 8.00 6810 1.80 DP8304 3.50 7.00MHz 1.50 14412 7.50 XR2206 4.50 7493A 741586 0.35 7415682 2.50 74410245 LM318 1.50 RC4151 2.00 6875 5.00 745189 1.80 1353691 3.50 7.16MHz 1.75 4.75 14416 3.00 XR2207 3.75 90325130C 760 7494 741590 0.48 7415683 3.00 74415573 LM319 1.80 RC4195 1.50 74S289 2.25 058830 1.40 8.00MHz 1.50 2.60 14419 2.60 592211 R032513LC 7.00 7495A 741591 0.90 7415684 3.50 74415574 LM324 0.45 RC4558 0.55 5.75 8154 8.50 058831 1.50 8.867MHz 1.75 4.50 14490 4.20 XR2216 7496 74LS92 0.35 7415687 3.50 LM334Z 1.15 S566B 2.20 6.75 8155 3.80 93415 6.00 DS8832 1.50 10.00MHz 1.75 744L5580 2.80 14495 4.50 XR2240 1.20 7497 741593 0.54 7415688 3.50 LM335Z 1.30 S50240 9.00 8156 3.80 93L422 7.50 DS8833 2.25 10.50MHz 2.50 74100 74LS95B 0.75 7415783 21.00 145000 6.50 LM336 1.60 SAA1900 16.00 ZN404 1.00 93425 6.00 DS8836 1.50 10.70MHz 1.50 4000 14599 2.00 LM339 0.40 ZN414 0.80 74107 741596 0.90 SERIES SFF96364 8.00 8205 2.25 DS8838 2.25 REAL TIME 11.00MHz 3.00 74109 7415107 0.40 22100 3.50 LM348 0.80 SL490 3.00 ZN419P 1.75 D7002 8.00 12.00MHz 1.50 7.00 8212 2.00 74110 7415109 0.40 4000 0.20 22101 LM358P 0.50 SN76013N 3.00 ZN423E 1.30 8216 1.60 MC1488 0.60 14.00MH2 1.75 22102 7.00 PROM. 74111 7415112 0.45 4001 0.24 LM377 3.00 SN76023N 3.00 ZN424E 1.30 8224 P.O.A MC1489 0.60 14.31MHz 1.60 74S SERIES 40014 0.48 LM380N-8 1.50 ZN425E83.50 74116 7415113 0.45 4002 0.25 SN76033N 3.00 8226 4.25 28122 4.00 MC3446 2.50 14.756MHz 2.50 40085 1.20 LM380N 1.50 2.15 ZN426E83.00 74118 7415114 0.45 4006 0.70 56761156 8228 5.50 24510 2.50 MC3459 4.50 15.00MHz 2.00 74500 40097 0.36 LM381 AN1.70 ZN427E88.00 74119 7415122 0.70 0.50 4007 0.25 SN76489 4.00 8243 2.60 185030 2.00 MCS3470 4.75 16.00MHz 2.00 74502 40098 0.40 LM383 3.25 ZN428E84.50 74120 7415123 0.80 0.50 4008 0.60 SN76495 4.00 8250 9.50 18S4030 2.00 MC3480 8.50 17 734MHz 1.50 40100 1.50 LM384 2.20 ZN429E82.25 74121 7415125 0.50 74504 0.50 4009 0,45 SN76660 1.20 745188 1.80 MC3486 2.25 18.00MHz 1.50 40101 1.25 1.00 ZN447E 9.00 74122 7415126 0.50 74S05 0.50 4010 0.60 LM386N-I SP02564L2 7.00 8251A 3.25 745287 2.25 MC3487 2.25 18!32MHz 1.50 74S08 40102 1.30 LM387 2.70 ZN449E 3.00 TELETEXT 74123 7415132 0.65 0.50 4011 0.24 SP8515 7.50 8253C -5 3.50 745288 1.80 MC4024 5.50 DECODER 19.969MHz 1.50 74610 40103 2.00 LM389 1.89 ZN450E 7.50 1.50 74125 7415133 0.55 0.50 4012 0.25 TA7120 1.20 82554C -5 3.20 745387 2.25 MC4044 5.50 20.000MHz 74S11 40104 1.20 LM391 1.80 TA7130 1.40 ZN459CP 3.00 74126 7415136 0.45 0.75 4013 0.36 8256 18.00 82523 1.50 MC14411 9.00 SAA5020 6.00 24.000MHz 1.75 74128 7415138 0.55 74620 0.50 4014 0.60 40105 1.50 LM392N 1.10 TA7204 1.50 ZN1034E 2.00 MC 14412 7.50 SAA5030 7.00 48.000MHz 1.75 40106 0.48 8257C -5 54.00 825123 1.50 74132 7415139 0.55 74522 0.50 4015 0.70 LM393 0.85 TA7205 0.90 ZNA1040 8.60 75107 0.90 5445041 18.00 1161.411Z 2.5 40107 0.55 825129 1.75 74136 7415145 0.95 74530 0.50 4016 0.36 16394CH 4.00 TA7222 1.50 2NA134J 23.00 8259C-5 4.00 75108 0.90 SA450509.00 PX01000 12.00 40108 3.20 74141 7415147 1.75 74S32 0.60 4017 0.55 LM709 0.35 TA7310 1.50 ZNA234E9.50 8271 P.O.A 75109 1.20 40109 0.80 74142 7415148 1.40 74S37 0.60 4018 0.60 8275 29.00 75110 0.90 40110 2.25 74143 7415151 0.65 74538 0.60 4019 0.60 VOLTAGE REGULATORS 8279C-5 4.80 75112 1.60 40114 2.25 EE PROM Please note: 74144 7415152 2.00 74S40 0.50 4020 0.80 8282 4.00 75113 1.20 40147 2.80 74145 7415153 0.85 74551 0.60 4021 0.60 lA FIXED VOLTAGE PLASTIC T0220 75114 1.40 All prices are subject to 7415154 74564 40163 1.00 74147 1.60 0.45 4022 0.70 +VE -VE 8284 4.60 2816 -30 15.00 75115 1.40 without notice 74148 7415155 0.65 74S74 0.70 4023 0.30 40173 1.20 2K +8 30.00 75121 1.40 change 40174 1.00 8287 3.80 74150 7415156 0.65 74585 3.00 4024 0.48 5V 7805 0.45 7905 0.50 8288D 9306 256oits 75122 1.40 40175 1.00 9.50 Only current prime grade 74151 A 7415157 0.50 74586 1.00 4025 0.24 6V 7806 0.50 7906 0.50 8755A 16.00 (16X161 4.50 75150P 1.20 74153 7415158 0.65 745112 1.50 4026 0.90 40192 1.00 6V 7808 0.50 7908 0.50 components stocked. 40193 1.00 12V 7812 0.45 7912 0.50 OTHERS 74154 74L51604 0.65 74S113 1.20 4027 0.40 LED. 74155 74151614 0.75 745114 1.20 4028 0.60 40194 1.00 15V 7815 0.50 7915 0.15 74156 74L51624 0.75 745124 3.00 4029 0.75 40244 1.50 18V 7818 0.50 7918 0.50 2N5777 0.50 0.125" 0.2" 74157 74L51634 0.75 745132 1.00 4030 0.35 40245 1.50 24V 7824 0.50 7924 0.50 BPX25 1.80 We also stock a wide 74159 7415164 0.75 745133 0.60 4031 1.25 40257 1.80 IA FIXED VOLTAGE PLASTIC T092 BPW21 2.80 RED TIL2090.12 111220 015 40373 1.80 TIL211 0.16 range of: 74160 74151654 1.10 745138 1.80 4032 1.00 5V 78105 0.30 5V 79L05 0.45 OCP71 1.80 GRN TIL222 0.16 40374 1.80 YEL TIL212 74161 74151660 1.50 745139 1.80 4033 1.25 6V 78L06 0.30 12V 79L12 0.50 ORP12 1.20 0.20 111226 0.22 80095 0.75 Red LEDs Transistors. 74162 7415168 1.30 745140 1.00 4034 2.50 BV 78L08 0.30 15V 79L15 0.50 ORP60 1.20 80C97 0.75 (R /G/Y) 0.30 COUNTERS 74163 7415169 1.00 745151 1.50 4035 0.70 12V 78112 0.30 ORP61 1.20 Diodes,Triacs Plastic. 74164 7415170 1.40 745153 1.50 4036 2.50 80C98 0.75 78115 SFH2O5 1.00 COO (Bi colour 15V 0.30 6.50 Bridge Rectifiers. 74165 74151730 1.00 745157 2.00 4037 1.10 TIL32 0.55 1.00 74C925 74166 7415174 0.75 745158 2.00 4038 1.00 OTHER REGULATORS TIL78 0.55 10 LED 74C926 6.50 Thyristors and 74167 7415175 0.75 745163 3.00 4040 0.60 TIL31B 1.20 Bar Graph: 74928 6.50 74170 7415181 2.00 745169 5.50 4041 0.55 FIXED REGULATORS TIL81 1.20 Red 2.25 7216B 22.00 Zenors. 74172 7415183 1.90 745174 3.00 4042 0.50 LM309K 1A5V 140 TIL100 0.75 Green 2.25 ZN1040 6.70 74173 7415190 0.75 745175 3.20 4043 0.60 LM323K 3A 51( 3 50 Please phone for 745188 1.80 78H05KC 5A 5V 5 40 74174 74LS191 0.75 4044 0.60 MAN66102.00 LM3914 3.50 745189 1.80 78H12 54 12V 640 DISPLAYS details. 74175 7415192 0.80 4045 1.00 NSB58815.70 LM3915 3.50 741S1944 745194 3.00 78P05 10A 5V 9 00 74176 0.75 4046 0.60 TIL311 8.50 LM3916 3.50 74178 74151950 0.75 745195 3.00 4047 0.60 VARIABLE REGULATORS TIL729 1.00 UDN6I18 3.20 74179 7415196 0.80 745196 3.50 4048 0.55 LM305AH 250 FND357 1.00 TIL7300 1.00 UDN61843.20 OPTO- ISOLATORS 74180 7415197 0.80 745200 4.50 4049 0.36 LM317T TO -220 150 FN0500/TI1730 MAN8910 1.50 ULN20030.90 74181 7415221 0.90 745201 3.20 4050 0.35 LM3I7K T03 2 40 1.00 MAN8940 2.50 ULN20040.90 74182 7415240 0.80 745225 5.20 4051 0.55 LM337T 2 25 FND507/TIL729 ULN2068 2.90 ILD74 1.30 rIL111 0.70 745240 4.00 11074 TIL112 74184 7415241 0.80 4052 0.60 LM350T 10A +VAR 400 1.00 DISPLAY ULN2802 1.90 2.20 0.70 TIL113 74185A 7415242 0.90 745241 4.00 4053 0.60 LM396K 10A +VAR 15.00 MA671/0L707 DRIVERS ULN2083 1.80 MCT26 1.00 0.70 MCS2400 TIL116 74190 7415243 0.90 745244 4.50 4054 0.80 LM723N 0 50 1.00 ULN2804 1.90 1.90 0.70 745251 MOC3020 55137 74191 7415244 0.80 2.50 4055 0.80 78HH05KC 54 5V 5 75 MAN3640 1.75 9368 4.50 75491 0.70 1.50 3.60 745257 SN139 74192 7415245 1.10 2.50 4056 0.85 78HGKC 54-I-VAR 650 MAN4640 2.00 9370 4.50 75492 0.70 1.75 74193 74LS247 1.10 745258 2.50 4060 0.70 78GUIC 1A +VAR 225 74LS248 1.10 745260 1.00 74194 4063 0.85 79HGKC 5A -VAR 675 LOW PROFILE SOCKETS BY TI WIRE WRAP SOCKETS RV TI 74195 74LS249 1.10 745261 3.00 4066 0.40 79GUIC IA VAR 250 7415251 745283 2.70 74196 0.75 4067 2.30 Bpin 9p 18p1n 16p 24pin 24p 8pin 25p 18p1n 50p 24pin 70p 74S287 2.25 SWITCHING REGULATIONS 74197 7415253 0.75 4068 0.25 14pin 10p 20pin 18p 28p1n 26p 14pin 35p 20pin 60p 28pin 80p 7415256 745288 2.00 ICL7660 2 50 74198 0.90 4069 0.24 l6pin 11p 22pin 20p 40pin 30p 16pin 40p 22pin 65p 40pin 100p 74199 74L5245740.70 745289 2.25 4070 0.24 SG3524 3 00 74221 74152584 0.70 74S299 4.50 4071 0.24 TL494 3 00 7L497 3 00 74251 7415259 1.20 74S373 4.00 4072 0.24 TURNED PIN Bpin 25p 16pin 35p 20pin 45p 28p1n 65p 2 50 74259 7415260 0.75 745374 4.00 4073 0.24 78540 LOW PROFILE SOTS. 14pin 30p 18pin 40p 24pin 55p 40p1n 90p 74265 7415266 0.60 745387 2.25 4075 0.24 RC4195 1 50

PLEASE ADD 50p p &p & 15% VAT TECHNOMATIC LTD (Export: no VAT, p&p at Costl MAIL ORDERS TO: 17 BURNLEY ROAD, LONDON NW101ED Orders from Government Depts. & Colleges etc. welcome. SHOPS AT: 17 BURNLEY ROAD. LONDON NW10 Detailed Price List on request. Tel: 01 -208 1177 4 lines. Telex: 922800 Stock items are normally by return of post. 11 r 305 EDGWARE ROAD, LONDON W2 Minimum "I cicphonc Order £5

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 15

www.americanradiohistory.com SUPER HY -LIGHT STROBE KIT VARIABLE VOLTAGE TRANSFORMERS Superior Quality Precision Made Designed for Disco, theatrical uses, etc. INPUT n-179 Approx 16 locales. Adjustable speed. Price E45 C2 p &p (Total Inc 230, 240V a.c. 50/60 OUTPUT 60 NEW POWER RHEOSTATS VAT E54.05; Case and reflector price E17 C2 p &p (total inc VAT 200W, to Max. 0.5KVA 21/2A Max. New ceramic construction, heavy duty brush £21.95). Foolscap SAE for further details including Hy -Light and E31.00 Industrial Strobe Kits. 1KVA 5A Max. assembly. continuously rated. 2KVA 10A Max. E45.00 25 WATT 5/ 10 /25r50/100/150/250/300/500/1k0 ULTRA VIOLET BLACK LIGHT 3KVA 15A Max. E59.00 1.5k12 £4.25 + 30p p&p. (t5.23 incl. VAT). [105.00 FLUORESCENT TUBES 5KVA 25A Max. 50 WATT 2504 £6.50 + 50p p&p 1E8.05 incl. VAT). El 90.00 100 WATT 1/5/10/25/50/ 100 411 40 can £10.44 51200 me VA11 10KVA 50A Max. /250/500/1 k4/1.5k4/2.5k4/3.5k4 E285.00 £10.25 + 75p p&p (12.65 7n 10 wan £7.44 El 25 p &p 59.99 inc VAT1 15KVA 75A Max. Intl VAT) and I i All V.V.Ts VAT In Nos 1-9. 112in dia brass bush. óin 15 wan 5.00 75p p &p 1E561 me VATI plus carriage Black Silver Skirted Knob calibrated Ideal for Rheostas ea. VAT. I Sin 10 wan £4.00 15p p &p 55.46 inc' VATI 3-PHASE VARIABLE VOLTAGE TRANSFORMERS above 30p IM 8 wan £3.E0 i me 50p p &p on VATI Dual input 200 -240V or 380 -415V. Star connected ' INSULATED TESTERS NEW! gin 6 wan E3.00 i 50p p &p 5402 Inc VATI 3KVA. 6KVA. 1OKVA. available. Phone for details. Test to I.E.E. Spec. Rugged metal construction bin 4 wan E3.00 50p &p 1E4.02 inc VATI P Comprehensive range of TRANSFORMERS L.T. ISOLATION 8 AUTO suitable for bench or field work onstanl speed 230V AC Ballast Kit for either Bin. 9,n or 12in tubes f5.50 p &p 55p clutch. Sire L 8in.. W 4in., H bin. weight 6.96 Inc. VATI. (110-240V). Either cased with American socket and mains lead or open 61b. 500v. 300 megohms. £49 p &p 12 158.65 mcl. For 13ín. & 18in. Tubes £6 p &p 75p 1E7.76 inc. VATI. frame type available for immediate delivery. Leaflet on request. VATI. 1000V 1000M0 E55 p&p £21E65.55 incl. For 12V DC op. 12ín 131n. tubes E5.50 p 75p inc. & only &p 1E7.18 SPECIAL OFFER: Brárld new Safety Isolation *. VATI SAE for leaflet. VATI Transformers. Primary 0- 104 -11- 129 -V. 175 WATT SELF -BALLASTED BLACK UGHT MERCURY BULBS. 0- 104 -110 -120V. Secondary 0 -104- 110 -120V. L.T. TRANSFORMERS Available for either B.C. or E.S. fitting. priceE11.80 p &p 11.25 (total VAT [151 0- 104 -110 -120V. 2KVA @ £40.00. 3KVA @ £60.00. Special Offer' 0- 63V- 0.6.3V at 10 Amp (12V 0 10 Amp or 6V at 20 Amp) Price E9.00 p &p í2.O0 inclusive VAT 400W UV LAMP & BALLAST complete - £53.80 + E 3.50169.50 in- 4KVA with 0 -110V, Secondary only @ £80.00 +Car - - of E12.65 N.M.S cI VATI riage and VAT. 'Phone for further details. GEARED MOTORS 400W UV LAMP only, £25 r- p &p E 2.501E31.63Mel VAT/ 5 rpm 240V AC Mt by Caner, E6.05 fl p &p 58.11 Inc VATI N M S SINGLE DIAPHRAGM COMPRESSOR NMS 20 rpm I I5V AC Synchronous, torque approx 801b in C20.00 i E4 &p (Total inc Max. 20 PSI. One CFM approx. 240 volts A.C. £18 £2 p &p 1£23 inc. VATI p rROBOT ENTHUSIASTS VAT £27.601 N M S ESCAP precision Swiss -made ironless rotor. 6V DC geared Motor TRANSFORMER 240V operation. £9.15 E2 W p &p (Total Inc VAT C12.121 EPROM ERASURE KIT 28 rpm Torque 201b in. h p 110V with 70.1 gearbox. 6V DC - 16 r.p.m. 3V- 8r.p.re. amazing reversible 180th AC Price E9.50 p &p El W Why waste money? Build your own EPROM ERASURE for a Inc Power; no load current; only 10 ma. approx. Size: 4 e 2 )cm. Ex- (Total VAT £12.991 fraction of the of a made -up unit. Complete kit of parts less Suitable TRANSFORMER for 130 -240V AC Price 40 equipment, tested and guaranteed. ONLY £4.50 + 50p p &p (total price operation E520 p&p El case to include 12. 8 watt 2537 Angst. Tube. Ballast unit, pair of inc. VAT £5.75). (Total Inc VAT £7.591 N M S hi-pin leads, Neon indicator, safety microswitch. on/off switch 38.8 rpm GEARED MOTORS Torque 3515.in reversible 115V AC inc start SOLID STATE RELAY and circuit. capacity. Price. £11.55 r p &p £2.00 (Total inc. VAT £15.58). N.M.S. LESS CASE: Price £13.60 i 75p p&p inc. VAT £16.501. Single make will switch up to 250V. A.C. 10 amps. Recommended (Total Suitable TRANSFORMER 230V AC operation. Price £5.20 + 50p p &p ([6.56 Incl. operating voltage 13-20V. D.C. but will work at less than 5V D.C. silent, con Warning: Tube used in this circuit is highly dangerous to the VAT) in tactless. opto isolated. Suitable for use with T.T.L. Logic for switching maim eyes. Unit must be fitted suitable case. 100.7 rpm 651b in reversible 115 volt AC price E30.00 p &p £4.50 voltage. Mfr. by Teledyne. Offered at fraction of mfrs. puce; E3.00 o 45p (Total inc. VAT £39.68) p &p (total Inc. VAT £3.971. N.M.S 12V D.C. BILGE PUMPS Suitable TRANSFORMER tor above E10 p &p El 50 513.22 inc VATI 400 G.P.H. 1511. head, 3amp. E8.00 i £1.00 p&p MICRO -SWITCH 57 met 240V 1/22 h p continuously rated REVERSIBLE 5011/ in manuf by E6.90 for 10 post paid. inc. VAT. 1E10.35 inc. VATI Button type 10amp c/o contacts. Wynslruments New Ideal for garage doors. curtains etc ONLY E12.03 E2 00 700 G.P.H. 10h. head, 3.5amp, £11.50 i f1.50 p &p p &p linci VAT £16.101, inclusive capacitor VORTEX BLOWER & SUCTION UNIT 514.95 inc. VAT). Powerful multi -stage dynamically balanced totally enclosed rotors, 1750 G.P.H. 15ft. head, Ramp, E15.00. £1.75 p&p 71 rpm Torque IDIb in reversible 1 70th h p 110V AC motor Price E9.50 El W 112in. inlet and outlet, 110V AC. £22.00. Switchable transformer for f1926 inc. VATI. p&p 'Total Inc VAT £12.991 240V AC £8.00 p&p £3.00 - total £34.50 inc. VAT. :41 . Il Suitable TRANSFORMER for 230 -240V AC operation Price £520 i p &p El 40 BLOWER ITolal Inc VAT £7.691 N M S VBL4 CENTRIFUGAL FROM STOCK AT PRICES 240V AC powerful 1/50 h.p. 0.23A motor. £18.00 + f2.00 p &p -total 24Y DC 200 rpm1010/in MI. by Carter. Ex- equip. tested. £8.00+ £ 1.50 p& p (Total inc. VAT £23.00. N.M.S. THAT DEFY COMPETITION Inc. VAT 110.93). AC GEARED MOTORS C F. BLOWERS 2301240V AC SYNCHRONOUS, 2 rpm. 6 rpm. 6 rev per day Any type £4.10 50p 12/24V DC CENTRIFUGAL BLOWER c DC MOTORS SMALL AC CAPACITORS p &p (Total Inc VAT £6.10) 0.4A producing 30 cub. £7.50 + £1.00 p&p - MICROSWITCHES STROBE KITS total inc. VAT £9.78. N.M.S. RELAYS FLASHTUBES CHECK METER FAN REED SWITCHES . CONTACTORS 230/240 AC 40 amp, fully reconditioned £7.50 £1.75 p&p (Total Inc. VAT COOLING or EXTRACTOR SOLENOIDS A C. or DC SYNCHRONOUS £10.61) Quiet smooth running. Size 43/4 x43/4 x112. PROGRAMME TIMERS MOTORS Supplied for 240V AC operation. Price E5.75 WIDE RANGE OF XENON TUBES SANGAMO WESTON TIME SWITCH + El p &p - total inc. VAT £7.75 N.M.S. WRITE/PHONE N YOUR ENOUIRIES Type 5251 200/250 A.C. 2 on /2011 every 24 hours. 20 amps contacts with 240V. A.C. SOLENOID VALVE. Designed for Air /Gas at override switch- Diameter 4 -e3 -. Price £9.50 r £1.50 p &p (12.65 inc. VAT & A.C. CAPACITOR. 16U1- 900V. A.C. 50 /60Hz. Ideal P&P). Also available with solar dla R&T. Other types available from stock. 0.7. Water 5 psi. Inlet- outlet l ". Forgedbrass body. power factor correction, etc. 91 x 6 x 41 ins. Wt. 7,4Kg. N.M.S. New Manufacturers' Surplus Manuf. Dewraswitch Asco. Price: £6.50 + E1.00 p &p. R&T Reconditioned and tested Price: £12.00 + £3.00 p&p. 1E17.25 incl. VAT). N.M.S. 1E8.63 incl. VAT) N.M.S. Goods normally despatched within 7 days. Ample parking space SERVICE TRADING Personal callers only. Open Saturdays Showroom open WIZ 9 Little Newport Street 57 BRIDGMAN ROAD, CHISWICK, LONDON W4 5BB. Tel: 01 -995 1560 Monday-Friday London WC2H 7JJ ACCOUNT CUSTOMERS MIN. ORDER £10 Tel: 01 -437 0576 CIRCLE 9 FOR FURTHER DETAILS. Newnes Technical Books NEWNES NEWNES ELECTRICAL RADIO and POCKET BOOK 19th edition £8.95 s.cover ELECTRONICS This well established pocket book has been completely updated to provide handy and POCKET BOOK concise coverage of an 16th edition £5.50 s. cover extremely wide range of topics An invaluable compendium of from wiring regulations to facts, figures programmable controllers. and formulae An invaluable ready- from aerial dimensions to reference source for zener diodes. Now completely electrical and revised and re- designed, this mechanical engineers, edition is indispensable to service installation contractors and designers, students, service technicians. engineers and those with an 512 Pages. Illustrated. interest in radio and electronics 0 408 01575 6 176 Pages Illustrated. Available from bookshops, 0 408 00720 6 but in case of difficulty fill in the order form below.

NEWNES TECHNICAL BOOKS ORDER FORM Please send me copy(ies) of Newnes Electrical Pocket Book at £8.95 (plus £1 p.&p.) copy(ies) of Newnes Radio and Electronics Engineer's Pocket Book at £5.50 (plus £1 p.& p) Please note: Postage and Packing free if you order2 or more books. I enclose a cheque/Postal Order made payable to Newnes Books for (CAPITAL LETTE IRS PLEASE) NAME ADDRESS EWW

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UK offer only. Please allow 28 days for delivery. If I am not completely satisf ied I may ret u rn the book /s within 14 days of delivery and you will refund my money. CIRCLE 76 FOR FURTHER DETAILS. 16 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Naiad training robo Robot arm interfaces with Apple, BBC, Commodore and IBM computers. ' Design by Peter Wells and Dick Becker

The control electronics of conveyor belt, indexing table cards for the Commodore 64, by R.H.Becker Naiad are split between and so on. Apple IIe and IBM computers the three printed- circuit The robot works with parallel are available. Connection is boards: computer interface, data from the computer and the made to the 1MHz bus solenoid driver and power fastest way of interchanging connector, expansion port (rom supply. The computer interface data is by connecting straight games socket) and expansion shown below, communicates onto the bus of the computer. slots respectively. with the host computer bus, Computer manufacturers pro- The signals required for the provides the power for the d.c. vide a variety of means of gain- computer interface are: eight motor, generates 5V signals for ing access to the bus and there data lines, the five least - the solenoid driver board, and are two edge connectors on the significant address lines, the processes signals for return to interface board. The first con- read /write signal, a block the computer. There are also a nector is specifically for the decode of a minimum of 32 number of inputs and outputs BBC computer and the second addresses, and the clock. For for interfacing to additional one for other machines. Leads equipment such as sensors, terminated with suitable plug-in continues on page 20

Data latch, R -2R Axis 3 Feedback & Feedback a - dc Simulator a -dc kidder & d- ac d -ac simulator amplifiers

Simulator

Commodore/ Apple /IBM Data r latches

Select Power

BBC-

I-Axis3 amp ;. _.. PaF

Axis 3 drive indicators Spare i/o Driver bd Motor f/b connection

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 j

www.americanradiohistory.com COMMODORE /APPLE BBC 1MHz BUS MEMORY EXPANSION

DO C1 D0 DO C9 DO S8 -- C8

S7 IC1 74LSO4

C7 1A 2 56 IC 74LSO4 IC4 74LS21 C6 A 3 4 BLK 4 b D7 D7 C8 D7 07 6 C/A S5 BBC C100V OVp VALID W 10,1217 OV OVp VALIDW JL 54 A0 A 51 AO AO ÍC2 IL C4 74LS21 5 6 9 >8 cS3

C3 A4 S2 A4 S5 A4 C/A HFCK C121 M '-°1 2 1MHz 56 BLK1 C13 FRED--' 1MHz Cg CR%W Link 1 BBC HFCK C17 R/W S10 02/D3 BLK

C161MHz 10 CN2 12 BBC A4 C/A 9 VALID R VALID R 1MHz 13 CN1 Jl lag /03 +SV C2 C1 t 10y DAC0800 T7nT A,D 18 2 m.s.b 5 1 A y015 OEL V 12 16 13 mixed grounds BAO D A 07 A 2 8 14 OEF 7 is 5 BD7 4 5 6 11 f Ref 54 5 - EXIP3 ..--c. IN7 -/VPf 13 EDCT 14 6 6 7 IC60 +5V 7 L M,-tEXIP4 i 8 4 1 11 9 9 1 9 OE IC7 IC.12 IC, OEF c EXIP7 IC13 * 6 13 12 9 = 1 ,-t BA 62A A000B09 7 746245 766374 VFB4 74LS0 10 13 7 15 10 21 m.s b. M^ VALIDR S.Cr18 BD 16 4 16 11 20 1 1S IC9 28. i- D 17 3 18 19 12 DO 19 27 AvN,, 7415138 Y7 0 A - DIR C Vcc 1 - 18 I data NO VFBO _ 19 11 1 13 A 25 D +51- 15 24 B 13135 C3 23 14 r_ BD6 SD0 100n 22 BD BDp 17 is ALE WCK6 3 7 4 5 SDO IC606 - SC' CK fOOli +5Vt iS 7 6 SD1 ) 6 10 l 17 23 - EOCF IC15 9 IC601c,d IC602c,d ~ a 8 WCKJ 1 HFCK 13 761S374 12 IC604 IC606 C N EOCL 14 15 IC603c,d 74600 6 10 (7 OEL 3 5 SD2IC601e,f d 3to9 DIR 17 16 SC K EOC 4 SD 4 22 4 _ rc 2,76 18 BD ALE 74604 BD0 9:14 "6040,b irS03c,d 20 25 A BDO 74600 WCKO R8 19 24 11 1 20k B' BD1 p r-S05 R7 18 23 C' BD2 19 ls.b R9 18 15 BD7 3I!! AO BAO 10 IN7 =Wv-EXIP5 16 14 WCK1 15 BD 811 iL ° IN6 °WV-EXIP64 16 13 WCK2 0 17 15 R13 14 I016 812 1 12 7 ó-VLO2 A3 74LS374 12 14 800 815 IC8 13 1A D3 9 116 8 A000809 ó28 -EXOP310 R17 9 7 R18 27 o,wVL4 119 1 K6 4 7 BD6 WCK7 5 R20 26--/V\ CN3'4 - All 10k m.s.hAll 20k OEL VALI DW pitch Molex header CN4 15 -pin 0.1 17EXIP 1 R2 20k CN5 10 -pin 15EXIP2 EDCT EOCF 1 CN6 20-pin fl A 01 CN7 CN7 8-pin B C16T. +5V List of spare inputs & outputs 015T1,u 47n OVO IC10 IC11 IC7 IC8 IC9 CN7, 7 + _

-17 EXOP1 -12 ®EXIP3 10 EXIPS EXOP4-12 SII-1 . CN7,4 S 0.4-15V CN7 5 -4,-+12V Q EXIP1 0 1 o SIL SIL SIL2 c 40ff SIL 11 EXIP6 3 EXOPS-11 C18T100: EXIP2 -15 EXOP2 -11 0 17T1} O OEXTP4 SIL3O 2k2x4 CN7, ® EXOP6-10 CN7 3 OVA OVm 10 O 6- EXOP3 SIL4 , 0 EXOP7-9 C19T1u C20T100i5V CN71-10.- EXOPB -7 CN7, 2 -12V

18 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com VALID W BBC VALID W 7 i 13 12 W VALID W LIA VALID 32 6 +15V 1 1-7-1,10u -r 13 74LSO4 16V+SVt BBC VALID R C3 A 11 Y aoZ . VALID R I R45

12 111 3+ 8 C/A VALID R "\/\/\. IC 1 VALID R 27k 1Q CO 74L5153 IC6 .- +10` S1 Ref R46 R47 T +SV 10k R48 10k

C21-36 147n 10k 10y 16V D

R49 + V 1. 10k Tr2 Leds mounted 6 next to connector PC4558 111110.7r BC212L 5 1 10VRef

C/A HECK R51 68

pp PC mounting BBC HECK -15V DPCO switch (slide)

COMPUTER SELECT HFCK

10V Ref CN3,1 014 5ki CN3,10 -10V R38

-VÌ M 1k R5 CN6,9-13 -10V CN6,14-18 Vref. OVA 2 5k1 R36 R37 IC607 RC4558 Gn Sk1 100k Io R22 05 2V4 100n +15V -re-+12V 10n R35 15k VLC R42 D6ir'V4 Comp 470 R43 C10=lOOn 1C18 3 M 12 4 -15V 1458 . 10k 470 100n R44 C?0 IC19 A 10k 10k L M 13700 R34 10k 4.4V Ref A Tr3 BC 212L `N6,7 3 SD0-1 1N4148 (CNS. 1) D3 3 27k

6 SDD 2 1 (CN5, 21 IC601 rN6, 8 74LS04 Feedback pot 0V R26 470 27k .A +15V Mounted 1M R30 4k7 on robot

-10V Ref.

0101 1 `íG1 references +10V Ref. 1N4148 Cumponent R103

F /back BC 212 L R1 - 55. 101-103 up to 901 - 903 -; pot R101 Ci -37. 101-102 up to 901-902 axis 0 D10271 1N4148 DI - 9. 101-102 up to 901- 902 :`l0 ir1-3. 101 9)1 1(101 11-1 -1J. 101 up to501, 601, 2,4,6 & 607 F /back pots TJn mounted 1458 on robot 1..'J 1left VL0113,4

Ditto axis 1, 2,, 4 Simulator ditto axis 0,1,2,3,4

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 1 ,

www.americanradiohistory.com ROBOT TRAINER

r---- CN 14141 1 -1-18V(1 CN,,142 )VS U:

Axis 1 52 [Ni1 5

R201-205 . Tr201-203 R CN116 r- - - i D201-205. C201 , 001 , CN13 1 suo 1 -0-1-VVAr Axis 1 53 CN11 7 CN13 2 I : R602 R206- 210,Tr204 -206 SD0 2 CN11 8 R110 0106 R106 R101 D101 R102 D206 -210, C202 CN13

, 3 ; R603 SD1 1 5k6 8V2 1k2 5k6 8V2 1k2 CN13R604 Tr SDI 21 Axis 2 S4 CN119 Trio Tr10 R301 -305, Tr30t -3(3 R107 R103Tr102 1 [N13 5 ' R605 SD Í- CN1110 D301 -305, C301. ZTX600 33 ZTX75 ZTX600 33 ZTX751 2 ' CN73 R606 SD22: . ;NVv Axis 2 S5 CN12 1

' CtJ13 : 13102 Cl 7 R607 R306_310, Tr304 -306 0107 [102 D104 SO4 1' Mn ')CN12 2 . D306 -310. C302 2200109, 220y

; 1 CN 8 i 1N 1N R608 27V 25V 27V 29/ SD4 2 Tr106 4004 Tri 4004 109 R105

¡N13 10 i R609 SD5 1 i Axis 4 S6 CN123 330 R401_405.Tr401 -403 330 CN124 1k2 13401 -405, C401 ZTX eZTX 1k2 1k2 Axis 4 S7 CN12 5 651 651 108 R406-410, Tr404-406 ° CN126 Iri N11 3 CN112 CN1I1 D406 410, C402 CN114 Red 0110 Green 90Q9A0OQ4 0105 Q.0 0995L4 49 Axis 0 S1 Axis 0 SO Axis 5 (AIR) 58 CN129 R501 -505, Tr501-503 CN1210 D501-505, [501 the IBM the generation of a that it will work in either transferred to the digital -to- permitted on the input of the a- block decode and the direction. This is necessary as analogue converter IC14. The to-d converter. combination of signals i/o write data needs to be received back output of the d -to -a converter is The feedback signal from and i/o read to read /write takes from the robot as well as sent buffered by IC6o7a providing a 0 IC18b is compared with the dac place on the IBM plug -in card. and there is a direction signal on to + 5V signal. Being an eight - output by IC18a to give an error Although only four computer pin 1. Normally this signal is low bit system there are 28 i.e. 256 signal in the range of -5 to + 5V types have been mentioned, and the computer data is passed possible levels, therefore for and this then passes through almost any computer or to the data bus of the robot, but each bit data change there is an ICIgb which is a variable gain microprocessor system will when the analogue to digital output change of 20mV. transconductance amplifier. control the Naiad providing converter signals are read, the The reference voltage for the The current out from pin 12 is there is access to the bus and a direction signal goes high and d -to -a converter is + 10V and is proportional to the voltage 20 -way cable is made. data on the bus of the robot is derived from the + 5V rail by across its input pins 13, 14 and Operation of the interface, transferred to the bus on the IC6a. With +5V on pin 3, the the gain is proportional to the pp: 18 & 19, follows. Circuits computer. output settles at the voltage current entering pin 16. ICI and IC2 gate together A4, the The lowest four address lines which also gives + 5V on pin 2. The gain controlling current clock, read/write and a link - are also buffered with half of As R46 and R47 are equal the comes from voltage -to- current selectable choice of block IC10 and the addresses decoded output is twice the input. IC6b converter IC19a, the voltage to decodes (Jim and Fred) to by IC9 and IC11. IC9 decodes the inverts the + 10V to provide a which comes from a discrete - generate valid write and valid addresses to give the signals - 10V rail. As the - 10V rail is component d -to -a converter read signals defining the `output- enable learn' and used for powering the vari- comprising R7 to R21 and ICso7b conditions that data is being `output -enable feedback' for the ous potentiometers used for Seven out the outputs of data sent to the robot, and is required two a -to -d converters and `end - position sensing of the robot and latch IC16 feed an R/2R ladder from it, respectively. Circuits of- conversion test' which is used the simulator, the current network giving an output in the IC3 and IC4 act similarly for for checking that the converters output capability of the range of 0 to 2.5V which is computers other than the BBC. are ready to be read. IC11 operational amplifier is boosted buffered by IC6o7b. This type of Only one computer can be decodes the addresses to give a by Tr2. converter is not as accurate as connected at any one time and a write -clocks signal for the three Axis 3 feedback (position IC14 but although a couple of slide switch shown, positioned data latches IC13, IC15 and IC16 sensing) potentiometer output is percent difference in position is between the edge connectors, and to give the signals `address buffered by IClsb The potentio- very important, this amount of selecting which interface is latch enable' and `output enable' meter nulls out the offset change in the gain of the system operative, and this is shown by for the converters. The unused voltage which is the voltage on is hardly noticeable. Sources of led indicators DI and D2. The outputs of the decoders function the potentiometer at the zero error in the discrete component switch selects directly the clock as external outputs for operat- (lowest) position. The gain of version are the resistors and indirectly, by data selector ing peripheral equipment. the stage is less than unity to themselves, which are 1% IC5, the valid write and valid Data latch IC13 is the one give an output range of 0 to + 5V tolerance, and the differing reads signals. written to, for defining the next for the 250° of movement of the impedances of t.t.l. outputs in To avoid loading heavily the position of axis 3, the d.c. motor - axis. The circuit has around it the high and low states. TT bus of the host computer the driven wrist elevation. The two diodes and a transistor to logic is intended to sink current data bus is buffered by IC12 data, which is held on the latch limit the output to no more than rather than supply it and the which is a transceiver meaning until written to again, is 5V, which is the maximum output impedance is about 200. 20 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com ohms higher in the high state. applied to turn them on. saturates, turning off Triol and write operation is irrelevant but The error signal from ICigh is However once turned on, they also turning on Tr102. This in the examples given later, zero finally amplified to a level will stay on until the voltage places the charged capacitor is always used. Finally a read suitable for driving the motor by drops below about 8V. A across D104. The voltage on the operation takes data from one of power operational amplifier continuous 24V is therefore a solenoid is now equal to the the converters. Conversion IC20. The potentiometer nulls waste of energy which causes supply rail plus the charge on takes about 100µs so if in doubt out the input offset so that zero unnecessary heating inside the the capacitor (less the small as to whether sufficient time has error signal gives zero output. robot base and the solenoid drops across D104 and Tr103). elapsed for the conversion (little As motors do not start to move driver board is used to supply The solenoid has a resistance of doubt when using Basic!) the until 2 to 3V is applied to them, more appropriate voltages to about 100 ohms so the time state can be checked by reading the gain of the stage is boosted the solenoids. The board takes constant of the capacitor the end -of- conversion signals. (by blocking the feedback path the 5V control signals from the discharge is 22ms which is more Although there is no mention with zener diodes D5 and D6) so interface board and briefly than adequate for turning on the of it in the data book, a -to -d that almost any error will cause applies over 30V to the valve which normally has a turn - converters can catch out the an output sufficient to just turn appropriate solenoid turning it on time of about 5ms. unwary with a phenomenom the motor. Once 3V output is on very rapidly. This surge is To enable the computer to known as s.c.r. breakdown. If reached, the diodes conduct and then followed by a steady 17V to read the positions of the axes of this occurs heavy current is the gain of the stage drops to give a holding current which the robot and of the simulator drawn leading to overheating that set by the ratio of R37 to R36. causes only 50% of the heat there are two a -to -d converters. and eventual destruction. This Diodes D7 and D8 indicate the resulting from the use of a IC7 reads the feedback from the can be triggered by voltage direction of drive to the motor. steady 24V. robot whilst IC8 is for the learn spikes on the bus or over - Controlling the solenoids is The solenoid drive circuitry, axes of the simulator. Spare voltage on the inputs. To avoid rather simpler than the motor as (page 20) is repeated for the nine inputs are used as external any chance of breakdown, the the aim is simply for the valves. Taking solenoid So: inputs from any peripheral converters are connected to the computer to turn them on or off when the input signal is at OV, equipment. The ADC0809 is an buffered bus of the robot rather and the eight outputs of data which represents the off 8 bit, 8 channel multiplexed than straight onto the computer latch IC15 together with one of condition, Tr103 is off and its converter. bus. There are also resistor the outputs of IC16 set the states collector high turning on Trio. First the converters are network on the converter inputs of the nine solenoids. To The voltage across D104 and Roy, written to, to define the axis to and voltage limiters on the prevent a programming error is insufficient to turn on D101 be read. Buffered data lines 0, 1, amplifiers feeding them. from simultaneously turning on hence Tr102 is off. C101 charges 2 are used to define the learn Each signal from the potentio- both valves of an axis, thereby almost to supply voltage, from axis and data lines 4, 5, 6 to meters passes through a buffer causing a hydraulic short current flowing along the path define the feedback axis. Next (IC1o1, up to IC504), similar to circuit, gates 601 to 604 are D104 - C101 - R103 - Trim. they are written to again to start that of axis 3, providing offset used to disallow this condition. When the input signal switches the conversions, which occur adjustment and limiting for the The solenoids are 24V types to +5V, D105 glows indicating simultaneously on the two converter. meaning that 24V should be this condition and Tr103 converters. The data sent in this The power supply, below

03 1N4001 CN 109 r- -C+18V CN9 2

14V !al 09 1.5A _ C10° 6 )--,\ AA".2lJ 63V I1700y 7 4W T4700u D 68 6Vd c. II 16Vd.t. 8) C OVS CN0 1

- +15V analogue CN8 4 16V 7815 7812 453mA IC3 IC4 +12V motor CN8 S

2200u i,u C4 2200» CN101 J3 T 35V 35V T16V CN103 analogue CN8 3 110 2200N Çt02 OV motor CN8 6 04 35V a. c. 0 71 2200 mains 16V; T16V I C2 12V motor CN81 450 mA 110 7915 7913 15V analogue CN8 2 8 x 1N4004 CN10 6 i 130 7805 +5V logic CN8 8 8V@ 05 1A C 1N 9T35V CN 107

OVO CN8 7

Solenoid master switch

013,[11, R1 ensure 36V is available at CN9 2 at 240V Water pump supply switch on in case any solenoid trigger signals are high

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 21

www.americanradiohistory.com ROBOT TRAINER

provides regulated supply rails of +5V, +15V, -15V for the computer interface board, + 18V unregulated for the solenoid driver board and 240V for the pump. The Naiad is memory mapped (i/o mapped when used on the IBM) meaning that the computer treats the robot as if it were part of its memory (i /o space on the IBM) and can be written to or read from. Table 1 gives the addresses used by the robot. Operation is most simply shown by examples and for these, BBC Basic will be used. In BBC Basic both poke and peek are represented by ?.

To: define address of start of block decode JIM A = &FD00 rotate axis 0 clockwise turn on solenoid So) set all bits low except Do ?(A +1) =1 Table 1. Addresses used by Naiad. A is address of block decode. rotate axis 0 anticlockwise turn on solenoid S1) set Write Addresses Data Sent D1 ?(A +1) =2 all bits low except A + 0 Axis 3 position Data range 0 to 255 (whole low raise axis 2 (turn on solenoid S4) set all bits range) except D4 ?(A+ 1)= 16 A + 1 Solenoids 0 - 7 DO (1) SO 0 set all raise axis 2 and rotate axis clockwise D1 (2) S1 ?(A + 1)= 17 bits low except Do, D4 D2 (4) S2 high (G is close the gripper set Do of next latch D3 (8) S3 of axis 3 an even integer defining the gain D4 (16) S4 amplifier) ?(A+2)=G+1 ?(A+2)=G D5 (32) S5 open gripper again D6 (64) S6 send axis 3 to lowest position ?A=0 ?A=128 D7 (128) S7 send axis 3 to centre position A + 2 Solenoid 8 DO (1) S8 1/2 ?(A+2)= 128 set amplifier gain to of maximum Axis 3 gain Data rane 0 to 254 (even read axis 0 feedback(set data lines low on ?(A+6)=0 ?A+7)=0 numbers) multiplexer) A + 3 EXOP1 Data irrelevant F0 = ?(A + 17) A +4 EXOP2 read axis 3 feedback (set D4, D5 high on ?(A+6)=48 ?(A+7)=0 A +5 EXOP3 multiplexer) A + 6 Set adc multiplexer 0 Learn, feedback axes 0 F3 = ?(A + 17) 1 Learn axis 1 read axis 3 learn (set Do, D.1 high on 2 2 multiplexer) ?(A+6)=3 3 3 ?(A+7)=0 4 4 L3 = ?(A + 16) 5 . 5 read analogue input EXIP5 ?(A+6)=7 6 EXIP6 ?(A+7)=0 7 EXIP5 EXIP5 = ?(A + 16) 16 Feedback axis 1 enable external device on EXOP1 ?(A+3)=0 32 2 EOCF = ?(A + 18) read end -of- conversion feedback 48 3 AND 1 64 4 18): EX- 11 read external digital input EXIP1 B= ?(A + 80 EXIP7 IP1 = (B AND 96 EXIP4 8)DIV8 112 EXIP3 A + 7 Start conversion Data irrelevant You can see that very simple table, a conveyor system using a A +19 EXOP4 statements will operate the axes stepper motor for position A +20 EXOP5 of the Naiad together with incrementing and a range of A +21 EXOP6 external devices. Data back sensors. A + 22 EXOP7 from the robot and external A + 23 EXOP8 devices is also easily obtained by the host computer, and Read Addresses Read Data programs performing servoing and interacting with peripheral A216 Learn adc Data range 0 to 255 (whole devices are readily accom- (inc. EXIP5,6) range A + 17 Feedback adc Data range 0 to 255 (whole plished. A large amount of soft- inc. EXIP3,4,7) range ware has already been written The Naiad is manufactured by A + 18 End -of- conversion Test DO (1) Feedback adc for the Naiad and will be Cybernetic Applications, West (inc. EXIP1,2) D1 (2) Learn adc supplied with it. Even more is Portway Industrial Estte, D2 (4) EXIP2 being written and peripheral Andover, Hants SP103WW, Tel D3 (8) EXIP1 equipment is under develop- 0264 50093, and is available ment. The first devices to be either ready -built or as a self- available will be an indexing assembly kií. 22 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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www.americanradiohistory.com * COMPUTER PERIPHERALS * TEST EQUIPMENT RALFE e ELECTRONICS 1602A. VAT TEL: 01 -723 8753 HEWLETT -PACKARD LOGIC ANALYSER E250. 10 CHAPEL STREET, LONDON, NW1 1.6MB 8" FLOPPY DISC DRIVES - New 3- 220MHz E150 VAT KNIGHT SWEEPGENERATOR Stock BAUSCH & LOMB METALLURGICAO MICROSCOPE f 500 +VAT aae . Ir AIRMEC2OKVIONISATION TESTER 209. £150 +VAT .... BRAND NEW At a surplus price. Fully Shugart compatible'MFE 1504 £ 95 +VAT BRUEL & KJOER DEVIATION BRIDGE CORPORATION' Model M -7W DOUBLE -SIDED industry standard 8" £250 WAYNE KERRAutobalance Universal 8ridgeB641 Floppy disc drives. Double-density. up to 1.5MBytes. Power L ta 11.11H disco - SULLIVAN Inductance bridge R400. Measures requirements ±5V and 24V B 1.1A. 240V. AC 50Hz. C375 VAT mmahon.002uH LOWEST PRICE EVER. í16O- INC. VAT. CARRIAGE & HANDBOOK. GENERAL RADIO Capacitance bndge1617A £125 VAT BPL RC &L Component comparator with in /out limits in- DRE 4000A DRIVES dicator unit E250 +VAT SIERRA Bi-directional power meter El 25 + VAT Data Recording Equipment Model 4000A 5 + 5 MB Top - TEKTRONIX 7603 4 trace 75MHz El 250 BIRD 4370 Thruhne Wattmeter E 135 + VAT loading disc doves in stock. Brand new including lull TEKTRONIX 454 2 trace 1 50MHz. (600 POLYSCOPS SWOB I & II í2501f450 + VAT technical manual. Few remaining £250 each + VAT. HEWLETT PACKARD 1 707A dual trace BOONTON 778 Capacitance limit bridge E 175 + 25MHz E250 GEN RAD Oscillator 450- 1050MHz C95 + TELEGUIPMENT D54 dual -trace 10MHz E150 * MULTI -RAIL LINEAR PSU's * GEN RAD 1 606A RF Bodge E 1 25 + TELEDUIPMENT -trace 50MHz E425 - 4 HEWLETT -PACKARD 3490A DMM E350 + D83 dual SE Labs SM 1 t 1 dual -trace 1 8MHz E 1 50 . k .r, brand new COUTANT ESM-Series Power Supplies at DATRON 1051 DMM £350 + Stock continually changing. please 'phone ,urplus priers. Model ESM15.2 giving regulated. stabilised DC 454 £650 outputs 5V rß 15A and í12V to 215V a 1.5A each and an un- stabilised 24V B 2A. 240V AC input. Measures 5.8x11'. Fully FM SIGNAL GENERATORS enclosed In ring mat cartons with handbooks. £45 each VAT (+ AUDIO TEST GEAR carriage E51 ['WAR 5815M Signal generator covering from 0,1MHz to 184MHz. Narrow deviation model. MAINS DR BATTERY TEKTRONIX 7603 RADFORD Series 2 Oscillator f85 + VAT OPERATION MODEL 1525. E295 VAT. ST506 WINCHESTERS RADFORD Series 2 Distortion meter.. f 95 + VA T MARCONI TF2330 Wave Analyser E350 FITTED WITH WOELKE Wow & Flutter meter E 9 5 + OSCILLOSCOPE AMBER 4400 Multi- purpose audio test WAYNE KERR EQUIPMENT two 7A1 8A Y- amplifiers and We have in stock genuine SEAGATE ST506 5'd' Winchester disc drives in little fully functional with set 125 + sold used. condition complete 7B53AN time -base plug -in. OEM manual. Formatted capacity 5MB. WAYNE KERR Autobalance Universal Bridge f Complete: £1250 + VAT. FEW ONLY REMAINING - f 195inc. VAT for 5MB and 8841 E250+ VAT Sine. for 10MB version. Prices including carriage and WAYNE KERR Autobalance Universal Bridge E24 handbook warred qty. 8421 E125 +VAT copy and 90 -day WAYNE KERR VHF Admittance bridge 6801 MARCONI + VAT PHILIPS COLOUR GENERATOR E45 TEST WAYNE KERR B201 RF Capacitance /Conduct 8" SHUGART DISC DRIVES bridge E 125 +VAT Phipps PM55191 TV Colour pattern generator. 12 pat- 1; e.. es EQUIPMENT WAYNE KERR Torque-Vane X -Band WATTMETER .: terns. UHF & Video outputs. Condition as -new corn - U182 E275 +VAT TF10668 /1 AM /FM Sign gen GENUINE MODEL plate with manual. E425 + VAT. SHUGART 10- 470MHz f450 - WITH SA800. Solt- sectored single TELONIC 2003 SWEEP GENERATOR TF995B/5 AM /FM sig gen sided industry standard 8' PLUG 0- 1000MHz OSCILLATOR -IN, 1.5- 220MHz £425 floppy disc doves. 800116 markers, attenuator and RF detector plug-in TF1 064 AM /FM sig gens £95 in VAT storage. Supplied excellent ESCAP DC MOTORS units E295+ TF2604 Electronic Voltmeter.. f 125 condition. little -used. Removed TF893A Audio power meters E85 Nom fully functional equipment. reduction gearboxes So made precision 6V DC motors with 70.1 TF2700 Universal bridge f 200 Price including VAT. carriage gdmog final drive of 16RPM ,r, 6V. Diameter 2'bcros = 4cms speed TF2000 Audio sig gen /attenuator and Zerox of nandbook - C95 long. PRICE INC. VAT&CARRIAGE.... T525 Airmer/Racal 4- channel display oscilloscopes for £175 colleges. educational etc. 17" CRT. DC 1OKhz. Fully IFS-equp. tested & guaranteed/. - TF2330 Wave analyser audio E 350 TEKTRONIX 4907 FILE MANAGER E150 + VAT operational.. £125VAT TF2002 MF /HF AM Sig generator f400 MAINS CONDITIONERS TF791 D Deviation meter f 175 Constant -voltage transformers TF2606 Differential DC voltmeter * INSTRUMENT COOLING FANS * SOLA 230V IKW cvt....f95 + VAT £125 STEPPER MOTORS ** ** ADVANCE 230V 500W f75 + TF1152A RF power meters 25W All fans available ex -stock and GUARANTEED Brand new stock of 'ASTROSYN' Type 20PM- CLAUDE LYONS 3KW f175- £75 230V 10W 5 -Blade 3ì+3;,Y1' NEW E7 SERVOMEX 5KW £175 - SAUNDERS 6058 7 12.5GHz -ig A055 stepper motors. 28V DC. 24 steps per rev. 115V 13W 5 -Blade 3:. *3 -x1- NEW E6 SERVOMEX 3KW £125+ yen _.. El 50 - 15 oz -in torque r' 100PPS. Body length 21/2... 115V 41.41.1!- 5 -Blade NEW E5 carriage on any type El 0 each diameter 2 , shaft Ira' diem x 41/4" spirally 115V 7W 4'- 3 -Blade WHISPER £5 threaded. Weight 16oz. Price each f11.501p&p 230V 40W Papst 350M /hr Ex- equip. t13 PLEASE NOTE. All our used equipment Is sold m lull working condition and carries a 90 day war 5001. Connections supplied. VAT INC. ranty For our mail-order customers. we otter a money back if not satisfied guarantee An prices include VAT lep - 500 OFFICIAL ORDERS ACCEPTED FROM GOVERNMENT BODIES ETC.

CIRCLE 37 FOR FL RTHER DETAILS.

A compact mains- powered unit with one balanced input and ten a.c. and d.c iso- 10 OUTLE lated floating line outputs. *Exemplary R.F. breakthrough speci- DISTRIBUTION fications giving trouble -free operation in close proximity to radio telephones and links AMPLIFIER 3 *Excellent figures for noise, THD, static and dynamic IMD * Any desired number of outlets may be provided at microphone level to suit certain video and audio recorders used at press conferences * Meets IEC65 -2, ßS415 safety and I.B.A. 'signal path' requirements Also available as a kit of parts less the VICCOM MODEM (UNIVERSAL) case and all )(LA connectors for one or EUROPEAN CCITTT STANDARD ten outlets. For all computers such as: CCITT V.21 ORI. 300 BD F. Duplex Broadcast Monitor Receiver 150kHz- IBM, Apple, BBC, Commodore, CCITT V.21 ANS. 300 BD F. Duplex 30MHz *Stereo Disc Amplifier 3 and 5* £110.00 Moving Coil Preamplifier * Illuminated spectrum etc CCITT V.23 600 BD H. Duplex PPM Boxes * PPM Drive Boards and OPTIONS CCITT V.23 1200 BD H. Duplex Ernest Turner Movements * Stabilizer and Frequency Shifter Boards Peak RS 232 interface cable (F) for BD F. * CCITT V.23 75/1200 Duplex Deviation Meter * Programme and De- IBM PC £8.00 (Videotex -Viditel, Prestel) viation Chart Recorders * PPM5 20 pin RS 232 interface calbe (M) for CCITT V.23 1200/75 BD F. Duplex DIL hybrid * Stereo Microphone Ampli- Apple II £8.00 (Videotex /viewdata Host) fier. Advanced Active Aerial Stereo Coder Interface cable for BBC £5.60 Boards. USA BELL STANDARD SURREY ELECTRONICS LIMITED Interface cable for spectrum Bell 103 ORI. 300 BD F. Buplex The Forge, Lucks Green (with interface I) £6.70 103 ANS. BD F. Duplex Cranleigh, Surrey GU6 7ßG Bell 300 Tel. 0483 275997 VICCOM MODEM - £79.00 Bell 202 1200 BD H. Duplex For CBM -64 or other Commodore comptuers with user -port, and for PRINTERS - MONITORS - TERMINALS - PERIPHERAL the SPECTRUM. VIDEOTEX/VIEWDATA Burroughs MT710: Intelligent Green 12" VDU with 3 Work with most Viewdata Telecommunication softwares: micros and 64K store. RS232. Programmable. Only £ 149 1 Softwares and VIP Terminal Top Spectrum£16.00 new + £ 5 P &P. Program (CBM -64) For CBM 64 £25.00 12" Open chassis Video Monitor: by Hitachi standard Expandable with a power unit For BBC £39.00 composite Video and 12v input. Green screen, wide for other computers. For IBM PC £75.00 bandwidth. £40.00 + £7.00P. CBM- 64IVICCOM INTERFACE For bullet, Morrow MD11, Cased Video Monitors : 12" or 15" Green Screens £8.00 CABLE Northstar advantage £70.00 standard composite video & mains £60.00 + £7.00 SPECTRUM /VICCOM P &P. INTERFACE CARD & CABLE, Centronics 306 Line Printers: Professional fast AND TERMINALIVIEWDATA VIDEOTEX /VIEW DATA (120 cps), SOFTWARE £20.00 superb quality 80 column printer. Parallel i /f. ONLY £99 Host Softwares: + £15.00 P+ P. POWER UNIT £26.00 Datatel for CBM 64 £75.00 OPTION Poseidon for BBC £170.00 Texas Silent 700 Printers: Whisper quiet 80 col matrix Auto answer /auto dial card (This Note: these softwares work with printer with RS232 interface. ONLY £99.00 + £7.00 card works with VIP Terminal AUTO ANSWER /DIAL CARD P &P. Program for CBM -64 and the Diablo 630 Daisywheel printer: OEM i/f NEW £599 + £1 5 P &P. videotex host softwares) £35.00 Calcomp 565 Drum Plotter: OEF £450 + £10 P +P. 6 months guarantee COMPUTER SOURCE Approved by PTT (Dutch BRAHMSLAAN 129 Many more bargains. Phone for your requirements. WE ALSO BUY. Telephone Company) 2625 BV DELFT Modems for use in the U.K. BECINHAM PERIPHERALS LTD HOLLAND, Callers welcome SAE for LIST should be approved by British by appointment 5582 and enquiries Telecom TEL 015. 613195 34 RodwayyRRoad, Bromley DEALERS REQUESTED Kant BR13JL DETAILS. CIRCLE 63 FOR FURTHER DETAILS. CIRCLE 55 FOR FURTHER 24 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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Antennas more that by using an "open-sleeve" acceptance of "revolutionary" essential for people to get - dipole as the feed element, the 1125 -line, 60Hz, h.d.tv together before taking up a width bandwidth of a Kraus corner systems. firm stand and quotes as a reflector antenna can His almost wickedly valuable precedent the The bandwidth of many effectively cover 240 to provocative attack on the successful adoption of the current receiving antennas for 400MHz, a bandwidth ratio of widely -promoted NHK /Sony Compact Disc standard u.h.f. television and v.h.f. radio 1:1.7. Incidentally earlier work production standard was following early discussions is barely adequate and can by King and Wong was used presented under the urbane between Philips and Sony. produce problems. The by James Miller in the design chairmanship of recently performance towards the limits of his helical antennas for retired Stuart Sansom who, of the various "groups" tends 435MHz (E &WW, June 1985, only a few weeks before, had Early radio to fall off, particularly at the pp. 43 -6). been arguing equally strongly high- frequency end, for A new end -fire radiator in favour of the NHK Dr Geoffrey Phillips resolutely example, when rainwater antenna, the corrugated production standard as one of tackled the near -impossible in collects on the elements. For surface plane (c.s.p.) system, the founder -members of Sony attempting to cover "the Band 2 radio, many of the has been reported by C.A. Broadcast. history of sound broadcasting" multi -element beams in use to King and D.A. Downs, based Mr van der Klugt confirmed from Faraday in 1831 to improve stereo reception were on work carried out at the US that Philips expect to begin current re- engineering by the designed with an upper limit of Naval Research Laboratory, marketing first-generation BBC of the v.h.f. network for 100MHz and are becoming far Washington DC (Electronics MAC receivers in 1987, though circular polarization, all in the less efficient as the band Letters, Vol 21, No 24, 21 he did not elaborate on course of a single IEE lecture. extends up to 108MHz. The November 1985). whether these would be nevertheless he succeeded in problem also occurs on some of They note that many suitable for D2 -MAC or C- spotlighting, if only briefly, the older transmitting antennas applications require the use of MAC or both. surprisingly large number of which, for local radio, were narrow -beam endfire radiators. The 60Hz proposals, the landmarks in radio designed for use below A popular microwave approach formulated by Japan with broadcasting. 100MHz and are now having to is the polyrod antenna support from the USA and He noted the early work in be changed to accommodate comprising a dielectric rod fed Canada, attracted much Belgium in 1914, interrupted the new Geneva Plan 1984 by a short section of opposition at the recent CCIR by the Great War and then frequencies. waveguide. However, at u.h.f. meeting. It failed to achieve succeeded by the famous However, the design of such antennas become heavy the desired status of a draft Hague Concerts of 1919 to antennas having broader and cumbersome due to the recommendation, and remains about 1922 to which UK bandwidth is making progress. weight of the dielectric. They simply a proposal. With so listeners were invited to At the 1985 International have evolved an antenna much opposition from 50Hz subscribe and which were also Conference on Antennas and consisting of a pair of countries, it would appear to sponsored for a year by the Propagation (ICAP85) several corrugated surfaces mounted have little chance of being Daily Mail. The Melba papers were published on back -to -back with a dipole feed formally approved as definite broadcast from Chelmsford in wideband u.h.f. antennas element perpendicular to the recommendation at the 1920 was followed by the suitable for television surface with its mid -point in pleanary assembly of the CCIR procrastinations of the British applications. A Polish paper by the plane of the surfaces. Each next May. It could be, of government, finally resolved R.J. Katulski of Gdansk of the 21 -inch corrugated course, possible for countries by the building of 2L0 London, University, Poland, analysed surfaces has 42 slots, 1.5 -in to go ahead without CCIR 2ZY Manchester, SIT the log. pyramidal periodic wide and 1.5 -in deep. The endorsement. Birmingham, the long -wave (l.p.p.) antenna which antenna weighs 151b compared In his lecture, Mr van der transmitter at Daventry (5XX) comprises two log.- periodic to an estimated 601b for a Klugt said: "Philips anticipates in the era of the British structures mounted in comparable polyrod. a technical solution, concerning Broadcasting company (1922 - diverging planes. His design Measurements at 500, 750 and the 50 /60Hz impasse. If we 1926), and the old Savoy Hill was claimed as suitable for 1000MHz show half -power achieve what we now believe is studios in the IEE building in television reception throughout beamwidths of 50 °, 31° and possible, an umbrella standard which he was speaking, with the range 150 to 900MHz with 25° respectively. Sidelobe for studio production for their "meat safe" more gain than a comparable levels are 20dB down, conversion to both 50Hz and microphones. Steel tape log.- periodic array. considered low in comparison 60Hz, one of the stumbling recording was a feature of the A BBC paper on antennas for with previously-reported blocks will be removed. It 'thirties, first with the outside broadcast links surface -wave antennas. would seem obvious that major Blattnerphone and later the included log. -periodic arrays, modifications to the Japanese Marconi -Stille machines. parabolic dish reflectors with h.d.tv system will be required He acknowledged the early log.- periodic feeds and a Philips embrace before it can adequately meet "Empire" broadcasts in 1927 conical logarithmic-spiral the test of providing the best and 1928 by Gerald Marcuse antenna that forms a "rove" MAC service for the most people." on 31 metres with 1.5 kW, antenna with circular We have an important not -to- followed by the BBC from polarization for mobile links, There was a piquant flavour to be- missed opportunity to G5SW at Chelmsford and with all three types suitable for the 1985 Shoenberg memorial create an orderly video - finally the official start of BBC use from 580 to 950MHz. Lecture of the Royal compatible world ... but if external services in 1932. Conical logarithmic- spiral Television Society. Given by fear of no decision drives us to The progression from crystal antennas are also attracting C.J. van der Klugt, vice - making a decision that puts sets to valve sets with their increasing interest for president of Philips, it argued more than half the world at a "reaction" whistles to upset communications applications. very strongly in favour of disadvantage, then we have the neighbours gave Dr Jimmy Wong and Howard "evolutionary MAC" and - at failed to use the opportunity Phillips the opportunity to King of the Aerospace least for the 75 per cent of the now available to good stress the advantages for Corporation have show (IEEE world with 50Hz mains advantage." medium -wave reception of the Trans on Ant. & Prop., Vol supplies and 50 -field television To obtain agreement on old- fashioned "frame" and AP -33, No 8, August 1985) systems - strongly against world standards he believes it modern "ferrite -rod" aerials ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 25

www.americanradiohistory.com COMMUNICATIONS COMMENTARY

that can help to reject over obstructed paths in which interference, including local he found interesting signal electrical interference. He also enhancements just after sunset highlighted the anti -fading and just before dawn. properties of the two -section Ray Cracknell, G2AHU 725 -ft mast radiator on which (former ZE2JV) received the the old "Third Programme" Wortley Talbot trophy and an used to go out from Droitwich. ARRL award for technical He admitted that the UK had excellence. As one of the been slow to adopt v.h.f. radio. pioneers whose detailed The classic paper by Howard observations led to a better Armstrong had been published understanding of trans - in 1936 but it was not until equatorial propagation, since 1954 that the service began his return to the UK he has from Wrotham, although this continued his studies of followed exhaustive tests not 50MHz propagation. It may be only of f.m. /a.m. but also a.m.l. The original PCGG transmitter as it was displayed in recalled that he had the in which a very broad receiver the Nederlands Postmuseum at The Hague, greatest difficulty in response permitted the use of Netherlands. Not visible are the huge aerial loading persuading the Radio very effective noise limiters on coil and the rotary machines used for powering the Regulatory Department to pulses that had not been transmitter. PCGG operated on a wavelength of 670 renew his British licence sharpened by a narrow i.f. This meters. without having to retake the system, he considered, came examinations! very close to f.m. in There appears to be a good performance. English listeners were CH radar chance that the new 50.0 to introduced. 50.5MHz band will be released In 1917 Idzerda, as manager Adding to the excellent series on a 24 -hour basis to UK PCGG of Nederlandse Radio - of papers presented last year at amateurs about February 1986. Industrie, had persuaded the three -day IEE seminar to It is clear, however, that DTI The mention by Dr Phillips of Philips to begin manufacturing mark the 50th anniversary of are undertaking a major the Hague Concerts deserves radio valves which they agreed British radar, readers may revision of the terms of the to be elaborated upon. These to do if he would agree to buy wish to note several special amateur licence. were organized by 35- year -old at least 180 valves per year. So articles in The GEC Journal of A Raynet Trophy was Hanso Steringa Idzerda after began, early 1918, production Research (Vol 3, No 2, 1985). presented to Staffordshire he obtained a licence to of Philips -Ideezet "soft" These include a detailed amateurs who had helped transmit music and voice on valves. In the first year he sold account by B.T. Neale "CH - organize emergency PCGG in The Hague. His first 1200 of them. His broadcasts the first operational radar" communications with Mexico transmission was on November were intended to promote the providing technical and after the recent earthquake. 6, 1919 after the programme of sale of his receivers. Later it is operational details of the his "Radio Soiree -Musicale" believed he quarrelled with 25MHz Chain Home with its had been advertised the day Philips, though he had initiated transmitters built by In brief before in a Dutch newspaper, their entry into valve Metropolitan- Vickers and and the station remained in manufacture. receivers by A.C. Cossor Ltd Arthur Watts, G6UN, who service until October, 1924. It The Dutch claim PCGG as to THE specification. died recently aged 91 was a preceded KDKA in 1920. the world's first broadcast W.E. Willshaw describes the World War I member of the Wireless World drew attention transmitter, though this tends evolution of the microwave Royal Navy Intelligence to these broadcasts in June to be disputed by the Belgians, magnetrons to which Eric Department and, as president 1920 and special concerts for and there was also Prof. Megaw of the GEC Research of the RSGB in 1939, was Fessenden's Christmas Eve laboratories and Gutton of responsible for the recruitment "broadcast" in 1906. SFR, Paris contributed of several hundred pre -war PCGG actually employed a significantly. The account by radio amateurs as Voluntary Simplified circuit of the form of narrowband frequency Willshaw is one of the most Interceptors of the Radio PCGG transmitter. The modulation on 670 metres, detailed accounts of this major Security Service (MI5) carbon microphone in being received best with the UK development by Boot and working under Lord Sandhurst series with coil L2 effects receiver slightly detuned. Randall. ... During June 1985 a new frequency modulation In 1940 the original world record for a tropospheric transmitter was donated to the contact on 430MHz was Dutch Postmuseum where for established between many years it was regularly KH6HME, Hawaii and a demonstrated on dummy load Amateur station near San Francisco. On and is still located. Radio 1296MHz KH6HME worked Hanso Idzerda, unhappily, N6CA in Los Angeles. Both was arrested by the Germans distances exceed 4000km over on 3 November 1944, found in the Pacific path that appears to possession of radio equipment, Awards support v.h.f. and u.h.f. signals (and may have been involved in at intervals of several years . . . the clandestine Dutch radio RSGB awards this year did The ARRL has proposed a service) and shot without trial reflect some genuine band plan for 24MHz as at Wassenar. experimental work. Roy Jones, follows: 24.89 to 24.92MHz My thanks to Dick Rollema, G3NKL received the Mullard c.w. only. 24.92 to 24.93 PAOSE, for much of this Award for some careful c.w. /digital. 24.93 to information. observations of 10GHz signals 24.99MHz s.s.b./s.s.tv. 26 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Data conversion This supplement to January's data conversion feature contains the first part of a comprehensive list of d -to -a and a -to -d converter i.cs and modules.

Digital -to- analogue converters are given in the first part of the show the conversion method used. With the aid of last month's table and analogue -to- digital devices in the second. There's news glossary, the abbreviations used should be clear. of a new molybdenum i.c. process on page 29 and an example of Speed is given as seconds for conversion. With most of the converter grounding on page 32. devices, we have given typical parameters. Where the typical An extra column is included in the a -to -d converter section to value is unclear we have given a worst -case figure.

Manufacturer Device Bits Speed Interface Tech. Features AMD DAC08 8 85n Par. Bip. Mult., 0.1% linearity, differential I o/p Am1408 8 250n Par. Bip. Mult., 0.2% linearity, 157mW, I o/p Am1508 8 250n Par. Bip. Mult., 0.2% linearity, 157mW I o/p Am6012 12 250n Par. Bip. Mult., 4mA diff. o /p, 230mW Am6022 12 75n Par. Bip. Mult., 4mA diff. o /p, 500mW Am6070 12 300n Par. Bip. Companding for control systems, 72dB Am6080 8 160n Proc. Bip. Mult., 0.1% linearity, 5ppm / °C, I o/p Am6081 8 200n Proc. Bip. Mult., 0.1% lin., range mpx, diff. I o/p Analog Devices AD390 4x12 8µ Proc. Hyb. Quad, ±s41.s.b. linearity AD558 8 lµ Proc. Hyb. 2 range, 5V supply, 75mW AD561 10 250n Par. Bip. ±ya.s.b. error AD562 12 1.5µ Par. Bip. Mult., ±t2l.s.b. error, I o/p AD563 12 1.5µ Par. Bip. Mult., ±4,1.s.b. error, I o/p, int. ref. AD565 12 250n Par. Bip. 225mW, I o /p, internal reference AD566 12 350n Par. Bip. 180mW, I o/p AD567 12 500n Proc. Bip. 500ns to ±Ibit, 1% 10V reference AD569 16 6µ Proc. Bi/mos Ratiom., 0.02% linearity, V o /p, 150mW AD667 12 4µ Proc. Bip. 4µs to 0.01 %, 1% 10V ref., 300mW AD1408 8 250n Par. Bip. Mult., 0.1% linearity, 157mW, I o/p AD1508 8 250n Par. Bip. Mult., 0.1% linearity, 157mW, I o/p AD3860 12 5µ Proc. Hyb. o /p. amp., +- 421.s.b. linearity, int. ref. AD6012 12 250n Par. Bip. Mult., ±l.s.b. linearity, I o /p, 230mW AD7110 6 150kHz Par. C-mos Log. 0 to -88dB, 1.5dB res., 100dB s/n AD7111 8 3µ Proc. C-mos Log. 0 to -88dB, 0.375dB res., 5V supply AD7115 9/12 5µ Proc. C-mos Log. 0 to -19.9dB, 0.1dB res., b.c.d. i/p AD7118 6/17 0.4µ Par. C-mos Log. O to -85dB, 1.5dB res., 5V supply AD7224 8 7µ Proc. C-mos 10V o /p, 2 i/p regs, +ve supply AD7225 4x8 5µ Proc. C-mos 4 sep. refs, + or ± rails, V o/p AD7226 4x8 7µ Proc. C-mos 4x8bit, positive supply, V o/p AD7240 12 550n Par. C-mos -1+ l.s.b. error, 30mW, +ve supply, V o/p AD7520 10 500n Par. C -mos Mult., 20mW, 2ppm f.s. / °C, 5V supp., I o/p AD7521 12 500n Par. C -mos Mult., 20mW, 2ppm f.s. / °C, 5V supp., I o/p AD7522 10 500n Ser /par. C -mos Mult., positive supplies, I o/p AD7523 8 100n Par. C -mos Mult., I o/p AD7524 8 150n Proc. C -mos Mult., t l.s.b. acc., 5V rail, 10mW, I o/p AD7525 12 lµ Par. C -mos 34e-digit b.c.d. i/p pot., +- ;gl.s.b. lin. AD7528 2x8 350n Proc. C -mos Mult., dual latches, I o/ps matched to 1% AD7530 10 500n Par. C -mos Mult., I o/p, 20mW, 5 to 15V supply AD7531 12 500n Par. C -mos Mult., I o/p, 20mW, 5 to 15V supply AD7533 10 600n Par. C -mos Mult., I o/p, 5 to 15V supply AD7534 14 1.5µ Proc. C -mos Mult., 8bit bus, 0.5ppm / °C gain co., I o/p AD7535 14 1.5g Proc. C -mos Mult., 0.5ppm / °C gain co., <20nA o/p leak. AD7541 12 600n Par. C -mos Mult., I o/p, ±1 l.s.b. gain error AD7542 12 24 Proc. C -mos Mult., 40mW, ±4fibit linearity, 4bit bus AD7543 12 2µ Ser. C -mos Mult., 40mW, -Sibit+ linearity AD7545 12 2µ Proc. C -mos 2ppm / °C gain coeff., 5V supply, 0.5mW AD7546 16 4 -10g Proc. C -mos V o /p, 50mW, l6bit bus /latch AD7548 12 1.5µ Proc. C -mos 8bit bus, muli., 5ppm / °C gain co., +ve supp. AD7549 2x12 1.5µ Proc. C -mos Mult., 4bit bus, 3 l.s.b. f.s. error, I o/p AD9700 8 1On Latch Bip. 125MHz camp. vid. + sync, -5V supp., int. ref. AD9702 3x4 5n Par. Bip. RGB channels, 125MHz samp., e.c.1. /t.t.l. i/p AD9768 8 5n Par. Bip. Vid. 100MHz samp., 20mA o /p, int. ref. DAC08 8 85n Par. Bip. Muli., 0.1% linearity, I o/p DAC71 16 5µ Par. Hyb. 0.003% lin., 7ppm / °C gain co., V or I o/p DAC72 16 5µ Par. Hyb. 0.003% lin., 5ppm /°C gain co., V or I o/p DAC80 12 2µ Par. Bip. ± 1.s.b. linearity, int. ref., I or V o/p DAC85 12 2µ Par. Bip. t141.8.b. linearity, int. ref., I or V o/p DAC87 12 2µ Par. Bip. tyl.s.b. linearity, int. ref., I or V o/p DAC100 10 375n Par. Bip. t.t.1. /d.t.l. i /p, I o/p, int. ref DAC1136 16 6µ Par. - ± 11.s.b. linearity ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 '7

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Manufacturer Device Bits Speed Interface Tech. Features DAC1138 18 104 Par. Hyb. ±411.s.b.linearity DAC1146 18 64 Par. Hyb. 1ppm / °C, high linearity HDD0810 8 10n Par. Hyb. Vid., 7557 o /p, sync i /p, int. ref. HDD1015 10 15n Par. Hyb. Vid., 7511 o /p, sync i /p, int. ref. HDD1206 12 24 Par. Hyb. I/p register, 6MHz update, o /p. buff. HDD1409 14 54 Par. Hyb. 200kHz sample rate, o/p buffer HDG805 8 8n Par. Hyb. Video, -5.2V supply, sync i/p HDG605 6 6n Par. Hyb. Video, -5.2V supply, sync i/p HDG405 4 4n Par. Hyb. Video, -5.2V supply, sync i/p HDH0802 8 200n Par. Hyb. 10V o /p, video, i/p buffer HDS0820 8 20n Par. Hyb. 10mA o /p, video, i/p buffer HDH1003 10 300n Par. Hyb. 10V o /p, video, i/p buffer HDH1205 12 500n Par. Hyb. 10V o /p, video, i/p buffer HDM1210 12 175n Par. - Mult., 10mA o /p, 10MHz 5dB analogue b.w. HDS0810 8 lOn Par. Hyb. -5.2V rail, 7551 o /p, e.c.l. i/p HD60820 8 20n Par. Hyb. 10mA o /p, video, int. ref., i/p buff. HDS1015 10 15n Par. Hyb. -5.2V rail, 7511 o /p, e.c.l. i/p HDS1025 10 25n Par. Hyb. 10mA o /p, video, e.c.l. i /p, int. ref. HD61240 12 40n Par. Hyb. 16mA o/p, e.c.l. buff., int. ref. HD81250 12 35n Par. Hyb. 10mA o /p, video, e.c.l. i /p, int. ref. Analogic AH8304TC 4x3 10n Latch Hyb. 1V RGB o /ps, t.t.1., synchronous blanking AH8304TM 4x3 50n Latch Hyb. As TC but with 32 word colour mem. AH8308E 8 7n Latch Hyb. 1V comp. vid. o /p, 5V supply, t.t.l. i/p AH8308T 8 15.5n Latch Hyb. 1V comp. vid. o /p, 5V supply, t.t.l. i/p AH8308TC 8x3 10n Latch Hyb RGB 1V o /p, t.t.l. i /p, synch. blanking AH8404TC 4x3 40n Latch Hyb. RGB 1V o /p, t.t.l. i /p, 0.6W. AH8404TM 4x3 50n Latch Hyb. As 8404TC but with 52 word mem., 0.8W MP1480 12 104 Proc. Mod. 4 -20mA current loop o /p, bin. or b.c.d. opts MP1814 14

www.americanradiohistory.com New molybdenum- gate c -mos e- technique increases converter speed and accuracy E

A newly developed c -mos i.c. process involving the use of Resistor Contact to process with low gate overlap molybdenum is now being contact V- Source Dram Source Dram Vdd molybdenum capacitance results. Effective used to manufacture a high- r gate length of 21.tm with 0.1pF speed and accurate flash overlap gate capacitor and converter which, it is claimed, less than 1ns gate delay are outperforms much more achieved. 4kA° hybrid devices. Molybdenum is also used expensive ` l_J L. iJ LJ 12p U P+ Sampling at up to 2MHz N P. N. J+ P + P. N« as a first layer metal with ± bit accuracy, the cmos II P- / cmos II interconnect to further 11 -bit monolithic flash improve circuit density and speed without other converter costs significantly AI Second nitride less than equivalent hybrid disadvantages, claims products says manufacturer Micropower. Typical and developer Micropower Vapox Si 02 Molybdenum molybdenum interconnect Systems. time delay is less than 0.5ps Two -step conversion is used Thin film resistor First nitride for each 101.1m length. (see subranging converter Moreover the molybdenum, under 'Converter terms'), one . with its low resistivity of 0.552 step for the five most - per square and ability to make significant bits and one for This speed compares with 10 capacitors. good contact, is easily plasma the six least significant. to 20ps delays for silicon. Direct ion implantation etched to fine tolerances to Through use of an 'overflow' Consumption of the device is greatly improves parasitic make the precision resistors bit, two devices can easily be 150mW. input capacitance. The needed for quantizing voltage connected in series to give Not only speed is improved. process is implemented using levels in a flash converter. 12bit resolution. Alternatively, Using molybdenum also what is claimed to be a Second layer interconnect two devices can be connected allows more accurate and unique reduced -width aluminium at 0.0250 per in parallel to give a 4MHz stable capacitors and molybdenum gate which does square with silicon nitride sampling rate. resistors to be made on the not overlap at the edges of dielectric between defines a Refractory molybdenum chip. Dry plasma etching is the source and drain regions. reliable high -value capacitor gate metal with a low used for the molybdenum The metal acts as a mask for of 0.8pF/25pm2. This further resistance of 0.552 per square pattern which gives precision ion implantation which brings reduces parasitics associated resulting in very short delays matched resistors. the source and drain regions with the capacitor bottom of 0.5ps over 101.im at 3Nm Molybdenum with the second back to the edge of the gate plate due to its much reduced width is the main feature of layer of aluminium is also as the diagram shows. size and increases dynamic the patented c -mos process. used to produce 'auto -zero' A non -critical self -aligned range of the input signal.

Manufacturer Device Bits Speed Interface Tech. Features

ZN436 6 lu Par. Bip. V o /p, 5V supply ZN454 4x3 8n Par. Bip. RGB o /ps, syncs, int. reference, ext. gain set ZN558 8 800n Par. Bip. Int. reference, latches, 5V supply, V o/p Honeywell CAL24010 12 - Calibrator, 1 to 0.001 decade attenuator (S. P. Tech.) DAC805 8 5n Par. Hyb. 200MHz samp. vid. + sync, int. ref. /latch, HDG805 compat. DAC9700 8 5n Par. Bip. 200MHz samp. vid. + sync, int. ref. /latch, AD9700 compat. DAC34o10 4x3 5n Par. Bip. 200MHz samp. RGB + sync, int. ref. /latches, -5V supply DAC34020 4x3 lOn Par. Bip. 100MHz samp. RGB + sync, int. reference /latches Intech DAC3400 4x3 15n Par. C-mos 40MHz samp. RGB + sync, 5V 250mW, latches DAC3405S 4x3 15n Par. C-mos 40MHz samp. RGB + sync, int. ram, 5V DAC3800 8x3 - Par. Hyb. 40MHz samp. RGB + sync, latches, 500mW DAC3808 8x3 - Par. Hyb. 40MHz samp. RGB + sync, memory, 1.5W DAC5150 4x3 13n Par. E.c.l. 80MHz samp. RGB + sync, int. reference /ram DAC5151 4x3 7n Par. E.c.l. 150MHz samp. RGB + sync, int. ref., latches DAC1840 8 15n Corn. bin. C-mos 40MHz samp., vid. /sync o /p, latches, -5V supply DAC1842 8 15n Bin. C-mos 40MHz samp., vid. /sync o/p, latches, -5V supply Intersil AD7520 10 500n Par. C-mos Mult., 5V 20mW supply, I o /p, 200nA o/p leakage. AD7521 12 500n Par. C-mos Mult., 5V 20mW supply, I o /p, 200nA o/p leakage. AD7523 8 100n Par. C-mos Mult., 5V supply, 8 /9 /lObit lin. opts., I o/p AD7530 10 5oOn Par. C-mos Mult., 5V 20mW supply, I o /p, 300nA o/p leakage. AD7531 12 500n Par. C-mos Mult., 5V 20mW supply, I o /p, 300nA o/p leakage. AD7533 10 600n Par. C-mos Mult., 5V supply, 8 /9 /lObit lin. opts., I o/p AD7541 12 lu Par. C-mos Mult., 5V supply, 11 /12bit lin. vers., I o/p ICL7112 12 50on Par. C-mos Mult., 5V supply, ±0.02 /0.01% lin., I o/p ICL7113 3dig. 500n Par. C-mos Mult., 5V supply, b.c.d. i /p, I o/p ICL7134 14 34 Proc. C-mos Mult., + or +/- o /p, preliminary ICL7520 10 500n Par. C-mos Mult., 20mW, 8, 9 or 10 bit Micro Networks DAC71/I 16 lu Par. Hyb. -2 or ±1mA o /p, int. ref., ± 0.003% f.s. linearity DAC71/V 16 10u Par. Hyb. 10 or ±10V o /p, int. ref., ±0.003% f.s. linearity DAC80/I 12 300n Par. Hy b. -2 or -lmA± o /p, int. ref., comp. bin. /b.c.d. opts DAC80/V 12 34 Par. Hyb. 5 V o/p ranges, int. ref., comp. bin. /b.c.d. opts DAC85/I 12 300n Par. Hyb. -2 or ±1mA o /p, int. ref., ±l or bit lin. opts DAC85/V 12 34 Par. Hyb. 5 V o/p ranges, int. ref., ±- or y bit lin. opts DAC87 12 3u Par. Hyb. 5 V o/p ranges, int. ref., < ±sgbit linearity, 0.9W DAC88 12

* Preliminary data only; these devices do not use R -2R ladder.

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 29

www.americanradiohistory.com DATA CONVERSION

Manufacturer Device Bits Speed Interface Tech. Meth. Features AMD Am6108 8 lu Proc. Bip. Int. ref., 0.1% lin., ratiom. Am6112 12 7u Proc. Bip. S.a. Frog. modes, 15mA ref. o /p, 8bit bus, lbit lin. Am6148 8 lu Proc. Bip. Int. ref., 0.1% lin., ratiom. Am6688 4 5n Par. Bip. Samp. 100MHz rate, 50MHz b.w., e.c.l. Analog Devices AD376 8 15u Hyb. Ref. AD570 8 25u Par. 3s Bip. S.a. Ref. & int. ck, 10 or ±5V i/p AD571 10 25u Par. 3s Bip. S.a. Ref. & int. ck, 10 or ±5V i/p AD572 12 <25u Ser /par Hyb. S.a. 0.012% lin., long term stab., 900mW AD573 10 20u Proc. Bip. S.a. Ref. & clock, 10 or ±5V i/p AD574 12 25u Proc. Hyb. S.a. 12bit bus, 250ns access, 4 range i/p AD575 10 30u Ser. Bip. S.a. Ref. & int /ext ck, 4 range i/p AD578 12 3u Par /ser Hyb. S.a. 0.012% lin., long term stab., 4 range AD579 10 1.8u Par. 3s Hyb. S.a. 0.05% lin., long term stab., 4 range AD670 8 l0u Proc. Bip. S.a. Sig. cond. i /p, 5V supp., int. ref. AD673 8 20u Proc. Bip. S.a. Ref. & clock, 10 or ±5V i/p AD5010 6 lOn Par. Bip. Flash 100MHz, 450mW, e.c.l. o /p, ;+bit lin. AD5200 12 50u Ser /par Hyb. S.a. No adj., 0.4% f.s. abs. acc. AD5210 12 13u Ser /par Hyb. S.a. No adj., 0.1% f.s. abs. acc. AD5240 12 5u Ser /par Hyb. S.a. 0.012% lin., long term stab. AD6020 6 20n Par. Bip. Flash 50MHz, 450mW, e.c.l. o/p AD7550 13 40m Proc. C -mos Q.slo. Ratiom., 1ppm / °C, 4,bit rel. acc. AD7552 12 160m Proc. C -mos Q.slo. Ratiom., 1 l.s.b. error AD7571 10 80u Ser /par C -mos S.a. Diff. i /p, int. ck., 10bit + sign AD7574 8 15u Par. 3s C -mos S.a. Ratiom., 5V supp., diff. i /p, 30mW AD7576 8 l0u Proc. C -mos S.a. 15mW, 5V supp., high i/p imp. AD7578 12 100u Proc. C -mos S.a. 8bit bus, auto -zero, 75mW AD7581 8x8 66u Proc. C -mos S.a. 8 -i /p mpx, 64 -bit mem., ratiometric AD7582 12 100u Proc. C -mos S.a. 4 -i /p mpx, 8bit bus, auto -zero AD7820 8 1.4u Proc. C -mos Subrng Ratiometric, 5V supp., 75mW AD9000 6 13n Par. Bip. Flash 75MHz, e.c.l. o/p ADC71 16 45u Ser /par Hyb. S.a. 45µs for 14bit, 0.003% lin., 850mW ADC72 16 45u Ser /par Hyb. S.a. 45µs for 14bit, 0.003% lin., 850mW ADC80 12 25u Ser /par Hyb. S.a. 0.01296 lin., ref. o /p, 5 i/p ranges ADC84 10 61.1 Ser /par Hyb. S.a. 0.048% lin., ref. o /p, 5 i/p ranges ADC85 12 10 Ser /par Hyb. S.a. 0.012% lin., ref. o /p, 5 i/p ranges ADC816 10 800n Ser /par Hyb. S.a. s5bit lin., 6 i/p ranges, 15V supp. ADC1131 14 120, Ser /par S.a. lOppm / °C gain drift, 14bit acc. /res. ADC1140 16 35u Par. Hyb. S.a. 0.003% lin. ADC1143 16 704 Ser /par S.a. to 0.003% diff. lin., 1ppm / °C, 150mW CAV0920 9 50n Par. P.c. Subrng 20MHz, e.c.l. o/p CAV1040 10 25n Par. P.c. Subrng 40MHz, e.c.l. o /p, range select CAV1210 12 100n Par. P.c. Subrng 10MHz, e.c.l. o/p HAS0802 8 1.2u Par. 3s Hyb. S.a. 0.05% f.s. error, low power HAS1002 10 1.7u Par. 3s Hyb. S.a. 0.025% f.s. error, low power HAS1201 12 lu Par. 3s Hyb. Track & hold, 1MHz word rate HAS1202 12 2.8u Par. 3s Hyb. S.a. 0.012% f.s. error, low power HAS1204 12 21.1 Ser /par Hyb. Sample 500kHz word rate, 4MHz bandwidth HAS1409 14 8u Par. 3s Hyb. Subrng Track & hold, 125kHz rate, for f /t.d.m. MATV811 8 90n Par. P.c. Subrng Small 11MHz vid., 74S o /p, buff. i/p MATV816 8 63n Par. P.c. Subrng Small 16MHz vid., 74S o /p, buff. i/p MATV 820 8 50n Par. P.c. Flash Small 20MHz vid., buff. i/p MOD1005 10 200n Par. P.c. Subrng 20MHz analogue b.w., t.t.l. o/p MOD1020 10 50n Par. P.c. Subrng 20MHz word rate, e.c.l. o/p MOD1205 12 200n Par. P.c. Subrng 5MHz word rate, t.t.l. o/p Analogic ADAM724 14 6.8u Par. 3s Mod. S.a. Int. ref., s -& -h, p.g.a., ± 0.003% lin. ADAM812 12x2 19.5u Par. Mod. S.e. Int. ref., s -& -h, ±0.025% f.s. error ADAM822 12x2 39u Par. Mod. S.a. Int. ref., s -& -h, ±0.025% f.s. error ADAM824 14 50u Par. 3s Mod. S.a. Abs. acc. ± 0.006% f.s., 20kHz rate, 0.9W ADAM825 15 59u Par. 3s Mod. S.a. As 824 but 18kHz rate, both have s -& -h ADAM826-1 16 2.3u Par. 3s Mod. S.a. Int. s -& -h, 10 or -10V± i/p options ADAM826-2 16 2u Par. 3s Mod. S.a. Int. s -& -h, 10 or ±10V i/p ADAM826-3 16 1.5u Par. 3s Mod. S.a. Unbuffered i/p ADAM834 14 63u Par. 3s Mod. S.a. Int. s -& -h, wide temp. rng, 0.9W, 501V noise ADAM835 15 63u Par. 3s Mod. S.a. As ADAM834 but 15bit, better lin. & temp. co. MP2316 16 27m Pulse Mod. 2 sl. Isolated with supply, p.g.a. & reference MP2321 3.5d 10m Par. Mod. Int. Ratiom., isol. b.c.d. o /p, int. supp. & ref. MP2322 12 10m Par. Mod. Int. Ratiom., isol. bin. o /p, int. supp. & ref. MP2712 12 5u Par /ser Mod. S.a. Int. ck /ref., 4 i/p ranges, ±0.015% abs. ace. MP2713 13 10u Par /ser Mod. S.a. Int. ck /ref., 4 i/p ranges, ±0.009% abs. ace. MP2714 14 10u Par /ser Mod. S.a. Int. ck /ref., 4 i/p ranges. ±0.007% abs. acc. MP2734 14 6.8u Par. 3s Mod. Int. ck /ref., 4 i/p ranges, ±0.007% abs. acc. MP2735-1 15 5u Par. Mod. Subrng Audio ±0.005% t.h.d., int. ref., 3dB idle noise MP2735-2 15 5u Par. Mod. Subrng 2735 -1 with no s -& -h, 200kHz not 125kHz rate MP8008R 8 3u Par. 3s Mod. Samp. 0.02% differential linearity, ±5V i/p MP8014 14 10u Par /ser Mod. S.a. Int. ck /ref., ±0.006% abs. ace., 10 or ±10V i/p MP8015 15 15u Par /ser Mod. S.a. Int. ck /ref., ±0.006% abs. acc., 10 or ±10V i/p MP8016 16 32u Par /ser Mod. S.a. Int. ck /ref., ±0.003% abs. acc., 10 or ±10V i/p MP8037 17 4ms Par. Mod. Subrng Ratiom., int. ck /ref., ±0.005% abs. acc., 10V i/p SHAD2A 16x2 17.5u Par /ser Mod. 3-sl. Audio 150kHz samp. sing. ch., -86dB distortion Burr-Brown ADC1OHT 12 50u Par /ser Hyb. S.a. Ck /ref., -55 to 200 °C, ±0.012% f.s. lin., 0.25W ADC60-12 12 3.5u Par /ser Mod. S.a. Int. ck /ref., 6 i/p ranges, ±0.195% f.s. lin. ADC60-10 10 1.88u Par /ser Mod. S.a. Int. ck /ref., 6 i/p ranges, ±0.0488% f.s. lin. ADC60-8 8 0.88u Par /ser Mod. S.a. Int. ck /ref., 6 i/p ranges, ±0.0244% f.s. lin. ADC71 16 SOu Par. Hyb. S.a. Int. ck /ref., 6 i/p ranges, ±0.003% f.s. lin. ADC72 16 50u Par, Hyb. S.a. Int. ck /ref., 6 i/p ranges, ±0.003% f.s. lin. ADC73 16 170u Par /ser Mod. S.a. Int. ck /ref., 4 i/p ranges, ±0.00075% f.s. lin. ADC76 16 15u Par. Hyb. S.a. Int. ck /ref., 6 i/p ranges, ±0.003% f.s. lin. ADC80-10 10 21u Par /ser Hyb. S.a. Int. ck /ref., 5 i/p ranges, ±0.04896 f.s. lin. ADC80-12 12 25u Par /ser Hyb. S.a. Int. ck /ref., 5 i/p ranges, ±0.012% f.s. lin. 30 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Manufacturer Device Bits Speed Interface Tech. Meth. Features ADC82 8 2.811 Par /ser Hyb. S.a. Int. ck /ref., 6 i/p ranges, -0.2%`- f.s. lin. ADC84-10 10 611 Par/ser Hyb. S.a. Int. ck /ref., 5 i/p ranges, ±0.048% f.s. lin. ADC84-12 12 1011 Par /ser Hyb. S.a. Int. ck /ref., 5 i/p ranges, *- 0.012% f.s. lin. ADC85 10/12 6/1O0 Par /ser Hyb. S.a. As ADC84 10 & 12bit, but better temp. co. ADC100 16 200m Par /ser Mod. Int. Ck /ref., 0.005% lin., models for bin. & b.c.d. o/p ADC731 16 17Oµ Par /ser Mod. S.a. ADC73 with instrumentation amplifier i/p ADC803 12 1.511 Par. Hyb. S.a. Int. ck /ref., 3 i/p ranges, ± 0.012% f.s. lin. ADC804 12 1711 Ser. Hyb. S.a. ±0.012% f.s. lin., <500mW PCM75 16 1711 Par. Hyb. S.a. Audio, 0.004% f.s. t.h.d., int. ck /ref. Data Trans.** DT5701 12 1911 Par. Mod. 16 ch. mpx, 4 ranges, ser. o/p opt. DT5710 12 611 Par. Mod. 16 ch. mpx, 4 ranges, ser. o/p opt. DT5703 12 Par. Mod. 4 ch. mpx, 10mV to 10V i /p, isolated DT5704 12 1011 Par. Mod. 4 ch. s/h mpx, 10V i/p DT5712 12 254 Par. Mod. 16 ch. mpx, 10mV to 10V i/p DT5714 14 7011 Par. Mod. 16 ch. mpx, 5mV to 10V i/p DT5716 16 35Oµ Par. Mod. 16 ch. mpx, 5mV to 10V i/p DT5722 12 2.511 Par. Mr- 16 ch. mpx, opt. p.g.a., 3 range i/p DT5726 16 611 Par. Mod. 4 ch. mpx, ±10V i/p Ferranti ZN425 8/6 lm Par. Bip. Ramp Internal reference & counter, 5V supply ZN427 8 l0µ Proc. Bip. S.a. Internal reference, ratiometric ZN432 10/8 1511 Par /ser Bip. S.a. Int. ref. & amplifier ZN433 10/8 111 Par /ser Bip. Track. Int. ref. & amplifier, ZN435 8 80Oµ Par. Bip. Ramp Int. ck, ref. & count., 5V supp. ZN439 8 511 Proc. Bip. S.a. Int. ref., ck, ' , 41 or lbit lin. options ZN440 6 60n Par. Bip. Flash 16MHz rate, ± bit lin., t.t.1., 0.7W ZN447 8/6 911 Proc. Bip. S.a. Int. clock & ref., -k.bit*- linearity ZN448 8/6 911 Proc. Bip. S.s. Int. clock & ref., ±+obit linearity ZN449 8/6 911 Proc. Bip. S.a. Int. clock & ref., ±lbit linearity ZN5o1 10 1511 Proc. Bip. S.a. Int. ref., 1 or 2byte read, ?obit lin. ZN502 10 1511 Proc. Bip. S.a. Int. ref., 1 or 2byte read, ±lbit lin.

Intersil ADC0801 8 <100µ Proc. C-mos S.a. Diff. 5V i /pp., 5V supp., ±± bit lin. ADC0802 8 <10011 Proc. C-mos S.a. Diff. 5V i /p, 5V supp., ±ktbit linearity ADC0803 8 <10011 Proc. C-mos S.a. Diff. 5V i /p, 5V supp., -;tbit*- linearity ADC0804 8 <10011 Proc. C-mos S.a. Diff. 5V i /p, 5V supp., ±lbit linearity ICL7109 12 0.03 Proc. C-mos 2-sl. Xtal i/p ck, diff. i /p, 15µV noise 8052/7104 14 -16 - Proc. /ser.- 2-sl. 2 i.c., ratiom., int. ck, ref., auto zero 8068/7104 14 -16 Proc. ser. - 2-sl. As above but 2 not 1MHz analogue bandwidth Micro Networks ADC80 12 2511 Par /ser Hyb. S.a. ck/ref., 5 i/p ranges, 10 /12bit opts ADC84 12 811 Par /ser Hyb. S.a. Int. ck /ref., 5 i/p ranges, 10 /12bit opts ADC85 12 811 Par /ser Hyb. S.a. As ADC84 but 15 not 30ppm /C gain drift ADC87 12 811 Par /ser Hyb. S.a. As ADC85 but for -55 to 125 °C MN574A 12 2511 Proc. Hyb. S.a. 8 /l6bit read, ± 0.012% f.s. err. int. ck /ref. MN5065 8 100µ Par /ser Hyb. S.a. Int. ref., 12V 70mW supp., ±5V i/p MN 5066 8 100µ Par /ser Hyb. S.a. Int. ref., 12V 70mW supp., 10V i/p MN 5100 8 1.511 Par /ser Hyb. S.a. Int. ref., 9 i/p ranges, ±st- l.s.b. lin. MN5101 8 900n Par /ser Hyb. S.a. Int. ref., 9 i/p ranges, -± l.s.b. lin. MN5120 8 6u Par /ser Hyb. S.a. Int. ref., 4 i/p range options MN5130 8 2.511 Par /ser Hyb. S.a. Int. ref., 4 i/p range options MN5140 8 2.511 Par /ser Hyb. S.a. As 5130 but ±12V not ±15V supply MN5150 8 2.511 Proc /ser Hyb. S.a. Int. ref., ±4, l.s.b. linearity MN5200 12 5011 Par /ser Hyb. S.a. 0.05% f.s. err., 0.9W, int. ref. opt. MN5210 12 1311 Par /ser Hyb. S.a. 0.05% f.s. err., 0.9W, int. ref. opt. MN 5240 12 511 Par /ser Hyb. S.a. Int. ck & ref., 5 buffered i/p ranges MN5243 12 211 Par /ser Hyb S.a. Int. ck & ref., 6 i/p ranges, l0 /12bit opts MN5244 12 211 Par /ser Hyb S.a. Int. ref., 6 i/p ranges, 10 /12bit opts MN5245 12 900n Par. Hyb. Subrng Int. ref., 0.024% f.s. err., 5V i/p MN5245A 12 900n Par. 3s Hyb. Subrng Int. ref., 0.024% f.s. err., 5V i/p MN5246 12 900n Par. Hyb. Subrng Int. ref., 0.024% f.s. err., ±2.5V i/p MN5246A 12 900n Par. 3s Hyb. Subrng Int. ref., 0.024% f.s. err., ±2.5V i/p MN5247 12 450n Par. 35 Hyb. Subrng Int. ref., 12bit monot., 5V i/p MN5248 12 450n Par. 3s Hyb. Subrng Int. ref., 12bit monot., ±2.5V i/p MN5250 12 17511 Par /ser Hyb. S.a. 0.1% f.s. abs. err., 80mW, 4 i/p range opts MN5260 14 25011 Par /ser Hyb S.a. 0.05% f.s. err., 300mW, ±10V i/p MN5280 16 1000. Par /ser Hyb. S.a. 0.006% f.s. linearity, 6 i/p rngs, int. ref. MN5282 16 5011 Par /ser Hyb. S.a. 0.006% f.s. linearity, 6 i/p rngs, int. ref. MN5284 16 5011 Par /ser Hyb. S.a. 15bit monot., 7 i/p rngs, 300mW MN5290 16 3511 Par /ser Hyb. S.a. 0.003% f.s. lin.. 6 i/p ranges. int. ck /ref. MN5291 16 3511 Par /ser Hyb. S.a. As 5290 but 13 not 14bit mon. over temp. range MN5420 12 +4 3.1.0 Par. Mod. Float. pt., 120dB - 100V in 10V, 320kHz rate MN5610 12 1311 Par /ser Hyb. S.a. l.s.b. lin., 915mW, four range options MN5700 12 250µ Par /ser Hyb. S.a. 1% f.s. err. at 200 °C, int. ref., 4 i/p rngs MN5815 8 700n Par /ser Hyb. S.a. Int. ck /ref., 6 rngs, log. sel. + or t i/p MN5825 8 lµ Par /eer Hyb. S.a. Int. ck /ref., 6 rngs, log. sel. + or ± i/p MN7120 8 711 Paras /ser Hyb. 8 ch. mpx, 75k ch. /s, int. ck, ±4,bit lin. MN714O 12 4011 Par. Hyb. S.a. 8 ch. mpx., int. ck/ref., 0.1% f.s. abs. err. MN7150-8 12 911 Proc. Hyb. 8 ch. mpx diff. high -Z i /p, int. ck /ref. MN7150-16 12 911 Proc. Hyb. 16 ch. mpx high -Z i /p, int. ck /ref., 50k ch /s ** Company produces expanders for some listed devices and a large number of analogue input /output modules for specific computer buses and applications.

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 31

www.americanradiohistory.com A +5V

3p3

All diodes 1SS97 120

2SC1730

Video A/D IN in =fir check 22 22n 22n 30 150 T 2SC1730 2SC 621 25[1621 5R1 5R1 82 2SA781 IS1587 2SK43

360 20k 820 120 1k 1k

Offset A 5V A -5V A+5V 3y3 510 10k 510 2SC1730

D 51 } 51 330 -5V A +5V D II 510 -5V T22n 3N3 T nn

rtt 1 254530 ecl A 9 -5V

HD10105 22n

51 V RB 1 1 check 22n T3p3 T22n 510 19 ,18 ,17 ,16 n5 1 D CX20052 -5V

Converter grounding 5 6 '7 '8 '9 High -speed circuits around a video a -to -d converter may need separate analogue and digital supplies and always 5

need careful grounding, as so separate analogue and D this Sony application circuit digital grounding and supplies 5V for the CX20052 are common practice, even for all 4k3 3p3 O O O O 2n demonstrates. Note also the some slow converter l.sb. D7 D2 m s b liberal decoupling. Digital applications. Further details circuits in and around a on the application circuit are conversion i.c. are mostly fast, available from Hakuto.

Addresses Data Translation The Business Centre Fairchild 9th Floor Adretta Analog Devices Molly Millar's Lane 230 High Street Hewlett Packard Snamprogetti Hse North St. Central Avenue Wokingham Potters Bar Components Group Basing View Wellington East Molesley Berks RG11 2QZ Herts EN6 5BU Miller House Basingstoke TA21 8LZ KT8 05N The Ring Somerset Surrey Hants RG21 2YS DDC Ferranti Electronics Bracknell AMD (UK) Analogic 128 High St Fields New Road Berks RG12 1XN House Hungerford MCP Electronics AMD The Centre Chadderton 38 Rosemount Rd Goldsworth Rd 68 High St. Berks RG17 ODL Oldham Intel Alperton KT13 8BN Pipers Way Woking Weybridge Lancs OL9 8NP Middx HAO 4PE Surrey GU21 1JT DI -AN Systems Swindon Burr Brown Mersey House Ginsbury, Sylvan Wilts SN3 1RJ AMI Microsystems Cassiobury Hse Battersea Rd 108 High St. Princes House 11 Station Rd Heaton Mersey Stroud Intelligent Artefacts Princes St. Watford WD1 1EA Stockport SK4 3EA Rochester Cambridge Rd Swindon Kent ME2 4TR Orwell Wilts SN1 2HU Coole Marketing Electrovalue Royston The rest of this list of i.cs and 26 Pamber Heath Rd 28 St Judes Rd Harris Semiconductor Kent SG8 5QD modules, together with relevant Amplicon Electronics Pamber Heath Engelfield Green PO Box 27 addresses, will appear next Richmond Road Basingstoke Egham 145 Farnham Rd Intersil Brighton BN2 3RL Hants RG26 6TG Surrey TW20 OBH Slough SL1 4XD Semicon. Div. month. 32 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com CIRCUIT IDEAS

New approach to instrumentation Vino amplifier design This idea deals with two new concepts, leading to a 1M R 330 programmable amplifier 10k design. The first circuit uses E300 10k I theoretical results by Sun, 11 +/ 1N4148 according to which effective 15V resistance Reff of a resistor and switch in series is approximately proportional to IC:LM324 (R + R0,,)Tsd = R TS /d where R is the on resistance of the switch, Ts is the switching period and d is the on time in a period. Circuit gain A is given by -Vin 12 R1 d V (1 +2R O )T_S 15V Gain of this instrumentation amplifier may be programmed by choosing the ratio of d/Ts, where fs = 1 /Ts, is the sub - audio switching frequency. To obtain a positive output you, voltage, a fourth op -amp with feedback diode is applied to give the absolute value of the output signal. +V1 12 Two voltage op -amps at the input of the instrumentation amplifier are used in the second design. The difference the transconductance of the A =19.23(1 +2R1 /R2)RI,.. K. Kraus amplifier is replaced by a op -amp where g is le /2VT Rokycany transconductance op -amp with which is 19.23L; control Supposing (1 + 2R1/R2) is Czechoslovakia two linearizing diodes. For a current I < 2mA. constant, gain A may be Sun Y. and Frisch 5., Resistance Multiplication by Means of transconductance op -amp, Gain of the instrumentation programmed either by Switching. IEEE transactions on between the output current amplifier shown in the second resistance R or more simply Circuit Theory, Vol. CT -15, Sept. and input voltage I, = gVi is figure is given by by control current L. 1968 No.3, pp.184 -192.

use provide additional safety is in Pulses for medical case the mains transformer primary and secondary short. We needed a device capabled Output voltage is José I. Crakovski of producing 30 -100V at 50mA independent of mains voltage Buenos Aires from 5V pulses for use as a variations. Resistors R1,2 Argentina stimulator for diagnosing nerve palsy. The 5V pulses come from a medical computer. Initially we used a k pulse amplifer with a regulated power supply to 2 ms compensate for fluctuating n J L`.'SV t0 mains voltages, but this later 5 100V approach is much simpler. TransistorTr1 is saturated by each positive pulse from the pulse transformer. This - 100k transistor's collector current o pulses are applied to a shunt 1.5V_ft -pulse ro regulator, so output 7V ii o amplitude depends solely on Z=10 n 02ms the potentiometer setting. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 3`

www.americanradiohistory.com Vin 0 -10V -ofVin dt

lal

"cc

10k -s-rn t Economical long- time -constant integrator Ibl

17.17711,

Long time -constant integrators may be taken as an integrator. replaced by a current source, between 11,is and 5 days. can be built if output of a Using a programmable frequency Cascading timers gives voltage -to- frequency converter timer, the design is similar extremely long time constants. is connected to a counter and cheaper (r.h. diagram). f = V,n/NCREVK Kamil Kraus feeding a d -to -a converter Duration of timing cycle T is Rokycancy (block diagram). Resulting given as NRC where N is an where. VK is 3.8V for BC252C. Czechoslovakia output is the integral of input integer in the range Output is the integral of input because each v -to-f converter 1 <_ N <_ 225. When resistor R is voltage with a time constant

18 to 30V Class -B output At low power, the driver transistors feed the load. without adjustment These are mounted on the same heat sink as the ouput In this class B output stage, devices and operated at the setting up is eliminated by highest practical output using a transistor and two current by making their fixed resistors to provide bias emitter resistors as low as voltage. As shown, the circuit possible, at between 4.7 and is capable of delivering 20W, loa

but output power can be Graham Nalty To solenoid valves increased by using Darlington Audio Kits actuator etc. output transistors and 3V bias. Derby

discharges until voltage across Bias Power watchdog it is less than the combined vol age pinch -off voltage, when the Pulses from a computer port transistor turns off rapidly. keep this power watchdog Devices with from 3 -7V circuit activated by holding the pinch -off voltage are suitable p- channel power fet on. for this arrangement. Older d- The dual fet network mos devices with gate zener provides negative resistance. diodes or less than 40V drain - When the network is unbiased, source voltage should not be DON'T WASTE GOOD Submissions are judged current equal to the lower of used. IDEAS We prefer circuit on originality or the two IDES can flow, keeping Components R and C are ideas with neat drawings usefulness - not exluding the p- channel device off even chosen to suit the application. and widely- spaced imaginative modifications in the presence of considerable Leakage of the fet is typically typescripts, but we would to existing circuits so interference. less than 1nA in the pinched - rather have scribbles on these points should be Once current supplied by the off condition. "the back of the brought to the fore, 2N7000 exceeds zero, the j -fets M.D. Bacon envelope" than let good preferably in the first soon pinch off. If the watchdog Taunton ideas be wasted. sentence. pulses fail, the RC network Somerset 34 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Burglar alarm Piezo BCY70 sounder In spite of the simple appearance of this circuit, ik lock /unlock, arm (optional) it has many features - keypad +Ve delay, alarm delay, 15min alarm timeout, eight sensor loops and an anti -tamper interlock. There 4081 are four mat and four loop sensors. CK T The keypad is straightforward and may be 100k I 4013 replaced by a key switch. Heart of the circuit is a 4060 oscillator and divider which provides T r timing. 1k8 1k8 In safe mode, the oscillator and bistable On arming, the first 60s cycle // //ARM/ devices are reset. SAFE elapses and inhibits the clock but enables the sensor latch. When triggering occurs, the clock 10k is enabled and after 60s the alarm is set for a o` 2M2 f further 7.5, 15 or 30min depending on the Loop circuit setting. After this period, the circuit returns to the initial armed mode ready for the Gnd , To control O circuit next break -in. --100y Switching the keypad to safe at any time 4M2 1 *Ve the control circuit. Affected zones are * Ve resets O indicated by leds. Use a lead -acid accumulator Unused Tp J and not an NiCd battery - it is more reliable. keys 4013 Cutting the keypad wire does not stop the 100k 11,, alarm. a 1k8 Quentin Rice ' ! r /ERROR Lower Kingswood A 47k Surrey

Simple charger for 4060 Outputs AA cells +Ve Alarm 9 1012 13 4 O Constant current of 50mA for +Ve

14 -16 hours is usually needed 100 for AA NiCd cells. S1 1k 4013 Overcharging at the correct To Loop current does not harm the key. O an pad batteries so overnight 110y S CK D charge is possible using a 4093 constant -current charger. Gndo 10k Up to six cells can be charged at once using this simple circuit. Besides Anti - tamper indicating that the cells are properly conncected and being +Ve j/ charged, the led forms a constant- voltage source. When CK the cells are not connected, the led is off. o--vn,-+-- Resistor R determines Pads charge current. V. Mehra Chandigarh India 4BC107 .: 10y 10k gAr. \M j11oUlk 100 I H % i 10p Loops ENO

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 35

www.americanradiohistory.com Shaft encoder counting ao Croft's circuit for shaft encoder generated compared with A7 counting in the November Croft's system. The first Or A1 - Quad issue is effective in many gate produces a transition at A8 2 -to -1 applications but it can every transition of either of the A2 line multiplexer miscount if repeated reversals quadrature lines. Ag occur. A brief negative transition is As the first timing diagram produced by the second Or A10rA3 shows, if the shaft is gate at every transition from Multiplexers may be repeatedly reversed over a the first gate because the LS157 or 257 fraction of a cycle it is possible signal on one of its inputs is to produce a unidirectional inverted and delayed compared A4 count even though no net with the other one. MA4 motion has occurred. can Trailing edges of these A11 This A5 happen in practice if there is pulses clock the counter, after mechanical bounce on starting the up /down line has had Al2 A, or stopping the shaft. plenty of time to settle. A- A6 A13 To solve this problem, a one - M. Winder bit longer counter is needed; Reading University twice the number of counts are Berkshire /414 MA7 .Á- CAS

UP/DOWN RAS

Quadrature U/D D -type shaft encoder bistable "Delay to allow CLOCK eg 4029 outputs IC time for the multiplexer to settle MAO to MA7 before Count K H producing Reversal up l Reversal Spurious down count Multiplexer for 16 or 64K d -r I Stop In designing a Z80 -based multiplexer during refresh, and computer, I produced this A14 during read /write cycles. circuit allowing simple Row -address strobe RAS is switching between 16 and 64K produced by the MREG d -rams. memory request signal. Switch For 16K rams, the usual signal MUX is provided by the UP/DOWN multiplexed addresses are next clock cycle after MREQ low Quadrature produced as MA0_6. A further goes provided that RFSH shaft encoder multiplexed address is needed is high, therefore not switching signals for 64K devices, for which I during refresh. Column - used the remaining top two address stobe CAS is produced bits of the address bus A14, 15 to from MUX after delay and provide multiplexed addresses inversion. for 16 and 64K d -rams during Using this circuit and simple write /read cycles. wire links on the p.c.b., 16K d- A problem with 64K rams is rams can be exchanged for that during refresh they need 64K types using the same A7 on MA7, not A14 as it would sockets and p.c.b. Analogue voltage multiplier be on the system described so R.J. McClelland far. To overcome this I use the Liverpool Suitable for low- frequency RFSH signal to gate A7 to the Merseyside applications, this circuit was designed for use in MULTIPLIER DIVIDER measurement of patients' breathing patterns. Differential B inputs A are provided, and A+ 100k 100k must always be positive with respect to A_ . Input B can be A--'. . . positive or negative, as the 10CK 100!< 4016 analogue switch is at a virtual earth. The circuit can be rearranged as shown to form a divider. FET op amps Remaining i.c. elements 100k e.g, TL081 A+ CMOS +12V were used in sample- and -hold OV circuits. 100k Op amps +12 G.G.R. Rutter -12 London 36 ELECT a NIC ESS WORT;

www.americanradiohistory.com IQD- Lf)D The world shrinkers IQD Limited North Street Crewkerne IQD's state -of- the -art DTMF signalling technology now Somerset TA18 7AR England brings you Smartpatch 5700, which allows you to dial Telephone: (0460) 74433 direct into the telephone network while you are on the Telex: 46283 move, and to accept incoming calls regardless of your location. Smartpatch 5700 is the only intelligent tele- communications interconnect system with British Telecom approval. Smartpatch 5700 complements IQD's extensive range of DTMF products, which includes the Codepad, Micropad and Selcall devices. loD keeps you in fy touch. Iwl COMMUNICATION DEVICES CIRCLE 16 FOR FURTHER DETAILS. Vftt'wAto AC -DC POWER SUPPLIES 0 COMPUTE Available with 3 variable outputs. Input 200 -250V. 50Hz or 100 -120V. 60Hz to order You've heard that - Output 1: 0 -30V 25A. DC Output 2: 0 -70V 10A. AC Output 3: 0 -250V 4A. AC * Industries from brewing to aerospace use FORTH * It is easy to learn and apply ALL CONTINUOUSLY VARIABLE * It is interactive, is yet compiled for speed Other units are also available with outputs of: * Assembler code can be included 0 -60V 12A. 0 -120V 6A. 0 -240V 3A. * Development is done on the target system Fixed output models 12, 24 or 50V * Your VDU, IBM compatible or BBC programs the TDS900 * TDS900 series computers have a full- screen editor * TDS900 series has both N- channel and C -MOS versions AC -AC Frequency Changers * TDS902 consumes 25mA and has 62K bytes memory For changing 60Hz A mains to 50Hz or 50Hz mains to * Execution times in microseconds can be measured 60Hz. Input 100 -127V or 200 -250V, 50 to 400Hz, Single Phase. * TDS900 cards have hardware multiply and 16 bit timer Output 100 -127V or 200 -250V, Single Phase. Six * They have interrupts, both internal and external different models are available; 60, 120, 200, 300, 500 or 1000VA. Also special fixed frequency * Some have non -volatile memory, some 9.8MHz clocks /variable models available. * TDS971 offers RS232 and IEEE -488 expansion * TDS972 adds RS232, A to D and parallel ports DC -DC Converters * TDS973A gives opto- isolation on 32 input /outputs Isolate DC input from DC output. To provide DC output levels different than that of DC input. FORTH computers start at £99 VALRADIO POWER LIMITED Triangle Digital Services Ltd AK INTERNATIONAL BUILDING, LAWRENCE ESTATE, 100a Wood Street, London E17 3HX GREEN LANE, HOUNSLOW, MIDDX TW4 6DU ENGLAND. -570 Telephone 01- 520 -0442 Telex 262284 (Ref M0775) Tel: 01 5622 S TACKLING POWER SUPPLY PROBLEMS SINCE 1937 CIRCLE 29 FOR FURTHER PET:AII-S. CIRCLE 72 FOR FURTHER DETAILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com PHONE P. M. COMPONENTS LTD TELEX 0474 60521 SELECTRON HOUSE, SPRINGHEAD ENTERPRISE PARK 966371 4 LINES SPRINGHEAD RD, GRAVESEND, KENT DA11 8HD TOS -PM

ease a d 3 additional INTEGRATED CIRCUITS STK015 6.95 TBA530(ii 1.10 TDA2624 1.95 CATHODE RAY TUBES carriage per tube. STK025 3.96 TBA640 1.26 TDA2630 1.96 AN124 2.50 MC13270 0.96 STK043 9.50 TBA5400 1.35 T1342632 1.95 CME622W 19.00 DB7.38 55.00 M38-121LA 65.00 AN2140 2.50 MC1349P 1.20 STK078 11.96 TBA5600 1.95 1242640 1.96 CME822GH 25.00 DG7.32 45.00 M38-122GW 65.00 AN240P 2.80 MC1361P 1.50 STK416 7.95 TBA680C 1.46 TDA2461 2.16 CME14280H 46.00 DG13.2 46.00 M38-140LA 65.00 AN812 2.16 MC1367 2.36 STK433 6.96 TBA680C 1.45 TDA2680 2.16 CMEI 428W 39.00 DH3-91 55.00 M38-142LA 85.00 AN7140 3.60 MC1368 1.58 511436 7.95 T8A48000 1.45 TDA2671 A 4.50 CME1523W 39.00 DH7.91 45.00 M38-341P31 65.00 AN7146 3.50 MC1495 3.00 STK437 7.95 TBA570 1.00 7042681 2.95 CME1431GH 39.00 DP7.5 36.00 M38-344P39 65.00 AN7160 2.95 MC1496 1.25 STK439 7.96 1564113.50 1042593 2.95 CME1431W 39.00 DP7.6 36.00 M40.120W 69.00 BA621 3.35 MC146108P7 ST8461 11.50 TBA6616 2.50 TDA2800 6.50 CME202GH 46.00 DN13.78 36.00 M43-12LG/01 65.00 CA1362E 1.75 7.96 TBA720A 2.45 TDA2810 2.60 CME2024W 46.00 M44-120LC 65.00 MC1723 0.50 CA3088 0.48 TA7081AP 3.96 TBA7600 2.66 TDA2811 A 1.95 CME2325W 45.00 F 18-101 GM 76.00 M44.120GR 65.00 CA3123E 1.50 MC3357 2.75 TA71081' 1.50 18A800 0.89 TDA2840 3.60 CME3128W 45.00 F18.101LD 76.00 M50-120GH 66.00 E78018 2.60 ML231B 1.75 TA7120P 1.66 TBA810AS 1.66 1042880A 2.75 CME3132GH 45.00 F21-130GR 76.00 M60-120GR 85.00 HA1377 3.60 ML232B 2.60 TA7130P 1.60 TBABIOP 1.86 TDA2690 2.45 CME3156W 45.00 F21-1301C 76.00 M60-120GV 65.00 HA1168W 1.50 MSM5807 6.76 TA7178AP 2.95 78A820M 0.75 TDA3310 2.95 CRE1400 25.00 F31-10GM 76.00 M50-120LC 65.00 HA1339A 2.95 PLL02A 5.75 TA7203 2.95 T948200 1.45 1043560 5.50 CV429 89.00 F31-10GR 75.00 M81-120W 75.00 HA1551 2.96 SAA500A 3.50 TA7204P 2.15 TBA890 2.50 UPC566H 2.95 CV1460 36.00 F31-10LC 76.00 45.00 7.26 SBAB LA1230 1.95 SAA1025 TA7205AP 1.15 11A920 1.66 UPC576C2 2.76 CVI 526 19.00 F31-10L0 75.00 SE4/D/P7 46.00 1.75 LA4031P 1.96 SAS6605 TA7222AP 1.80 TBA950/2X2.36 UPC1026H 1.95 CV2188 16.00 F31-1210 75.00 SE42BP31AL 66.00 LA4102 2.96 SA557OS 1.75 TA7227P 4.25 TBA990 1.49 UPC1028H 1.95 CV21B1 19.00 F31-13GR 76.00 SE42BP31 65.00 LA4140 2.95 SASBBO 2.85 TA7310P 1.80 CV2193 15.00 TCA270 1.50 UPC1032H 1.50 F31.13LD 76.00 SE5FP31 66.00 LA4400 4.15 SL9018 7.96 TA7313AP 2.96 L1PC1156H 2.75 CV5119 85.00 F31-13LG 75.00 1937 66.00 SL917B 6.66 TA7321P 2.26 TCA270S0 1.50 LA4420 1.95 TCA860 3.60 UPC11586 0.76 CV5320 85.00 F41-123LC 185.00 T948N 65.00 LA4422 2.50 SL1310 1.80 TA7609P 3.95 CVX389 55.00 F41-1411G TCA940 1.66 UPC1157C21.95 186.00 T948H 65.00 LA4430 2.50 SL1327 1.10 TA78114P 2.96 UPC11816 1.26 D9-110GH 39.60 F41.142LC 186.00 V4150LC 55.00 LA4481 3.96 SL13270 1.10 TAA310A 2.50 TDA440 2.20 UPC1182H 2.95 D10-210GH 46.00 V5004GR 58.00 LC7120 3.25 SN78003N 3.95 TAA320A 1.95 TDA1001 2.95 UPC1185H 196 D70-210GH6B13 65.00 M7-120W 19.00 V5004LD 69.00 M14-100GM LC7130 3.50 SN76013N 3.96 TAA350A 1.95 TDA1002A 2.96 UPC1191V 160 010.230GH 35.00 46.00 V6001 65.00 LC7131 5.50 SN76023N 3.96 TAA570 1.96 T0A1006A 2.60 UPC1360C 2.95 D10-230GM 36.00 M14.100LC 45.00 VB007DF31 59.00 LC7137 5.50 SN78033N 3.96 TAA661B 1.95 TDA1010 2.16 UPC1363C 246 D 10-293GY/90 55.00 M17-151GVR 175.00 V8008GW 69.00 LM324N 0.46 SN7811N 0.89 TA700 1.70 TD41036 260 UPC1365C 3.95 D13-30614 49.50 M17-151GR 176.00 V8034WA 69.00 LM380N8 1.50 SN76115N 1.25 TBA120AS/B/C/ TDA1037 1.96 UPC2002H 1.96 D13-4761.1/28 55.00 M19.100W 46.00 V8048CAL 69.00 LM380N 14 1.75 SN78131 N 1.30 SA/SB/T/U 1.00 TDA1170 1.95 D13-61GL/28 85.00 M19-103W 55.00 VB048J 49.00 LM3B3T 2,95 SN78228DN TBA396 1.60 TDA1190 2.16 656 0.35 D13-51GM/26 85.00 M23.11 OGH 55.00 VB084BP31 66.00 M23.111LD LM3900N 3.60 2.96 T94398 0.75 TDA 12700 3.95 556 0.60 D13-456H/01 66.00 66.00 V6064CLA 65.00 M51513L 2.30 SN76227N 1.06 TBA440N 2.56 TDA1327 1.70 723 0.50 013-4710H/28 69.00 M23-112GM 56.00 VB089GH 56.00 1.95 M23-112GV M61615L 2.96 SN78533N 1.66 T844800 1.26 TDA2002 741 0.35 D13-800GM 59.00 66.00 V8070P31 65.00 M61621L 1.60 áN78644 2.65 TBA510 2.60 10A2020 2.95 747 0.50 1313-81 OGH 69.00 M23.112GW 55.00 V7030 59.00 MB3712 2.00 SN76570N 1.00 TBA5100 2.50 TDA2030 2.80 748 0.35 D13-511 GH 59.00 M23.112KA 56.00 V7031GH 59.00 MC1307P 1.00 SN76650N 1.16 TBA520 1.10 TDA2190 3.95 7805 0.65 D13-811GM 59.00 M24-120GM 59.00 V7031/87A 59.00 MC1310P 1.60 SN78860N 0.80 TBA6200 1.10 TDA2622 1.95 7808 0.60 D13-830014 59.00 M24-120LC 69.00 V7035A 49.00 MC1327 1.70 STK014 7.96 T8A630 1.10 TDA2623 2.95 7815 0.66 D14-160014 76.00 M24-120WAR 59.00 V7037GH 46.00 D14-160GM 76.00 M24-121GH 55.00 VB004GR 65.00 M28-12GH 0.90 D14-1820H/84 69.00 65.00 V800BGH 66.00 SEMICONDUCTORS BC232 a.35 8E690 1.50 HCA 18334 M2B-131C 49.00 80233 .36 8E691 1.75 RCA18335 0.80 D14-172GR 56.00 V8010A 66.00 M28-13LG 49.00 8D234 0.35 8E742 0.35 SKESF 1.46 D 14-1720V 55.00 VCR 139A 11.50 1314-173GH M28-13GR 49.00 80236 0.49 BFT43 0.36 TIP29 0.40 65.00 2611.1 13.60 AAY1Z 0.25 BC178 0.16 BD237 0.40 BFW92 0.86 TIP29C 0.42 D14-173GM 53.00 M2B-131GR 55.00 11.60 M28.133GH 3BPI AC125 0.20 BC182 0.10 130238 0.40 8E529 0.30 TIP30C 0.43 D14-173GR 55.00 66.00 30PI 11.50 AC128 0.45 BC182LB 0.10 BD242 0.66 BFX84 0.28 TIP31C 0.66 D14-181 GH/98 55.00 M31-101GH 66.00 TIP32C 0.42 3H/OBM 55.00 AC127 . BC183 0.10 80248 0.75 BFX85 0.32 M31-182GR BOB D14-181GJ 56.00 55.00 3WPI 18.60 AC128 0.28 BC1B3L 0.09 60378 0.32 8FX88 0.30 TIP33C 0.95 D14-181GM 53.00 M31-182GV 53.00 TIP348 0.96 4EPI 30.00 AC128K 0.32 BC184LB 0.09 BD410 0.65 BFX88 0.25 1314-181GM50 69.00 M31-184W 66.00 AC141 0.28 BC204 0.10 BD434 0.65 BEY BO 0.21 TIP41A 0.45 58115 9.00 O 14-182GH 59.00 M31-1B4GH 85.00 30.00 AC141K 0.34 BC207B 0.13 BD437 0.75 8E761 0.21 TIP41C 0.45 M31-184P31 6BHP1 BEY 52 0.26 TIP42C 0.47 014-200BE 89.00 85.00 30.00 AC142K 0.45 BC208B 0.13 80438 0.75 M31-185W 58HP1FF AC178 0.22 BC212 0.09 BD520 0.65 BFY90 0.77 TIP47 0.85 D 14-2000A/50 86.00 69.00 5BHP31 30.00 AC178K 0.31 BC212L 0.09 80538 0.65 61548 1.76 TIP120 0.60 D14 200GM 75.00 M31-1900H 66.00 5CPI 10.00 AC187 0.25 BC212LA 0.09 BD597 0.96 BRV39 0.46 1IP125 0.65 D14-21 OGH 76.00 M31.190GR 66.00 8EP7/S 39.00 TIP142 1.75 AC187K 0.28 BC213 0.09 BD589 0.45 BR100 0.26 D14-270GH/50 75.00 M31-190LA 66.00 13.50 80701 1.25 BR110 0.49 TIP161 2.96 1361,1 AC188 0.25 BC213L 0.09 1314-310W 110.00 M31-191GV 66.00 13BPA4 17.50 AC188K 0.37 BD702 1.25 8R103 0.56 TIP2955 0.86 BC214 0.09 D14-320GH/82 85.00 M31-220W 59.00 17DWP4 25.00 ACV17 1.15 BC214C 0.09 80707 0.90 BRC4443 1.15 TIP3055 0.55 M31.270GY TI591 014-340GH/KM 45.00 65.00 32J/1085 89.00 AD142 0.79 BC214L 0.09 BDX32 1.60 B71004/020.86 0.20 M31-271P31 85.00 8E115 BT108 1.49 TV 108/2 1.50 014-340KA 46,00 8BD/89B/690/49L AD143 0.82 BC237B 0.09 0.36 M31.271GW 66.00 AD149 0.70 BC238 0.09 5E119 0.35 BT116 1.20 201308 1.35 D18-100GH 86.00 AD181 0.39 BC239 0.12 9E119 0.65 BT119 3.15 2N2219 0.28 018-100GH/86 69.00 M31-271W 65.00 15.00 AD182 0.39 BC251A 0.12 BF127 0.39 BT120 1.86 202222 0.29 018-1006H/87 66.00 M36-141W 75.00 1273 39.00 AD161/2 0.90 BC252A 0.15 8E154 0.20 BU105 1.96 202905 0.40 018-100GH/79 89.00 M38-170LG 75.00 1564 45.00 AF108 0.50 BC258 0.25 8E158 0.22 8U108 1.69 203053 0.40 D18-100GH97 66.00 M38-101 GH 65.00 1844 80.00 AF114 1.95 BC258A 0.39 BF180 027 95124 1.25 253054 0.59 D18-180GH 69.00 M3B-103GR 66.00 9442E1 76.00 AF115 2.96 8C284 0.30 9E167 0.27 135125 1.25 203055 0.52 D21-10GH 65.00 M38-120w 66.00 964470M 75.00 135128 263702 0.12 AF116 2.96 BC300 0.30 0E173 0.22 1.60 DG7-5 66.00 M38-120WA 65.00 95449GM 75.00 AF117 2.95 8C301 0.30 13E177 0.38 BU204 1.55 203703 0.12 D87.13 35.00 M38-121GHR 86.00 7709631 78.50 AF121 0.60 BC303 0.26 9E178 0.26 BU205 1.30 253704 0.12 AF124 0.85 BC307B 0.09 8E179 0.34 BU208 1.39 203705 020 AF125 0.35 BC327 0.10 BF180 0.29 811208A 1.62 253706 0.12 AF128 0.32 BC328 0.10 BF181 0.29 BU208D 1.85 2M3708 0.12 AF127 0.85 BC337 0.10 8E182 0.29 8U3276 1.20 2N3733 9.50 NEW VIDEO SPARES & HEADS AF139 0.40 BC338 0.09 B F183 0.29 BU407 1.24 2N3773 2.75 1.35 AF150 0.60 BC347A 0.13 13E184 0.28 BU500 2.25 203792 VIDEO BELT KITS AF178 1.95 BC461 0.36 8E185 0.28 BU50BA 1.95 204427 1.95 2N4444 1.16 Akai VS9300/9500/ Sanyo VTC 5500 3.75 AF239 0.42 BC478 0.20 13E194 0.11 132526 1.90 VIDEO HEADS BC527 5E195 0.11 BUBOY 2.25 255294 0.42 9800 £3.75 Sanyo VTC 9300 3.75 AF212 3.76 0.20 3H138 Suitable for Most JVC ASY27 0.85 BC547 0.10 5E198 0.11 BUY69B 1.70 205296 0.48 Ferguson 3V16 4.50 Sanyo VTC 9300P.... 3.90 AU108 4.50 BC548 0.10 BF197 0.11 MJ3000 1.98 205298 0.60 and Ferguson models 529.50 JVCH HR 3330/3600 4.50 Sharp VC 6300 3.75 AU107 3.50 BC549A 0.10 5E198 0.16 MJE340 0.40 205485 0.45 3HSSIHI Suitable for Hitachi JVC HR 3360/3660... 4.50 Sharp VC 7300 175 AU110 3.50 BC550 0.14 5E199 0.14 MJE520 0.48 205498 0.95 VT13000, VT8000. VT6000, Panasonic NV 300 ... 4.00 Sharp VC 8300 175 AU113 4.50 BC557 0.08 5E200 0.40 MPSA13 0.29 2SA715 0.80 VT8500. VT7000 £33.95 Panasonic NV 20008. 3.75 Sharp VC 9300 175 BC107A 0.11 BC5578 0.80 8E241 0.16 MPSA92 0.30 2SC495 0.80 4HSS Suitable for most Panasonic 30008 3.75 SL 30008 3.75 MRF237 4.95 2SC498 0.80 Sony BC1078 0.11 BC558 0.10 BF245 0.30 National Panasonic Models Panasonic NV7000... 3.50 Sony SL 6000/8080 4.50 BC108 0.10 1.80 8E257 0.28 MRF450A 13.96 2SC1098 0.80 BCY33A £32.95 Panasonic NV 86008/ Sony SL C7 /J7 4.00 BC108A 0.11 BD115 0.30 8E258 0.28 MRF453 17.50 2SC1108 2.50 Suitable for MRF454 26.50 2SC1172Y 2.20 4HS3IUIN) BC108B 0.12 BD124P 0.59 8E259 0.28 Panasonic Models 370 and BC109 0.10 80131 0.42 8E271 0.26 MRF455 17.50 2SC1173 1.15 BC108B 0.12 BD132 0.42 5E273 0.18 MRF475 2.96 2SC1306 1.40 380 E33.95 SANYO ORIGINAL VIDEO PARTS BC109C 0.12 80133 0.40 8E336 0.34 MRF477 10.00 2SC1307 1.75 BC114 0.11 80135 0.30 8E337 0.29 MRF838 13.96 2SC1364 0.50 ISETAMIX VIDEO HEADS SANYO ORIGINAL BC116A 0.15 90136 0.30 8E338 0.32 OC18W 2.50 2SC1449 0.80 PS36It Pin) Suitable for Sony PART NUMBER MODEL DESCRIPTION 20C11378 1.25 BC117 0.19 BD137 0.32 8E355 0.37 0C23 1.50 and Toshiba 5000 Series and Reel OC28 1.50 2SC19(79 1.25 4-529- 108008 VTC5160 Motor 3.8W 9.95 8C119 0.24 BD138 0.30 8F362 0.38 NEC PV2400 £39.50 4-627T -23501 VARIOUS Motor Assy. 9.75 9C125 0.25 BD139 0.32 BF363 0.85 OC29 2.26 2SC1945 2.85 RSV -3 -B Suitable for Sony BC139 0.20 130140 0.30 BF371 0.26 0C32 2.26 2SC1954 0.95 4-627V -51000 5150 Capston Motor 29.95 2SC1957 0.80 516000 BISON SLD7ME 143 -0- 4904-00900 FVHP815 Geer Idler Aisy. 5.95 BC140 0.31 80144 1.10 9E394 0.19 0C42 0.76 E39.50 BC141 0.25 BD7SOC 0.29 BF422 0.32 0C44 0.75 2SC1969 1.96 143- 2 -457T -05900 VTC9466 Stopper Ring Base 0.55 BC142 0.21 BD159 0.65 13E457 0.32 0C45 0.65 2SC202B 1.15 DS11 -10 -R Suitable for 143- 0 -545T -01701 VARIOUS Pinch Roller Assy. 8.95 BC143 0.24 80160 1.50 BF458 0.36 0070 0.46 2SC2029 1.95 Sony SLC5 SLCB SLC7 £39.50 143- 0 -545T -01700 VARIOUS Pinch Roller May. 1.95 BC147A 0.12 50158 0.55 9E459 0.36 0071 0.65 2SC2078 1.46 Sanyo Had for 143- 0- 551T- VTC9300 Idler Aasy. 0.95 BC1478 0.12 50179 0.72 BF467 0.68 0072 0.85 2SC2091 0.86 VTC9300/9500 £41.50 Loading Roller 0.95 0.95 2SC2098 2.95 143 -0 -6611 -03800 VARIOUS BC148A 0.09 80182 0.70 8E494 0.46 0075 Sanyo Head for VTC 143 Reel Ddve Pulley 8.50 8E495 OC81 0.50 2SC2186 1.95 -0- 8821.01201 VTC5150 BC748B 0.09 80183 0.70 0.45 5300/5000 E41.50 FVHP615 Mod KIt IC BA8304A 1.95 BC149 0.09 BD201 0.83 BF595 0.23 0C171 3.50 2SC2314 0.80 143 -0-9974 -00100 BC157 0.12 80202 0.85 8E597 0.25 R20086 1.45 2SC2371 0.36 8C158 0.09 BD203 0.78 B FR39 0.23 R20108 1.45 200234 0.50 Video Head Cleaning Tape VHS automatic wet /dry 6.50 VIDEO ALIGNMENT TAPES BC159 0.09 80204 0.70 BFR40 0.23 62322 0.58 3N211 2.95 Video Head Aerosol Cleaner 0.85 BC174 0.09 BD222 0.46 BFR81 0.25 62323 0.66 3SK88 0.96 Video Copying Lead and Connector Kit'ZV' 7.95 S-2P Colour Bars 30 min. 49.50 BC174A 0.09 80223 0.69 BFR88 0.30 82540 2.48 3SK88 0.96 S-3P Steintape 30 min. 49.50 9C177 0.15 BD225 0.48

LINE OUTPUT TRANSFORMERS E H T MULTIPLIERS VARICAP TUNERS PUSH BUTTON UNITS N4001 0.04 DIODES BV2238000.90 54003 0.04 DECCA 100 7.96 44119 0.80 65298-4000.22 54004 0.05 DECCA 1700 MONO 9.95 ITT CVC20 6.35 ELC1043/05 MULLARD 8.65 DECCA, ITT, CVC208WAV 7.96 ITT 10.19 BA116 0.13 BY299-8000.22 04005 0.06 DECCA 1730 8.96 ITTCVC30 6.36 ELC1043/06 MOLLARD 8.85 CVC6 7 -WAY BA145 0.16 BYX10 0.20 54007 0.06 DECCA 2230 8.25 PHILIPS GB 550 6.96 U321 8.25 PHILIPS G8165018 -WAY 14.49 6.91 BAI 48 0.17 B7%38-1506 N4148 0.02 GEC 2040 8.95 RANKT20A U322 8.25 7.67 11 00 BA154 0.06 0.20 64448 0.10 GRUNDIG 1600 15.45 THORN 3000 /3500 U324 OUICK BLOW FUSES 8.00 20MM BA156 0.16 BYX38-6006 66401 0.12 GRUNDIG 510 -6010, 2222, 5011 -6011 THORN8500 0.80 56402 0.14 THORN 9000 8.00 100MA Bp each BA157 0.30 13.45 THERMISTORS BAX13 0.04 9X555-8000.30 N6403 0.12 ITT CVC20 8.20 UNIVERSAL TRIPLER 5.45 200MA - SAMP 12p each BAX16 0.06 BYX71-8001.10 66408 0.13 ITT CVC30 8.25 VA1040 881058 0.30 B2Y96C30 0.35 65407 0.18 PHILIPS 06 8.50 REPLACEMENT VA1056S 0.23 20MM ANTI SURGE FUSES 61161 0.79 C5413 4.60 N5408 0.16 PHILIPS 69 8.99 VA1104 0.70 CSI OB 6.45 TT44 0.04 BY128 0.10 PHILIPS G 1 1 13.99 ELECTROLYTIC CAPACITORS VA8850 0.45 100MA - 800MA 15p each BY127 0.11 0A47 0.09 TT923 0.16 PYE 725 10.95 VA1097 0.25 14 - 6AMP 12p each BY133 0.16 0A90 0.05 112002 0.10 REIM T204 12.40 DECCA 301400-400/350V1 2.85 0.06 8'1164 0.46 0491 TANDBERGE 90' 11.15 DECCA 80/ 1 00 1400/306VI 2.99 8Y178 1.20 0495 0.06 ZENER TELEFUNKEN 7114 11.16 DECCA 1700 SPARE & AIDS 04202 0.10 /WI 79 0.83 DIODES THORN 1590 9.60 1200-200-400-350V/ 3.56 8T182 0.55 I621DR 6.00 THORN 8000 23.50 GEC 21101800/300V1 2.25 HEAT SINK COMPOUND 1.00 PUSH PULL MAINS SWITCH 1N236 5.00 THORN B7184 0.35 BZX81Series THORN 9000 9.96 ITT C VC 201200/400V I 1.80 FREEZE IT 0.96 MECCA, GFC, RANK. 97199 0.40 1623C 5.00 0.15 THORN 9900 2240 PHIIPS G 1600/300V1 2.26 SOLDA MOP 0.64 ETC.1 1.02 6.00 87205 014 IN23ER BZY98Series THORN MAIN TRANSFORMER PHILIPS G912200 x 63VI 1.19 SWITCH CLEANER 0.85 PYE IF GAIN MODULE 6.99 6Y200.8000.33 1N23WE 5.00 0.10 3000/3500 9.70 PHILIPS G111470/250V1 2.35 W D40 1.75 ANODE CAP 127kVI 0.69

38 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com PHONE P. M. COMPONENTS LTD TELEX 0474 60521 . SELECTRON HOUSE, SPRINGHEAD ENTERPRISE PARK 966371 4 LINES SPRINGHEAD RD, GRAVESEND, KENT DA11 814D TOS -PM

UF85 1.20 3011108 68M8 0.58 6L19 3.96 13E1 145.00 955 1.00 A SELECTION FROM OUR M8225 3.95 12-.00 Q5108/45 4.00 UF89 2.50 30/141K 11.50 6BM6 155.00 6L6GC 2.95 13EM7 3.50 958A 1.00 ME1401 29.50 05150/15 6.95 UL44 3.50 3A/147J 7.50 6BN4 1.65 6L6GCIGEI 1457 1.95 1299A 0.60 ME1402 29.50 STOCK OF BRANDED VALVES 05150/30 1.15 3A/167M 10.00 6BN6 1.85 4.50 170W4A 2.95 1619 2.50 ME1501 14.00 7.00 UL85 0.85 05150/45 3A2 3.95 6857 4.50 6L6GT 1.95 17EW8 0.95 1625 3.00 A1714 24.50 EBF80 0.95 EL822 12.95 MH4 3.50 3.96 UU5 3.50 051200 3A3A 3.95 6658 3.95 6LD20 1.15 17728 4.50 1626 3.00 A8134 7.50 EBF83 0.95 EM1 9.00 MHL6 4.00 UU7 8.00 051202 3.95 304 1.10 6805 0.75 6LF6 7.50 1803 6.00 2050W 4.50 A1998 11.50 EBF85 0.96 EM4 9.00 ML4 4.50 UU8 9.00 051203 4.15 3AL5 0.95 6605 0.75 6LJ8 2.50 19005 3.56 2050 3.95 A2087 EBF89 0.70 EMBO 0.70 M548 5.50 UY41 3.50 -.l 051205 3.95 3072 3.35 66076 0.72 6LQ6 4.95 19AU4GT 2.50 3534 4.00 A2134 14.95 E13F93 EM81 0.70 MU14 3.50 UY85 0.70 0.95 051208 1.05 382 3.00 6BL7GTA 3.95 6N7 2.50 1903 17.00 404A 10.95 A2293 6.50 EBL1 2.50 EM84 1.65 MZ 1. 100125.00 V235AI1K 0S1207 0.90 3B4 7.00 6685 0.70 6N7GT 2.50 19H5 33.50 927 15.00 A2426 29.50 EBL21 2.00 EM85 3.95 N37 12.50 250.00 051208 0.90 387 4.50 65R7 4.95 6P15 1.50 1906 9.00 1927 25.00 A2599 37.50 EC52 0.75 EM87 2.50 N78 9.85 V238A/1K 051209 3.15 295.00 3824 10.00 6688 2.15 6P25 4.00 2002 10.50 4212E 25000 A2792 27.50 EC70 1.75 EN32 15.00 002 0.85 051210 1.50 6BRBA 2.15 4313C 4.00 1 3626 24.00 6P26 4.00 2001 0.70 A2900 11.50 EC80 9.50 EN91 1.50 OA2WA 2.50 V240C K 051211 1.50 3828 12.00 6657 5.50 6P28 2.00 201F6 7.95 4328D 9.00 A3042 24.00 EC81 7.95 0592 4.50 003 2.50 225.00 051212 3.20 3626 1.50 6BW4 1.50 607 1.75 2011 0.95 5642 9.50 A3283 24.00 EC86 1.00 ESU150 14.95 OB2 0.85 V241C1K Q51213 5.00 3C4 1.00 68W6 5.35 60707 1.20 20P1 0.55 5651 2.50 AC/HL/DD 4.00 EC88 1.00 ESU872 25.00 082WA 2.50 195.00 051215 2.10 66W7 1.50 6R7G 3.15 20P3 0.60 5654 1.95 AC/THI 4.00 EC90 1.10 EY51 0.80 0C2 2.50 C2464A/2K 3C23 19.00 051218 5.00 24.00 6BW8 4.00 6540 1.50 20P4 1.95 5863 1.95 ACT22 59.75 EC91 5.50 EY81 2.35 0C3 1.50 315.00 3C45 0037 9.50 3CB6 1.50 66X6 0.48 650707 1.35 20P5 1.15 5670 3.25 AH221 39.00 EC92 1.95 EY83 1.50 OD3 1.70 V339 3.50 0V03-12 4.96 3CN3A 2.50 66X707 3.50 65C7 1.50 21108 2.60 5672 4.60 411238 39.00 EC93 1.50 EY84 5.95 0M4 1.00 V453 12.00 QV05-25 1.75 3C56 0.95 6826 2.50 6507 1.35 2481 39.50 5687 4.50 AL60 6.00 EC95 7.00 EY86/87 0.50 0M5B 3.00 VL5631 10.95 QV06.20 29.50 3CX3 2.50 68Z7 2.95 65117 1.35 251601 1.75 5692 3.50 AN1 14.00 EC97 1.10 EY88 0.55 0M6 1.75 VP4B 4.50 QV08.100 3CY5 1.50 6C4 1.10 657707 1.20 25806 1.75 5696 3.50 ARP12 0.70 EC157 439.50 EY91 5.50 ORP43 2.50 VP133 2.00 145.00 306 4.50 6C5 1.95 6567 1.35 29C1 19.50 5704 3.50 ARP34 1.25 EC8010 12.00 EY500A 2.50 ORP50 3.95 VR75/30 3.00 QV2-2500 30210 29.50 6C6 2.50 6SK7GT 1.35 8.50 5718 8.15 ARP35 2.00 ECC32 3.50 EY802 0.70 P61 2.50 VR101 2.00 29606 45.00 3E22 49.50 6C8G 1.50 651_70T 0.85 30C17 0.40 5725 2.50 ECC33 3.50 EX35 0.75 P41 2.50 5105130 1.50 053-125 65.00 3EH7 1.95 6C11 2.50 65N7GT 1.35 1.48 5726 1.50 AZ11 4.50 ECC35 3.50 EZ40 2.75 PABC80 0.50 VR1 50/30 1.15 30C18 054-250 70.00 3E77 1.95 75Q7 1.35 0.95 5727 1.95 ECC81 1.15 EZ41 2.75 PC86 0.75 VT52 2.50 3F5 054.400 76.00 3V4 2.50 6C18 2.50 30FL1 1.00 5749 2.50 BL63 2.00 ECC81 Special EZ80 0.75 PC88 0.75 VU29 4.50 6557 1.95 910 4.00 3W4GT 2.50 6CA4 4.95 6U4GT 1.75 30FL2 1.35 5750 1.85 85450 67.00 Quality 1.95 EZ81 0.75 PC92 3.50 VU39 1.50 R16 12.00 465516 115.00 6C07 3.50 6U6WA 3.50 5751 2.95 85810 55.00 ECC82 0.65 EZ90 1.50 PC97 1.10 W21 4.50 30FL12 0.95 R17 1.50 4.650 59.00 6CB5 3.95 608 1.15 1.10 5763 4.95 85814 55.00 ECC82 Philips F606 2.95 PC800 1.10 W77 5.00 30FL13 R18 2.50 4687A 9.50 6CB6 1.95 6080 1.50 30FL14 1.25 5814A 3.26 CIK 19.00 1.95 FW4/800 2.95 PC900 1.25 W729 1.00 R19 2.50 4.1250 72.50 6CD6GA 4.50 1.25 5823 9.50 C3JA 9.50 ECC83 0.86 PCC84 0.40 W739 1.50 6560 30L1 0.45 R20 1.20 4.2500 79.50 6CF6 1.50 1.50 5829W0 6.50 ECC83 Brimar G5511K 9.00 PCC85 0.54 X24 4.50 65601 30L15 0.60 C6A 9.00 R1169 55.00 4.4000 87.50 6CG7 2.25 5636 5.50 C7108 85.00 1.35 0180I2M 6.95 PCC88 0.70 5861065 4.95 6X25 1.00 30L17 0.60 RG1-125 4.95 4832 35.00 6CH6 6.95 5678 7.50 C1134 32.00 ECC83 Philips 024012D 9.00 PCC89 0.70 076M 1.95 6X4 1.50 30P4MR 1.00 RG 1 . 240014.50 481174 1.75 6CL3 3.95 1.00 1.00 5840 3.50 C11484 115.00 1.95 GC10B 17.50 PCC 189 0.70 XC24 1.50 6X5GT 30P12 RG3-250A 3.50 4626 1.95 6CL6 3.25 5842 11.00 C1149,1 195.00 ECC84 0.50 GC10D 17.50 PCC805 0.70 XC25 0.50 6X5GTY 1.00 30P18 0.80 RG3 1250A 4C27 6CL8A 1.50 5847 10.95 C1150/1135.00 ECC85 0.75 GC10/4B 17.50 PCC806 0.80 XFW47 1.50 25.00 6X86 2.25 30P19 1.00 35.00 4C28 25.00 6CM5 1.60 5879 8.50 C1534 32.00 ECC86 2.75 GC1014E 17.50 PCE82 0.80 XFW50 1.50 7A6 4.50 30PL1 2.60 RK2K25 82.50 4CB6 1.95 6CM7 2.95 707 5886 13.96 C3E 28.50 ECC88 0.95 GC12I48 17.50 PCF80 0.85 X02-6400 2.00 30PL13 0.60 RK-20A 12.00 4CX250B 49.00 6C56 0.75 7AD7 1.75 5894 39.50 CCA 2.80 ECC91 2.00 GD86W 6.00 PCF82 0760 135.00 1.75 30PL14 RL76 1.50 4CX2508 6CW4 8.50 786 3.50 5.50 5899 4.50 CC3L 0.90 ECC180 0.72 GDT120M 5.00 PCF84 0.65 505.500 22.50 31JS6C RPL16 12.00 EIMAC 59.50 6CY5 1.00 787 330/158M 5963 1.75 CK1006 3.50 ECC189 1.95 GN4 8.00 PCF86 XI1.5V 1.50 2.50 RPY13 2.50 4CX2508M 606 2.50 7C5 19.50 5965 2.25 CL33 2.00 ECC8015 3.60 GN10 15.00 1.20 XL628F7 7.50 3.60 RPY43 2.50 75.00 6DC6 2.35 7C6 2.50 3505 4.50 6005 1.85 CV Nos Prices ECC803S 4.95 GR10G 4.00 PCF87 0.40 XNP12 2.50 RPV82 2.50 6078 0.95 7E7 35L6GT 2.00 6012 16.00 request ECC804 0.60 GS10C 16.50 PCF200 1.80 XR1.1600A 4CX250K 2.50 RR3-250 15.00 EIMAC 95.00 6DK6 1.15 7H7 3.50 35W4 0.70 6021 3.65 D3A n 27.50 ECC2000 12.00 GS10H 12.00 PCF201 1.80 49.50 RR3-1250 35.00 4CX125C 6005 5.95 7AU7 1.50 35Z3 1.85 6057 2.50 D63 1.20 ECFBO 1.15 G512D 12.00 PCF800 0.40 X61-32000 R5613 45.00 125.00 60068 2.50 777 4.50 6058 3.95 DA41 22.50 ECF82 1.15 GT1C 14.00 PCF801 1.35 79.50 EIMAC 5.50 38HE7 RS685 54.95 4CX3500 60760 1.50 754 6059 3.75 DA42 17.50 ECF86 1.70 GT1C SIS 13.00 PCF802 0.80 XR1-64000 95.00 2.50 40606 5.50 RS5688 52.15 4CX350F 79.50 60W4 2.15 8138 2.50 42 6060 2.25 DA90 4.50 ECF200 1.85 GTE175M 8.00 PCF805 1.25 99.50 6.95 SBF17 5.95 6E5 3.95 47 6062 4.50 DA100 125.00 ECF202 1.85 GTR150W 1.00 PCF806 1.00 5502 25.00 4XC1500B 8810 2.50 6.00 S6F33 28.95 6E04 4.95 1.50 6063 2.00 DAF91 0.70 ECF801 0.85 GU20 35.00 PCF808 1.25 565 6.95 398.50 8805 1.95 50A5 511612 38.00 4057 2.25 6E07 2.50 1.96 SOCS 6064 3.25 DAF96 0.65 ECF805 2.50 GU50 17.50 PCH200 1.50 Y602 12.00 8FQ7 0.96 03012K 12.00 4GV7 2.25 6EA8 2.50 1002 1.25 1.15 6067 1.95 DC70 1.75 ECF806 10.25 GXU1 13.50 PCL82 0.85 YD1100 75.00 50CD6G 5104,1K 10.00 4J52 75.00 6E68 1.76 10DE7 2.50 50EH5 1.50 6072 4.20 DC90 1.20 ECH3 2.50 GXU3 24.00 PCL83 2.50 YJ1060 285.00 5109,16 15.00 4JC6A 2.95 6EM5 2.50 10F1 0.75 50756 2.95 6080 8.50 DCX-4-1000 ECH4 3.00 G%U50S5 PLC84 0.75 YL1020 29.00 5130 5.59 6EM7 2.50 52KU 2.00 6080WA 9.50 12.00 ECH35 3.50 14.50 PCL85 0.80 YL1070 195.00 4X1500 35.00 10066 1.95 5130P 5.95 YL1071 195.00 5A/102D 9.50 6EU7 1.95 10P14 2.50 53CG 15.00 6132 10.00 DCX4.5000 ECH42 1.00 GY501 1.20 PLC86 0.85 SC1/800 5.00 6EU8 1.75 6136 2.60 1.00 PLC800 0.80 YL1290 65.00 5A152M 9.00 10P18 0.78 61SPT 4.50 25.00 ECH81 0.65 GY802 SC1/1100 8.00 6EV7 2.95 61466 9.50 DET16 28.50 ECH83 0.78 G230 1.00 PLC805 0.90 277 1.20 5A163K 10.00 7581 3.50 SC1I1200 5.00 6EW6 1.50 10LD12 6157 2.50 DET18 28.50 ECH84 0.69 0231 1.00 P0500 3.50 Z302C 12.00 5A170K 6.25 0.85 75C1 2.50 SC1/1300 6.00 6EW7 4.50 11E3 6158 3.20 ECH2000 1.50 GZ32 1.00 PD510 3.65 2359 9.00 50.180M 9.00 55.00 80 4.50 DET23 35.00 SC1/200 9.00 6F1 2.00 6201 6.45 100 69.00 Z5055 15.00 50206K 10.00 12A6 3.95 83 8.50 DET24 39.00 ECL80 0.60 GZ33 4.50 PEI SD6000M 6F5 4.95 6205 DET25 22.00 ECL82 0.65 GZ34 2.15 PEN25 2.00 Z520M 4.00 5AMB 2.15 12AD6 1.50 84 3.00 6.96 45.00 1.20 6F6 2.50 12A08 1.50 6211 2.50 DEt29 32.00 ECL83 2.50 GZ37 4.50 PEN40DD 2.50 Z521M 8.00 5056 85A1 8.50 SP41 5.00 5AR4 2.00 6F6G 2.00 12AL5 1.00 1.50 6267 4.50 DF91 0.70 ECL84 0.74 HAA91 1.00 PEN45 3.00 Z7000 3.00 85A2 SP42 3.00 5AU4 1.50 6F7 5.50 12076 6350 3.50 DF92 0.60 ECL85 0.69 HABC80 0.90 PEN45DD 3.00 Z749 0.60 0.95 90AV 10.00 SP48 4.95 58.110M 10.00 6F12 1.50 12ÁT7 1.15 90C1 2.70 6360 4.50 DF913 0.65 ECL86 0.80 HBC90 0.76 PNE46 2.00 Z759 19.85 55501 35.00 6F13 3.00 12AT7WA 6388 14.50 DF97 1.00 ECL805 0.69 HBC91 0.80 PE06-4oN 42.00 Z8000 3.00 513.254M 14.50 2.50 90CG 13.50 ST11 1.50 58-255M 19.50 6F14 1.00 12AU6 1.50 6545 8.50 DH63 1.20 EF37A 2.00 HF94 0.75 PFL200 0.95 Z803U 18.95 90CV 12.50 STV280I40 56-256M 9.00 6F17 2.75 12017 0.65 6550 10.95 DH77 0.90 EF39 1.10 HF94 1.50 PL21 2.50 ZA1000 12.50 91AG 9.00 11.95 58-257M 9.00 6F21 2.50 12AV6 1.95 19.50 6688 6.50 DH79 0.56 EF40 4.50 HK90 1.05 PL36 0.95 201001 1.50 92AG STV280/80 58-258M 14.50 6F23 0.60 12057 2.50 92AV 12.50 6870 11.50 DH149 2.00 EF41 3.50 HL2K 4.95 PL38 1.50 ZA1002 1.50 19.95 5C22 125.00 6F24 1.25 12AX4GT 1.00 9501 6.50 6887 9.50 DK91 0.90 EF42 3.50 HL23DD 4.00 PL81 0.72 2C1040 8.00 5042 4.95 57180E1895.00 6F25 1.25 12AX7 68838 9.95 DK92 1.20 EF50 2.60 H141 3.50 PL81 A 0.72 2401005 8.00 0.65 T82.5/300 5R4GB 3.50 6F28 1.25 12AX7WA 2.50 108C1 1.50 6973 5.95 DL35 2.50 EF55 4.95 614200 3.50 PL82 0.60 ZM1021 8.00 85.00 5R4GY 3.50 6F32 1.25 12057 7025 2.50 DL63 1.00 EF70 1.20 HL90 0.70 PL83 0.52 2M1023 7.95 3.95 15062 6.95 582-300 45.00 5T4 5.95 6F33 17.00 120Z70 1.95 7027A 4.50 DL70 2.50 EF71 1.50 HL92 1.50 PL84 0.78 2M1041 14.00 150C2 1.50 TB3.2000 5U4G 2.50 6FG5 1.95 12B4A 4.50 150C4 7032 2.00 DL73 1.50 EF72 1.20 HL133xDD3.50 PL88 1.00 ZM1082 9.00 2.15 395.00 5U4GB 2.50 6F07 2.95 12606 7059 2.50 OL92 0.95 EF73 1.00 HT2 4.00 P195 1.75 ZM1084 10.00 1.50 155ÚG 25.00 TBL-2.300 5V4G 1.25 656G 5.50 126E8 1.95 7167 3.95 DL93 1.10 EF80 0.55 HY90 1.00 P1302 1.00 2M1177 9.00 18587 1.50 275.00 55307 1.95 60080 0.80 128470 7189 3.50 DL94 2.50 EF83 3.95 HVR2 3.00 PL345 12.50 ZM1202 65.00 2.50 211 33.50 TD 1 100025.00 5Z4GT 0.85 6GK5 1.50 7193 7.50 7P9- 7A PL500 1.10 ZM1263 4.00 126L6 1.75 274A 15.00 DL96 2.50 EF85 0.50 60.00 TD03-10F 35.00 6066 1.95 7199 7.50 K3118 PL504 1.15 ZM1612 3.00 6/30L2 0.70 126570 2.75 307 5.00 OL510 13.50 EF86 2.25 85.00 TD3.12 4.00 6057 2.15 7247 2.95 DLS16 10.00 EF86 Special 08613 45.00 PL508 1.75 1A3 4.50 6A1203K 9.00 12CA5 1.95 328A 15.00 TDD4 5.50 4.95 6057 2.50 7360 13.50 DM70 1.95 Quality 3.15 KT8C 7.00 PL509 4.85 1AC6 1.20 6A7 12CX6 1.20 388A 17.50 TP25 1.50 6A8G 1.50 6GW6 2.50 120066 7462 15.00 DM160 2.75 EF89 1.50 KT33C 3.50 PL519 4.95 10E43.60 3.50 42505 9.00 TSP4 7.00 2.00 601 9.50 431U 4.50 7475 5.00 DY51 1.50 EF91 1.95 KT36 2.00 PL802 5.95 16307 1.95 6AC7 12DW4A 3.50 TT11 1.50 6AF4A 2.50 6H3N 1.10 12DW7 7486 125.00 DY86/87 0.65 EF92 2.15 6744 4.00 PL802T 3.50 1822 10.00 2.50 5728 85.00 1.50 646 1.95 705A 7527 85.00 DY802 0.72 EF93 0.95 KT45 4.00 PL820 2.95 1624 14.95 6AG5 12E1 17.95 8.00 TT21 45.00 6AG7 1.95 6H6GT 1.95 12E14 EF94 0.85 6761 4.00 PL5557 29.50 1627 55.00 38.00 708A 8.00 1122 45.00 6HF5 5.50 7551 6.95 E80L 29.50 EF95 1.50 KT63 2.00 PY32 0.80 1635A 29.50 6AH6 2.50 12GN7 3.95 715C 45.00 TT100 57.00 1C1 6074 2.00 6HF8 2.50 12HG7 4.50 724A 275.00 7558 9.46 11. KT66 2.50 E8 12.00 EF97 0.90 OSRAM P733 0.50 TTR.31MR 6H56 4.95 7586 15.00 15.00 1C5GT 2.50 6077 2.00 129076 4.60 726A 75.00 E82CC 3.50 EF98 0.90 P781 0.70 65.00 6J4 2.15 7587 29.50 E83CC 3.50 EF183 0.65 6766 USA 9.95 P582 u.70 6065 1.60 127707 3.50 803 14.95 TY2-125A85.00 2.50 6J4WA 3.15 1265 1.95 7591A 4.95 E83F 5.50 EF184 0.85 KT66 GEC 14.95 PY83 0.70 6066 805 39.00 TV4.400 85.00 1FD1 2.50 6AL5 0.60 675 2.50 126707 1.50 807 1.95 7609 47.00 E86C 9.50 EF730 1.80 KT 77 Gold Lion PY88 0.85 1G3GT T56-600W 2.50 6AM4 3.25 676 2.00 1268 1.95 810 85.00 7733 5.50 E88C 7.95 EF731 3.50 10.95 PY500A 1.95 17307 2.50 365.00 6AM5 6.00 677 4.15 12SA7GT 1.95 811A 15.00 7788 25.00 E88CC 3.50 EF732 3.50 KT81 7.00 PY800 0.79 152 4.50 7552/250 6AM6 1.50 67660 3.95 12507 4.75 812A 35.00 7868 3.95 E88CC Siamans EF800 11.00 KT88 USA 10.95 PY801 1N5GT 2.50 375.00 6AN5 2.65 6JE6C 4.95 12SH7 1.95 813 8012 15.00 Special 5.95 EF805S 13.50 6788 G Lion 0.79 1P28 25.00 23.5Ö 018-20 2.75 6AN8A 2.65 6JU8 2.50 1251(7 1.95 E9OCC 7.95 EFBOBS 114.50 18.95 083300 54.95 1135 0.90 U19 11.95 6005 1.75 6756C 4.95 125.17 E9OF 7.95 EF612 0.65 KT67 9.00 083-1750 114 0.70 1.50 8298 14.50 U24 2.00 60128 0.85 4.15 1250701 E91H 4.50 EFL200 1.50 KTGW61 2.50 139.50 1U4 1.75 6770 1.95 833A 95.00 U25 0.90 6085 5.95 6K7G 2.00 12587 E92CC 3.96 EH90 0.72 KTW62 2.50 0853500 1U5 1.00 2.60 866A 4.50 U26 0.90 6088 3.95 6K8G 3.00 12507GT 1.50 872A 27.50 E99F 6.99 EK90 0.95 KTW63 2.00 495.00 1 X2B 1.40 U37 9.00 6055 1.50 6606 5.50 13D3 El 30L 25.00 EL32 0.95 67263 2.50 OE03-10 4.95 122 8.95 3.20 873 60.00 U41 6.95 6056 2.50 2.50 1307 EL33 4.00 L63 1.50 DE08 200 205150 11.50 6KM8 3.20 884 5.50 U50 2.00 6057G 4.50 6678 2.95 1309 3.20 930 9.95 E182CC 9.00 EL34 2.25 L102/2K 6.95 145.00 U82 3.00 267 1.50 E180F EL34 Mullardl L12012K 12.00 0F40 85.00 6076 0.75 611 2.50 13DE7 2.50 931A 13.95 8.50 U191 0.70 2822 69.50 1.75 E186F Philips 4.50 L87-20. 95.00 OP25 1.00 6078 6L15 3.15 13087 2.95 954 1.00 8.50 . U192 1.00 2C39A 32.50 6AU4 2.00 E188CC 7.50 0136 1.95 LS9B 6.95 OQE02.5 19.50 U193 0.65 2C39BA 39.50 6AU6 0.95 E 1 T 15.00 EL37 9.00 M502A 60.00 OQE03-12 7.95 2C40 U251 1.00 37.00 V6 E280F 19.50 EL38 4.75 M537A 80.00 0E03-20 35.00 60 0.75 U801 0.75 2C42 29.50 6AW8A 2.60 E283CC 10.00 EL41 3.50 M5143 155.00 QQE06-40 UABC80 0.85 2C51 0.75 6028 5.95 AUDIO TAPE HEADS E288CC 13.50 EL42 2.00 M8079 6.00 45.00 CALLERS WELCOME UAF42 1.00 2C53 32.00 687 2.80 E810F 26.00 ELB1 6.95 M8082 7.50 OQV02.6 19.50 2CY5 1.50 14000 HEAD 1 W OPEN MON -THUR FRI UBF80 0.60 688G 1.50 A1770119V11121 4W 9AM- 5.30PM E1148 1.00 EL83 M8083 3.25 00V03-10 5.50 5.95 UBC41 2.95 2021 1.50 0.95 5772E0111AD 291 E1524 8.95 EL84 0.75 M8091 7.50 00503.10 81306 9AM- 5.00PM UBC81 1.50 2021 W 2.50 6807 4.50 EA50 1.00 EL85 4.50 M8096 3.00 Mullard 15.00 2E22 49.00 24 -HOUR ANSWERPHONE SERVICE' UBF89 0.80 66080 3.50 ELECTRO.OPTICAL EA76 1.95 EL86 0.85 M8098 5.50 OQV03-20 UBL21 1.75 2E26 7.95 ACCESS & BARCLAYCARD PHONE EA79 1.95 EL90 1.75 M8099 5.00 25.00 UC92 1.20 2J42 93.00 68C8 1.00 952. 9200 EABC80 0.70 EL91 6.00 M8100 5.50 OQV03-20B 2755 350.00 6604 1.50 ORDERS WELCOME UCC84 0.70 19.02 EAC91 2.50 EL95 1.75 M8136 7.00 32.00 UCC85 0.60 2625 27.50 6BD6 2.50 UK ORDERS P &P Cl EAF42 1.20 EL153 12.15 M8137 7.95 00V06 40A 2625 Raytheon 66E6 0.72 UCF80 1.00 YBLBE 088 C8T WES PLEASE ADD 15% VAT EAF801 2.00 ELI 83E 3.50 M8161 6.50 27.50 UCH21 1.20 75.00 EB34 1.50 ELI 8P 3.50 M8162 5.50 00507.50 UCH41 2.50 2K26 95.00 68G6G 3.00 EXPORT ORDERS WELCOME E841 3.95 EL360 8.75 M8163 5.50 83.50 UCH42 2.50 2629 250.00 68118 1.95 CARRIAGE AT COST E891 0.85 EL500 1.40 M8190 4.50 0020320 2K48 140.00 6E98 1.50 UCH81 0.65 PLEASE SEND YOUR ENQUIRIES FOR EBC33 2.50 EL504 1.40 M8195 6.50 42.50 UCL82 1.75 2656 250.00 66J6 1.20 EBC41 1.95 EL509 5.25 M8196 5.50 Q575/20 1.50 UCL83 2.50 305 4.50 6BK4 4.00 SPECIAL QUOTATIONS FOR LARGE EBC81 1.50 EL519 8.95 M8204 5.50 0375/40 3.00 UF41 1.15 3A1078 12.00 66670 1.95 REQUIREMENTS. EBC90 0.90 EL802 3.65 M8223 4.50 0592/10 5.00 UF42 1.15 3A /108A 9.00 6816 195.00 EBC91 0.90 EL821 8.50 M8224 2.00 0595/10 4.85 UF80 1.75 3A/109B 11.00 6018 1.15

CIRCLE 27 FOR FURTHER DETAILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 ,n

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www.americanradiohistory.com G. Wareham Short -wave by loop aerial Modifications to the earlier designs enable the aerial to be used with domestic receivers

In April 1985, S. Mukherjee Having eliminated direct The aerial and downlead are described a useful indoor pickup of short -wave signals, balanced, but the receiver input short-wave aerial for use the next job is to deal with pick- circuit is not. A balun is with well- screened receivers. up by the downlead. This is needed, and this can take the His design is not very suited to done in two steps. First, an form of a centre -tapped auto - ordinary domestic receivers unscreened, unearthed loop is transformer (c), made with a because their lack of screening substituted for the original bifilar winding of hookup wire allows signals to bypass the design. Any thick, insulated on a magnetic core. Possible loop. The result is loss of direc- wire (such as mains flex) can be core materials are pieces of fer- tionality and, at the same time, used for the loop, the signals rite aerial rod, ferrite toroids, trouble from local interference being extracted via a trans- and tuning slugs of the through - of the kind which a magnetic former. The primary is formed hole type, which can be used as aerial rejects. by passing one or two turns of toroids. In general, the number Some relatively simple the loop conductor round a fer- of turns needed is 5 -10, connec- changes can avoid these pro- rite rod (a). (An aerial rod from ted as shown. The balun is blems. The first requirement is an old m.w. receiver is ade- placed either just outside or just to provide the receiver with quate.) Coupling to the inside the screening box, with some sort of screening enclo- unscreened twin downlead is its centre tap connected to the sure to exclude direct pickup. A effected by a secondary wind- foil by a short lead (fold its end complete screening box is ing: two or three turns will into the foil or staple it to the impracticable since it would generally be optimum, but the foil). Coupling to the receiver is prevent access to the controls. user can easily experiment with by wrapping a few turns of Experiment shows that an different numbers. For reasons insulated wire round the end of open- fronted box will work, explained below it is useful to the built -in telescopic aerial. (I provided that it is deep enough make the secondary detach- find that this is still the best for the receiver to be pushed able. method, even in a receiver well inside. Although considerations of which also has proper aerial Fig. 1 (a) shows the one My tests indicate that a card- symmetry suggest an arrange- and earth terminals. It is not or two -turn primary on board box covered with alum- ment like (a), where the loop necessary to earth the screen- ferrite rod and, at (b), the inium kitchen foil makes an can float above earth in a ing box except when power recommended capacitor adequate short -wave screen. balanced fashion, practical use supply considerations require it position. At (c) is the On long and medium waves the is eased by putting the tuning as explained later. balun to match aerial and amount of screening provided capacitor at the bottom (b) Check for downlead pickup downlead to receiver and by the thin foil is reduced, where it is easily reached. I by slipping the secondary coil (d) shows the method of enabling the receiver's ferrite have not noticed any impair- off the transformer rod. Signals avoiding signal injection aerial to function on these ment in performance from the P42 from the power -supply bands. assymmetry which results. lead.

Battery leads from Rx.

Filter To loop coupler

Ferrite rod

To loop coupler To Rx To Rx.

d c from adaptor (a) lb) lc) Id)

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 41

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continued from p46 INDOOR LOOP Structured Softare, and will be creation a a big splash in an should vanish or at least pleased to supply full details on existing smooth pool of energy become very noisy. request. than as a big bang appearing from AERIAL P.G. Craven nowhere in a complete void. If a receiver is mains opera- J.C. Davies J.N. Kidman ted, the mains lead brings If you happen to live near a Bromborough Southampton unwanted signals into the powerful radio transmitter you will Wirral screening box. A power -supply find that short -wave reception is Merseyside filter is then required. My own marred by breakthrough by the receiver is a battery-powered local transmission. This can occur Reference NAVAL MARCONI one which can be mains -driven even when the wanted station is far 1. Welch, P.D., A Fixed -Point Fast via an external adapter (trans- removed in frequency from the Fourier Transform Error Analysis. In the November issue you had an former- rectifier unit) which local transmission, through such IEEE Trans Audio & article by Nigel Cawthorne, which mechanisms as intermodulation. Electroacoustics AU -17, 2, 151 -157 I am happy to say was supplies the required low -vol- In principle, the directional (JUne 1969). complimentary to Marconi in most tage d.c. via a long lead. In this properties of a loop aerial can be respects, but did rather belittle the case, the appropriate side of the utilized to null the local Marconi Fast Tune (MFT) range d.c. supply is connected to the transmission but, in practice, a of equipment. I would like to point screening foil and the 'live' side simple loop oriented in the vertical ADD -ON CURRENT out that in addition to the drive taken to the receiver via a plane does not give a complete and 10kW amplifiers we also have three -terminal capacitor -type null. The reason is that the ground DUMPER a 50kW i.s.b. amplifier, a IkW filter (d). A lead from the earthy wave from the local transmitter is amplifier and a transceiver based not quite vertically polarized but I was very interested to read Erik on the drive /receiver battery terminal of the receiver in tilted by wave drag. Margan's add -on circuit to convert development. But by far the most is foil com- connected to the to The loop null can be improved a conventional Class B amplifier important part of MFT2 is the plete the circuit. A conven- by tilting the loop away from the output into a non -switching type. I remote computer control system tional pi- section LC filter can vertical to match the interference. have, in the past, tried to develop that goes along with the basic also be used: I had good results Readers who suffer from local - such a circuit, but have never been hardware; this system allows for from a home -made filter where station interference might find it fully satisfied with my efforts. Mr automation in service selection the series L was a tv frame coil useful to construct short-wave Margan's circuit appear to be a which includes frequency, mode, on a ferrite ring core and the Cs loops in a way which permits some very competent solution. audio source and antenna were 100nF polyester film adjustments of tilt. For most cases Mr Margan gives no clue selection, along with any other capacitors. Whatever arrange- a tilt range of 0 -30° will be regarding the value of Re. aspect that needs controlling. sufficient. However, analysis of the circuit I would also take this ment is used it is essential to R. Jones indicates that if Re is less than opportunity to point out that our keep the connections between Dorchester about one fifth of the value of Re, new Swordfish transceiver is not, capacitors and screening foil Dorset the circuit current limiting will as depicted in the picture caption very short - a centimetre or come into operation before Tr3 or Redifon's R800 v.l.f. receiver. less. If longer, their inductance Tr4 are turned off. P.A.T. Turrall, impairs filtering. The case of FFT I would be very interested to Publicity Manager, my feed -through filter is the know of the effect of Mr Margan's Marconi Communication Systems, earth terminal and contact with Your contributors Larsen and modifications on the distortion Chelmsford Dyrik express the hope that their figures of a typical Class B the foil is made by bolting the amplifier and the extent to which filter unit to the screening box. article will inspire readers to experiement with machine code an improvement in sound quality The earth connections are may be heard. made by trapping the bared f.f.ts and spectral analysis. RELATIVELY We took this path some years Graham Nalty ends of the earthy d.c. leads ago and can report that indeed Borrowash BORING between filter and foil. many happy hours can be spent Derby I have not so far attempted a optimising an implementation of H. Morgan complains in your July filter for a receiver with a built - the f.f.t. algorithm, and one issue that relativity is boring. This in mains power unit. A dicovers many subtle issues that do view will be shared by many balanced filter would pre- not seem to be covered in the ENERGY physicists, but they do not seem to sumably be needed, with the standard literature. have noticed that one cause of the earth line connected to the foil Starting from the Basic program TRANSFER confusions and contradictions is and to mains earth. Safety given, the main decision to be that it is not a scientific theory. made in preparing a machine -code P. L. Taylor (Wireless World, p. 15 This Einstein considerations suggest that the made quite clear version is how to represent the October 1985) likes the choice when he said that the "real basis of screening box should itself be data arrays D and E. If floating between e.m. wave energy transfer the special relativity theory" was enclosed in an insulating box to point is used, execution will be through space, as required by the the Lorentz equations (Bull. Amer. avoid contact with the foil. little faster than in Basic. With Poynting vector, or through wires, Math. Soc., 41, 1935). Physics is If the receiver can be battery fixed point, however, optimizing as required by the Slepian vector. based on matter, motion and force: operated it is useful, when test- the dynamic range is a non -trivial There is, in fact, a third choice equations in physics are only ing power -supply filters, to set problem, since the data values advocated by Cambridge Professor relations between terms that up the receiver with the filter in grow in a way which cannot G. H. Livens. Writing 'On the flux represent numbers obtained by reasonably be predicted at the of energy in radiation fields' at p. measurement; and situ but the mains power off. If these are put outset. Automatic rescaling is thus 313 of his 1926 book 'The Theory into Nature by ourselves. They can the receiver is now battery usual and desirable, but this raises of Electricity', published by never tell us, just as Einstein could operated it can be seen if sig- yet another level of subtlety if the Cambridge University Press, he not, whether an ether was a nals are getting into the box via rounding or truncation inherent in argued in favour of an alternative necessary physical assumption or the filter. a rescaling is not to contribute to Poynting's theory. Waves do not not: at one time he had said not; When operating a well - further errors. Welchlconsiders need to carry energy at their speed and then later "space without ether screened receiver, bringing three strategies, none of which is of propagation. Their generation is unthinkable ". Moreover, one's hand to the controls intro- optimal. merely adds energy to a common Lorentz's times were dates and duces stray signals. This can be For those who are more pool of energy in the field medium these do not enter into physical interested in the finished article at the locality of the transmitter laws. an advantage since it allows the than the joys and frustrations of and their absorption draws on that Many other confusions are receiver to be pretuned to the development, we have made our pool in the locality of the receiver. caused by lack of linguistic care. If required frequency before BBC spectrum analyser I like this third alternative, because we think carefully about light, for tuning in the loop. commercially available through it is easier for me to picture example, we realise that we never 42 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com see light, or anything moving, and I hoped that by now I had made Sync ap. to that beams and rays cannot be it clear that I am perfectly well oscilloscope found in highly evacuated regions, aware that it is possible to use Wv so that reflection may be re- electrolytic capacitors in such a Triangular wave +15V 10 radiation. One fact about light has, way as to generate disturbances in ip from function 10k however, been verified sufficiently an applied audio signal; the point I generator Point to give us considerable confidence wish to make is that there is 3k3 A in its truth; this that if we have a nothing new or mysterious about 56k source and a receiver at a fixed this. The effect (low- frequency distance from one another on a harmonic distortion when an 1k8 rigid body, the time delay of electrolytic is allowed to cyclically 680 interaction between them is always depolarize) is logical and d/c where c is a universal constant. predictable, and therefore I have suggested that c should be avoidable. It should not arise in a called the constant of interaction: no properly- executed audio design. hypothetical element is then To recapitulate, the important Reference capacitor involved (such as ether, waves, point is simply to ensure that there photons and the rest) and action at is no significant a.c. voltage across a distance is not ruled out (as the capacitor in question. When an Point A Maxwell admitted long ago). This electrolytic is used as a coupling or one fact allows us to settle the dc- blocking component there is no !Scope Y1 thought experiment involving a reason why there should be; if Id iff. train passing an embankment, there is then you have, accidentally signal which relativists use to 'prove' the or otherwise, made a high -pass +4V supposed relatively of simultaneity. filter of dubious accuracy due to 3k3' The train and the embankment the wide tolerance of electrolytics. n`-4V said to be struck by lighting at The a.c. voltage across the 22k are k-10ms two places a apart. An capacitor can then give rise to Cm.r.r. distance trim observer on the embankment, half- unpleasant effects, of which way between the two flashes, is depolarization is probably the L------said to find them both worst, as it has depressing simultaneous, but the observer on implications for the longevity of Circuit as above the train is said not to agree. In the component. A7 °O this case there are two rigid bodies iScope Y2 - the embankment and the train - Distortion Output level = +20dBm cut and both observers are at a analyser All op-amps 072/2 + 'Voltage o ppu distance d/2 from both flashes. The supplied with ±15V Ag Jacross time for interaction is thus the 47u 25V c.u.t Balanced i p same for both flashes so that both 680 that you must avoid using expensive devices such as the observers should find simultaneity. electrolytics (including tantalums) AD524 conventional If the sources are said to be -a as filter elements, for which instrumentation -amplifier moving with respect to the purpose they are quite unsuitable arrangement using TL072s gives observer on the train, this should anyway, due to their wide exactly the same results in this cause no difference, since the tolerances, and confine them to case, providing close attention is 'velocity of light' is held to be Frequency Sig.loss t.h.d. V. across wt.lpk) coupling duties, where it is easy to paid to trimming the c.m.r.r. My independent of the motion of the 50 Hz 01 dB <0012% 0.93 for there to be no arrangement is shown in Fig. 2. source. arrange 30 o 02 0032 1.48 significant signal voltage across However, I am inclined to think As length- contraction is 'proved' n n o them. Simply ensuring that there is this is just a complicated way of in thought experiments by 25 03 0050 1.84 no premature 1.f. roll -off is demonstrating the same effect that founding it in the supposed 20 n 0.4 o 0086 219 normally sufficient to take care of Fig. 1 produces. Taking, for relativity of simultaneity, is clear 15 o 0.7 o 018 n 2.82 this point. example, a 10ms input pulse at that length contraction is also 10 o 1.4 o .047 n 3.67 use of unbiased electrolytics point A, the change in voltage delusory. The for coupling purposes has a history across the capacitor under test A note of interest is a recent Figure 1 shows my own, simpler, of at least twelve years, going back (c.u.t.) is 5.8 volts peak to peak, statement from a colleague of method of demonstrating that to the introduction of the first the c.u.t. being reverse -biased by Einstein's who says that in his later capacitors generate distortion practical op -amps. It was about 2 volts for part of the cycle; years Einstein abandoned material really when misused. This is a simple clear that the use of +/- power the capacitor is not being treated consequences implied by relativity, high -pass filter; below it is shown a rails, while giving designs a greatly kindly. This voltage is measured which included his thought table of the distortion produced, appreciated freedom from d.c. using A7,8,9, which forms a experiment purporting to show against input frequency. standing currents flowing down second instrumentation -amp. that people can get younger by Harmonic distortion is signal earths, would demand the across the c.u.t. However, I submit rushing about - the Twins unmeasurable from 20kHz down to operating under that this ingenious test has no Physics, use of electrolytics Paradox (Foundations of 30Hz, where things suddenly start zero -bias conditions. relevance to properly -designed 15, 9, 1985). to go wrong. Under these There were many hasty audio coupling networks, as I have G. Burniston Brown conditions, it is at this point that consultations with capacitor explained above. The lifetime of a Padstow the peak voltage across the manufacturers before it became capacitor used in such a way will Cornwall capacitor reaches 1.4V. This seems clear that reliability would not be very uncertain. to be the threshold at which the normally be a problem. This is Consider in what the capacitor dielectric film starts to attributable to the absence of circumstances this effect could come undone, though dielectric signal voltage across the capacitors constitute a real problem; the most ELECTROLYTICS absorption effects could be playing in a well- designed coupling obvious is the case of a warped a part. Perhaps a capacitor arrangement. record feeding its signal through to AND DISTORTION manufacturer would like to Having studied the test -circuit a preamplifier. However, it is contribute some information on provided by Mr Curl, I can confirm normally considered that even a Since both Mr Curl and Mr this point. that a non -nullable pulse residual is badly warped disc is unlikely to Armstrong (Letters, November Experimenting with different indeed produced; my own test produce subsonic levels greater 1985) are writing on the same values of R and C confirms that the assembly produced waveforms than -20dB below the general topic, it seems logical to try to crucial factor is the peak a.c. similar to those accompanying Mr levels in the audio band,2 and it answer their complaints in the voltage across the capacitor. The Curl's letter in HiFi News 1. It is will be noted that in Fig. 1 it is same letter. conclusion to be drawn is simply not necessary to use exotic and necessary to use signal levels only ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 43

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just inside op -amp headroom to HiFi News. It has become the References readiness increased by highly induce the if distortion. accepted norm to pay a quite J. Curl, Letter, 'Front End', HFN/RR personal criticism and advertising Nevertheless, it is always good undue amount of attention to Aug, 1985, p15. to accept new and expensive 2. T. Holman "Dynamic practice to place the subsonic people simply asserting that such - Range techniques and attitudes as Requirements of Phonographic filtering as early as possible in the and -such an effect occurs (it really inevitably better, rather than just Preamplifiers. ", AUDIO audio chain. The preamplifier does sound better without July, 1977, different! ...) any pp72 -79. design that opened this audio can sort of objective evidence. Any 3. D.R.G. Self, "A Precision Far more insidious is the overall of worms has its subsonic filter "new effects" allegedly discovered Preamplifier. ", Wireless World Oct, rise in basal and transient immediately after the disc preamp. need the following before 1983. redundant sound, as well as greatly stage,3 and in fact the only becoming even slightly 4. Jung & Marsh, "Picking Capacitors" increased radio and mains -borne electrolytic capacitor the signal has respectable. AUDIO Feb, 1980, pp52 -62. noise and interference, even with passed through before it is the one a) A set of double -blind, 5. P. Baxandall, "Views" HFNIRR July, competent filtering. 1985, pp15-17. at the very input, where signal properly- conducted (no easy David White a levels average 5mV rms. I would matter) listening tests to show that Llangefni suggest there will be no problems the effect really does exist, verified Gwynedd there. by a rigorous statistical analysis. PRECISION One criticism that may well be b) A theoretical mechanism for levelled at my reasoning is that the operation of the effect that is at PRGAMPLIFIER MAXWELL sinewave- and -analyser testing is least logically consistent, if not actually plausible. hopelessly unhip, and that there I agree with Mr Armstrong The consistence of Ivor Catt's are all sorts of degradation This second condition in (November, 1985 Letters) that Mr misrepresentation of Maxwell's phenomena that ignore sinusoids particular is almost always lacking Self does appear pedantic, even laws is remarkable. Whatever in the wilder made but mangle music. I have yet to see statements didactic, in print, but think that Mr deficiency they do contain, if any, proposed any plausible mechanism about audio design. Self has a point in which, however, it is certainly not at the elementary that could ignore single sinewaves If I can now address Mr there is confusion of engineering level claimed in the issue of anywhere in the audio band, and Armstrong in particular, I must say and other factors. November 1985. (`The Hidden yet still affect complex signals. the gold flashing on his telephone Ultimately, uncontrollable Message in Maxwell's Equations'). leaves me unmoved. I assume it is variations in manufacture result in The basic problem remains In the course of writing this there to enhance reliability in what are, on a scale of perfection, apparent ignorance of vectors and reply, I re -read the reference Mr unfriendly environments, as given gross differences between the role they play in Maxwellian Curl cited. In some ways the the millions of telephones installed individual items of components, let theory. Ivor Catt seems to think articles by Jung and Marsh4 are their reliability is of great alone the differences to which Mr that Maxwell's laws are some kind impressive, including as they do a importance. I would suggest that it Curl draws attention (EWW Nov, of elaborate hoax supported by an comprehensive survey of capacitor is unlikely that his 'phone company 1985) for capacitors. On this scale establishment conspiracy to theory and construction, are attempting to scale the higher of perfection every item within suppress 'alternative' theories. He culminating in some pictures of pinnacles of hi -fi reproduction. auditoria and studios, performance, also believes that equations (9) and distortion residuals very similar to Secondly, I am also unimpressed recording or transmission, (10) in his latest diatribe represent those I obtained with the circuit of by the wire -crushing thumb -wheels including links, and reproduction, the views of the conspirators. If Fig.1, though they nowhere.make (or was it thumb -crushing wire - including rooms, has a similarly they did, he would indeed have a the point that no -one in their wheels?) on his electricity meter. highly variable effect on what we point. But, sad to say, the senses would make a high -pass These are to ensure an accurate can hear, as well as undoubted windmills that this exuberant filter with electrolytics. From this absolute measurement under high - variations in our own biological knight errant is tilting at are they go on to state that "When current conditions, whereas in systems on different social and significantly different from the music is the a.c. signal, the sonic audio a gain variation of a few emotional levels and time scales. reality of Maxwell! degradation is one of compression tenths of a dB are quite In the mid -fifties I knew several The mistake he makes is or a restriction of the dynamic unimportant, always assuming that professional musicians and as I got fundamental and disastrous. It is range." I find this statement they are not level- dependent, of to know them it became plain that, entirely necessary to modern em remarkable, if not actually course. despite acute musical appreciation theory that the E field vector is frightening, as it implies that the As for Mr Armstrong's defective of the 'sound' of auditoria and of perpendicular to the H vector. capacitor is either turning up the head amp., miraculously taking up different performers' effects on Why, then, do equations (9) and gain in the presence of a low its p.c.b. and walking after a shot performances, when it came to (10) not show this? Without the signal, or turning it down in the of expensive capacitors, all I can radio and record reproduction they direction property of a vector, em presence of a high one. I do not say is that as far as I am concerned were largely indifferent to sound theory would fail to account for believe that any such effect could this kind of anecdotal evidence is quality. What, it seems, they had such simple phenomena as be measured with any type of worse than useless. If Mr been taught to look for were the reflection. Ivor Catt attaches some capacitor, I and fear that this is Armtrong really has foúnd a new minds and emotions of the mystical importance to Zo; anyone another example of an unjustified psychoacoustic effect, then I would composer and performer(s) at work who was properly conversant with conceptual leap beteen a known dearly like to know how it works, and it was these that they were EM theory would not. Zo is derived physical phenomenon, 1 and an so I can use it. However, my own listening for and identifying with. from the magnitude of the E and H extremely speculative conclusion. I suspicion is that it's one more case As with language, it was 'the vectors; their directional property to regret say that such conceptual of "experimenter effect ". meaning' rather than detailed is eliminated and most that is pole -vaulting is common in hi -fi I the One more thing. try not to take syntax and sound that they useful in the theory with it. Zo is press, and is in danger of making all of this too seriously, but I think responded to. not a 'primitive': it lacks the whole field an object of ridicule must decline to be labelled a So for those who like realistic directional information. to those involved in serious pendant just because I insist that quality of sound (in other than live Ivor Catt's difficulties with the engineering. science and engineering are about performances), whether we put expression of physical concepts in reality and repeatable into any new system any capacitors mathematical form do not seem to I cannot believe that I am the measurements rather than who finds it at all or even specially selected be confined to electrical matters. only one disturbing unsupported assertions. I am an that people make such ones may perhaps produce the True enough, if he walks along the engineer, and I hope that my ultimate of what can be heard, but plank far enough in the direction extraordinary claims without any approach to engineering is attempt to explain how such a each single system will have an (hooray for direction!) `v', 'h' does scientific, because I cannot think of individual sound, unlikely to be indeed decrease but so does `x'. mechanism could conceivably any other that would work. operate, or making even the perfect reproduction of the Sorry, Ivor old son, but you are You might as well accuse an original. But if we can accept this wrong again, as you walk along the roughest numerical estimate of its accountant of pedantry when he magnitude. sound then we can relax and enjoy plank it is because it is going fails to embezzle his client's as many as possible of the backwards underneath you that it I should like to say that I agree money. subtleties of performance rather leads to that sinking feeling. whole -heartedly with the views D.R.G. Self than be obsessed with those of the Dermod O'Reilly expressed by Mr Peter Baxandall Bow sound alone. Particularly, we have Antwerp in the correspondence columns of London WC to beware of a psychological Belgium 44 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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supplied only on disc Many other features including, selectable 40 /80T. Please specify display colours, comprehensive line drawing £25 printer type when facilities, TAB settings, etc. +VAT p &p free ordering The latest version of DIAGRAM is now fully compatible with the Marconi Tracker Bali, which allows 'scrolling' of the screen and many of the editing features to be carried TtACK R £51.50 out using the tracker ball. BALL +VAT p &p free DIAGRAM is supplied in an attractive hard backed disc includes CON art master software wallet with keystrip and All orders sent by return of post comprehensive instruction manual.

39 Brownlea Gardens, Seven Kings, Ilford, Essex IC3 9NL 9 Tel 01-5991476 CIRCLE 7 FOR FURTHER DETAILS. METER- PROBLEMS?

137 Standard Ranges in a variety of sizes and stylings available for 10 -14 days' delivery. Other Ranges and special scales can be made to order. Full Information from HARRIS ELECTRONICS (London) 138 GRAY'S INN ROAD, W.C.1 Phone: 01.837 7937 Telex: 892301 CIRCLE 47 FOR FURTHER DETAILS. FOR S100 USERS FULCRUM (EUROPE) LTD

Distribute & technically support over 160 different S100 products. Ltd Select from manufacturers like: Hilomast MACROTECH INT. ADVANCED DIGITAL CORP. ACKERMAN DIGITAL SYSTEMS INNER ACCESS CORP. LOMAS DATA PRODUCTS COMPUPRO CALIFORNIA COMPUTER THE STREET HEYBRIDGE - MALDON SYSTEMS DUAL SYSTEMS TELETEK INTERCONTINENTAL MICRO - SYSTEMS SEMIDISK SYSTEMS INC HIGH TECH. ELEC. LTD I/O TECH. INC. SD SYSTEMS ESSEX CM9 7NB ENGLAND SOLID STATE MUSIC KONAN CORPORATION JADE COMPUTER PRODUCTS MULLEN Tel. MALDON (0621) 56480 COMPUTER PRODUCTS INC DATA SYSTEMS CONSULTANTS ILLUM. TECH. INC. ZENITH DATA SYSTEMS BICC -VERO Telex No. 995855 CALL US ON (0621) 828763 VALLEY HOUSE, PURLEIGH, ESSEX CM3 6QH. ENGLAND TELEX 946240 C WEASY G - Easylink I.D. 19010455 CIRCLE 13 FOR FURTHER DETAILS. CIRCLE 24 FOR FURTHER DETAILS. 46 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com o Compact disc DIGITALö AUDIO mastering

Our Compact Disc series, in- John Watkinson explains away the confu- troduced in the January 1985 issue, has so far featured: sion of p.c.m. adapters for use with video Principles of optical storage, March & April 1985 recorders, contrasting three different for- Channel code and disc for- mats and detailing the more advanced mat, May & June 1985 Compact Disc players, codes of convolutional interleaving used August & November 1985. in the smaller v.c.rs.

To cut a Compact Disc a digital recording must be made which contains ex- actly the same sample values as Digital input will appear on the disc. Unlike Dig ital Analogue ' Encode to A -to -d Vid vinyl disc cutting, where the Analogue _._ pseudo converter to v c r cutter operator has control over input IDub video level, the Compact Disc cutter faithfully transfers every digit from the master tape. The disc Reference Timing generator video mastering recorder is designed toyer to produce that tape. There are currently less than places in the world where ten Decode Video Analogue D - to -a from Compact Discs are cut for dupli- output converter video h cation, so it is usually necessary samples vcr Digital Fig. 1. Block diagram of to send the master tape to the output p.c.m. adaptor. Note the disc plant. The robustness and dub connection needed for convenience of a tape cassette producing a digital copy are ideal for this journey. between two v.c.r.s. The bandwidth of a digital stereo signal is about 2Mb /s, addition to producing sampling of line rate, and the sampling and some years ago the only de- rate clocks and time code. rate used will be derived from vices able to record this band- An analogue to digital conver- the frequencies in the tv stan- width economically were video ter allows a conventional dard. Thus the sampling rate of recorders. Digital data were en- analogue signal to be recorded, the disc was determined by coded to resemble a tv wave- but this can be bypassed if a video standards even though the form sufficiently well to fool an direct digital input is available. disc itself has no video signal unmodified v.t.r. Originally, Similarly, a d -to -a converter is structure. The frequency of video recorders were open -reel provided to monitor recordings 44.1kHz is derived as follows. devices, but once the U -matic and this too can be bypassed by In the 525/60 monochrome tv cassette and its smaller relatives the direct digital output. Also standard there are about 245 Betamax and VHS came into be- visible in Fig.1 are encoder and useful (i.e. not blanked) lines in ing they were soon adopted for decoder units that convert bet- each field, giving a line rate of digital audio recording. Digital ween digital data and the video - 245 x 60 = 14,700 lines per se- mastering recorders for CD like signal known as pseudo - cond. If three samples per chan- work today on the same prin- video or composite digital. nel (left and right) are stored in Fig. 2. Typical video ciple. A typical line of pseudo video one video line the rate of 3 x signal from p.c.m. adap- A digital audio recorder which is shown in Fig.2. The line is 14,700 = 44,100Hz is obtained. tor. Data swings over only uses a video cassette recorder is divided into bit cells, and within This sampling rate may also be 0.3 volts to avoid ac- depicted in Fig.1, in which the them black level represents a obtained on the 625/50 tv stan- tivating pre- emphasis. digital audio unit is often refer- binary zero and about 60% of dard by using 294 lines in each Peak white pulse prevents red to as a p.c.m. adaptor. The peak white represents a binary field, since 294 x 50 = 14,700. a.l.c. increasing gain. unit has five main sections. Cen- one. The restriction to 60% is Data sync signal White level ref. signal tral to operation is sync and tim- because most video cassette 0 r-, - ing generation, which produces recorders use non -linear pre ei of 03 III Data sync pulses for control the emphasis misinterpreting the á 7 video waveform generator and pseudo video. Clearly the bit 1- 0.3 01 Pedestal level locking the video recorder, in rate must be an integer multiple > ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 l;

www.americanradiohistory.com DIGITAL AUDIO

cassettes recorded in the USA 2 3 CRC (a) or Japan can be cut in Europe I 5z 512 1-256-1 and vice versa. I

-r- The first problem arises with 104 205 30+6 CRC 1 b1 h70-1 Data at/ /'\ the introduction of NTSC colour 1 \ 1- Ì broadcasts. The field rate was 03 Control bit reduced to 59.94Hz to move 4 5 6 CRC (c) harmonics of the new colour (a) subcarrier away from the sound Peak white, subcarrier inherited from the Fig. 5. In this one 35 -line Sync pattern monochrome standard. interleave block of If a p.c.m. adaptor is slaved to 1610/1630 format, block Ln Ln.7-6D Rn.690 n.2-12a Rn.2-iso S MCC". an NTSC generator, the sam- is divided into three sec- 14.8 +16 =128 bits 1 pling rate falls to 44100 x tions of 113 lines each, I, 168 bits -1 59.94/60 = 44055.9Hz and the two data, one parity. Horizontal sync.pulse timecode generator enters a Three passes through the ( h) mode called `drop frame' where- interleave memory are by the timecode can continue to needed to create the read real seconds and minutes signal structure (1, 2, 3). 196 even though there are no longer Large L/R interleave 14 16 12 16 14 16 16 16 16 16 16 22 I4 a whole number of fields in a allows interpolation if

An 1W...n Woad I W..41 Wodd I W m P2 W..1 P1 I second. dropout exceeds 114 The CD sampling rate and lines. timecode are irrevocably lock - lc) ed,2 and therefore a master tape with 44055.9Hz sampling rate recorder. The consumer would, Fig. 3. Video line from and drop -frame time code will however, expect to be able to PCM 1610 has control bit Diversity of standards be rejected by the disc cutting use the v.c.r. for regular tv that determines the use of Unfortunately the diversity of machine. Compact Disc and recording as well. Thus the pre- emphasis and television standards has led to a NTSC audio are incompatible. EIAJ format is in fact two selection of 44.1 or complex situation for p.c.m. But digital sound tracks from incompatible formats: the first a 44.0559kHz (a). Note adaptors. The Compact Disc is a PAL -synchronized broadcasts sampling rate of 44055.9Hz us- peak white ref. In video world wide standard, and it are compatible because the pre- ing the 525/59.94 NTSC timing, line from PCM -F1 in 16bit would be a desirable goal for cise 50Hz field rate of PAL can and the second 44.1 kHz samp- mode (b) and address at mastering recorders to record be locked to the 44100Hz rate ling with 625/50 timing. Both beginning of video line also to a standard format. by a ratio of 882:1. are intended for use with Beta - from JVC unit (c). The official CD mastering for- The position is further compli- max or VHS recorders. mat is that produced by the cated by the existence of further The consumer division of Sony PCM1610, and this only standards. One of these is the Sony sold the EIAJ- format exists in one version, which uses EIAJ standard for consumer PCM -F1. Built with custom the 525/60 monochrome stan- p.c.m. adaptors. These devices l.s.i. chips made economic by dard because of its Japanese were originally intended for the volume sales, and with battery origin. Thus even in Europe, top end of the hi -fi market place capability, it cost only a few discs are mastered on 525/60 and enable a domestic v.c.r. to hundred pounds. With a match- video recorders so that master become a digital stereo ing portable Betamax v.c.r., the

11y2 H

Ri 5 8

, 111111111101® L6 IOI L C L4 RS L6 C

Line 0 L11

111131113ICIMIm R7 R8 CI IR103I9104IR10SI

ILQI®I11Q----'--' Ló I6i1Q1 L9 L105 , . . , ISE= TE M::: 111Imm0li! PS OEM P8 m0 P103 P104 P105

L11 L12 L22 1-...- L 23

Fig. 4. In the I R1 I R2 I R3 I R4. , R5 I R6 I R7 R8 R9 I -IR103IR104IR105 PCM1610 /1630 format, 3 I L1 I L2 I I L4 I error correction is via an L3 L5 I L6 I L7 I L8 I L9 ,I- - 1103 104 110 exclusive -or term com- L1IR2IL3 C IR4ILS C LI 'ROC l9 I I- 1103 R104 R105 puted from the two IL7IR8I C

samples shown. c.r.c. __ 1 I ^II character detects errors, L23 L24 L34 parity term corrects. Redundancy is 100% 48 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com SL -F1, digital audio recordings Typical waveforms are shown could be made on location. in Fig.3. By contrast, the PCM1610 All three systems use exten- was intended for professional sive interleaving to combat Interleave Data use, and relatively small volume burst errors caused by tape delay memory to tape production meant it was imple- dropouts. The PCM1610 has LO r - OL mented with s.s.i. chips, which the most basic interleave /cor- made it large and heavy and rection system which sub- RO 16 words OR very expensive. Sales were divides each field into seven somewhat damaged by the blocks of 35 lines each, and 14 bits LO ?2 words OL PCM -Fl: a peculiar situation for interleaves within the blocks. ot6 samples correction method is a 48 words OR Sony since they made both! The error of 16 bits RO As a consumer product, the cross -word code. The PCM -Fl PCM -F1 was not ideally suited and the JVC system both use the LO 64 words OL for Compact Disc mastering. convolutional interleave ap- There are no direct digital out- proach and more advanced o 80 words OR puts, only an analogue output, codes. P14 and for this reason not too much The cross -word code of the Par ty generator 96 word OP trouble was taken with d.c. off- PCM1610 is shown in Fig.4. In- Remaining P2 2 bits 112 words OS sets in the converters. There is put samples 1 to 3 form a code of 6 12 L J (1) with a c.r.c. charac- samples also an 11µs timing error bet- word at 606 bit ween channels, as a result of us- ter. Samples 4 to 6 form a se- input ex -or gate LRL code genera o -OCRCC ing single converters multi- cond code word at (c) with a plexed between left and right. c.r.c. çharacter. The exclusive - These problems have been or terms of the sample pairs overcome in adaptor units sup- shown form a third code word plied by independent companies with a c.r.c.c. at (b). In the case corrupt, P1, P2 and P3 from the Fig. 6. In 16bit mode, 14 such as RTW and Harmonia of an error, the c.r.c. fails, but end of line 11 and Ll, R2, L3 of the bits of each sample Mundi Acustica. They modify does not locate the error. All from the middle of line 23 are us- are stored as words (L, R) the PCM -F1 to give a direct samples in the codeword are ed to correct Rl, L2 and R3, and and the extra two bits of digital output and use digital fil- presumed faulty. For example so on. If the dropout continues each sample stored as ters to remove offsets and tim- 4,5 and 6 are declared faulty. up to 13I lines, two code words 12bits of another word. ing errors, and then produce a Sample 4 is obtained from the of the related three will be des- Parity is generated on the direct digital output that is com- exclusive -or of the first symbols troyed and correction is impos- 16bit data, and 14 of the patible with the 1610 and /or in codewords (a) and (b) (10 sible. Interpolation will then be parity bits are stored in with the AES /EBU digital inter - (104) = 4), and so on. The used. the P -word. Remaining connect standard. system is not very efficient and For example, if lines 0 to 12 two bits are added to the To add to the confusion, Sony the amount of redundancy is are destroyed, L4, R5 and L6 12bits of sample data to then introduced the PCM701, a equal to the amount of data. will be uncorrectable (amongst complete the S -word. semi -professional version of the The interleave over a 35 -line others) but because of the inter- F1, which is rack mounting and period includes a left /right chan- leave in line 23, L3 and L5 can non -portable. They then drop- nel interleave (Fig.5). Dropouts be used to recreate L4, R4 and Fig. 7. Interleave diagram ped the Fl which provoked such up to 114 lines long are fully R6 can be used to recreate R5, of JVC format showing an outcry that they had to re- correctable, since this magni- and L5 and L7 can be used to re- parity generated before introduce it. tude will not destroy more than create L6. and after an interleave to In addition to the 1610 /U- one of the three related code If the corruption is more produce cross - matic and the F1 /701 /Betamax words. For example if line 0 is severe, previous samples can be interleaving. rivalry, there is a third conten- der from JVC for mastering which uses industrial VHS transports. Some disc pressing - An plants accept the JVC cassettes. ¡D°D6 wn

i 9 _3 wón. I Formats contrasted B All three p.c.m. adaptors use the D66 w6n.2

video waveform on a binary 12 D99 w6n.3 channel, with black represen- To tape ting zero and 50 or 60% of peak 116 I DI32 1, .2. white representing 1. However, I n consúmer recorders with a.l.c. 2e 145 1 would increase the gain of such 0I65 w60.2.

a signal, and so to prevent this DI98 the JVC system uses a peak w6n.5

white pulse once per field. The p2 203 6n L a white Cross ..--1:132O3 PCM -F1 uses peak interleave pulse once per line. The delays PCM1610 is intended for use Interleave +CRCC 1- Parity delays with semi -professional U -matic generator C RC recorders which have no a.l.c. and has no peak white pulses. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 49

www.americanradiohistory.com DIGITAL AUDIO

A O

W...4 O

W6n

Wodd O 9 `0 W6nr1

W..011 0 -8 De -O

P2 P2 Pl O D12 Woe corrn corrn corro ,12 corr n -0 (1) (1) (2) 121 From W.ren O 6 I 016 6 tape I Wodd D1L5 ,1 --0 6W 5

PO 21. -Id 024 H

Pz 0 3

Error flags CRCCO CRC Error I detection

Fig. 8. De- interleave and held to substitute current the power of the error correc- process. On replay if a line gives correction diagram for samples, but eventually the tion system is reduced. The B- a c.r.c. error, all samples are JVC format. Depending machine has to mute to prevent adjacent decoding system will flagged bad. Fig.8 shows the upon distribution of er- noise. In practice, dropouts are not be discussed further here as correction process; after the rors, it may be better to usually much smaller than 114 it does not apply to Compact first de- interleave, the P2 sym- correct with either Pl lines, but the system has to Disc mastering. In 16bit mode bol can correct single errors, but first or P2 first: multiple interpolate if a random error oc- the PCM -Fl reverts to a system not multiple errors. re-interleave and de- curs near a burst. The simple shown in Fig.6. The principle of cross inter- interleave allows both code of the PCM1610 relies on Simple exclusive -or parity leave is that double errors in one choices. See text. the relatively large trackwidth produces a P word from six interleave show up as single er- of the U -matic format to give samples. After interleave, a rors in the cross interleave and good SNR. It is not suitable for c.r.c. character is added to the vice -versa. Thus further de- VHS or Betamax video cassette end of each line. If the c.r.c. fails interleave allows the P1 term to recorders even if the a.l.c. is for a given line, all samples on correct single flagged errors. On defeated. the line are flagged bad. After re- interleaving to P2, many of de- interleave, this results in the double errors will have been single errors with flags in many converted to single errors in the Convolutional Interleave different P -code words, and Pl process, so at the second at- correction is possible. However, tempt P2 can fix the remaining Both the PCM-F1 and the JVC the presence of a random error single errors. A final de- inter- system use a much more due to noise in the vicinity of a leave to the real -time sequence sophisticated approach to allow burst error due to dropout may allows Pl a further chance at the use of smaller- format v.c.rs. cause two error flags in one P- correction, but the probability They use convolutional inter- code word, which is uncorrec- of this stage operating is small. leaving which spreads the effect table. Interpolation will then be The powerful error correction of burst errors more evenly. necessary. of the JVC system allows opera- The PCM -Fl works in two The most advanced system is tion on the smaller VHS type modes. In 14bit wordlength that of the JVC machine2, which v.c.rs and although JVC do not mode, the machine uses both B- uses cross interleaving. The advertise the suitability of Beta - adjacent error correction and cross -interleave is formed with max for commercial reasons, it erasure (pointer) correction, and simple parity only, and with should be equally compatible. this is very powerful against c.r.c.c. after interleave to act as One problem with domestic random errors near to burst er- a pointer. In this respect the v.c.rs is that the low linear tape rors. In this mode the PCM -F1 interleave resembles that of the speed results in dismal audio conforms to the EIAJ standard DASH format3 more than the tracks (analogue) making time - for 14bit consumer p.c.m. adap- cross interleave of the Compact code recording difficult, not a tors. However, in 16bit mode, Disc, which uses Reed -Solomon problem with the U -matic which is necessary for master- redundancy without an addi- machine. ing, the 14bit format is retained tional c.r.c.c.. The arguments and the extra two bits in each of for cross -interleaving given in six samples and one parity word the June article4 on Compact are stored in place of the 14bit Disc format still apply. B- adjacent redundancy. Thus Fig.7 shows the interleave continued on page 62 50 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com REAL WORLD CONTROL with BBC BASIC

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www.americanradiohistory.com BROADBAND CABLE T.V. TAYLOR REPEATER AMPLIFIERS

Application other than Cable T.V. includes C.C.T.V. (up to 26 Channels 8MHz wide on V.H.F. Repeaters, and up to 65 Channels 8MHz wide on U.H.F./ V.H.F. Repeaters). Suitable for outdoor mounting.

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E2V9 46300 9dB 1dB EZU9 476880 see 1dB

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C SCP Screw-on coaxial pug for 5.9mm Outside Demeter cable

D SAC Screw -on right angled connector TAYLOR BROS (OLDHAM) LTD E SFC Screw -on female line connector F SMC Screw-on male line connector

BISLEY STREET WORKS, LEE STREET, HST 14 Heat shrink sieeve for SCP14

OLDHAM, ENGLAND. HS110 Heat shrink sleeve Tor SCP10 TELEPHONE: 061 652 3221 TELEX: 669911 CIRCLE 23 FOR FURTHER DETAILS.

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www.americanradiohistory.com Linsley Hooc Synchrodyne by J.L. a.m. receiver 2 - Oscillator circuit, construction and commissioning

In the first part of this Signal article, I discussed the Ostrength design requirements for a 0 high quality a.m. radio receiver, © having good sensitivity, low de- Phase det 1 of modulator distortion, freedom Mu e from whistles and with H output adjacent -channel selectivity which is user -adjustable. Phase shift circuit One of the most satisfactory 90° Local Fig. 1. Basics of direct - ways of achieving these design oscillator conversion process requirements is the use of a `synchrodyne' (direct- conver- sion) receiver, of the form shown in Fig. 1, in which the incoming signal is heterodyned with a local oscillator held in Phase frequency and phase synch- det 2 ronism with the incoming carrier. This allows direct recovery of the modulation 74H04 74H74 74 H 86 Fig. 2. Phase -locked loop Voltage imposed on that carrier, and Divide using practical devices controlled Exclusive by two renders adjacent -channel sig- oscillator OR nals as higher-pitched audio tones - depending on the frequency separation between the wanted and unwanted car- riers - which can be removed by appropriate post- demodula- 220k 1111 tor audio filtering. 11071 The essential feature of this Amplifier kind of receiver system is the Input r f. signal Fig. 3. Time and phase of oscillator fi maintenance a local relationships of in synchronism with the in- 3N 201 generator coming carrier: this is achieved quadrature by a phase -locked loop consis- ting of phase sensitive detector sive -or gate, whose logic (vol- la) 2, the voltage -controlled oscil- tage /time) sequence is shown in lator (v.c.o.), and the 90° phase - Figs. 3 (a), (b) and (c). la) Oscillator ou put Time shifting arrangement, shown in This circuit arrangement 1. in the lower part of Fig. generates two outputs, (b) This p.1.1. function can be quadrature, both of which are achieved economically, in a at half the frequency of the con- manner which is usable over a trolled oscillator. If one of lb) =2 output O wide frequency range, by the these, say the output from the use of high speed c.mos inte- exclusive -or gate, is taken to Icl grated circuits, as shown in Fig. one of the inputs of a suitable

2. In this an oscillator, of which phase- sensitive detector, and (cl Exclusive OR output 090 the output frequency is voltage this is used to provide an ampli- controllable to some extent, for fied and filtered control voltage (d) example by the use of a to the voltage -controlled oscil- Faulty variable-capacitance diode in lator, then the other output (d) Fault condition whi h can arise due parallel with an LC tuned cir- from the circuit of Fig. 2, will, to uncompensated t me delays cuit, is fed to a divide -by -two when the loop is in lock, be in m = 2 stage stage, and thence to an exclu- accurate phase and frequency ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 53

www.americanradiohistory.com SYNCHRODYNE

system, due to the unavoidable noted, as a possible pitfall for +5V time delay introduced into the the unwary, into which I C¿ . T100n second input fed to the exclu- walked myself, is that the pin 14 TOV sive-or, as a result of propa- connections for the 74HC86

12 gation delay in the divide -by- quad. exclusive -or are not the © Out two stage (a 74HC74 dual flip - same as for #2 those the flop). This can impair the simul- 74C86/CD4070. I have shown taneity of the rising and falling the required pin connections in

74HC04 edges of the waveforms of Fig. Figs. 4 and 5. 1M (Hex inverter) Out 3(a) and 3(b), and lead to the There is a wide range of 100p C3 #1 type of fault waveform shown possible phase detectors usable in Fig. 3(d). Compensation for in the phase -locked loop shown L 1k5 10p this small, unwanted, time in Fig. 2. I have chosen the delay is provided by the use of LM /MC1496P (14 -pin, d.i.l.) the small sequential propa- double balanced modula- BB105B gation delays of the three tor /demodulator for this pur- T Varicap diode , 390p 3 to 30p unused inverter stages of the pose, because it is relatively R3 Loop 74HC04. This gives a clean inexpensive, widely available, control quadrature output waveform, and designed specifically 220k voltage for ln without unexpected glitches. this type of application. There 0V are some constraints in The use of the 74HC04 hex. its use, __Ganged to particularly when employed as inverter as an oscillator is very r.f. tuning a synchronous demodulator for capacitor *Non- inductive capacitor satisfactory from the point of frequency stability, and, radio signals, which I will dis- cuss later. However, in the p.1.1. although I have not sought to Fig. 4. Phase -locked local synchronism with the incoming application, its discover how high an output performance is oscillator signal. quite trouble free. frequency is possible with this I have shown the complete The circuit employed for the kind of circuit, it will certainly circuit of the phase locked oscil- oscillator, and which uses a work at frequencies well above lator, having a synchronous 74HC04 high speed c.mos hex. 10MHz, which is more than in phase inverter, is shown in Fig. 4, and adequate for present needs, output with the incoming signal, in Fig. 7. Since the quadrature- generating lay- where the required operating phase- opposed outputs are out of divide -by -two stage and frequency range - of 3.2 MHz available from the 74HC74, exclusive -or gate is shown in 1100kHz will give, following these have been used to Fig. 5. frequency division, a tuning generate push -pull drive signals range of 1.6MHz- 550kHz. There is, unfortunately, an to the 1496 demodulator, since inherent snag in this type of A point which should be symmetrical operation of this

78 LO5 +20V ..L 14

8 IC3 C6 R11 4 74HC86P 4 p Nam t00n IC1 74HC04P 1005 = C7 R51k 5 >41 12

3

R1 3 Irá --1 510P 1M / MC1495P 5 100p 0 14 2 1k5 27k 3 S RS S RS 11 1n

8 D ICZ D 12- VC3 VC2 3to 74HC74P *Varicap 5 r 30p 0 390p BB1058 2 H S 7 u 1n k C. R3 9 100n

220k

` - ---- Ganged to rf. + 14V (nom) Oscillator .A11 decoupling capacitors Signal tuning capacitor output O +7V (nom.) ceramic types ( non-inductive) input

Fig. 7. Complete phase -locked oscillator

54 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com i.c. helps preserve lock divided by the matched tran- symmetry in the loop. sistor pairs, Tr314 and Tr516, Considering this circuit in before being recombined at the C5S100n C detail, the first inverting gate of output pins 6 and 12. y 100n ICI is biassed into its linear Because of the high degree of 14I -I- 14 Z region by R1r and positive feed- matching which is possible in back is applied via C3. 'Squeg- transistors manufactured in #2 1/2 74HC86 ging' in the oscillator, which i.cs, in the absence of any in- Inputs from oscillator can happen with the 'HC' series puts to pins 8 and 10, any signal 114 O inverters in this circuit, though applied at the E input will be #10 9 not with the lower speed c.mos, combined with an equal and I/274HC74 is prevented by the small opposite signal due to long - 2 +2 5 6 resistor R2. tailed pair action of Tr1 /Tr2, 1Q 90 The operation of the and will result in a null output LM /MC1496 can be explained at pins 6 or 12. Similarly, in the Exclusive OR with reference to the internal absence of any input to E or E, Q circuit diagram of the i.c. any signal applied to the oscil- shown in Fig. 6. In this, a long - lator inputs Q or 71 will be 0V tailed pair of transistors, Tr1 nulled at the output pins. ` Non-inductive capacitors and Tr2, are fed from separate, However, if signals are high dynamic impedance, con- applied simultaneously to the stant current sources CCI and signal and oscillator inputs, the CC2. This allows the conversion output at pins 6 or 12 will be the Complete symmetry of opera- Fig. 5. Quadrature gain, and internal balance to be sum and difference frequencies tion, where this is desirable, waveforms generator controlled by the external resis- of these two, and in the particu- can be obtained by small adjust- tor `Rs' which will normally be lar case of applied signals ment to the forward bias very low in comparison with the which are in phase, the output applied to Tr1 and Tr2, using source impedances, (CCI and will be a d.c. shift, super- the type of circuit shown in Fig. CC2), but high in comparison imposed on the frequency sum 8(b). This is unnecessary in the with the dynamic emitter out- component. case of the p.1.1. circuit of Fig. put impedances of Trt and Tr2. The particular circuit layout 7, where the normal internal Effectively, therefore, a sig- required for the use of the 1496 balance of the 1496 i.c. is quite nal applied to the E input will is shown in Fig. 8(a), in the case adequate. appear, because of long -tailed of a single supply line opera- The output of IC5, in Fig. 7., pair action, as two equal but tion, with the required d.c. is taken via a pair of unity -gain opposite amplified current out- input biassing obtained from a buffer stages, IC6a /b, to a puts at the collectors of Tr1 and simple potential divider chain variable -gain amplifier stage, Tr2, where it will be equally across the d.c. supply line. IC7, of which the h.f. response is rolled off by C13. A d.c. offset pot., VR2, is used to set the out- put of IC7, (TP6), initially, to half the supply line voltage ( +10V), with the gain control Fig. 6. Internal layout of pot. VR3 approximately at the LM /MC 1496 balanced mid -point position. modulator

+Vs IC6a

R16 IC7 TL071

22k Output Output 211072 12 6 VR

1M 13 Tra t) 100n a 0 R17 Osci Motor MA C MEW 22k input Id= 10 a VR4 R20 3k3 18 10k TL072 82k R C15 Tri 10k C19 3k3 47N E1 C*4 100n Gain adjust Signal 1 input

E Approx. pri. /sec. Lac LRF Range coupling ratio

MW 66pH 266pH 20T:100T (20 %) Current (0.5 to 1.65MHz) set

LW 1.5mH 59mH 80T:7001 (12 %) 14 100 to 350kHz OV

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 55

www.americanradiohistory.com ated r.f. output from a signal Windows and generator, of 2 some -20mV performance monitoring amplitude, injected into pin 4 of IC5 and small adjustments 0 +20V 820 to made to VR2 and VR3 until the On a desk top, you can have 1k 2k2 3k9 3k9 best phase coincidence is access to many information Oscillator 3 obtained, on lock, between the sources anti work aids at the input O 10 O Output signal input and the frequency same time. At first, having a 1k divided oscillator output, as computer only meant that the 12 number of items on the desk O Out monitored at TP2. In the absence of an oscillo- were reduced. The computer Osc. +20v scope, correct performance, could only run one program input0 MC1496/ and its screen was only useful 1596 47k while in lock, can be seen if a 1k for displaying text and simple Signal > voltmeter is connected between input0-- f i 4 TP6 and the OV line, when a diagrams. to voltage of 1 -2 volts, Displays such as the one on 1k excursion é 100n on either side of the mean our front cover mean that the output potential - depending whole desk can be cleared. Signal on the signal generator output The Sun workstation used to 1k - should be observed as the produce this display -a in Eo- MC1496 typical mixture of windows, 14 signal generator, or oscillator in ,\AA. J tuning, is swung a few hundred 'icons' and 'pop -up menus' - 6k8 Ibl Hertz on either side of the runs as part of a network, loon 1k lal central lock frequency. giving access to many different T i 00V A modulated signal may then programs and data bases, OIL pin numbers shown) be applied and VR1 adjusted to apparently all at the same give the least audio output time. signal present at TP6. If an Modern v.d.us such as this oscilloscope is not available, one give very high resolution this adjustment could be made colour displays, without Fig. 8. Use of MC The potentiometer VR4 is with a pair of high impedance flicker, that can be viewed for 1496/1596 as double used to set the proportion of the headphones connected between long periods. Using windows in balanced demodulator, output control voltage applied TP4 and TP5. Similarly, small this way makes managing with single-supply to the 2 -10pF Varicap diode, adjustments could be made to tasks much easier so the user operation is shown at (a). (VC3), and initially this pot. can VR2 and VR3 using the same is soon familiar enough with the Method of nulling be set to maximum output. The technique, since phase coinci- system to take on more and spurious responses is at particular type of diode dence at TP2 implies phase more activities. (b). employed, provided that it has a quadrature (with minimum a.f. As the number of tasks suitable capacitance range, is output) in the switching wave- increases, it becomes more and unlikely to be particularly form applied to IC5. more important for the user to important. I used BB105B As a final step, when the understand how the system is units, simply because they were receiver is complete, and work- handling the load. With this in to hand. ing satisfactorily, the values of mind, the workstation has The circuit, with the excep- VR2 and VR3 may be 'tweaked' built -in performance tion of the 'HC' c.mos i.cs, is to give the maximum signal monitoring giving a graph -type not particularly critical in strength indication on a signal, display, as on the right of the respect of the d.c. supply vol- somewhere near the middle of picture, or an analogue meter tage, but it is suggested that a the m.w. band, with the aerial display as shown in the top + 20 volt line shold be used. sensitivity control adjusted to left. However, since the high speed give about a half -scale reading, Processor and memory use c.mos i.cs are very critical in since the greatest value of the can be displayed, but equally respect of applied voltage, a.g.c. indication, other things importantly, information about especially if a high degree of being equal, will indicate the the network linking the local oscillator stability is best phase coincidence at the workstation to other systems. desired, the d.c. supply to these MC1496 signal demodulator Monitoring of Ethernet data three i.cs is separately (IC8). packets and network load is stabilized by a low -power vol- Again, when the receiver is possible and to make efficient tage regulator i.c., IC4 (78L05). finally complete, the maximum use of the network, the number output setting of VR4 may pro- of collisions can be indicated. bably be determined by the The Sun -2 series Commissioning the p.1.1. need to avoid too great a diffi- workstations use a 68010 processor Since the correct operation of culty in locking on to a strong and the Sun -3, used to produce our cover, can run the p.1.1. is crucial to the satis- signal at the top (low tuning factory performance of the capacitance) end of the m.w. some two million instructions receiver, it is suggested that, if band. each second using a 68020 16.67MHz a suitable oscilloscope and processor with 68881 signal generator is available, co- processor for floating -point operations. the circuit should be tested, Hart Electronics, Ltd., of Peny- The next article will before the remainder of the cir- lan Mill, Oswestry, Shropshire, deal with the receiver's cuit is put into operation, by have offered to make available r.f. and demodulator tuning the oscillator into a kit of parts for the assembly stages synchronism with an unmodul- of this receiver. 56 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com LANGREX SUPPLIES LTD 2N3702 ' 0.11 Climax House, Fallsbrook Rd., Streatham, London SW16 6ED 2N3703 0.11

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RST Tel: 01-677 2424 Telex: 946708 RST 263707 0.11 2613708 0.11 2N3709 011 1X'202 5.50 ' ZTXI07 J.12 0.22 BDI37 0.30 8E259 0.311 ïcrics 04211 1.00 ' 2N708 7.TX108 0.12 203710 0.11 SEMICONDUCTORS BDI38 0.30 6F336 0.3,I I R5140 0.60 047200 1.50 0C'203 5.50 2N930 0.25 7.00 ZTX109 0.12 203711 0.10 0.30 BF337 0.30 CRS340 0.75 047201 1.30 0C204 2611131 0.35 A0027 1.00 0(177 0.13 80139 0.13 253771 1.20 60 OAZ206 1.50 OC205 I000 ZTX350 2N1132 0.35 AA119 O.Ir` AS715 2.20 BCI78 0.28 BD140 0.30 0F338 0.30 CRS3 0.90 1.20 0C206 8.50 ZTX301 0.14 201302 1.80 203712 AAY30 0.17 ASZI6 2.00 130140 2.00 8E621 4.111 (1E3(66 7.00 042207 1.50 BC179 0.15 ZTX302 0.14 201773 1.60 BFS28 2.50 GEX541 0('16 5.00 0C207 18.00 201303 0.90 A4713 0.30 ASZI7 1.60 131182 0.11 BDI81 0.75 6.50 2513819 0.50 0C20 6.00 OCP71 2.50 ZTX303 0.14 261304 300 44215 0.30 ASZ20 4.50 13087 0.09 00183 0.75 BFS61 0.30 (13M 3.00 263820 0.60 0C22 4.50 ORPI2 2.40 ZTX304 0.14 201305 I.00 44717 0.30 ASZ21 4.75 BC 184 0.11 BD237 0.35 BES98 0.30 GM0378A 1.73 0.80 R200R13 ).9S ZTX311 0.13 261306 7.00 203823 AC107 0.55 AUY10 3.50 BD238 0.35 BElV10 I.00 K5100A 0.45 OC23 I0.00 RC'212 0.11 ZTX314 0.25 2N3866 1.00 0.35 0.91 HFWII 1.01 511E340 0.79 0C24 1.50 R2009 2.25 261307 1.20 A('125 0A145 0.13 6(213 0,11 80X10 2613904 0.10 1.75 620108 2.00 ZTXSW 0.14 2161308 4.00 AC126 0.33 134148 0.15 6C'214 0.11 1317X72 2.00 BFX84 0.228 \11E370 0.73 0C25 11C'44 0.48 ZTX501 0.14 2161309 1.50 2613905 0.10 ACI27 0.40 64154 0.06 eC217 0.09 00010 2.40 BFXRS 0.28 \11E371 1.05 0C26 1.50 T1C2260 1.20 ZTX502 0.14 201613 0.30 2N3906 0.10 AC128 0,35 04155 0.11 BC238 0.09 BDY20 1.50 80X87 0._28 711E520 0.75 0C28 5.50 711.209 0.29 ZTX303 0.14 0.12 ACI41 0.33 134156 0.06 8('301 0,36 80Y60 1,50 BFX88 0.28 711E521 0.73 0('29 440 261671 5.00 -2144058 T10294 0.35 ZTX504 0,20 201893 0.70 2N4059 0-20 AC14181 0.45 BAW62 0.05 B('703 0.36 6F115 0.30 6F050 0._28 \1JE2955 2.25 0C35 4,00 T10304 0.36 ZTX571 0.20 2N4060 0.12 AC142 0.40 BAX13 0.05 BC307 0.09 6F152 0.16 BFYSI 0.2s' \11E3055 2.00 0C36 4.00 202147 8.00 0.25 2N4061 0.12 0.19 0.28 MPF102 0.35 0041 1.20 71P314 0.25 ZTX350 2X2148 2.75 AC'1420 0.45 BAX16 0.06 13C308 0.09 13E153 0F052 2N4062 0.15 1.30 7IP324 0.25 10914 0.03 262218 0.32 0C'176 0.35 BC107 0.12 0.09 135 54 0.17 gF664 0.36 7.117F103 0.55 00'42 8('327 0.03 2N4124 0.13 0.20 gFY9() 0.65 \10F104 0.55 0C'43 1.50 TIPJIA 0.53 i54916 262219 0,32 A('187 0.35 BC108 013 8C328 0.09 6F159 0.13 1.25 TIP34A 0.60 N4001 004 2N2220 0.22 2N4126 ACI88 0.33 BCIW 0.14 BC337 0,09 BFIW 0.20 BSX19 0.2' \IPF105 0.55 0C'44 TIP4IA 0.38 N4002 0.04 2162221 0.22 2N4248 0,25 ACY17 2.25 8C113 0.12 6C338 0,09 13E166 0.35 BSX20 0.2' \IPS406 0.17 0('45 0.85 T1P424 0.42 N4003 0.04 2612222 0.20 2N4288 015 ACYIR 1.53 8CI14 0.12 3,75 8E167 0.30 05X21 0.27 41PS456 0.17 0(71 0.65 B0,'V30 0.04 2N4289 012 0.45 1.65 \IPSUOI 1.11 0072 2.20 T1P110 0.40 N4004 2612227 7.50 ACY 19 1.80 8C115 0.12 BC03I 3.75 6F113 137106 0.12 0073 1.45 T10117 0.45 N4005 0.04 262368 0.23 204400 ACY20 1.50 13016 0.19 BCY32 3.75 8FI17 0.30 8TY794001( \IPSUO6 1.37 TIPI25 0.35 544006 0.04 21627694 0.23 2614401 0.12 ACY2I 1.55 8C117 0.24 0(2073 2.50 B11178 (1.30 31x1 \IP5U56 1.71 0074 1.40 TIPIJO 11.45 04007 0.05 202484 0.24 204402 0.12 ACY39 4.00 BCI18 0.30 BCY34 2.50 8FI79 0.10 811205 1.20 NE555 0.45 0C'75 1.40 TIPI3I 0.45 164009 0.06 2N2646 0.75 263457 0A5 AD149 1.00 BC125 0.25 BCY39 3.60 13FI80 0.30 BU206 1.20 NKT401 4.00 0076 1,60 T1P132 0.48 N4148 0.03 2612904 2615458 0.40 40161 0.50 8C126 0.25 BCY40 3,00 BF181 0.25 130208 2.00 NKT403 3.50 00'77 2.75 0.30 110135 0.45 6154130 0.10 26129044 0.30 2615459 0.40 ADI62 0.60 BC135 0.18 0.32 6FI82 0.30 BYIW 0.42 NKT404 4.00 0('81 0.90 0('042 0.11 26017 16.130 I)45 1.75 00'817 1.20 TIP 137 (148 05401 2N2905 0.30 AD7.11 12.50 0C'136 0.1 11 8('643 0.45 6E183 0.30 60126 0.I5 T10140 0.85 644 0.04 262906 0.22 25019 25.(0 ADZI2 12.50 BCI37 0.22 6C038 0.23 8F184 0.30 BY127 015 047 0.15 0082 0.95 TIP141 0.85 6920 010 262907 0.22 26024 3500 AF106 0.60 BC 147 0.12 RCY70 0.21 8F185 0.30 BZX61 0.1' OAIO 0.55 0083 1.40 TIPI42 0.85 5921 0.12 0,12 26023 35.160 41/14 3.50 BC148 0.12 13E194 0.15 Scrics ()A47 0.15 0084 1.40 202924 B('071 0.21 1.00 25026 4(1.00 0.15 0.10 I)470 0.22 OCI22 6.50 TIP2955 0.60 2G301 2X2925 0.22 AFII5 3.50 BC149 0.12 BC'Y72 0.21 13E195 BZY88 2.50 6.50 TIP29557 2G302 1.20 2512926 0.12 25103 AFI 16 3.50 B(1157 0.12 BCZI 3.50 13F196 0.15 Series 0479 0.21 0C123 0C119 12.00 1IP3055 ti 1.. 2G306 1.50 2163053 0.30 26302 5.50 AFI17 4.00 BC153I 0.11 BDIIS 0.35 13F197 0.15 BZY91 8.I0 0A81 0.21 T1030557 II I 216401 1.50 267(154 0.55 2S303 5.30 AEI 39 0.55 0C'159 012 81)127 2.10 6F'200 0.33 Scrics II485 0.21 (X'40 18.g1 I8.00 7.5140 21,1696 0.30 203055 0.70 25322 5( AF186 0.75 BC167 0.10 130124 2.50 01224 0.12 BZY93 0.12 ()490 0.08 IC'141 ZS170 112. 2N697 0.36 203440 0.60 2S324 4.16) 411239 0.65 BC170 0.09 00131 0.42 13F241 0.12 Scrics 0491 0.08 OC170 4.40 75178 0.?4 2X698 0.38 2513441 0.75 29701 12511 AFZII 3.75 6C171 0.11 80)32 0.42 8F244 0.35 BZY95 1.64 0493 0.08 0C'171 4,40 75272 (1.23 2N705 2.50 ' AFZI2 5.00 0(172 0.09 81)133 0.27 0F257 0.30 Scrics 1162101 0.15 0C200 4.00 203442 1.00 -0`7 76278 0.37 2N706 0.20 263614 5.50 A6026 1.40 BC177 0.09 130136 0.27 0F258 0.30 8ZY96 2.6, 1)A202 0.15 OC201 5.50

5545 150.00 vALVCp EIROCÇ' 10.50 EFR6 1.SU (¡X111 IS.15 ()D3 67.24 L'F41 2.00 , 4250A NO.IßI 6CG7 2.50 2ÁL] I.]3 '1Y3-63 SSSIA 120.50 GJ EI80F 12.05 EF89 2.50 (¡XL'_2 7.5U 074 1)Y7-125 72.W U1)42 2.Ip 4000A N7.IN1 6CH6 17.50 2AV6 2.50 5.75 55524 153.35 E182CC 13.25 EF91 2.95 GXuI 25.40 P('86 2 "' 1104-250 74.00 UF80 1.75 4632 20.00 6421.6 2AW7 3.50 9.00 5672 9.00 A1834 E186F 11.50 EF92 6.37 GXU4 44.50 PC88 2.50 I?V4-000 80.00 UF85 I.73 4C'35 120.W 6CW4 8.00 2AX7 1.15 13.50 5654 3.00 A2087 [IBRCC' 6.91 EF93 I.50 (¡XU <0 211.00 P('93 I.15 )7V5-500 199.00 UE89 2,00 a('X2500 5ri;31 6D2 1.50 2407A 4.00 5651 4.45 42130 17,50 E.280E 22.31 EF94 3.00 0C'97 I.'S UL41 5"W 4CX850A 105.0 6DK6 3.00 2B4A 3,50 150 GY501 VYS-70WA 4.50 16.W I 5670 42293 E283CC 12.50 EF95 5.99 G732 4.00 PC'30 472.00 UI-84 1.15 4X1500 60.00 6DQ68 3.73 2806 2.50 5675 28.00 A2426 35.50 E288CC 17.50 E098 2.00 ("737 4.75 P(C'0.3 1.50 IJ7011-20 32.70 UM80 2.00 4X 1500 56.00 6EA8 I00 2BE6 2.50 A2521 25.00 5687 6.00 0810F 35.48 EF163 2.IM) GZ74 4.0() 0('('85 1.50 6.00 UY41 2.25 50254M 35.00 6EB8 2.50 2807 2,75 k10 5696 3,50 A2310 15.00 E452 32.25 EFIN4 2.01 (¡7.37 4.75 14.1.68 200 k17 3.00 11581 2.25 56255M li,g) 6EW6 2.25 2857 7.W 5718 7.50 43343 45.W EA76 2.50 EFöMS 12.00 KT61 S.q) PCC'XY I.] k 1 l.00 VLS63I 13.W 5C22 156.00 6E6 3.W 2E1 20.W A731 2.75 5725 5.50 EA8C80 1.25 EF0055 15,00 KT66 1500 P('C'189 2.V51 019 9.24 XG1.2300 55.00 01180E 1650.10 6F23 1.60 2E1177 28.00 2,60 5.50 5726 11.37 AZ41 EAC'91 3.50 EH90 1.75 6-1-77 Gold 51C1105 1.M1 k20 2.50 XG2.640) 584(16 6F28 1.60 2E14 65,00 5727 7.05 BK448 114.9() EAF42 2.50 EKW I.3Ú Lion 1200 PC'C810 I.MI 11113-250 32.68 I41.90 5114G 3.00 6F33 33.50 2E1 170.00 155.35 5759 2.50 BK484 E4F801 2.00 E132 2.50 PC'E82 21111 0G3-2504 32.68 XG5-500 30.00 3U4G13 2.50 6H1 14.00 9H4 27,50 KT88(ìoid 5751 4.00 8590 58,00 E183 4.00 2.50 47.50 E841 4.00 lion 2(L00 PC'F8(1 2.6 1 RG3-1250 59.00 X02-64(0 5V4G 6H2N 2.75 9H5 60.00 5763 4.50 05810 E891 1.50 LI 3441111 4.00 KTW61 2.50 PC'F82 1.50 k(i4-1230 61.60 165.00 553G1 2.50 6H361 2,75 489 67.23 58144 4.00 1315 58.95 EBC33 2.50 01.36 2.50 51, XRI.1600.A 577 4.00 6H6 3.00 OCI5 2.00 61W'62 2.50 P(E86 2 RG4-7000 99.45 5840 4.00 13TI7 I85.50 EBC.41 2.50 E1.4I 2.80 KTW63 2.50 201 SJ,7S S7.4C¡ 2.50 614 5.50 OC17 2.00 P(FX7 k63-230 4U.00 5842 12_.00 BTI9 44.05 EBC81 1.50 E1.42 2.50 M8079 12.34 XR1.3200 110.00 574G7' 2.50 616 8.93 -0C18 2.00 PCF200 3.25 it 63.1250 45.75 5876A 71.50 BT29 749.15 EBC'W 1.25 0181 5,25 MNOBU 11.25 p<'02111 7.25 s11E12 65.00 X111.32004 61111.2 1.75 617 4.75 OFS 1.56 5874 5.W 13169 354.80 ow 1.50 El-83 6.00 9.82 ..XRI-64W 6404 1.75 6JE6 7.50 OFL12 1.38 M8081 PC'E8111 IJO 6.00 17.50 8T95 129.90 2.25 586 EBE83 1.75 ELN4 M8082 9.69 PC1-802 2 \I3OP 6,00 150.00 114g7 3.00 61(416 2.50 OFL.12 1.80 C13L31 4.00 3.00 2.50 EBFR9 1.50 EI.86 2.75 M8083 10.25 PC'FROS I() ïrV28040 YDI120 395.00 6AC'7 666GT 2.75 0E1.14 2.00 5963 C'I.37 4,00 3.50 E13L31 10.00 01.90 7.25 M8091 10.43 0<1-806 I.'1 14.00 Y0)240 49000 64644 4.25 61(7 7.00 .011 1.50 59115 1,00 6005 2.25 Cy 11 3.00 EC'90 1.25 EI.91 7.79 M8096 6.N() PCI-808 1.' s1-3/280-130 7803U 25.00 64(17 6K8 7.00 0L15 2.50 20.00 6021 '.SO CIK EC91 8.00 EL95 2.00 M8097 N.10 P('IX2 215 21.00 Z2S9 25.00 OAKS 3.00 6KD6 7.00 0117 2.00 C'lA 22.00 1U.50 3.9y 5657 I_.25 EC'92 I.]5 EL SXIAN 8,15 P('INl 115 .I141 5.00 TM1001 8.00 OAKS 61.66 l.ql OP4 2.Sg 22.00 6,50 6058 12.34 C314 ECI57 440.00 EI.360 M8099 8.00 PCIN4 2 sU42 10.00 7M1020 9.00 6AK6 2.30 616GA 3.50 OP19 .30 25.00 6059 6.00 DA41 EC'C33 4.50 EL500 3.W M8I50 111.30 P(L86 251 D0J-10 35.00 7M1021 9.00 6415 1.50 616GC 5.75 OPLI .00 18.70 4,50 10.50 6061 6.00 0A42 ECC35 EL509 11 .75 D03-10F 35.00 7M1022 900 6AM4 300 6L6GT 3.50 OPLI4 .RO 348176 PC'LBfi 2.51 3,75 DAE'91 1.75 El .821 13.00 RAMS 9.69 Mµ3 ECC40 5.50 M8177 12.25 P(I.8051852'1 15 50.00 7M1023 9.00 61.1 2.50 .OPI.IS .80 1.75 6064 10.25 DAF96 ECCRI 1.75 01.822 13.97 M8140 6.m PD500 6.16 Ill 37,50 ZMI(10(1 19.86 6AM6 602 6N2P 2.50 5W4 .50 0ET22 35.00 6067 11.75 ECC82 1.75 ELL80 19.00 M8141 11.55 PE06405 45.16 722 77.50 7M1041 16.66 6ANS 6570 2.50 005 .50 49.00 60]2 6.00 DET ECCRJ 1,75 EM30 6.00 M8142 N.75 PFI.200 2.51 (100 60.00 7MI042 17.]] 64084 2.50 5BI 6.05 6080 14.01 DF91 1.75 EC'Cg4 1.75 OMISO 2,50 M9144 ].511 PI3h 2 V2-125 75,00 I0JGT 3.50 6AQ3 607 7.00 5CI 4,50 DF96 1.75 2.SU 697A 215.(0 ECC'XS 1.75 LMriI M8149 M1.5(1 PI.NI 04-400 N4.W I024 25.00 6456 6P225 4.10 SAI 7.30 I` 60970 210).00 DK91 (.75 ECC86 2.30 EM84 2,00 M8161 9.33 PL81A 2.I1 -64-5 00 IIO.W IB3SA 48.00 6AS7G ` 6Q7 3.]5 5A2 6.43 DK92 2.00 61364 12.00 ECC88 3.50 EM85 2.75 M8162 11.75 PI 82 1.5 -55-500 225.00 I867 61.00 6016 1' 6K7 1.25 90100 20.00 61460 12.W DK96 1.75 ECC89 2.00 EM87 2.50 M8163 8.25 PI 83 1'6R00 220,00 IRS 1.75 60USGT 6RHH86KN8 90AV 2000 6159B 19,50 0192 2.W EC'C91 8.93 [N72 23.50 M8190 2.6 155 1.75 6406 90C1 6.00 500 PL84 065004 9.50 DL94 1.75 E091 6.50 . 6189 ECC189 2.10 M8195 I0.83 P1504 5 2.51 SIS.W 144 1.73 6AV6C¡A 6SÁ] 90CG 14.54 6201 11.40 DL96 1.75 ECC807 1)5 E692 6.96 M8196 7.50 P1-50X 5.5 Y6-5(00B 24515 11.50 6406 65('l 90C\' 13.03 6I42 20.00 DI.S10 14.00 ECC808 3.00 EY.I3 2.75 M8204 ].(IS PI.509 66 395,00 2C'794 60,00 64 X5(1-7 651- 92AG 20.00 6550 8.00 DLSI5 12.50 ECF80 1.50 EY81 2.50 M8212 I1.37 P1.519 6.0 y6-Sq10W 20'47 70.00 607 6511- ... 92AV 20.00 ULSIO 12.50 68838 12.50 ECF82 1.50 EY83 2.50 M8223 6.31 PI N01 1.51 446.00 2021 3.25 6130 6517 3.2' 9541 8.45 12.50 6973 4,00 DL519 ECFR6 2.50 EV84 9.24 M8224 6.30 P1,802 6.00 707-60004 2E26 8.25 6646 6507 3.50 5082 6.50 2.00 1.75 7025 ICAO DM70 ECH75 3.00 E086 Mg223 4.50 P5802 h.(M 552.00 2142 VN.m 6HA' ° 6507(11 3.00 5087 8.35 DM71 2.00 EY88 I.75 7027A 8.(0 ECH42 3.30 MN24N 14.01 PY3J 2_.51 TV7-6qß)W 2155 245.00 fi13AS'` 65N7GT 3.50 SW"2 3.25 DM160 4.75 7551 6.25 ECH81 3.50 EY550A 300 M0290I 115.00 PYRI 1.50 552.00 2170A 78700 6B( J 6507 3.40 50C4 6.00 1.50 7586 15.00 0087 ECH83 2.30 E0802 1.75 Mt/14 2.50 P582 1.50 TZ40 23.00 22708 336.00 680.6 65117 4.00 _II 35.00 DY802 1.50 7587 23.00 ECH84 2.50 0735 1.73 MX119 55.00 1710 1.25 1118.20 3.50 2025 12500 613116 6557 2.75 2348 125.00 E551. 0.00 7609 56.50 ECLRO 1.50 E74() 2.50 MX123 76.00 PYRR 2.00 L'19 13.75 74007 115.00 6616 6U5G 3.50 03 25.00 E80CC 5.00 7868 6.00 ECL8I 1.75 E741 2,50 MX145 56.70 P55004 4.(0 025 2.50 35007 100.00 6004 61184 2.25 O5 45.00 E80CF 1.27 1.50 - 7895 12.40 ECL82 1.50 E7.80 MXI51 17.25 058lß1 1.511 U26 2.50 1A5 7.00 661 ` 6V6(1T 4.25 907 3.75 HOE 4.19 8068 16.50 FC-1.163 3.00 17.X1 1.5(1 MX152 131.25 PY8(11 1.5(1 U37 12.00 71324 II.50 6617()T 84.50 6X4 2.00 RIIA 18.33 E801 3.73 8136 2_.50 F.CL84 1.50 E7.9(1 3.00 MXI61 152.25 QE351 X2_30 UABC80 1.25 3028 I5.73 6856 IIS.01 6XSGT ).75 812A 75,W 6.50 8417 6.00 E8142G ECL85 1.50 FW4-5IXI 3.50 MXI61 20.25 QQV02-6 1810 UAF42 2.50 7029 20,03 6656 2.00 7137 2.50 813 vavlc 6500 EBIL 3.27 18042 11.58 ECL86 1.75 FW4-800 3.50 MX164 25.52 QQV(13.10 25.(0 17041 7.00 38240M 17.50 6007.A 3.30 7C7 4.00 8734 193.16 8.10 18045 10.49 E82C(' E5-37 5.00 G1.371K 3500 MX166 141.00 QQ7/03-204 11BC41 2.25 30241M 17,50 6087 600 7C6 2.50 8664 20.07 8.40 1804 1200 Ee7CC EF39 2.75 G5516 12.00 MX168 50.01 48.38 UBF89 1.50 3C27 23.00 601184 3.50 7H7 4.00 8724 20.00 E86C 8.25 EF40 5.00 GI80.2M 17.50 N78 15.00 Q0906404 UCC84 1.75 3C24 24.50 6067 6.00 787 4.25 922 6.50 E88C 8.25 Tcslcd 0E41 3.50 G240.20 12.00 0A2 7.25 461/0 CICLOS 1.85 7CXI00A 47.00 68W6 6.00 757 7.50 9314 18.50 10.J7 EvEVU¡pmrnl ERNC'C EF42_ 4.50 (14(0.1K 17.50 OA3 2.5(1 QQV(I750 11FC80 2,00 3E29 43.00 fiBW7 1.5(2 7Y4 2.25 1624 4.00 1('X2508 8.50 E90C'C 9.47 EFSU 2.50 GN4 9.50 OA4 6.50 69, 74 UCH32 2.50 354 2.00 613X7G7 5.00 7Z4 2.00 1625 3.50 VQZ20 CV Denims E9OF 9.90 EF54 5.00 GN4A 9.00 0132 4.35 6-4QA 62.20 UC'H81 2.50 3V4 1.75 66Z6 2.75 HEI 55.00 2050 7.50 6.25 Large stocks E91H EF55 7.50 GN4A 9.00 083 2.5(1 QU37 12.50 UC1.82 1.75 4-654 60.00 6C4 1.25 124H8 5.00 4212E 300.00 Prices on E92C'(' 8.75 EF80 1.75 G516 16.00 0(2 4.35 QV03.12 6.80 C7.83 2.75 4-1254 60.00 6CB6A 2.50 12476 1.50 4212H 100.50 5 lication E99F 9.10 0E83 4.00 GTIC 25.50 OC3 2."U5 QV04-7 3,50 6C.D6GA (0 12477 1.75 3344 110m app EI30L 18.50 0E85 1.70 GU 50 20.00 QY'Bg-150Iflfl.50 12AU6 2.50 GU5I 20.00 l 74119 74156 0.48 CIRCUITS Jö4 ú ix aiz ó vs 4 AA5]0 2575 TAA630S 75 BASES CRTs 7486 0.54 74121 0.54 74170 1.20 .01 SADPI 55.0 '400 0.16 7416 (1.48 7440 0.36 74911 0,72 74122 0.70 74172 4.00 1-44700 1134480Q .50 07(Junskincd 2AP1 8.50 5CP1 10.(0 7400 0.35 7417 0.48 7441 0.48 7491 0.76 74123 060 74)73 0.72 V('Rt176 IU,IR1 74125 74174 TBASNQ .50 0.40 21301 9.00 5CPIA 40,00 7401 0.36 7420 0.48 7442 1.25 7492 0.54 0.60 0.60 VCR5I7C IO.W 74126 784530 .50 87G Skirted 0.50 7001 12.00 50154 15.00 1402 0.36 7422 0.36 7430 0.30 7493 0,54 0.50 74175 .00 TBASSOQ ,75 89A Unskincd 31701 5.00 51107 25.0 74()7 0.36 7423 0.36 7451 0.30 7494 0.70 70128 0.55 74176 .50 CRT so c kris TBASMI Q 75 0.40 IEGI 10.00 DC17-5 63.32 '401 0.42 7425 0.36 7453 030 7495 (). 65 74176 0.70 74180 .48 Prices on 74141 0.46 74190 .20 164671 .75 BOA Skirted 0.50 31117 6.00 DG7-81 58.07 7405 0.42 7427 0.36 7454 0.30 7496 0.60 application 74141 1,30 74191 .20 TBA]W .50 g9D 0.55 3GP2 6.00 0G7-32 58.07 7406 0.48 7428 0.36 7460 0.30 7497 J.W 1/Csockcts 74145 0.72 74192 .10 TBA]000 ,]5 Inl Octal 0.40 UPI 8.00 DG7-36 65,00 2407 0.55 7430 0.36 7470 (1.48 74131 0.04 Tcxas 74147 74193 18A750Q .513 31172 8.00 0113-91 56.83 7408 0.36 7432 0.76 7472 0.70 74107 0.36 1.50 0.60 Loom' 0.55 Iow Pro(ile ... .W 74148 1.40 74194 1.10 1134800 71P7 10.00 DH7-I I 113.12 7009 0.36 7433 0.55 7473 0.48 74109 0.54 Nuvistorbasc Xpin 100 TBA920 .75 2,00 3KP1 15.00 VCR138 12.50 '410 0.36 7437 0.36 7474 0.36 74110 0.48 74150 1.60 74195 0.72 1ópin 119) 74196 1.00 TBA99Q .50 Valvcscreening 3RPI 35.00 VCRI38A 12.50 -411 0.40 7478 0.36 7475 0.65 74111 0.51 74151 0.36 1.40 74197 1.00 TCA270Q .00 8.00 (6 I 7476 0.48 1.50 74154 cans all si zcs0.40 7WP1 20.W VCR I79A 7412 0.42 7439 0.36 74116 74155 20 1 ('A'6114 .2. 7413 0.36 7480 0.32 74116 1.20 060 74198 2

Terms of business: CWO. Postage and packing valves and semiconductors 50p per order. CRTs £1.50. Prices excluding VAT, add 15%9' Telephone 01-677 2424/7 Price ruling at time of despatch. Telex 946708 In some cases prices of Mullard and USA valves will be higher than those advertised. Prices correct when going to press. E. & 0.E. Account facilities available to approved companies with minimum order charge £10. Carriage and packing £1.50 on credit orders. Over 10,000 types of valves, tubes and semiconductors in stock. Quotations for any types not listed. S.A.E. Open to callers Monday-Friday 9 a.m.-5 p.m. WW1 CIRCLE 17 FOR FURTHER DETAILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Are you CP/M Plus (vers 3) Developing Systems For NASCOM and Gemini computers Consider our modular approach Nasbus/80 Bus compatible Features: CPU card CP/M 2.2 file compatibility Z80 CPU incorporating memory mapping Banked memory system 64k RAM on board (expandable) Z80 S 10 providing two RS232 channels Fast warm boot from banked memory CTC providing programmable baud rates Faster disk access: - P 10 providing parallei/centronics LO Directory hashing, memory cashing, multi sector I/O Parallel keyboard port Better implementation of USER levels VIDEO card (VFC) 80 by 25 line output Greatly extended and user friendly utility commands Fast memory mapped display 20 transient utility commands On board floppy disk controller Includes MAC the DRI assembler Can be used with CPU card under CP/M Multi command entry on single line Available in kit or built and tested Multiple drive searching facility DISK card (MPI) Mixed 3 ", 3.5 ", 5.25 ", 8" drives supported Console redirection SASI Winchester interface Password file protection Z80 S 10 providing two serial channels Date and time file stamping CTC providing programmable baud rates Larger disk and file handling RAM card 29 additional BDOS calls 64k to 256k (in 64k steps) Supports 64/32k paging 4k mapping Extended BDOS capability by easily attached RSXs Available in kit or built and tested Winchester, floppy and virtual disk CLOCK card (RTC) Mixed drive/formats Attaches to any Z80 P10 Full source code of BIOS supplied Retains Centronics parallel output PLUS PLUS PLUS liunIllllll Battery backup PRICES CPU £230 MPI £185 Now Only £199 VFC £199 RAM (64k) £150 RTC £35 RAM (256k) £285 Excluding post and packing and VAT All prices exclude carriage and VAT For further information contact: `T1f3P 8D Systems Ltd fTRD Unit 2 Stoneylands Road, Egham, Surrey Tel: 0784 37674

c I ltJ LE 6 I I )K FURTHER DETAILS.

SMALL SELECTION ONLY LISTED Etc £100 to C150. MA250 - 1.6MC /S to 31.6 MC /S RING US FOR YOUR £100. MA1350 for use with RA17 receiver £100. MA259G REQUIREMENTS WHICH MAY BE Precision frequency standard 5MC/S - 1MC/S - 100KHz £100 to £150. Panoramic Adaptor IN STOCK RA66 £150. RA137 and RA37 £4010 05 LF convertors 10 to 980KC/S. RA218 Independent SSB unit £50 RA98 SSB-ISM Coverlor £50. RA121 SSB -ISB convertor £75. EC964 /7K Solid stale - single channel - SBB - mains or battery -1.610 27.5 MC /S and 400 to 535KHz £100 with manual Plessey PR155G Solid State 60KC /S - 30MC /S £400. Creed 75 Teleprinters - Fitted tape punch and gearbox for 50 and 75 bauds - llOvolts AC supply - in original transport tray sealed in polythene - lik new £15EA. Redden TT11 Audio Teleprinter con - verlor receiver solid slate - supply 110 or 240AC - Made for use with above teleprinter enabling print -out of messages recieved from audio Input of communica- tion receiver £15 with circuit tested. Rediton TT10 Con- vertor as above but includes transmit facilities £20. Oscilloscopes stocks always changing Tektronix Portable Battery or Mains Oscilloscope. SE Laborato- - 465 100MC /S £750. FM Recorder Sanghmd Sabre ries 111 Oscilloscope Solid State General pur- - - - 111 14 channels £350. Transtel Matrix printers pose Bandwidth DC to 18 /20MC /S at 20MV /CM - - - AF11 R- 5level Baudot Code up to 300 Bauds for + 11 GHz SATELLITE TV RECEIVING EQUIPMENT Dual Channel - - print out on plain teleprinter paper £50 to £100. Trans- Rise time 19NS Calibrated Sweep -C- alibrator - - IelAH11R-As above butalso 8 level ASCII (CCITT No LNA's LNC's RECEIVERS, FEED HORNS ETC. Display 10CMSx8CMS Power AC 95 Volts to 100- - - 2 and CCITT No. 5) Like new £100. Army field tele- Dealer enquiries welcome 190 Volts to 260 or 24 Volt DC battery - Size. phone sets. Type F and J Large quantity in stock W.25.5.CM H25.5CCMS 56CMS Deep -L - For further details contact - - - f6 to £15 depending on type and quantity P.O.R. Don WT11.4KGS Carrying handle Tested in fair condi- - - 10 Telephone half tion with operating instructions £120.00. Cable - mile canvas containers HARRISON ELECTRONICS £20. Night viewing Infra -red AFV periscopes - Twin Eyepiece - 24 volt dc supply £100ea. Original cost to 22 MILTON ROAD, WESTCLIFF -ON -SEA, ESSEX SSO 7JX Tel: (0702) 332338 government over £11,000ea. Static Inverters - 12 or 24 volt input- 240 volt AC sinewave output - various wattages P.O.R. XY Platers and pen recorders various - P.O.R. Ferrograph series 7 Tape recorders mono £100, stereo £150. Signal Generators various - TF995/A3 £60. TF801 D /8s- 10MC /S to 485MC /S £90 Electronic TF144H /A4 £90. TF1060/2 £60. HP6IMA - £90 £140 ,.). HP608 £50 HP614A £100 HP6188 £100 HP620A £100. 1 Marconi TF1064B/5 £100 TF791 Deviation meter £100 Corporation ffi TF893A Power meter £50 Aerial mast assembly 30ft high complete with 16ft whip aerial to mount on top - 94Ra` a . guyropes -insulators- Base and Spikes etc., in heavy THRULINE`R) Directional Wattmeters duty carrying bag - new £30. Raul frequency counter Type 836 £50 Tektronix plugs- Ins -1 Al £50, 1 A2 £40, Latest Bulk Government Release - Cossor Oscillo- 1A4 £100 MEW. All items are bought direct from H.M. TERMALINE RF Coaxial Load Resistors scope CDU150 (CT531/3) £150 only. Solid state general Government being surplus equipment: Price is Ex purpose bandwidth DC to 35MHz at 5MV /CM - Dual works. S.A.E. for enquiries. Phone for appointment Channel - High brightness displsy (8.10cm) Full for demonstration of any items. Also availability or TENULINE® Attenuators and accessories delayed time base with gated mode - Risetime IONS price change. V.A.T. and carriage extra. - Illuminated graticule - Beam linder - Calibrator from stock 1KHz squarewave - Power 100 - 1200.200V - 250 volts AC- Size W26CM- 41CM deep -WT 12.5 K.G. EXPORT TRADE AND QUANTITY carrying handle - colour blue - protection cover front DISCOUNTS GIVEN Aspen Electronics Limited containing polarized viewer and camera adaptor plate JOHNS RADIO (0274) 684007 - probe (1) - Mains lead. Tested in Fair condition with WHITEHALL WORKS, operating instructions £150.00. The exclusive UK representative for Bird Electronic - 84 WHITEHALL ROAD, Communication Recievers. Racal 500KC/S to 30MC /S EAST BIRKENSHAW, BRADFORD in 30 bands 1MC/SWIDE - RA17 MK11 £125. RA17L BD11 2ER 1/3 Kildare Close, Eastcote, Ruislip £150. RA117E £200. New Metal Louvred Cases for Middlesex HA4 9UR above £25. All receivers are air tested and calibrated In our workshop - supplied with dust cover - operation WANTED: REDUNDANT TEST EQUIPMENT - Tel: 01 -868 1311 Tlx: 8812727 instructions - circuit - in fair used condition. Racal RECEIVING AND TRANSMITTING EQUIPMENT - Synthesisers (Decade frequency generators) MA350B VALVES - PLUGS - SOCKETS SYNCHROS Solid Slate for use with - MA79 - RA217 - RA1218 ETC. CIRCLE 14 FOR FURTHER DETAILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Forth in control The computer language Forth is particularly suited to the control of machinery, argues David Sands, who explains how it may be implemented in control applications.

People tend to adopt Forth then scans the user's line 4 Wait for the ADC to languages and then acting on each word, and if complete. David Sands is a consultant defend them fervently. everything works out OK then 5 Read the ADC. in industrial automation and For example, Pascal enthusiasts Forth types OK. 6 Scale the result according software, with a small to the calibration factor company, Sands Technology, expounds its virtues and ignore was 2 of the transducer. in Cambridge. In 1979 he the drawbacks such as tedious - the stack one of the first to import de- bugging and editing. Basic, All arguments are passed 7 Leave the scales result on personal computers from the the single most popular between procedures on a data the stack. USA. In the same year he language in the world, is not stack. You can have variables, Each tank has it's own service designed a low -cost speech standardised, suffers from a but they are not used much. Part routine, called LEFT -TANK synthesizer for personal multitude of dialects and is of the reason for this is to maxi- and RIGHT -TANK. The total computers. Two years later slow, unstructured and messy. mise the performance of the of both tanks is given by:- he designed a talking A favourite target for scholars system. Almost any language LEFT -TANK RIGHT -TANK + dashboard for a car. He has of better languages it never- will first convert a formula to Now LEFT -TANK and also worked on natural - Forth RIGHT -TANK are not values! language translation using theless is arguably more effi- items on a stack. Because speech input and output, and cient in terms of returns on users are interested in speed of Nor variables. We are not doing on low -cost robot arms. programming effort, especially execution they are prepared to PRINT X + Y. They are whole for shorter calculating pro- keep account of the stack them- procedures which leave their grams. selves. Suppose you wish to add results on the stack. There can The truth is, of course, that 3 and 4 together and print the even be other words between there are "horses for courses "; result: LEFT -TANK and RIGHT - different languages are suited to TANK as long as they don't different tasks. Forth is >4 5 + . (return) 9 0K take off or put on extra items on particularly suited to the control the stack for example: It has some short- of machinery. Forth scans the user's input line comings, which I accept but LEFT -TANK BLA -BLA and first puts 4 on the stack, + . which become less important RHUBARB RIGHT -TANK then puts 5. The Forth word ' +' once the full power of Forth is then takes two values off the 3 the dictionary. realised. - stack (5 and 4). adds them Instead of a handful of key- together and puts the answer on words as in Basic, there are the stack, the value 9. The Forth about 150 or more words, which abbreviation '.' then prints it. are organised in a "dictionary". What Is Forth? There is now nothing on the Forth interprets a user's word Without wishing to embark on a stack. If we try to print again we by searching down the tutorial of Forth, I would just get: dictionary until it finds it, then like to outline the fundamentals carries out the activity which is for the benefit of readers not > . 0 STACK UNDERFLOW! in the "definition" of the word. acquainted with the languages. If the word isn't in the Note: In all my examples of ex- which is not ok. dictionary then Forth tries to changes between man and But the Forth data stack doesn't convert it as a number. If it isn't machines I will underline text exist to make everyone think a valid number either, then typed in by the user. I won't like a machine. At worst post -fix Forth rejects it as an error. keep mentioning the need for notation is an unfortunate side- Most low level words in Forth the return key. The computer's effect. Imagine that we wish to tend to be abbreviations, or response will be in upper case calculate the total content of two single characters, for example but not underlined. My tanks of chemical. Each tank the Forth word for "print" is comments will be in lower case. has a transducer in it with quite just a full -stop (.) whereas There are probably four a complicated service routine, higher level procedures have fundamental principles. as follows: highly descriptive names. 1 Select transducer and 1 - Command line energise. The Forth word " + " takes Commands numbers are 2 Allows filters to settle. 4 - definitions. the two top numbers from typed in by the user, separated 3 Command the analogue- This principle is fundamental to the stack and replaces them by spaces, finishing with return. to- digital converter Forth users. It is the building- with their sum. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 59

www.americanradiohistory.com FORTH CONTROL

Summary block approach to pro- using a colon sign, followed by tically for trends, machine gramming. the name of the procedure, then performance etc. This is known Forth is a highly productive Forth, straight off the disk, the definition ending with a as language in terms of programming Statistical Process Control or effort. Communication between consists of a "kernel" of some semi -colon: 'SPC'. programmer and machine is 150 or more "words" or A number of transducers are : TANKS? commands, most of which connected to a multiplexer improved by the development of a LEFT -TANK RIGHT -TANK and vocabulary specific to the applica- execute machine code when- analog -to- digital converter. The tion. Programs produced with ever they are used. The ADC is an Analog Devices Forth have higher integrity and programmer must define new AD574 used in 12 -bit mode on are more efficient than programs words in terms of words in Now all you have to do is type an 8 -bit microprocessor bus produced with other methods. terms of words he /she has TANKS? to yield the total in (actually a Z80), on I/O ports Data types are few but highly 0 already define plus words from both tanks, or alternatively and 1. The read /convert input of suited to digital hardware. The use the kernel as necessary. These TANKS? can of the stack is an efficient way of be included in the the ADC is driven from bit 0 of passing arguments. In fact there new words are added to the definition of some grander port 4. Now, suppose we are not are now single chip micro- existing dictionary. Hence the procedure. just starting on the software but computers available with Forth programmer begins by defining that the hardware is not proven built in, such as the 65RF11. New short concise procedures which either, being a bread -board microprocessors are being can be tested individually. In Control applications prototype. developed with stack oriented this way the programmer builds To illustrate the above archi- tecture. up a range of fully tested principles more fully I can modules which are then used to outline part of a genuine applica- Hardware development construct more powerful tion. The system being Assuming that sufficient of the procedures, and so on until the programmed is a dedicated system is running to support final application programme is computer which reads from Forth, or that a processor complete, which can be just one linear displacement transducers emulator is being used which is The heart of a statistical word. The modular approach checking tolerances on motor running Forth, then things can process control circuit imparts a very high degree of components. Deviations from be typed in at the keyboard which can be controlled confidence to the final tolerance are displayed on a during debugging of the by Forth, as described in application. colour screen in bar graph form hardware. Checking of a proto- the text. New procedures are created and are later analysed statis- type module or circuit addition might proceed as follows:

do > 0 4 OK A4 Board Output OUT decoder buffer This sends the value 0 out through port 4 to set the ADC to A7 d3 741585 74LS75 convert mode. (check with logic probe). +5V Board 10 enäb e Output >4 OUT OK enable Chip This sets the ADC back to read decoder mode. (check with logic probe) a -to -d Suppose there are problems enable L C O O with the wiring. We can there- Board address/ 74LS 139 fore define a word to keep Enable Input Input writing to port 4 while we look 17 RI enable buffer for the missing signal with an 14 oscilloscope. You can't do this 13 with an ordinary monitor 15 program. You can't do it nearly 7415125 as quickly by a do writing test Data enable routine in any other language. Bear in mind that you might

dO need to devise many test Data d3 routines during the develop- D buffer 6 ment of some hardware. To dp 16 28 d3 Status check the above read /convert Read /convert 5 line you might enter: d3 74 LS 245 Ref. in d4 d4 a -d > :TEST1 1000 0 DO 0 4 1 I -ta OUT A 0 574 4 OUT LOOP; OK d7 +10V ref.out 07 d7 do > TEST1 Offset Data mode select Luckily is d3 27 Forth fast enough to CS issue the OUT signals with +5V 11 sufficient regularity to be visible -15v 14 7 Analogue kp high + 15V on an oscilloscope. If Basic were is 9 ov Día cannon low used you might be trying to view OV analogueT a 10 microsecond trace generated every 10 milliseconds by BASIC. This would dim the 60 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com trace by a factor of 1000 making To do this we need a variable to usefulness of this we could have The machine had a hydraulic it invisible. Forth is therefore a hold a value of 0 or 2. When the a condition whereby a value of, pump from which oil was fed to powerful engineer's tool. variable's name is used its say, more than 800 on channel 4 the steering valve via solenoid address is put into the stack. is an alarm condition. valves controlled by my system. The Forth word `!' stores a value Suppose the diameter of a One problem with output ports into the address, i.e. into the certain component were being is that although they latch (i.e. modules Hardware service variable. The Forth word @ checked by two transducers memorise) what you send to Hardware devices are best fetches a value from the variable mounted each side of the them, their contents cannot be programmed in stages or and leaves it on the stack. component. The two trans- read back. They are therefore a modules. In the case of my ducers are required so that if the kind of write -only memory VARIABLE SCALE example of the Analog Devices shaft were not straight then any (worn?). If you wish to change AD574 Analog -to- Digital con- The rest of the code is then reading produced by one the state of one bit on a verter first let's get control of modified so: transducer due to non - particular port without altering the read /convert line: - :CONVERT straightness would cancel in the any of the other bits then ideally (Note in practice, programs are SCALE @ 4 OUT (SET other. Suppose the transducers you read the port, after a bit, entered on to disk, and edited, CONVERT) are on channel 5 and 6. Then we then write it back. Because you before being compiled by 0 0 OUT (START could define a single word for can't do this it is necessary to Forth). CONVERSION) diameter to read both trans- keep account of each port in a an :READ ducers and add them together variable. My application used thus: 8 -bit microprocessor, a Z -80. I :CONVERT SCALE @ 1 OR 4 OUT (SET 14 OUT (SET CONVERT READ) had port 7 controlling 8 triacs, : DIAMETER 5 ADC 6 ADC + ; MODE) 0 IN OF AND 100 ports 8 and 9 controlling 16 DC 0 0 OUT (START 0 IN FO AND OR From now on whenever we want lamps. The triacs were CONVERSION) 1 IN OR diameter we need only use the programmed thus: 7FF - name; e.g.: VARIABLE TRIACS When the ADC has converted a > DIAMETER . 500 OK value, 12 -bit is avail- Finally, before using ADC the result the :ACOUT able in two parts: the upper 8 I must set up the multiplexer in An associated word might be:- DUP TRIACS! bits on port address 0 and the the signal conditioner by out- :TOOLARGE 7 OUT lower 4 bits with trailing zeros pouring the required channel on 800 > on port address 1. In my applica- port 2. e.g. 2 2 OUT selects tion I wired ADC data bits 0 to 3 channel 2. Any argument to ACOUT is to my bus on bits 4 -7, and ADC If the amplifier needs a settling This leaves a 1 (true) on the first DUPlicated. One copy is bits 4 -7 to bus bits 0 -3. The code time the signal conditioner stack if the argument is more stored in the variable TRIACS to read the ADC was therefore issues a busy signal which I than 800 units, or a 0 (false) if and the other is output on port 7. as follows. Note that hexa- input on port 6 bit 0. Servicing not. In a later definition yhou Various descriptive commands decimal numbering is preferred the signal conditioner is coded might enter can now be defined: in the context of hardware: - like this: DIAMETER TOOLARGE IF :READ ABORT THEN. : OILON TRIACS @ 1OR (SET 0 4 OUT (SET READ MODE) What is now happening is that : CHAN O 1) 0 IN (GET HIGH BYTE) Forth statements are taking on BIT TO 2 OUT ACOUT (OUTPUT OF AND (MASK LH NIBBLE BEGIN the readability of an English WHICH IS THE MOST sentence and becoming less AND SAVE IN 6 IN 1 AND TRIACS AGAIN) SIGNIFICANT 4 BITS) 0 = UNTIL cryptic. At the same time we are 100 " (SHIFT LEFT TO BITS to forget beginning the : OILOFF 8 -11) complexities of the lower levels. IN (GET TRIACS @ FE AND 0 HIGH BYTE We can afford to! They are fully AGAIN) The BEGIN -UNTIL loop traps (SET BIT 0 TO 0 tested and reliable. MASKING IT FO AND (MASK RH NIBBLE UNTIL bit 0 of port 6 changes to OUT) WHICH IS BITS 4 -7) 0 (false). Now I can build a OR (LOGICAL OR WITH BITS ACOUT `bigger' word thus:- Machine control 8 -11) CLAMPON 1 IN (GET LOW BYTE WHICH : ADC Out -put to a machine is most TRIACS @ 4 OR IS BITS 0 -3 PLUS 4 ZEROS) CHAN commonly achieved with the ACOUT OR (LOGICAL OR WITH BITS CONVERT following devices: 4 -11) READ Triacs - used to switch CLAMPOFF 7FF - (APPLY OFFSET SO e.g. READINGS FALL contactors and solenoids TRIACS @ FB AND BETWEEN +2048 & -2047) Note that the line: 2 OUT is solenoid valves. ACOUT not complete. It requires a Digital -to- analog converters - further item from the stack and used to issue a varying voltage : AIRON The ADC is fed from a TESA this is presumed to be on the to control such things as DC TRIACS @ OR ACOUT signal conditioner which stack before ADC is invoked. motors. : AIROFF 2 we (e.g. hexfets) converts the transducer outputs To select and read channel Transistors - TRIACS @ F7 AND into a DC voltage in the range would therefore write used to switch low voltage DC ACOUT + &- 10 volts. The amplifier in devices such as stepping motors 2 ADC the signal conditioner has a and bright lamps on the machine etc. etc. choice of two gains, which I ADC contains the word front. The DC outputs on parts 8 and 9 select by outputting on bit 1 of READ which leaves the value of In an application a few years ago can be handled 16 bits at a time port 4, bit 0 of which is already channel 2 on the stack. ADC is I designed and programmed a to suit Forth's 16 bit standard in use. It is necessary, therefore therefore a word which requires dedicated system to check the data size. Simply split the 16 -bit to add, the value of this bit to the one value on the stack and performance of hydraulic value into high and low bytes output whenever selecting read leaves one value behind on the control valves as fitted to cars and output separately on each or convert modes of the ADC. stack. To demonstrate the with power assisted steering. port. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 61

www.americanradiohistory.com DIGITAL AUDIO

Compact disc mastering continued from page 50 The PCM -F1 has no timecode Two of the greatest draw- circuits and dropout compen- functions and for Compact Disc backs of the use of v.c.rs for sator disabled, but a purpose - Fig. 9. The DMR4000 has cutting F1 /701 tapes have to be digital audio have been the lack built machine with extra replay

extra rotary heads for digitally dubbed . to PCM1610 of confidence replay, i.e. off - heads in the drum for confi- confidence replay. If an format using the RTW or Har- tape monitoring during record, dence replay, and an automatic additional decoder is in- monia Mundi Acustica inter- and the tendency of heads to head -cleaning mechanism stalled in PCM1630, the faces. clog due to a combination of (DMR4000). The PCM1630 machine can continue to The JVC system buries the inaccessibility and repeated generates the same tape format play with a clogged head. timecode and user bits in the passes during edit operations. as the PCM1610, but can switch Error status will switch pseudo -video waveform, so the In the replacement for the the replay section to the confi- output to the error-free poor analogue bandwidth of venerable PCM1610 and dence output of the DMR4000. decoder, whether VHS audio tracks ceases to be a V05850 U -matic system, Sony As an option a second replay playback or confidence problem. An adaptor is available have solved both problems. The channel can be fitted to the head. Delay compensates to produce timecode from the U -matit recorder is no longer an PCM1630 as shown in Fig.9. for displacement heads. JVC p.c.m. adaptor. industrial v.c.r. with the chroma During replay, the record/ playback heads drive one replay channel, and the confidence heads drive the second channel. r 7 DMR-4000 v.c.r Main Should one head become clogg- Rip output ed, error detection circuits will Demodulator head < H choose data from the other heads. Significantly, the d. -to -a. PB amp. Output amp converter of the 1630 uses over- Sub by a of two to Canf output sampling factor Demodulator head improve phase linearity. In the next two parts of the L series we discuss problems and techniques in editing digital recordings on rotary head r machines.

Decoder References Input Switch A Audio 0 1. See Fig.6 of ref.4. D - to -a output 2. Professional -use PCM audio pro- T converter cessor with high efficiency error correc- tion system, Yamada, Fujii, Mariyama & Decoder Error logic Input Saitoh. AES Convention, Los Angeles B 1980. L-- 3. The DASH Format, J.R. Watkinson. L Broadcast Systems Engineering October Optional extro decoder 1985. 4. Channel code and disc format, J.R. Watkinson, Electronics & Wireless World, June 1985, pp.80 -2.

and Development Centre of the German PTT in Darmstadt. HDTV HDTV (high definition television) is a new television Camera standard which aims to achieve A television camera, which even better picture resolution, sets new standards in picture that is, even clearer television recording quality, has been pictures, on larger screens with developed by Robert Bosch a width/height ration of 5:3 GmbH, on behalf of the (previously 4:3). When this Heinrich Hertz Institute for improvement in quality will Telecommunications reach domestic television Technology in Berlin. The screens, however, remains to development work was be seen, as it would require not sponsored by the Federal only further development of all Ministry for Research and the equipment required in the Technology. To date five of television studio but also the the experimental cameras have allocation of new frequencies been delivered, namely to the for transmission of the because HDTV productions - transferred to video discs or Heinrich Hertz Institute, the programmes, by satellite for unlike those from other 35mm film. HDTV technology University of Dortmund, example. systems - can be used in a would therefore enable Braunschweig Technical Nevertheless, the new "multimedial" way, which production studios and University, the technology could soon find its means that as well as being television stations to become Telecommunications Research way into production studios broadcast they can also be considerably more competitive. 62 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com by Peter Ferris Timing by remote control This versatile self- contained Z80 timer controls eight appliances with 100 on -off settings using coded r.f. bursts injected in the mains supply.

This project was origi- define the operating procedure setting can control any The author developed an early a my own whims. The combination of appliances, interest in electronics, building his nally conceived as to suit first radio at the age of 12 and simple electronic re- software will be described in and will operate on any going on to maintain all the placement for an electro- sufficient detail for changes to combination of days of the school's many television sets. mechanical immersion -heater be made by constructors with week. It may either repeat Having dropped out of a B.Sc. which had finally siezed of how a timer the weekly cycle indefini- course at London University, he timer, different ideas worked his way up through after years of unreliable ser- should operate. tely, or stop automatically industry, testing, fault- finding and vice. Then I decided that, to be The final design is based on a on any specified last day. then designing analogue control really useful, the timer should Z80 processor and has several Settings are suspended systems and test equipment. He be capable of controlling more features not usually found in rather than cancelled on the taught himself about microprocessors the hard way, be than just an immersion heater; commercially made timers. last day, and may be re- designing and building a Z80 it should have a timing resolu- One appliance is plugged activated without being re- development system from tion of one minute; it should be into a 13A mains socket entered from scratch. They scratch, and is now employed as able to store several different mounted on the control unit. may also be suspended or a senior design engineer with Dowty Electronics, where he is switching times for each appli- A further seven may be cancelled manually at any working on Z8000 -based control ance; and above all it should be remotely controlled by time. systems. self -contained (some advertised means of coded r.f. bursts All the stored settings, or controllers need to be hooked injected into the mains just those for a particular up to a home computer). wiring'. channel or a particular day, It was clear to me that a Up to 100 on- and -off sett- or all repeated settings, may microprocessor was the only ings may be stored. Each be examined and altered in economical way of achieving these requirements. I first con sidered using a single -chip Flat faced 'Windows' with filters microcomputer, to cut down triangular leds (colour to suit leds) construction time. One such device, Texas TMS1601A, is mask -programmed to operate as a four -channel timer, but TIMER OUTPUT unfortunately it lend it- doesn't ENABLED ON self easily to remote control CANCELLED ° with the operating program I-I I-I I-1 0 0 SOCKET - supplied. Also, it only provides <> I I 0 1 1 I a four -digit display (I wanted to I I I display on and off times I aD I together) and can only control SUSPENDED four appliances. 2 <> 2 Single -chip microcomputers 1 1 I I I I I I containing eprom, such as I I o. L O 3 aD 3 ABOXESR Intel's 8748 series, are still ACTIVE more expensive than multi -chip systems, and difficult for home 4 aD 4 constructors to find. I therefore settled for a general -purpose microprocessor with external V V V V V V V V 5 I <> 5 memory, since eight -bit proces- IMMERSION REPEAT SAT SUN MON TUE WED THU FRI b ' 6 sors are widely available at a HEATER very low prices. Standard SET LAST NEXT 1 NEXT T BATHROOM eproms are also cheap and they DOWN UP NORMAL NEW , D CLOCK STEP SETTING STEP SETTING / can easily be programmed \ HEATER using a home computer with a suitable attachment. Having to write the software myself gave me the chance to ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 t3

www.americanradiohistory.com REMOTE TIMER

turn. The display in this ter /timer circuit (c.t.c.). Chan- slightly shorter than the trigger tably bright display without mode shows on and off nel 0 divides the system clock interval. The Q output is there- resorting to Darlington drivers, times, day, channel and down to 500Hz, which is fore low, and the display especially if high- efficiency leds either active or suspended. further divided by channel 2 to enabled, for most of the time. are used. Although the colon For non -repeated settings provide a 20Hz interrupt for the As the control resistance is between the hour and minute the last day flashes. timekeeping function and the reduced the pulse becomes digits is always on, its leds are Settings are entered and display flasher. Channel 1 gene- shorter, reducing the display pulsed via Tr101 so that the altered step by step, with the rates a 601Hz interrupt for dis- duty cycle and hence the colon brightness tracks the rest relevant part of the display play multiplexing; it is also apparent brightness. To match of the display. flashing at each stage as a used as a clock for shift register the response of the eye, a The 32 keystrokes are prompt. A 'backstep' key IC13. Channel 3 is spare. CPU logarithmic potentiometer is connected as a four by eight allows mistakes to be cor- address line A2 is used directly used with the wiper tied to the matrix, which is scanned by rected without having to as a chip enable for the c.t.c, clockwise end. pulling each row line low in start again. which therefore occupies every This arrangement also pro- turn, and then reading the eight Individual digits of the on address in the i/o map which tects the display leds if a fault column lines together. Column and off times are altered has A2 zero. occurs which stops the display lines with no keys pressed are with 'up' and 'down' keys. Circuitry IC5, IC8a b, IC2b being multiplexed. Under fault pulled high by resistors on the The numbers wrap -round decode addresses for the other conditions, IC9a is no longer processor board. Debouncing when zero or the upper limit four i/o ports. The decoder is triggered. Its Q output stays the keys is left to the software is reached; impossible times inhibited when A2 is low to high, disabling both the seg- (to be described later). such as 27 hours cannot be avoid bus contention with the ment driver (IC11) and the digit entered. c.t.c. Lines A3 and A4 were decoder on the display board. Each channel has an output arbitrarily chosen for the select Without this protection, the 60 Power supply on /off key and a timer inputs. Signal IORQ is used as a mA segment current would The power supply is of conven- enable/disable key, with leds data strobe in both directions; it flow continuously in one digit tional design (shown on p.67 to indicate status. is not necessary to use Rl or or group of leds, instead of with the optocoupled switch Like most digital watches WR, because the software will being time -shared between the and remote -control trans- but unlike most timers, the never try to write to the input eight digits and four groups of mitter). The five volt regulator, clock may be corrected in port (IC6) or read from the out- leds. IC203, should be firmly bolted to two steps if it is within half a put ports (IC10, 11 and 13). Oscillator frequency is halved the metal box for heatsinking. minute of the right time. However, signal M, is gated by ICi2a to provide a 1MHz It should not be insulated from Most of these features are pro- through IC8a to inhibit the clock for the c.p.u. and c.t.c. the box because the OV line, vided by the software and incur decoder during the interni t The normal t.t.l. high level is which is connected to the metal no additional cost. Those that acknowledge cycles, when M, insufficient for the c.p.u. So R5 surface of the i.c., needs to be need extra hardware, such as and IORQ are both low and the pulls the logic 1 level up to earthed as a return path for the the remote control, could address bus retains the pro- + 5V. The halt indicator and R1 transmitted r.f. signal. The simply be left out if not gram counter contents. are optional. If fitted, the led 7805 is available either in a required. The key matrix is driven by appears to glow dimly most of TO3 metal can, or in a TO220 The control unit is construc- IC5c_f, their open -collector out- the time (it actually flashes at a plastic package with a metal ted on three printed- circuit puts avoiding the possibility of rate too fast to see), but it tab. Either type is suitable. boards: the first contains the damage if keys in different visibly blinks off when the A voltage doubler generates a processor and memory and rows are pressed together. clock minute increments, and raw 20V supply for the trans- most of the logic; the second The parallel-to- serial data sometimes when a key is mitter output stage. From this, holds the keyswitches, displays converter is IC13, clocked con- pressed. IC202 derives a stable 12V rail and display drivers; and the tinuously at 601Hz, but as the for the oscillator and driver third is shared by the optically serial input on pin 10 is tied low stage. coupled triac switch, the power the output is normally a stream The mains filter unit is optio- supply and the remote -control of zeros. When the processor is Display and keyboard nal, and various types may be transmitter. required to switch an appliance The circuit of the display/key- suitable depending on the on or off, it writes a byte into board is on page 66. External environment. The prototype the parallel inputs. Each bit connections are numbered to timer operated correctly for Processor board from D1 to D7 represents the correspond with the processor several weeks without a filter, The circuit of the processor required state of one of the board circuit. but then consistently went hay- board is shown opposite. Circuit remotely -controlled appliances Integrated circuits 101 and wire when an electric drill was IC2a decodes the upper two (1 for on, 0 for off). The H input 102 decode the four-bit digit plugged into the other half of address lines to divide the of IC13 is tied high to provide a number and drive one digit or the double power point where processor memory map into start bit, so Do is latched by group of leds at a time, via tran- the timer was plugged in. (The four parts, of which two are IC12b to control the eighth (or sistors 101 to 112. The choice timer behaved itself when the used for the eprom and ram. zeroth) appliance directly. The of transistor used is important; drill was moved to the next The eprom may be either a write strobe pulse also triggers a d.c. gain of at least 100 is power point on the ring main.) 2716 (2Kbyte) or a 2732/2732A the monostable ICob, which required at a collector current Fitting a filter as shown in the (4Kbyte). The timer program enables the transmitter for the of 500mA. Power disipation is circuit completely cured the fits into 2Kbyte, but as the time required to transmit one low because each transistor is problem. processor spends much of its byte. only conducting for one twelfth The fuse in the mains plug time in the halt state, it could be The other half of IC9 is used of the time. has to be rated according to the given additional tasks such as a as a pulse -width modulator to Transistors 113 to 120 each largest appliance likely to be program for decoding the control the display brightness. drive one segment or discrete plugged into the control unit Rugby time-code radio trans - It is retriggered at 1.66ms led of the digit or group of leds (i.e. probably a 13A fuse), and missions.2.3. intervals when the multiplexing selected by the digit decoder. this would not protect the Circuit ICS, a standard Z80 software moves on from one Resistors 125 to 132 set the cur- mains transformer if, for peripheral device, is a four - digit to the next. With the con- rent to about 60mA peak (5mA example, D204 or D205 went channel programmable coun- trol at maximum the pulse is average), which gives an accep- shortcircuit. The separate low- 64 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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66 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com current fuse (F1) is therefore volts across it when the triac is varies considerably from house transmitter essential, particularly because off. Ideally, the triac's r.m.s. Remote control to house. Measurements made the unit will be left on and current rating should be about The principles involved in at several locations suggest that unattended for long periods. A 50% higher than the maximum using domestic mains wiring to an impedance peak can be slow- burning fuse is required, load current, but in practice it is carry data signals are discussed expected somewhere between to cater for the relatively high possible to use, say, 15A triacs in reference 1, so I will not go 100 and 500kHz; a simple surge current at power -up. for most receivers, with one or into too much detail here. The method of finding the peak will two lower -current ones for neutral -earth pair of wires is be described later, with other appliances such as radios or used for safety. tips on testing and setting up electric blankets. Frequency -shift keying is the system. Optocoupled switch Snubber components C211 and used for data transmission, i.e. An optically -coupled triac R220 are included to limit the two carrier frequencies repre- driver, IC204, also contains a rate of rise of voltage across the sent logic 0 and logic 1. On Remote control receiver zero -voltage- crossing circuit. triac when an inductive load is page 67, IC201 is a voltage -con- The output stage is itself a switched off, which could trolled oscillator whose fre- A typical f.s.k. receiver might small triac and for loads of less otherwise retrigger the triac as quency is switched by the serial consist of: a bandpass filter than 20 watts, such as a por- soon as it is switched off. Their data. The triangular waveform with - 3dB points at the two table radio, the external triac optimum values depend on the from pin 4 is filtered by R205 carrier frequencies; a phase - and R221 may be omitted. (Con- maximum load current and the and C203, so that the power locked loop to recover the nect pins 6 and 4 of IC304 critical dV /dT rating of the amplifier delivers a reasonably original serial data; a serial -to- directly to the live input and particular triac used, though 1 pure sinewave to the mains parallel converter (usually a output lines respectively). kS1 and 47nF /500V is a widely - wiring. Transistors 203 and 204 uart chip which can detect Remember that high -current used combination. They may be keep the output stage biased off transmission errors); and a triacs can have significant omitted if only resistive loads except during transmissions. decoder, to determine whether off -state leakage currents, are to be controlled, or if the The choice of carrier frequen- the received command is especially when hot; a 5 watt phase difference between vol- cies depends on the impe- intended for this receiver, and load connected to a 15A triac tage and current is only a few dance /frequency characteristic if so whether to switch the may still have several tens of degrees. of the mains wiring, which appliance on or off. If two or

Set "off frequency Set ou put level Out 78L12

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IC4 MCP3041 These components Mains filter Trg fitted only during unit test (see text) (Optional) BC308 To oscilloscope input OV Triac May or may not be fitted Fi J - Channel 0 See text output 150mA slow blow

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ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 (ì î

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www.americanradiohistory.com more appliances are to be The first monostable is adjus- Start! Chi Ch.2 Ch.3 Ch.4 Ch 5 Choff61Chon .7 switched together, a separate ted so that its pulse finishes in bit off oft on on on Sto. bit data word must be transmitted the middle of the data bit IC301 Pin 6 for each one. corresponding with the particu- Since a receiver is required lar receiver (channel 6 in the IC302 pin 6 - for each remotely -controlled case of Fig.5). This trailing C308 appliance, I rejected this edge latches the incoming data approach on the grounds of bit into IC3o7a, from where it is C316 cost. Instead, I designed a transferred to IC3o7b by the novel receiver circuit which trailing edge of the second IC304 pin 11 offers good immunity from monostable pulse during the mains -borne interference at a stop bit. IC304 pin 4 Adjust to centre modest outlay. Extra gating circuits are with set timing The circuit is shown opposite. included to provide noise IC305 pin 7 potentiometer A Wien- bridge bandpass filter, immunity. To trigger the mono - IC301, is tuned to the lower (off) stables, a burst of mains -borne IC307 pin 15 carrier frequency. noise has to be at or very near IC305 pin 9 The comparator IC303a serves the on- frequency for a long three purposes. First, the enough time to discharge C316 1[307 pin 1 j base /collector junction of the below the logic 0 threshold. It inverting input transistor acts must have no significant com- as a clamp diode, holding the ponent at the off -frequency, negative peaks of the waveform since that would block the on- rooms. The switch is then the The serial data word to about 0.6V. Secondly, the signal at IC304c At the end of only means of local control (or always starts with an on- positive peaks of the shifted the first monostable pulse, the any control if the transmitter bit; the next seven each waveform are compared with noise must still be present, and fails). A switch is used rather represent the required the half-supply -voltage bias on at only one of the carrier fre- than a pair of push- buttons state of one of the remote the other input; if the peak -to- quencies; if neither or both are because it has the advantage of appliances; the stop bit is peak amplitude exceeds the present, the J and K inputs of providing absolute immunity always an `off'. bias, the comparator output IC307a would both be low, and from mains-borne interference switches low. Thirdly, the the latch would not change - including from mischievous open -collector output stage acts state. At the end of the second members of the household as a rectifier; C307 is charged monostable pulse the noise trying to switch the bathroom rapidly by the output transistor, must still be there, but now heater off when you've just set- but discharges more slowly only at the `off' frequency; tled down for a long soak! through R308. otherwise, the J and K inputs of Capacitors C319 and C320 pre- The output therefore remains IC307b would be held low via vent noise picked up on the low, although with some ripple, IC3o4d and IC3o6cd, and the out- switch wires reaching the SET when a large enough signal is put wouldn't switch. Even if a and CLR inputs to the latch. received. The filter R309 and noise burst managed to get over They are connected to opposite C308 is to remove short pulses those three hurdles, there is of supplies to ensure that if a caused by spikes on the mains course a 50% chance that it power cut occurs while the wiring. would only succeed in switch- switch is set to `remote', the The higher (on) carrier fre- ing the output to the state it appliance is switched off when quency is detected in the same was in already. power is restored. way by IC302 and IC3o3b The As with the conventional The d.c. supply for the recei- other two comparators in IC303 receiver, the output may fail to ver is derived from a miniature are not used. (If you're wonder- switch if noise occurs during a mains transformer. The ing why I didn't use the LM393 signal transmission. To over- receiver circuit is tolerant of dual comparator, which has come that problem, the control quite wide variations in supply nearly identical characteristics, unit repeats each timed trans- voltage, and no regulator is check the advertised prices - mission, ten seconds after the necessary. Load current is the LM339 quad version is stored switching time. about 17mA for the receiver it- usually cheaper.) self, plus a further 15mA The normal operation of the through the optocoupler and rest of the circuit is best under- Local control panel leds when the output is stood by referring to the wave- The three -position switch switched on. forms, above. The serial data allows the appliance to be word always starts with an on- switched on and off locally, To be continued bit. The next seven each repre- overriding the remote control. sent the required state of one of This is not strictly necessary Postscript. I have been asked the remotely -controlled applia- when the appliance is to be several times why the multiplexing nces. The stop bit is always an powered via a mains socket interrupt rate is 601Hz rather than 'off'. mounted on the receiver box, as a round figure like 600Hz. The The start bit triggers mono- the appliance could be plugged reason is that the c.t.c. channel has a four -bit prescaler, which divides References stable IC305a, via IC304b,c The Q directly into a wall socket or the 1MHz c.p.u. clock down to 1. The Intelligent Plug, N.McArthur, A. IC305a immediately But Wireless World, output of left unplugged. some 62.5kHz. This is further divided by Wingfield and I.Witten, triggers the second monostable, appliances, such as an immer- December 1979 the programmable eight -bit clock, IC3osb the Q output of which is sion heater or a bathroom 2. Micro- controlled radio-code counter. Dividing by 105 (decimal) N.E. Sand, Wireless World,June /July fed back to prevent retrig- heater, must be wired directly gives 595.24Hz; dividing by 104 1982 gering of either monostable into the receiver because power gives 600.96Hz, and that's as close 3. Rewbichron 2, J. Robinson, Radio & during the receive sequence. sockets aren't allowed in bath- to 600Hz as it's possible to get. Electronics World, April/May 1983 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 69

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www.americanradiohistory.com EX -STOCK INVERTERS TRANSFORMERS 121249 DC to 240V AC MAINS ISOLATORS 501259 or 25 -0-25V 30115V or 15 -0 15V 100W _...._ _. 065.95 PrilSec 120V x2 2x25V Tap Secs Volts 2 x 15V Tap Sacs. Volts 250W.._...... _.0208.00 3, 4, 5, 6, 8, 9, f 160-1000VA Tap Secs) available 5, 7, 8, 10, 13. available 500W _ _ 301.00 VA Price P &P 15, 17, 20, 25, 30, 33,40. 10, 12, 15, 18, 20, 24, 1000W f 424.00 '20 6.11 1.70 20-0.20 or 25-0-25V 25, 27, 30 or 15-0-15V 2000W _ 0636.00 40 9.96 1.89 509 25V Price P &P 30V 15V Price P &P 4000W 01215.20 2.10 0.5 1 4.34 1.47 0.5 1 3.35 1.36 T 100 11.63 DS CONSTANT VOLTAGE 1 2 1.48 16.47 2.36 1 2 5.28 1.50 4.54 90 200 TRANSFORMERS 1% 250 19.92 2.77 2 A 4 9.12 1.94 2 4 7.34 1.69 Spike-free stable mains 350 24.64 2.84 3 M 6 10.97 1.96 3 6 8.50 1.45 250VA _ (158.00014 500 30.69 3.10 4 P 8 14.80 2.22 4 A 8 10.15 1.99 500VA 0201.93 ,. 1000 55.65 4.70 6 S 12 18.91 2.30 5 M 10 12.55 2.10 FORTH COMPUTHE 1600 0380.50 ,. 1500 71.79 5.95 8 16 26.75 2.86 6 P 12 14.20 2.30 2KVA 0590.95 2000 86.38 6.35 10 20 31.74 2.20 8 5 16 19.00 2.36 3604 0951.05 3000 121.12 OA 12 24 37.99 3.36 10 20 21.92 2.46 4104 01173.00 6000 258.77 OA 12 24 24.36 2.63 5600 01470.00 115 or 240V sec only. 601306 or 30-0.30V 15 30 27.96 3.20 . (1697.75 Remember that 6KVA - 20 40 37.42 5.14 4001440 to 2001240 CT Pri 2.120V. 2x3OV Tap Volts available AUTOS 10KVA 03480.00 ,. 160.100080 Tap Secs) Sees. 18, 20, 105, 115, 220, 230, 240V VA Price P &P 6, 8, 10, 12, 16, AVOs & MEGGERS -up or down 60 9.98 1.90 24, 30, 36. 40, 48, 60, For step 8MK6(latest) 0152.50 Price P &P * FORTH is fast 100 11.88 2.10 24 -0.24 or 30-0-30V. VA 77169 Transistor Test E65 5.08 1.49 200 16.47 2.36 60V 30V Price P &P 80 Megger Batt 083.70 * It is interactive like BASIC 1 150 7.36 1.69 250 19.92 2.52 0.5 4.93 1.58 Megger Crank 0125.80 250 8.96 1.76 * It contains its own compiler 350 24.64 2.84 1 2 7.51 1.60 Full range AVOs, Meggers 13.96 2.34 500 30.69 3.10 2 4 9.66 2.00 500 Fluke, Edgecumbe * You can mix FORTH and assembler code 24.93 2.90 1000 55.65 4.20 3 A 6 13.96 2,10 1000 29.58 3.35 WW MODEM PROJECT * You can comment properly without penalty 2000 86.38 5.50 4 M 8 15.91 2.31 1500 4.20 Transformers T1, T2 DA 5 P 10 20.11 2.36 2000 44.34 * Names can be left long or shortened 3000 121.14 P &P 3000 75.22 5.10 06.90 pair inc VAT. 6000 258.77 00 6 S 12 22.95 2.78 * TDS900 series computers have a full- screen editor 8 16 32.26 3.20 5000 113.11 OA METAL OXIDE ¡W 241128 or 12.0.129 C 10 20 37.55 3.47 7500 175.51 OA (11100 * TDS900 series has both N- channel and -MOS versions 212V Secs. pri. 2409 5% RESISTORS 12 24 43.28 3.68 10KVA 201.89 OA 20, 33, 47, 75, 390. 12V 24V Price P &P 12, * TDS902 consumes 25mA and has 62K bytes memory CASED AUTOS 560, 1k, tkl, 0.34 15 2.53 90 430, 51011, * Address and data buses take 6800/6500 peripherals MINIATURES 240V Cable Input 1k3, 1k6, 1k8, 2k, 3k, 1 05 3.45 1.30 Sec 9 Amp Price P &P 115V USA socket outlets 3k9, 15k, 16k, 24k, 27k, * Many systems are just one TDS900 in a box 2 1 4.46 1.36 3 -0 3V 02 3.26 96 VA Price P &P 39k, 56k, 82k, 100k, 4 2 5.15 1.70 6.2 14.2 3.72 130 Y0 * Others may have one extra card for special needs 7.57 1.59 110k, 120k, 130k, 150k, 6 A 3 8.07 1.76 009 0.7 2.72 . 96 BO 9.81 1.69 2001, 220k, 270k, 300k. * All cards have mounting holes, or use a rack 8 M 4 9.43 1.82 9.2 0.33.2 2.53 .96 8.9.2 .5.2 3.53 1.30 150 12.70 1.99 IEEE 10 P 5 10.31 2.05 BRIDGE RECTIFIERS * TDS971 offers RS232 and -488 expansion 60.2 14.2 4.4e 2.31 250 15.47 2.78 12 S 6 11.43 2.15 15.2 2.2 2.53 .96 500 25.38 2.90 IA 400V .32 * TDS972 adds RS232, A to D and parallel ports 16 8 13.62 2.33 12-0 t2 .05 3.11 ss 1000 35.43 3.97 2A 200V .52 on 32 20 10 18.33 2.66 20.2 15.2 3.55 1.30 7000 * TDS973A gives opto- isolation input /outputs 0 63.49 4.76 350 100V f3.00 30 15 22.79 2.85 1527.2 5.66 1.70 E3.62 3000 91.14 OA 12.5A 500V 60 30 46.67 4.50 1527.2 A 7.66 50 O-CT.15V 5 2.66 .96 83 41 53.76 5.50 SPECIAL ALSO VARIABLE AUTOS OCT -15Y 4A 2.28 106 0, 210, 240V PR1 FORTH computers start at £99 96)48V. Pri 2x120V Also Valve Meins TO 14, 8, 0, 14V SEC PLEASE ADD 15% VAT Secs 2x361489 Matching types Output & 20VA f3.45 .75pp. ALL ITEMS AFTER P &P 60, 72, 84, 96, 360.0.36 Stock items by return or 48.0 -48V Triangle Digital Services Ltd WINDING SERVICES 72196 361489 Price P &P 3VA to 15KVA 1 or 3 BARRIE ELECTRONICS LTD 1 2 9.38 1.52 phrase Plus Toroidals 100a Wood Street, London E17 3HX 2 A 4 15.42 2.31 Unit 211, Stratford Workshops 3 M 6 18.68 2.52 EDUCATIONAL METERS Telephone 01- 520 -0442 Telex 282284 (Ref M0775) 4 P 8 23.84 2.60 Finger screw terminals Burford Road, London E15 2SP 5 S 10 33.84 3.36 0-10A or 0 -30V OC 6 12 42.38 3.68 78x89mm (3.98 each Tel: 01-555 0228 (3 lines) 8 16 46.23 3.98 50p P &P CIRCLE 6 FOR FURTHER DET.Alt.S. CIRCLE 71 FOR FURTHER DET: \ILS.

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CIRCLE 57 FOR FURTHER DET:\ILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 71

www.americanradiohistory.com by R.F. Coates 68000 board 5 Bob Coates continues his description of the Kaybug monitor software with a look at its system calls

The monitor offers 26 trol -S> characters have been 40- column mode, characters system calls or received. If `break' received, have bit 7 stripped and are out- subroutines for user does not return to caller but put as normal characters. programs to draw upon. These aborts user program and Entry conditions: a6= address handle keyboard input and returns to monitor. If 'hold' of start of string. screen output functions but also received, waits until a different Exit conditions: d0.b = 0; include number base conver- character is received before a6 = address of string ter- sions and a 32 -bit divide returning to caller. minator +l; all other registers routine. Entry conditions: do.b = Ascii preserved. The calls are invoked by set- character to be output. ting up the appropriate entry Exit conditions: all registers query: outputs a ' ?' and conditions and then executing a preserved. sounds bell/buzzer /bleep. Uses trap # 11 instruction followed outch. sendch: outputs character in by a word -sized number in- Entry conditions: none. then returns to caller without dicating which call is being Exit conditions: all registers made. checking for 'break' or 'hold'. preserved. do.b = Ascii All calls except renter when Entry conditions: outputs contents of completed return to the user character to be output. outhex: program and continue with the Exit conditions do.b. lowest four bits in do as an Ascii undefined, other registers hex character. Uses outch. next instruction, as if a jsr in- struction had been used. preserved. Entry conditions: do = hex value. Table 1 lists the calls outs: outputs a space Exit conditions: do = undefin- available in version 1.0 of the character. Uses outch (see com- monitor along with the number ments about 'break' and 'hold'). ed; other registers preserved. that follows the trap # 11 Entry conditions: none. out2hx: outputs contents of instruction. Exit conditions: all registers lowest eight bits in do as two A more detailed description preserved. Ascii hex characters. Uses of each call is now given. spaces: outputs a number of outch. Entry conditions: do= hex renter: this call terminates a space characters as indicated users' program and transfers by do.w. Uses outch. value. Exit conditions: control back to the monitor, Entry conditions: d= undefin- giving the monitor prompt. do.w = number of spaces re- ed; other registers preserved. Entry conditions: none. quired, 1 to 65535. out4hx: outputs contents of Exit conditions: not Exit conditions: all registers lowest 16 bits in do as four Ascii applicable. preserved. hex characters. Uses outch. Entry conditions: do = hex outch: outputs a character in pdata 1: outputs Ascii string do.b, then checks whether pointed to by ao and terminated value. Exit conditions: do) = undefin- Table 1 'break' or 'hold'

www.americanradiohistory.com building in d1. Returns after a program and returns to the Motorola S- format files monitor. If 'hold', waits for non -hex character with the last another character to be receiv- eight hex characters entered in This format provides a means of Ascii- encoding binary object ed (other than 'break' or 'hold') d1, leading zeroes being in- files for transfer between systems. before returning to caller. serted if necessary. Register d Returns with Ascii character in contains the non -hex ter- do.b, bit 7 forced clear. minating character and d2 the I I I S n Size Address Data Checksum Entry conditions: none. number of hex digits entered. 1 Exit conditions: do.b = 7 -bit Uses gpch. III Ascii character; all other Entry conditions: none. registers preserved. Exit conditions: do.b = non - ti is simply the Ascii code for the letter S. hex terminating character; for character to n is the record type: 0 = header, 1= data (16 readch: waits d1.l =eight hex characters; be received from input and bit address), 2 = data (24 -bit address), d2.1= number of hex characters returns with it without check- 9= end of file. entered; all other registers size indicates the number of bytes (hex) in this ing for 'break' or 'hold'. preserved. Entry conditions: none. record (address, data and checksum). Exit conditions: do.b = 7 -bit getadr: prompts operator to address is four or six hex characters for record Ascii character; all other enter an address. Returns with types 1 and 2 respectively. For types 0 and registers preserved. address in ao and number of 9 it is 0000. characters entered in d2. Re- data is the block of ascii encoded binary data. gets Ascii character gethex: jects odd addresses. Uses gpch. Each record typically contains a 16 -byte return- and converts it to hex, Entry conditions: none. block, but may be more or less. ing with hex value in do and 'c' Exit conditions: ao = address checksum is the one's complement of the sum of the bit in status register clear. If entered; d2= number of char- size, address and data. character was not a hex char- acters entered. acter, i.e. not 0 -9 or A -F, then Each record is followed by carriage return and line feed. returns instead with Ascii code range: prompts user to enter a This example shows the S -file produced for the object code and 'c' bit set. beginning and end address, giv- for example 1 (to be given in the next article). Uses getch: see comments ing the option of re -using the S00900006578616D3120FA about 'break' and 'hold'. last used values (as used by the S21440040070007200207C0000010052800601000A45 Entry conditions: none. PR command). If values 52084004105588601670 Exit conditions: (hex entered, updates ram registers S9030000FC character) do.b = hex equivalent begadr and endadr with new of character, s.r. 'c' bit = 0; values. If just entered, The header record holds the name of the object file as it (non -hex character) d0.b = 7 -bit registers left unmodified. was on the development system which produced this, Ascii character, s.r. 'c' bit =1. For Kaybug version 1.0. 'EXAM1'. All other registers preserved. begadr is at 40000016 and endadr at 40000416. conhex: as gethex, but does Entry conditions: none. eight -digit packed b.c.d. not get character from input. Exit conditions: begadr and number. Enter instead with Ascii endadr updated if new values Exit conditions: d1.1= binary character in d0.b. entered; all registers preserved. result; all other registers Entry conditions: do.b = 7 -bit preserved. Ascii character. Exit conditions: (hex strend: prompts user to enter divide: integer- divides the block start and end addresses in character) do.b = hex equivalent number in do by the number (as used by LW command). d1. Result is in d4 with re- of character, sr 'c' bit =0; (non - Returns with start address in a2 d5. hex character) do.b = 7 -bit Ascii mainder in and end address in a1. character, 'c' bit =1. All All numbers are in 32 -bit sr Entry conditions: none. other registers preserved. two's complement binary. Sign Exit conditions: a1.1= end ad- conventions used are: gpch: gets character from in- dress; a2.1= start address; all put and echoes to output. other registers preserved. dividend divisor result remainder Returns with it in do.b; if lower binbcd: converts a 27 -bit + case, converting it to upper binary number in do to eight case. Uses getch. packed b.c.d. digits in d1, with Entry conditions: none. 'c' bit in status register clear. Exit conditions: do.b = 7 -bit If input value exceeds max- Ascii character (upper case); all imum allowed (5F5E0FF16) Entry conditions: do = divi- other registers preserved. then d1 is undefined and the 'c' dend; d1= divisor. get2: gets two Ascii bit is set. Exit conditions: d4 = result; characters. Calls gpch twice and Entry conditions: d0.1= 27 -bit d5 = remainder; all other assembles the two characters in binary number. registers preserved. d0.w. Exit conditions (valid input): Entry conditions: none. d1 =8 -digit packed b.c.d. result, Exit conditions: s.r. 'c' bit =0; (invalid input) d0.w,b15 -b8= first Ascii d1= undefined, s.r. 'c' bit =1. Exception handling character; b7 = Ascii All other registers preserved. -b0 second The way in which interrupt character. bcdbin: converts an 8-digit exceptions are handled by the hexin: gets string of packed b.c.d. number in d0 to 68000 is to go to a specified characters from keyboard, con- binary equivalent in d1. location according to the excep- verting them to hex and Entry conditions: d0.1= tion designation, fetch a long ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 73

www.americanradiohistory.com 68000 BOARD

word (four -byte) address from it The exception processing A complete list of these 'jum- and re -start processing from sequence will thus be pers' is given in Table 2. 2 Table that address. 1. Get vector and go to that The remaining assigned Assignment Rom address There is a slight problem address. system exceptions, such as Bus

Level 1 400016 with the Kaycomp in that these 2. Execute jump instruction at Error, Address Error etc, can- Level 2 40001C exception vector addresses are that address. not be intercepted by Level 3 400022 Autovector the user Level 4 400028 interrupts in the eprom space and so a 3. Continue processing at jump program but can cause a return Level 5 40002E Level 6 400034 user program cannot alter destination address. into the monitor with an appro- Level 7 40003A them. Ram `jumpers' are provided priate message displayed. To circumvent this difficulty, for all autovector interrupts and Trap #0 400040 Trap #1 400046 for each interrupt vector that eight user interrupt vectors are trap *2 40004C Trap *3 400052 may be used on the Kaycomp, a also catered for. These are for Trap 84 400058 Trap six-byte block of ram is allo- vector numbers from 64 (4016) Trap #5 40005E crap #6 400064 instructions cated. The exception vector in to 71 (4716) and would be used To be concluded. Trap 87 40006A Trap 88 400070 eprom contains this address by 68000 peripherals inter- Trap 89 400076 and so processing will jump to rupting on IPLI. Trap #10 40007C this location. Trap instructions with vector

vector 64 400082 The six -byte space allows the numbers from 0 to 10 may also Vector 65 400088 user program to insert a `jump be used in user programs. Vector 66 40000E The DMS8832 memory module for this Vector 67 400094 User absolute, long' instruction, the These are handled in the same project is available under the type num- Vector 68 400096 interrupts Vector 69 400060 jump destination address being manner as interrupts. Trap ber EDH8832C (with the suffix - 15PC Vector 70 400066 that of the user's exception ser- numbers 11 to 15 are reserved for the 150ns version) from MicroCall, Vector 71 4000AC Thame Park Road, Thame, Oxfordshire; vice routine. for use by the monitor. tel. 084421 -5405.

by Tom Iva!! D.B.S. -a plan in search of some users David Withers men- sealed and just waiting for these programme feeds the tioned in the Decem- someone to start using it for full signals are in any case Asber issue (p.75) the broadcasting operation. `broadcast' to a number of most recent ITU pronounce- The Japanese came near to widely- spaced head -end ment on direct broadcasting by starting the first d.b.s. service receiving stations. And when satellites came at last year's in early 1984 when they reception of these trans- World Administrative Radio launched a satellite from their missions by individuals was Conference. This meeting, Tanegashima Space Centre and legalized, the comsats thereby WARC 85, formally approved placed it in geostationary orbit became broadcasting stations the d.b.s. plan previously in their allocated orbital in an even fuller sense, while worked out in detail at RARC position of 110 °E. But, as was still doing the job they were 83, a regional conference reported in E&WW, faults originally intended for. D.J. specially convened in 1983 for rapidly developed in the Standen's article in the ITU Region 2, which broadly transponders' travelling -wave December 1985 issue describe means the Americas. tubes and the whole project had this `quasi- d.b.s.' phenomenon A similar situation occurred to be downgraded to an in detail. in 1979 when the big WARC 79 experimental status. International planning for world conference formally Meanwhile, we have seen the satellite systems has actually agreed to the d.b.s. plan put unexpected development of been under way for two together for ITU Region 1 what has become known as decades or more. The ITU held (Europe, Africa, USSR) and `semi- d.b.s.' or `quasi- d.b.s.'. its first conference on extra- Region 3 (Far East and Transmissions from communi- terrestrial radio communication Australasia) at WARC 77, cations satellites, originally as long ago as 1963. This was which had been entirely intended purely for distribution when comsats were first devoted to satellite broad- of television and sound beginning to establish them- casting. As a result we now programme feeds within the selves as practical relay have a complete world -wide broadcasters' own networks, stations. The second World plan - in frequencies, have become, willy -nilly, a sort Space Telecommunications channels, powers, orbital of broadcasting in themselves. Conference followed in 1971. positions etc. all signed and When cable tv systems use Then came WARC 77 and 74 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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www.americanradiohistory.com RARC 83 as mentioned above. cies spaced at these intervals. terms of orbital positions for What has emerged, however, But perhaps the most marked different countries around the has been somewhat confusing. difference between the two geostationary orbit. Because The planning criteria and regional plans is in the orbital there are 150 or more countries methods used at WARC 77 and positions, or `slots', chosen for in the world the diagram does RARC 83 are markedly dif- the satellites in the geo- not attempt to show them all - ferent from each other. No stationary orbit. In WARC 77 it would be very difficult to doubt this is due to the lapse of these slots for Regions 1 and 3 read. Instead we have arbi- time between the two events, satellites are a regular 6° apart. trarily selected the fifty or so the development of spacecraft In RARC 83, however, they are countries that can be expected and radio technology during not equally spaced but have a to be the first in the field in star- this period, and the different variable spacing which ranges ting up d.b.s. services. On the interests and assumptions of from as close as 1° to as far assumption that these are likely the two groups of people apart as 11 °. to be the richest, most indus- concerned. Then in WARC 77 each coun- trialized nations, the broad criterion has been to take those try in Regions 1 and 3 has been assigned just one orbital posi- at the top of the league table of tion, and it shares this with Gross National Product per This roughly ... the whole situation here other countries. An exception is capita. means the the USSR which has five slots major capitalist and communist is still confused and uncertain because of its huge geo- countries. An exception to this rule of thumb is India, which and likely to remain so graphical area. But in RARC 83 several countries have more has been included because of its for some years than one slot. The USA, for ex- outstanding pioneering work in ample, has eight in all. satellite broadcasting. It was Another difference between the first country in the world to the two schemes is in the set up an experimental d.b.s. famous Both coniercnce, ;tatted number of channels assigned to system - the Satellite Instructional Television Ex- from the 12 -GHz frequency each country. WARC 77 gives 1975 in band specifically allocated to each country a standard ration periment of (reported satellite broadcasting. Within of five channels, whereas in this journal).* Television transmission stan- this, Region 1 is allowed to use RARC 83 there is considerable dards used for d.b.s. will de- 11.7 to 12.5 GHz, Region 2 has 'variation. Some small Region 2 pend on decisions outside of 12.2 GHz, while Region 3 can countries have as few as four laid in ITU operate in the two sub -bands channels while, for example, those down the world -wide They could 11.7 - 12.2 GHz and 12.5 - the eastern region of the USA plan. 12.75 GHz. From these alone has as many as 128. be, for example, predominantly allocated blocks of frequencies In the power flux densities NTSC in North America and Japan and predominantly C- WARC 77 and RARC 83 specified, however, the two worked out frequency plans are very similar. At the mac packets in Western channels, wave polarizations, outer edge of each `footprint' Europe, but the whole situation orbital positions, coverage WARC 77 lays down a require- here is still confused and un- and likely to so areas or `footprints' and ment for a minimum of -103 certain remain minimum and maximum dBW /m2, while RARC 83 speci- for some years. radiated powers. fies a minimum of -107 Britain, of course, is still a WARC 77 divided up the 800 dBW /m2 or a little higher in long way from establishing any MHz between 11.7 and 12.5 some situations. kind of d.b.s. service. The GHz into 40 channels spaced at The different structures of government- inspired Unisat equal intervals of 19.8 MHz. the two plans are significant in consortium collapsed last year; Each of these channels is 27 relation to their capacity to a new group called Britsat has MHz wide, so there is some deliver programmes and their put up another proposal and the frequency overlap, but this is flexibility of use in different government is reported to be taken care of by opposite direc- situations. What does this mean considering this and other cur- tions of circular polarization. in practice? As an illustration, rent suggestions. Meanwhile, it RARC 83, on the other hand, E.R. Reinhart of the Satellite looks as though France or Ger- split up the 500 MHz from 12.2 Television Corporation in the many may be the first to launch a to 12.7 GHz into 32 channels, USA has anlaysed the dif- d.b.s. service in Europe. This each of 24 MHz width. The ferences shown up by projected would be the outcome of obvious channel overlapping implementation of WARC 77 in Eurosatellite, a Franco -German here is again dealt with by Africa and RARC 83 in Latin manufacturing consortium which is opposite directions of circular America. He concludes that building two similar polarization. The spacing Latin American countries spacecraft, the TDF -1 for between transmissions with would not only get greater France and the TV -Sat 1 for similar polarizations is 29.16 numbers of channels for broad- West Germany. Electronic MHz. casting but would also have component manufacturers in In both plans the channels are greater flexibility for system Germany have already developed and put on the grouped into 8 channel - implementation than would be market various new compo- families. But in WARC 77 each possible for the countries of nents for receiver in- family consists of five frequen- Africa. designs work cies spaced at four -channel The accompanying diagram tended to from TV -Sat transmissions. intervals, while in RARC 83 gives some idea of what the each family has four frequen- whole d.b.s. plan looks like in 'December 1975, p.549 76 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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'SPECIAL Prices are es at going to press but may fluctuate, VALVES QUALITY please phone to tirm quotation. V.A T. included. 6Y6G 0.90 A1065 1.40 EF91 1.60 PL36 1.10 1A3 1.40 6BW6 6.26 0.70 A2293 8.80 EF92 2.90 PL81 0.85 1L4 0.80 68W7 1.80 6Z4 42900 13.75 EF95 0.95 PL82 0.70 1R5 0.80 6C4 0.70 724 1.90 2.90 AR8 0.75 EF96 0.60 PL83 0.60 1S4 0.65 6C6 1.20 906 19.50 ARP 0.70 EF183 0.80 PL84 0.95 155 0.65 6CH6 8.20 11E2 ATP4 0.60 EF184 0.80 PL504 1.00 1T4 0.65 6CL6 2.75 12A6 1.00 12AT6 0.70 pantechnic) B12H 3.90 EF812 0.75 PL508 2.40 1U4 0.80 6CW4 8.50 EFL200 1.85 PL509 5.85 1X28 1.40 6CX8 4.60 12AT7 0.85 CY31 1.40 0.60 1.25 EH90 0.85 PL519 5.85 2X2A 2.50 6CY5 1.15 12AU7 DAF96 12AU6 0.95 DET22 28.50 EL32 1.10 PL8021SE12.95 3A4 0.70 6D6 1.50 12AX7 0.65 DF92 0.80 EL34 1.80 PY80 0.70 3AT2 3.40 6F6 1.60 12BA6 0.90 DF96 0.70 4.55 PY81/800 0.85 3828 12.00 6F6GB 1.10 5.20 PY82 0.65 19.50' 6F7 2.80 120E6 1.25 DH76 0.75 EL37 3.45 DL92 0.60 EL82 0.70 PY88 0.60 306 0.60 6FBG 0.85 128H7 DY86/87 0.65 EL84 0.80 PV500A 2.10 3E29 19.00 6F12 1.50 12E1 18.95 DY802 0.70 EL86 0.95 00V03/105.95 3S4 0.70 6F14 1.15 12J5GT 0.55 12K7GT 0.70 E92C 2.80 EL90 1.00 10.00 4832 18.25 6F15 1.30 design manufacture and supply 12K8GT 0.80 E180CC 8.25 EL91 6.50 QQV03-20A 5R4GY 3.35 6F17 3.20 1207GT 0.60 2.25 EL95 0.80 27.50 5UAG 1.40 6F23 0.75 EA76 0.65 EABC80 0.80 EL504 2.70 OOV03-25A 5V4G 0.75 6F24 1.75 12SC7 12SH7 0.65 EB91 0.60 EL509 5.85 38.50 5Y3GT 0.95 6F33 10.50 POWER AMPLIFIERS E1519 6.90 00V06/40A 5Z3 2.80 6FH8 17.80 12SJ7 0.70 EBC33 1.15 1.45 0.90 E1821 8.20 28.50/49.50 5Z4G 1.25 6GA8 1.95 12507 EBC90 12S7GT 0.85 HIGH POWER ASSEMBLIES EBF80 0.60 E1822 9.95 OV03.12 5.75 5Z4GT 1.45 6GH8A 1.95 ELL801SE14.50 SP61 1.80 6/30L2 0.90 6H6 1.80 12Y4 0.70 EBF89 0.80 13D3 2.80 EC52 0.65 EM80 0.85 1121 32.20 6A87 0.70 6JU6 5.85 CONTROL CIRCUITRY EM87 2.50 TT22 29.50 6AC7 1.15 6J4 1.35 1305 0.90 EC91 4.40 19A05 0.85 EC92 1.85 EY51 0.95 UABC80 0.75 6AG5 0.60 6J4WA 2.00 1.15 2.30 1903 11.50 ECC81 0.95 EY81 0.65 UAF42 1.40 6AH6 6J5 EV86/87 0.60 UBF80 0.70 6AK5 0.65 6J5GT 0.90 19G6 10.35 ECC82 0.60 19H5 39.55 ECC83 0.65 EY88 0.65 UBF89 0.70 6AK8 0.60 6.16 0.85 for application in EZ80 0.70 UCC84 0.85 6AL5 0.60 CJ6W 2.80 2001 0.80 ECC84 0.60 1.30 E81 0.70 UCC85 0.70 6AL5W 0.85 6JE6C 5.90 20E1 ECC85 0.60 20P1 0.65 ECC88 0.80 GM4 5.90 UCF80 1.30 6AM5 4.20 6JS6C 6.40 GY501 1.30 UCH42 2.50 6AM6 1.50 6K7 1.45 25L6GT 1.60 ECC189 0.95 25Z4G 0.75 INDUSTRY ECC804 0.90 GZ32 1.05 UCH81 0.75 6ANBA 2.50 6KD8 5.50 GZ33 4.20 UCL82 0.95 6A04 4.40 6K06 4.80 35W4 0.80 ECF80 0.85 85A21.40,2.55' ECF82 0.85 GZ34 3.20 UF41 1.35 6AQ5 1.30 6L6M 4.60 PUBLIC ADDRESS 3.70 807 180/2.40' ECF801 1.05 GZ37 3.95 UF80 0.95 6A05W 2.20 6LBGC KT66 14.50 UF85 0.95 6AS6 1.15 6L6GT 1.95 812A 21.80 ECH 2.25 813 HI -FI ECH42 1.20 KT81 7.00 UL84 0.95 6AS7G 4.95 6L18 0.70 KT88 23.00 UM80 0.90 6AT6 0.90 6LD20 0.70 28.50/68.50' ECH81 0.70 8298 24.00 ECH 0.80 ML4 2.80 UM84 0.70 6AU6 1.25 6106 5.90 ML6 2.80 UY82 0.70 6AV6 1.25 607G 1.30 832A 8.90 ECL80 0.70 866A 5.05 ECL82 0.75 N78 9.90 UY85 0.85 6AX4GT 1.30 6SA7 1.80 0A2 0.70 VR105/30 1.25 6AX5GT 1.30 6SG7 1.80 866E 9.80 available ECL85 0.80 931A 19.80 0.90 082 0.80 VR150/30 1.35 68A60 6SJ7 1.80 ECL86 954 1.20 EF37A 2.15 PCL82 0.95 X66 1.80 0.70/1.207 6SK7 1.40 PCL84 0.90 X61M 1.70 6849 3.45 6SL7GT 0.85 955 1.20 EF39 1.50 956 1.20 EF80 0.65 PCL86 0.75 Z759 19.00 68E6 6SN7GT 1.60 OFF THE SHELF PCL86 0.75 Z749 0.75 0.65/120' 6SQ7 0.95 5763 5.75 EF83 3.10 6060 1.95 EF85 0.60 PCL805/850.85 Z8000 3.45 6006G 1.80 6SR7 4.60 P0500/5104.30 Z801 U 3.75 60J6 1.30 6V6G 1.50 6080 5.30 CUSTOMISED EF86 1.25 6201 5.20 EF89 1.60 PFL200 1.10 Z803U 16.00 6BQ7A 0.85 6V6GT 1.30 2.80' Z900T, 2.45 68R7 4.80 6X4 1.50 6146 10.35 C A D DESIGNED 6X5GT 0.65 61460 10.35 8068 12.50 VALVES AND TRANSISTORS NEW PYE 9001 0.95 valves, transistors, etc. Telephone enquiries for EQUIPMENT 9002 0.95 retail 749 3934, trade and export 743 0899. 9003 0.95 FIELD TELEPHONE, CABLE TYPE 010 & SPARES 132 Road FIELD TELEPHONES TYPE 'J'. Tropical, in metal cases. HARNESS "A" 0. "B" CONTROL UNITS "A" "W' tel. 01.361.8715 High 10 -line MAGNETO SWITCH -BOARD. Can "J1" "J2." Microphones No 5, 6. 7 connectors, work with every type of magneto telephones. frames, carrier sets. etc telex 266 873 New Southgate POSTAGE: E1 -E3 50p; £3 -E5 60p; £5110 80p; £10 -E15 E1.00; £15 -f20 E1.50 Minimum order E1.00. PANTEC G LONDON N11 1PG. COLOMOR (ELECTRONICS LTD.)170 Goldhawk Rd,LondonW12 9 a.m p.m. Tel. 01 -743 0899 or 01 -749 3934.0pen Monday to Friday -5.30 CIRCLE 21 FOR FURTHER DETAILS. CIRCLE 32 FOR FURTHER DETAILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 77

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Ex B , up to 1200 baud, full REDIFFUSION MARK 3, 20" COLOUR monitor. Fitted with standard 75 ohm 68A09 £8 6BB09 £10 8085A £5.50 8086 £15 duplex 4 wire or halt duplex over 2 wire line. ONLY composite video input and sound amp. This large screen colour display is ideal 8088 £8 NEC765 £8 WD2793 £28 8202A £85.00 PER PAIR +pp C10.00 for school and AUDIO VISUAL applications. £22 8251 £7 8748 £15 280A DART £6.50 shops, discos, clubs other Supplied For more information contact our Sales Office. in AS NEW or little used condition ONLY £145.00 + Carr. Z80A CPU £2.00. BUDGET RANGE EX EQUIPMENT MONOCHROME video monitors. Thousands of IC's EX STOCK send SAE for list. All units are fully cased and set for 240v standard working with composite video MATRIX PRINTERS inputs. Units are pre tested and set up for up to 80 column use Even when SPECIAL BULK PUR HA o t ese compact, igh MINOR screen burns exist - normal data displays are unaffected. speed matrix printers. Built in Japan for the Hazeltine 12- KGM 320-1 B/W bandwidth input, will display up to 132 x 25 lines. £32,95 DISK DRIVES Corporation this unit features quality construction 12` GREEN SCREEN version of KGM 320 -1. Only £39.95 apanese half height, 80 track double sided disk drives giving 100cps bidirectional, full pin addressable 9" KGM 324 GREEN SCREEN fully cased very compact unit. Only £49.00 by TEAC, CANON, TOSHIBA etc. graphics, 6 type fonts, up to 9.5" single sheet or Carriage and insurance on all monitors £10.00 Sold as NEW with 90 day guarantee ONLY £85.00 tractor paper handling, RS232 and CENTRONICS SUGART SA400 SS FH 35 TRK £55.00 parallel interface. Many other features. BRAND NEW SIEMENS FDD100 SS FH 40 TRK £65.00 and BOXED. COST £420. Our price Only £199.00 carriage on 51/4" drives £5.50 GOULD OF443 enclosed, compact switch mode supply with DC regulated Brand NEW metal 4 DISK CASES with internal PSU. DSKC1 for 2 HH or 1 FH drive £29.95 +pp £4.00 outputs of +5v @ 5.5a, +12v @ 0.5a, -12v @ 0.1a and -23v @ 0.02a Dim 18 x DSKC 2 for 1 HH drive £22.95 +pp £3.50 Dry Fit MAINTENANCE FREE by Sonnenschein 11 x 6 cm. 110 or 240v input. BRAND NEW only £16.95 DKSC 3 As DSK1 LESS PSU +pp £2.50 & Yuasa. GOULD G6-40A 5v 40 amp switch mode supply NEW £130.00 £12.95 DSKC 4 As DSK2 LESS PSU +pp £2.00 GREENDALE 19A -BOE Switch mode 60 watt open PCB with a fully regulated £10.95 A300 07191315 12v 3Ah NEW £13.95 8" IBM format TESTED EX EQUIPMENT. DC output of 5v @ 6 amps, and three semi regulated outputs of +12v, -12v, A300 071 9131 2 6v 3Ah NEW £9.95 SHUGART 800 /801 SS £175.00 +pp £8.50 A300 071 91 202 6 -0-6v 1.8Ah TESTED Ex +1 5v @ up to 1 amp. Dim only 11 x 20 x 5.5 cm. 110 or 240v AC input. TESTED +pp ex equipment. Only £24.95 SHUGART 851 DS £250.00 £8.50 E. uip £5.99 TWIN SHUGART 851's 2 Mb total capacity in smart AC -DC Linear PSU for DISK drive and SYSTEM applications. Constructed on a with rugged ALLOY chassis to continuously supply fully regulated DC outputs of +5v case, complete PSU etc. £595.00 MITSUBISHI M2894.63 8" DS 1 Mb capacity equiv. @ 3 @ +24v @ 5 circuit and overvoltage VDU TE ' amps, -5v 0.6 amps and amps. Short to SHUGART SA850R. BRAND NEW at £275.00 M /MALS protected. AC input. x 12.5 x 7 100 or 240v Dim 28 cm NEW £49.94 +pp £8.50 Standard VDU data entry termina s Carriage on all PSU's £3.00 DRE 7100 SS condition as seen £125.00 at give away prices!! of art Various PSU's Ex Stock SEE PSU section. OUME OVT108. Current product, state the Manufacturer's BRAND NEW surplus. HARD DISK DRIVES terminal with detachable keyboard, 12 Green screen, DEC LA34 Uncoded keyboard with DRE /DIABLO Series 30 2.5 Mb front load £525.00 2 page RAM. TVI 925, Hazeltine, ADMSA emulations, 67 quality gold plated switches on Exchangeable version £295.00. ME3029 PSU £95.00 software setup, 25 x 80, Clock Swivel and tilt base, X -Y matrix - ideal micro conversions DIABLO 44 /DRE4000A, B 5 +5 Mb from £750.00 Printer port, Function keys etc. BRAND NEW and etc. £24.95 BOXED AT ALMOST HALF PRICE Only £425.00 CDC HAWK 5 +5 Mb £795.00. CDC 9782 80 Mb 15" eacois AMKEY MPNK -114 Superb word RMO3 etc. £2500.00. ÁJ510 - EX RENTAL, Z80 controlled. green MOO= e own x addressing, 11100 processor chassis keyboard on single PERTEC D3422 5 +5 Mb £495.00 screen 24 80 display, graphics, cursor IM 116 features printer port etc. Very good condition TESTED complete 01 PCB with keys. Many a01a e RODIME 51/4" Winchesters ex -stock from £150 CALL such as On board Micro, Single 5v BASF 6172 23Mb Winchesters, as seen £199.00 with manual only £225.00 r. . rail, full ASCII coded character set ADDS 520 - Dumb terminal, used, 12" b/w screen aith 31 function keys, numeric keypad, cursor pad and 9600 baud SERIAL TTL Unless stated all drives are refurbished with 90 day RS232 interface and printer port. TESTED. ASCII OUTPUT!! Less than half price Only £69.00 with data guarantee. Many other drives and spares in stock ONLY £125.00. Carriage on terminals £10.00 Carriage on Keyboards £3.50 - call sales office for details. 100's of other terminals in stock CALL for more details.

: All prices quoted are for U.K. Mainland, paid cash with order in Pounds Sterling PLUS VAT. Minimum order value . Credit Card orderE /0.00. Minimum BONA FIDE account orders from Government Depts., Schools, Universities and established companiesE20.00. Where post and packing not indicated please ADD £1.00 + VAT. Warehouse open Mon -Fri E ..._...° 9.30 -5.30. Sat 10.30 -5.30. We reserve the right to change prices and specifications without notice. Trade, Bulk and Export I_ i 1 h i 1a ii 1 \1 ! i i 32 Biggin Way, Upper Norwood, London SE19 3XF I_ 11 -i I_ i I I\ i i i ' _1 Telephone 01 -679 441 4 Telex 894502 Data 01 -679 1888 .

78 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com ERS - PRINTERS - PRINTERS - PRINTER SUPER DEAL? NO - SUPER STEAL TELETYPE ASR33 GE TERMIPRINTER THE FABULOUS 25 CPS "TEC STARWRITER" DATA I/O TERMINALS /// Industry standard, combined ASCII 110 baud printer, keyboard and 8 hole paper tape punch and reader. Made to the very interface. highest spec the TEC Standard RS232 serial STARWRITER Ideal as cheap hard copy unit FP1500.25 features a or tape prep. for CNC and NC very heavy duty die cast machines. TESTED and in good chassis and DIABLO condition. Only £250.00 floor type print mechanism giving superb stand £10.00. Carr & Ins. £15.00. A massive purchase of these desk top registration and print a fraction printer terminals enables us to offer you quality. Micro-processor of its on ginal Cost, these quality 30 or 120 cps printers electronics offer full at a SUPER LOW PRICE against their DIABLO /QUME command compatability and rum contro via CPM WORDSTAR EX NEWS original cost of over £1000. Unit ETC. Many other features include bi- directional printing, switchable 10 or 12 pitch, comprises of full QWERTY, electronic full width 381 mm paper handling with up to 163 characters per line, friction feed keyboard and printer mech with print rollers for single sheet or continuous paper, internal buffer, standard RS232 serial SERVICE PRINTERS face similar to correspondence quality interface with handshake. Supplied absolutely BRAND NEW with 90 day guarantee typewriter. Variable forms tractor unit and FREE daisy wheel and dust cover. Order NOW or contact sales office for more enables full width - up to 13.5" 120 information. Optional extras RS232 data cable £10.00. Tech manual £7.50. Tractor Compact ultra reliable quality built unit column paper, upper - lower case, Feed £140.00. Spare daisy wheel £3.50. Carriage & Ins. (UK Mainland) £10.00. made by the USA EXTEL Corporation. standard RS232 serial interface, internal Often seen in major Hotels printing up to vertical and horizontal tab settings, the minute News and Financial inform- standard ribbon, adjustable baud ation, the unit operates on 5 UNIT rates, quiet operation plus many other NOW ONLY £499 + VAT BAUDOT CODE from a Current loop, features. Supplied complete with manual. RS232 or TTL serial interface. May be Guaranteed working GE30 £130.00. connected to your micro as a low cost GE1200120 cps £175.00 printer or via a simple interface and filter Untested GE30 £65.00 Optional floor to any communications receiver to stand £12.50. Carr 8 Ins. £10.00. DIY PRINTER MICH enable printing of worldwide NEWS, TELEX and RTTY services. SEMICONDUCTOR Brand New surplus of this professional printer chassis gives an Supplied TESTED in second hand outstanding opportunity for the Student, Hobbyist or Robotics condition complete with DATA, 50 and 'GRAB SAGS' a digitiser etc, entirely to their 75 baud xtals and large paper roll. constructor to build printer - plotter - amazing value contents own specification. The printer mechanism is supplied ready built, TYPE AE11 Mixed Semis £49.95 include transistors digital, linear, IC's, aligned and pre tested but WITHOUT electronics. Many features 50 Column ONLY triacs, diodes. bridge recs, etc. etc. include all metal chassis, phosphor bronze bearings, 132 character Spare paper roll for AEI 1 £4.50 All devices guaranteed brand new full head, 2 x two phase 12V TYPE AF11 R 72 Col. spec with manufacturer's markings, fully optical shaft position encoder, NINE needle £65.00 stepper motors for carriage and paper control, 9.5" Paper platten etc. + Ribbon guaranteed. TYPE AH11 R 80 Col. 100+ £5.15 etc. Even a manufacturer's print sample to show the unit's capabilities!! 50+ £2.95 ASCII /BAUDOT £185.00 TTL 74 Series. A gigantic purchase of an Overall dimensions 40 cm x 12 cm x 21 cm. Carriage and Insurance £7.50 "across the board" range of 74 TTL series Sold BRAND NEW at a FRACTION of cost ONLY £49.50 + pp £4.50. IC's enables us to offer 100+ mixed "mostly TTL" grab bags at a price which two or three chips in the bag would normally cost to buy. Fully guaranteed all IC's full spec. 100+ £6.90, 20,000 FEET OF ELECTRONIC 200+ £12.30, 300+ £19.50 AND COMPUTER GOODIES ENGLAND'S LARGEST SURPLUS STORE- SEEING IS BELIEVING!! MAINS FILTERS CURE those unnerving hang ups and data glitches caused by mains interference with professional quality filters. SD5A match- DEC CORNER MAO TAPE DRIVES box size up to 1000 watt 240 V Load ONLY £5.95. L12127 compact Many EX STOCK computer tape drives and spares by completely cased unit with 3 pin fitted PDP 1140 System comprising of CPU, 124k socket up to 750 watts ONLY £9.99. memory & MMU 15 line RS232 interface. PERTEC, CIPHER, WANGO, DIGIDATA, KENNEDY RPO2 40 MB hard disk drive. etc. Special offer this month on DEI Cartridge tape TU10 9 track 800 BPI Mag tape drive, dual EPROM COPIERS track system. VT52 VDU, etc. etc. Tested and drives ONLY £450.00 each. running. £3,750.00 CALL FOR DETAILS The amazing SOFTY 2 The "Complete BA11 -MB 3.5" Box, PSU, LTC £395.00 Toolkit" for copying, writing, modifying and DH11 -AD 16" x RS232 DMA listing EPROMS of the 2516, 2716. interface £1,900.00 COMPUTER/SYSTEM CABINET a PSU 2532, 2732 range. Many other functions DLV11 -J4 x EIA interface £350.00 All in one quality computer cabinet with integral include integral keyboard, cassette inter- DLV11 -E Serial. Modem support £190.00 face, serial and parallel i/o UHF modulator DUP11 Synch. Serial data i/o £650.00 switched mode PSU, mains filtering, and twin fan ZIF socket etc. D0200 Dilog - multi RK controller £495.00 cooling. Originally made for the famous DEC PDP8 ONLY £195.00 + pp £2.50. DZ11 -B 8 line RS232 mux board £650.00 computer system costing thousands of pounds. "GANG OF EIGHT" intelligent Z80 KDF11 -B M8189 PDP 1123 Made to run 24 hours per day the psu is fully controlled 8 gang programmer for ALL PLUS £1,100.00 screened and will deliver a massive +5v DC at 17 amps, +15V DC at single 5v rail EPROMS up to 27128. Will LA30 Printer and Keyboard £80.00 1 DC 5 The is copy 8 27128 in ONLY 3 MINUTES. Internal LA36 Decwriter EIA or amp and -15v at amps. complete unit fully enclosed with removable top lid, filtering, trip switch, power and run leds LCD display and checking routines for 20 mA loop £270.00 IDIOT PROOF operation. Only £395.00 + MS11 -JP Unibus 32kb Ram £80.00 mounted on ali front panel, rear cable entries, etc. etc. Units are in pp £3.00. -LB MS11 Unibus 128kb Ram £450.00 good but used condition - supplied for 240v operation complete with "GANG OF EIGHT PLUS" Same spec. as MS11 -LD Unibus 256kb Ram £850.00 full circuit and tech. man. Give your system that professional finish above but with additional RS232 serial PDP11 /05 Cpu Ram, i/o etc £450.00 for only £49.95 + Carr. 19" wide 16" deep 10.5" high. Useable area interface for down line loading data from PDP11 /40 Cpu, 124k MMU £1,850.00 16" w 10.5 "h 11.5"d. computer etc. ONLY £445.00 + pp £3.00 RT11 ver 3B documentation kit £70.00 RK05 -J 2.5 Mb disk drives £650.00 Also available less psu, with fans etc. Internal dim. 19 "w, 16 "d, 10.5"h. Data sheets on request KL8 JA PDP 8 async i/o £175.00 £19.95. Carriage £8.75 M18E PDP 8 Bootstrap option £75.00 VT50 VDU and Keyboard COOLING FONS -20 mA £175.00 S VT52 66 o" Keep your hot parts COOL end RELIABLE with our range of VDU and RS232 interface £250.00 EQUIPMENT COLING FANS ETRI 1261F21 240v 5 bade equipment Mn DISCOUNT x 80 38rrmm E9.95. ETRI 995U01 240v SI'mline s,m. 80 Due to our massive bulk purchasing programme, which enables us to bring you the Dim. 92 x 92 25mm. equipment gfan. NEW E9.95. v v 2.5' compact very quiet a GOULD JB.3AR Dim. 3' 3' Give your VT100 Birthday!!! best possible bargains, we have thousands of ICs, Transistors, Relays, Caps, PCBs. running 240v operation. NEW E6.95. MUFFIN- CENTAUR- Brand New VT100 Keyboards Sub-assemblies, Switches etc. etc. surplus to OUR requirements. Because we don't BOXER standard 120 v 120 x 38mm tans Order 110v OR only £85.00 have sufficient stocks of any one item to include in our ads we are packing all these 240v. 3 or 5 blade, NEW at 610.50 or tested EX EQUIPMENT items into OF A LIFETIME. Thousands of components at giveaway 65.50. Low Voltage DC Fans. BUHLER 69.11.22. EL 16v DC the BARGAIN micro aiature r rsible. Uses brushless s motor. 1000's OF EX STOCK spares for PDP8, PDPBA prices. Guaranteed to be worth at least 3 times what you pay. Unbeatable value and almost silent running. guaranteed 10.000 hr life.vMeasures PDP11, PD P1134 etc. SAE. for list. or CALL perhaps one of the most consistently useful items you will every buy!!! Sold by only 82 v 62 22mm. Current cost 635.00 OUR PRICE sales office for details. ONLY 613.95 complete with data. 120 x 120 v 38mm 14' weight. DC fans). PANSONIC FB- 12C12H 12v DC 5 blade 618.00 ALL TYPES OF COMPUTER EQUIPMENT AND 2.5kIs £5.25 + pp £1.25 5 kls £6.90 + £1.80 PAPST 41245 24 - 28v DC 5 blade 618.00. SPARES WANTED FOR PROMPT CASH 10kIs £11.25 + pp £2.25 20k15 £1 9.50 + pp £4.75 100's of other tans Ea Stock. PAYMENT. .Ili .!, 1,.' i',.t 8 Packing on all lan, 2 fiat 1000's of other EX STOCK items including POWER SUPPLIES, RACKS, RELAYS, TRANSFORMERS, TEST EQUIPMENT, CABLE, CONNECTORS, HARDWARE, MODEMS, TELEPHONES, VARIACS, VDU'S, M' PRINTERS. POWER SUPPLIES, OPTICS, KEYBOARDS etc. etc. Give us a call for your spare part requirements. Stock changes almost daily. Don't forget, ALL TYPES and QUANTITIES of electronic surplus purchased for CASH CIRCLE 73 FOR FURTHER DETAILS. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com Hitachi Oscilloscopes the highest quality from £299

- ; the most competitive prices +VAT

Hitachi Oscilloscopes provide the quality and performance that you'd expect from such a famous name, with a newly- extended 14 model range that represents the best value for money available anywhere. V- 212/222 20MHz Dual Trace V-650 60MHz Dual Timebase V -223 20MHz Sweep Delay V-1050 100MHz Quad Trace (illustrated) V-1070 100MHz Four Channel V -209 20MHz Mini- Portable V-1100 100MHz DMM /Counter V -422 40MHz Dual Trace V-134 10MHz Tube Storage V -423 40MHz Sweep Delay VC-6015 10MHz Digital Storage V -509 50MHz Mini -Portable VC-6041 40MHz Digital Storage Prices start at £299 plus vat (20MHz dual trace) including a 2yr. warranty. We hold the range in stock for immediate delivery. For colour brochure giving specifications and prices ring (0480) 63570 Thurlby- Reltech, 46 High Street, Solihull, W .Midlands, 691 3TB. CIRCLE 43 FOR FURTHER DETAILS. Add 8 channels to your 'scope New Thurlby 0M358 multiplexer £179.vat /r. The Thurlby 0M358 gives any oscilloscope an 8 channel display. Observing // // // //r/// // many waveforms simultaneously can be essential when analysing sophisti- cated equipment. Application areas include microprocessor based products, data transmission systems, A to D converters, frequency synthesizers etc. The 0M358 is ideal for digital equipment (it can often solve problems that would otherwise need a fast logic analyser) but, unlike dedicated logic test instruments, it is equally suited to analogue waveforms. .'ï The OM358 has a bandwidth of 35MHz and 3% calibration accuracy. Each input has an impedance of IMil - 20pF and accepts signals up to ± 6V. An 8 channel, 4 channel, or single channel display can be selected with triggering I!Ì from any channel. Colour data sheet with full specifications available. Electronics IIIThurlbt).Y I FP New RoadThurlby , St.lves, CamLtd bs. designed and built in Britain PE1 7 4BG Tel: (0480) 63570 CIRCLE 14 FOR FURTHER DETAILS. The world's most advanced low -cost bench multimeter! Thurlby 1905a £ 349 + VAT A complete high performance bench DMM

5t/2 digits; 0.015% acc; 1 kiV, 1mi? , 1nA. Full ac and current functions as standard A sophisticated computing and logging DMM Linear scaling with offset; null /relative Percentage deviation; running average dBV, dBm general logarithmic calculations Limits comparison; min and max storage 100 reading timed data logging RS232 and IEEE -488 interface options Thurlby Electronics Ltd I New Road, St.lves, Cambs. PE17 4BG III Thurlby pg Tel: (04.80) 63570 designed and built in Britain CIRCLE 45 FOR FURTHER DETAILS. Now Thurlby makes logic analysis affordable ! from the new Thurlby LA -160 £395 +vat 16 channels, expands to 32 2K word acquisition memory Clock rates up to 20MHz Non -volatile reference memory State and timing displays Search and compare facilities Selectable display formats Hard -copy data print -out An oscilloscope and logic probe are not enough to unravel the complexities of today's electronic equipment. A logic analyser is as essential for observing digital signals as an oscilloscope is for observing analogue signals, and now Thurlby puts one within every engineer's reach. Contact us now and get the full technical data.

Thurlby Electronics Ltd III Thurlbyl re New Road, St.lves, Huntingdon, designed and built in Britain Cambs. PE17 4BG, England. Tel: (0480) 63570 CIRCLE 46 FOR FURTHER DETAILS. www.americanradiohistory.com A FULL HOUSE DISTRIBUTING A GREAT DEAL

igital G °scigoscopes°gUe

Power supplies il D.M.Aus -:.: :. ï 16.4i Paxton Function generator coup Instruments Frequency Distributors of pck*star '0-'-$a'. BI -,.-w \ Electronic Test .:1 1 " ,,; ! ;/ Instrumentation tiIR Unit B1 ` -o9`c Pixmore Industrial Estate, Pixmore Avenue, Letchworth, .. ti /ll//: ,}, ,Y,.b - -, Herts SG6 1 JJ ti. i Y,1',f+ f,, Phone: _ . 1 _a'cs . 0462 685648

CIRCLE 22 FOR FURTHER DETAILS.

SATELLITE TELEVISION Buy direct from the manufacturers, low cost full band satellite TV systems. REPRINTS Write or telephone for details, or call in a reodymade sales aid at our factory showroom. Agents and Distributors required. NETWORK SERVICES LTD Units 7 -8 Newburn Bridge Industrial Estate Hartlepool, Cleveland TS25 1 UB Tel: 0429 74239

Quadrant Picture Library CARS BOATS PLANES Over a million photographs and transparencies from the turn of the century to the present day; If you are interested in a particular article or cutaway drawings and illustrations; colour advertisement in this publication why not take prints of civil and military aircraft; directories advantage of our reprint service. We offer an excellent, from the early í800s and much more besides reasonably priced service. For further details and a for advertising and PR agencies, authors. quotation publishers, TV programmers and solicitors. Ring Peter Baldwick on 01 -661 8623 Interested? Then write or telephone OI'l. at Quadrant House, The Quadrant, Sutton, Surrey 5112 SAS (lei: 01- 661 3 -) 2- ti ).

ELECTRONICS & WIRELESS WORLD FEßRUARY 1986 81

www.americanradiohistory.com ammo sows

Answering machines are very popular these days and we are pleased to offer a new model - the Betacom LR3 - which features a double tape, one to record your announcement and the other to record the messages. Unlike single tape answering machines, it is necessary to record the outgoing message only once and each caller will hear it repeated. The outgoing message may be changed by using the inbuilt microphone and the erase facility will clear the incoming message tape. If you are at home, a monitor allows you to hear the caller and if you wish to speak, use your telephone as normal. A fast forward cue search locates the next message and there is a marker sound to indicate the end of the day's messages and also a volume control. The Betacom LR3 is compact and in a smart grey and mushroom plastic. It is extremely good value at the special price of only £79.95 inc. p &p and two free tapes. It is easily connected to the power supply with the lead provided and a BT Approved jack plug is attached. The Betacom LR3 is BT Approved and Betacom offers a 12 month guarantee with a fast and efficient after sales service. If you are not satisfied return within 7 days for a refund to Betacom, D.M. Baylin Ltd., 76 Marylebone High Street, London, W1M 3AR

ELECTRONICS & WIRELESS WORLD OFFER, C/O PO BOX 14, No. 1 WAREHOUSE, HORLEY ROW, HORLEY, SURREY, RH6 8DW r ------u. To: Electronics & Wireless World Offer, c/o PO Box 14, No. I Warehouse, Horley Row, Horley, Surrey, RH6 8DW 1 Please send me Betacom LR3 Telephone Answering Machine(s) at only £79.95 inc. p &p and VAT 1 I enclose crossed cheque (with address on back) /PO No(s) value £ made payable to Betacom OR please ' debit my Access /Visa account by the above amount. Telephone orders 0293 -776634 1 My card number ' DATE SIGNATURE NAME ADDRESS 1 ' POST CODE -UK -readers -only. Subject - to availability.- - Allow - 28 days -for delivery. - Regd. - in England - No. - 151537 - - - - 82 -- ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com NEW PRODUCTS

Power supplies from Sweden

A range of 32 switch -mode discharged with opposite polarity supplies and a made -to- measure allowing the diode on the service based on á further 19 basic secondary side to conduct. This designs has been launched by technique allows considerable Rifa. Most of the supplies use a reduction in component -count as is 'flyback' circuit. This has only one shown by the picture. Both switching transistor and one diode. circuits perform the same task. The standard range includes d.c.- to -d.c. converters in ratings from 20 to 250W, with up to four outputs; a.c.- to -d.c. power supplies from 60 to 240W; customized units from 5 to 250W. The range has become available as a result of reorganization within the Ericsson group. Rifa, a A transformer with a specific subsidiary has taken over the inductance stores energy while the power supply division of its parent transistor is on. The energy which originally produced supplies cannot be passed to the secondary for Ericsson's own products. Rifa output as it is blocked by the AB, Market Chambers, Shelton diode. When the transistor is cut Square, Coventry CV1 1 DJ. off, the stored energy is EWW 209 on reply card. Adhesives for electronics

A range of products specifically 425 seals fasteners and locks aimed at the electronics industry adjusting screws against vibration. have been produced by Loctite. Ultra- performance Tak Pak 382 is Chipbonder is for the rapid an improved version of an placement of surface mounted adhesive for wire tacking and components so that they are held bonding smaller components. in position prior to soldering. The Black Tak 410 is a 'toughened' bonds are completely cured after 4 cyanoacrylate adhesive used for to 5 minutes of heat treatment or strain relief and the mounting of in 30 to 45s when exposure to low - large units and covers. It is intensity u -v light is followed by claimed to have a peel and impact 120 °C heat. The resultant bonds strength superior to many epoxy are flexible and shock -resistant resins. Further additions to the and can withstand wave soldering. "PCB Assembly Line" range The adhesive is coloured include a silicone sealant that does CPIM on a PC fluorescent pink to aid inspection. not tarnish copper or brass and used; a conversion utility to load Output 384 is a thermally - can be used for encapsulating CP /M programs onto IBM - conductive adhesive for heat components, a freezer aerosol, a For those who have grown fond of compatible discs, and a'bind' utility dissipation. It may be used to non -conductive solvent for their CP /M software and yet want to that attaches the CPemulator to the replace tapes, mechanical cleaning, a contact lubricant and graduate to a computer running PC- programme. All the software fasteners and non -conductive cleaner and spray -on protection DOS or MS -DOS, rescue is at hand developed on a CP /M computer can adhesives and is claimed to have a shield for p.c.bs against humidity from G -Tek, an American company then be run on a PC -DOS computer better heat -conductivity than zinc - and environmental pollution. It who have produced a CPemulator. without altering a byte. £199 ( + vat) oxide grease. It sets in 30s and is may be soldered through for spot This package makes your IBM PC, from Bytron Ltd, High Street, fully cured in one to four hours. repairs. Loctite UK, Watchmead, or similar, think that it is being run Kirmington, S. Humberside, DN39 Other adhesives are all Welwyn Garden City, Herts AL7 by a Z80 with CP/M. Two parts are 6YZ. EWW 222 on reply card. cyanoacrylate products. Assure 1JB. EWW 211 on reply card.

Video effects computer

An instrument from Fairlight, the repertoire includes a palette of Any shape may be used as a 'cut static devices can be added to an Australian makers of the over four thousand colours. Its out' or matte to control areas for image using a "cut and paste" Computer Music Instrument, has output can be stored on video -tape different foregrounds or technique. Many geometrical done to visual images what their and then recalled for further backgrounds, patterns or other functions can be called up for the synthesizer did to music. It is a manipulation or combination with effects. A live image can be frozen creation of charts, graphs and very versatile device for other images. and then manipulated using all the diagrams, which can have any of manipulating images. It has a wide Background and foregrounds can other facilities. An audio input 54 textures applied to them. range of applications but, we be created and made to move or may be used to control an image All this fits into a 19in rack - suspect, is most likely to be used have live images moving through and this can be combined with mounting box with a remote in providing the weird effects that them. Three planes are used in a freeze effects, 'trails' split or control console. The unit provides seem to go with pop music. The single CVI but more than one can mirror images to produce some connectors for synchronization Computer Video Instrument (CVI) be cascaded to provide a number spectacular effects. input and outputs and has two can take an image from a "live" of different planes. Using the input pad it is possible video inputs which may be camera, tape, film, a slide or still A chroma -key facility enables to pull an image out of shape and composite or RGB. An RS232 picture and manipulate the image still images to be panned or add colours or details; Dr Jekyll communications port enable in real time. It is also provided zoomed or stretched or a moving no longer needs to use a lot of control from an external computer. with a stylus- sensitive pad that sequence can produce the sort of changes in make -up to change into £4950 (+ tax) from Syco Video, 20 enables drawing or writing to be multi -image associated with Mr Hyde: it can be done for him Conduit Place, London W2. EWW superimposed on the image. Its stroboscope pictures. on the machine! Lettering or other 213 on reply card. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 83

www.americanradiohistory.com NEVI PRODUCTS

LCD oscilloscope

A hand -held, battery powered, 3.2MHz oscilloscope features a dual -trace liquid crystal display. The display consists of a 128 b 160 dot matrix with a display area of about 76 by 95mm. The internal memory is battery- backed for waveform storage which allows later waveform analysis. Features of the Y -axis operation include a scale of four vertical divisions for each channel, a nine -range sensitivity from 10mV to 5V /division and a frequency accuracy of ± 3dB or less from d.c. to 200kHz. The X -axis has 10 divisions with 20 sweep speeds from 5µs to 5s /Div: there are continuous and single sweep measurement modes and positive, negative and switchable trigger modes. Soar Model 1000 also incorporates a full -function auto - ranging digital multimeter. Cost just under £1000, exclusively from Advance House of Instruments, Raynham Road, Bishop's Stortford, Herts CM23 5FF. EWW 214 on reply card.

Serial line converter Universal PCM transcoder

Used one at each end of a data transmitter or receiver functions; For use on North American and multiplexers, channel service channel, the Serial line converters four modules in all. European digital transmission units, echo cancellers, digital cross from CDOS enable data RS422 extends the range of telephone lines, the Harris connects and p.c.m. repeaters. transmission to be established serial communication from the HC -5560. The four standard The device operates from a over longer distances than the 30m of RS232 to one km. Current p.c.m. coding schemes can be single 5V supply with a 100mA R8232 ports of the devices to loop transmission extends this accommodated: Alternative mark maximum current drain. It can which they are attached. This is even further; up to 5km. inversion (AMI), High- density encode and decode simultaneously; achieved by converting the The transmitter and receiver bipolar three (HDB3), Bipolar with includes an alarm signal driver; transmission level to RS422 modules can be adapted to cope six zero substitution (B6ZS) or can operate asynchronously with standards. Full duplex operation is with data from any serial source; with eight zero substitution loop -back control and transmission possible, with handshaking in RS232, t.t.l. and CCITT /EIA (B8ZS). HDB3 is the error detection. HC -5560 is priced either direction. The converter levels. The output from a uart or recommended CCITT standard. at £9.29 in quantities of 100. does not modify protocol or data a.c.i.a. can be connected directly. The device can be used in most Harris MHS Semiconductor Ltd, word format, which are The devices come in a case with a equipment that can communicate Eskdale Road, Winnersh, Berks determined by the equipment mains power supply but the with T1, T1C, T2 or RG11 5TR. EWW 215 on reply connected to the channel. double -sided board may be PCM -30/CEPT lines, including card. 20mA current -loop send and extracted and built directly into receive channels can be added by equipment. C.D.O. Systems Ltd, plug -in modules, which provide Unit 65, Corby Workshops, Corbe. either active or passive, Northants NN17 1YB. EWW 210 Surge suppressors

A new type of power integrated They switch in nanoseconds and can circuit is capable of diverting handle peak surge currents of 300A. dangerous transient energy away The three -terminal Surgector adds from sensitive electronic circuitry. direct access to the gate of the s.c.r. Called a Surgector, this RCA which allows the device to be monolithic device is a thyristor with triggered with a user -supplied a special diffused gate section which voltage -level detector. Current acts as a zener diode. This permits devices are uni- directional but a bi- the anode voltage to turn on the directional 225V device is about to device, giving it a very fast voltage be released. They are specifically rise time; lightning, for example, designed to protect telephone can rise at 1kV /ms. The Surgector equipment. However, the small device clamps the voltage by its (T0202) size and low cost make then zener action until the integral equally suitable for computers, thyristor turns on and shunts the alarm systems, cars, tv, outdoor excess voltage away. In most cases, lighting, c.a.t.v. and many other the protected circuitry never sees a applications. RCA Solid State, voltage greater than 130% of its Lincoln Way, Windmill Road, normal working voltage. Two - Sunbury on Thames, Middlesex terminal devices have off -state TW 16 7HW. EWW 223 on reply voltage ratings of 30, 58 and 225V. card. 51 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com PREAMPLIFIER MODULES All modules are supplied with in line connectors but require potentionmeters, JAYTEE switches, etc. If used with our power amps they are powered from the ®.wPROM appropriate Power Supply. Type Application Functions Price HY6 MonoPreAmp Full Hi Fi facilities £8-45 HY66 StereoPre -Ai.ip Full Hi Fi facilities £1195 HY73 Guitar Pre -Amp Two Guitars plus Microphone ..E12.45 HY78 Stereo Pre -Amp As HY66 less tone controls E1095 NEW! HY83 Guitar and Special Effects Pre -Amp as HY 73 Plus Overdrive and Reverb £1895 MOUNTING BOARDS: For ease of construction we recommend the B6 w a for HY6 £0.95. 866 for HY66 -78 £1.45.

IMOSFET MODULES Type Output Load Price Power Impedence Ideal for Discds, public address and Watts Irms) 0 applications with complex loads (line MOS128 60 4-8 £34.45 transformers etc.(. Integral Heatsink MOS248 120 4.8 £39 45 slew rate 20v/µs distortion less than 0.01% MOS364 180 4 £6445

BIPOLAR MODULES POWER SUPPLY UNIT Ideal for Hi Fi, Full load protection Type For Use With Price integral Heatsink, slew rate 15v /µs THE SPECIAL DISTRIBUTOR FOR SPECIAL AMPLIFIERS PSU30 PRE AMP £6.45

1 £16.45 ILP have long been recognised as manufacturers of top quality Type Output Load Price PSU212... Or 2 HY30 1 1 1 HY124 E18.45 amplifiers. Power Impedence PSU412... or 2 HY60, HY6060, for Watts Irms) f) PSU422... 1 HY128 £20.45 All ILP products are built to extremely high specification the PSU432... 1 MOS128 121.45 ultimate in hi -fi performance. They're unique in being completely HY30...... 15 48 £ 1045 PSU512.,. 2 HY128, 1 HY244 £22.45 encapsulated with integral heatsinks, and can bolt straight onto the HY60 30 4.8 £1045 PSU522...2 HY124 022.45 022.95 chassis. They're also extremely robust, ensuring high levels of reliability HY6060 30 +30 4.8 f21-95 PSU532... 2 MOS128 1 HY248 £22.95 HY124 60 4 £1745 PSU542... as well as performance. PSU552... 1 MOS248 £24.95 ILP Amplifiers are now available through Jaytee. The UK Distributor HY128 60 8 £1745 PSU712... 2 HY244 £26.45 with the availability and service to match the quality of the amplifiers. HY244....,120 4 £22-45 PSU722... 2 HY248 £17.45 HY248..,..120 8 £22-45 PSU732... 1 HY364 E27.45 POWER BOOSTER AMPURERS HY364 180 4 £3345 PSU742... 1 HY368 £29.45 2 MOS248, MOS364 E29.45 The C15 and C1515 are power booster amplifiers designed to increase HY368 .....180 8 £3495 PSU752... the output of your exisiting car radio or cassette player to 15 watt rms. Distortion less than 0.01% All the above are for 240v operation C15 15 watts £10.65 C1515 15 + 15 watts £19.78 ILP LOUDSPEAKER power 350 watt rms IJ size 12 inches Contact our sales dept. impedance 8 ohms NEW for information pack range 20 Hz to 5 KHz and price. D 143 Road, Betringe, Reculver FOR FREE DATA PACK PLEASE Jaytee Electronic Services, WRITE TO OUR SALES DEPT. Herne Bay, Kent CT6 6PL Telephone: (0227) 375254 All Prices include VAT, Post & Packing CIRCLE 90 FOR FURTHER DETAILS.

HART The Firm for QUALITY OSCILLOSCOPES - X.P. 1715& O,& Trace 200MHz Way Sweet- .. (1.500 MULTIMETERS TEKTRONIX 465 Du& Trace 100MHz De5y Sweep [900 type PM2517X SCSI 4 dpn. Auto temp. Complete TEKTRONIX 74035 with 7AIBN & 7853N. PHILIPS OMM with Batteries & Ludt IMP (51 ....._. ..OILY 05 For over 20 years Hart Electronics have been specialists in Quality Kits, cassette decks and Dual Trace 50MHz Delay Sweep _...._ [600 AVO 9s km _...... _.[5a manufacturers and importers our range offers the best possible value TEKTRONIX 454 Du& Tome 150MHz Delay Sweep (600 AVO Bs and -. cassette heads. As the actual AVD Model 73. Parka Muitinna Analogue/ 30 How. Complete wish TELFOUIPMENT on Du& Trace 50MHz Delay Sweep [350 battens, & Wads...... _...... __.... __.. . _...[18 for money. GOULD 053000& Dual trace 40MHz Delay Sweep. [350 TELEOUIPMENT 067 Dual Trace 25MHz we Sweep [250 LINSLEY HOOD 300 SERIES AMPLIFIER KITS COSSOR COU150 Dual Trace 35MHz Delay Sweep (200 S E. LABS SMI I I Dual Tine 19MH, AC or Fve,,, DC HART designed, integrated amplifier kits derived from Linsley - Superb, Operation PROFESSIONAL EN MONITORS display CompositeVideo Hoods articles in 'HiFi News'. EEKTRONIX 547 Du& Trace 50MHz Belay TB Delay Sweep (140 REUTERS oably BO column (40 each Ultra easy assembly and set -up with sound quality to please the most TELEOUIPMBNT 543 Ouu Trace 15MHz .('100 in Cased Good condition ONLY Ideal for any domestic sound systems if quali- TEKTRONIX 434 STORAGE Duel Trace 25MHt (800 discerning listener. basis Unit Dual Lan 10MHz (700 the individual GOULD 054050 with output 4002 ty matters to you. Buy the complete and save pounds off 5F' FLOPPY DISK DRIVES component price. LiINkHAFURS TONDOS I HEIGHT BRAND NEW Sage Sided Double Donny (BO H P SWEEP OSCILLATOR 6910 1 26Hz (400 Kit. E98.79 Double Sided Double Density K300 -35. 35 Watt. Discount price for Complete Other 0e5uentaa available [l00 MM 92 Double Sided Double Density BO Tech Un trod. (100 K300 -45. 45 Watt. Discount price for Complete Kit. E102.36 HEWLETT PACKARD 6168 I.8 426Hz [350 Type MARCONI 112001 AM/FM MHz 510MHz .51.200 P &P a & res 75 RLH4 &5. Reprints of Original Articles from 'Hi -Fi News'. £1.05 no Vat - MARCONI TF10661 t AMIFM 10470MHz. (375 DISK DRIVE PSU. 240V in 5V 1.6A & IN 1.5A Out 5,, Minoan: MARCONI 019950151.5220MHz. Narrow Dewatan (250 ' .75, Oit", Coed Unurod. 5051_(15 LINSLEY -HOOD CASSETTE RECORDER CIRCUITS ADVANCE SG63B AMIFM 4 230MHz ( 150 , ADVANCE SG628 AM 150KH, 220MHz (TD Complete very high quality low noise signal handling stages for any stereo cassette recorder. NEW EQUIPMENT Separate record and replay sections for optimum performance. Switched bias and equalisation to MARCONI 11144114 10K111 72MHz [55 H P TEST OSCILLATOR 651A IOH, 10MHz MO HAMEG OSCILLOSCOPE 605, Dual Trace 60MHz cater for chrome and ferric tapes. Very easy to assemble on plug -om PCBs. Complete with full RADFORD 1003 101IZ 100KHz 0.002% Distortion 30 f Delay Sweep,, instructions. RADIOMETER 5MG40 STEREO GEN 0300 Y P LEADER FM STEREO GEN 150231 [120 Component Tester E515 EARNER MODULAR PULSE GENERATOR SYSTEM HAMEG OSCILLOSCOPE 203.5 Dual Trace 20MHz STUART TAPE RECORDER CIRCUITS 1Ha IOMNz rseB Complete stereo record, replay and bias system for reel -to-reel recorders. These circuits will give Component IURT1ON MEASURING SET Saws 3. . 000 Tester £2711 studio quaity with a good tape deck. Separate sections for record and replay give optimum perfor- RAUFUHD GIS H P DISTORTION ANALYSER 331A (400 All Other Models Available. mance and allow a third head monitoring system to be used where the deck has this fitted. Stan- HP 43425 0' Meter ( 1,250 dard 250mV input and output levels. eBecosI IL Meer 1E1245 wit1 TF 1246 or Tf 1247. [505 H P POWER METER 4310 with The esme Mount IOWA, BLACK STAR COUNTER TIMERS (P &P E51 K900W Stereo Kit with Wound Coils and Twin Meter Drive. £55.13 I OGHO,... -.. (50 APOLLO 10 - 100MHz. RatiolPeriodlTime Interval etc MARCONI RF MILLIVOLTMFTER TF2603 50KHz 1500MHz InIV 3V [219 RJS1 Reprints of Original Articles. £1.30 no vat. ESO (176 MARCONI VALUE VOLTMETER 112600 10MZ 10MHz InV 300V APOLLO 100 - 100MHz (As above - with more funs ISO. (40 - E285 HIGH QUALITY REPLACEMENTCASSETTE HEADS tionsl BLACK STAR FREQUENCY COUNTERS (P&P E41 Do your tapes lack treble( A worn head could be the problem. Tape COUNTER TIMER ire 836...... [60 RACAL 32MHi UNIVERSAL Meteor 100 100MHz [99 heads are constantly improving and fittin gone of our latest replacement - Meteor 600 600MHz E128 heads could restore performance to better than newl Standard moun- - Meteor 1000 - 16Hz [175 tings fit most decks and our TC1 Test Cassette will make it easy to set p'4$ COMPUTER INSTRUMENTATION BLACK STAR JUPITOR 500 FUNCTION GENERATOR the azimuth spot on. As we are the actual importers you get prime parts BARREL PLOTTER 36 alit wlaTH, TWIN PEI; _. ... SinelSquarelTriangle 0.1Hz - 500KHz. P &P E4 £110 at lowest prices. All our heads are suitable for Dolby machines. nn many held 28 HC20 Permalloy Stereo Head. Good quality standard head fitted as original equipment on HEWLETT PACKARD LOGIC ANALYSER HUNG CHANG OMM 6010.31 digit. Hand decks. £5.11. ranges including 10 Amp ACIDC. me 16005. Complete with Probes & manual 5350 Complete with batteries & leads. P &P E4 [33.50 HS1 6 Sendust Alloy Super Head. Quite simply the best. Longer life than permalloy, higher output spec on request ferrite, fantastic frequency response. £9.91 than OSCILLOSCOPES PROBES. Switched X1, X10 P &P E2 AVO TRANSISTOR TESTER TTI69 Handheld GONOGO I0 msou HQ551 4 -Track head for auto -reverse or quadrophonic use. Full specification D730 /TXT record Testing Complete wth Batteries. leads & Instructions IP&P r31 £11 and play head. £9.73 NOW ONLY n2 Full data on these and other heads in our range are contained in our free list. PLEASE NOTE THIS IS A VERY SMALL SAMPLE OF STOCK, SAE HART TRIPLE -PURPOSE TEST CASSETTE TC1 we will be or Telephone for LISTS. Please check availability and tape From January 1st 1986 One inexpensive test cassette enables you to set up VU (Dolby) level, head azimuth Times: before ordering. Carnage all units 112. VAT to be £4.66 closed Saturdays Opening - speed. Vital when fitting new heads Complete with instructions. Monday to Friday 9am- 5.30pm with late added to total on Goods and Carriage. Send for your FREE copy of our lists with full details of our complete range of Kits, Components, night Thursdays until 8pm. PCBs, Cassette Heads and Decks. STEWART OF READING Telephone: 0734168041 ELECTRONIC KITS LTDD .C.O 110 WYKEHAM ROAD, READING, BERKS ROS 1PL 1, Penlyn Mill, LT ry, Shropshire SY1 O 9AF Callers welcome 9 a.m. to 5.30 p.m. Monday to Saturday inclusive i'Lr 24 hr SALES LINE (0691) 652894 Please add VAT CIRCLE 59 FOR FURTHER DETAILS.

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 85

www.americanradiohistory.com THE ELECTRONICS MAGAZINE !OFESSIONAL$ CAN'T RESIST.

tire la,. A advalled elam

*11-fibt44

F Electronics and Wireless World is the only electronics magazine to really tempt the professionals. It's the only one they take the trouble to pick up for themselves. That's because it's written for the engineer who sees electronics not only as a job, but also as a hobby. It's written on a technical level that doesn't talk down to you. It keeps you up to date with all the latest products and processes, applica- tions and equipment. And it covers every industry where electronics is involved. Just one look at the new look ti..;, magazine and you'll see why it gets pro- fessionals like you out of the office, and down to the newsagents. Wreé1d The leading magazine for electronics engineers.

86 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com NEW PRODUCTS

Write -once proms

Intel argues that the time consumed by extracting a u -v eprom, erasing it and then reprogramming it is too expensive to be worth it. So they have brought out a family of proms without a window so that once programmed they cannot be erased. What's more they have developed a Quick -Pulse programming algorithm that enables the devices to be programmed in 100th of the time required by u -v eproms - about four seconds. The software is implemented in Intel's own universal programmers as well as those sold by Data I /O. The proms are manufactured in plastic as opposed to the ceramic packaging of their erasable predecessors, which makes them robust and lower cost. between the ± 12dB rrange to a The proms are electrically and pin - Audio measuring system ± 1.5dB range for adjusting the compatible with the eproms and are reference level which is set in 1dB distinguished by the prefix "P" steps from the front panel. The instead of "D ". The range ubiquitous microprocessor can this can be omitted in receive -only instrument can be programmed comprises the P2764A, P27128 and The found lurking within the applications. externally through the bus to be P27256. Intel Corporation (UK) Ltd, be resulting in fast and The level measurement range is ranged automatically, allowing Pipers Way, Swindon, Wilts SN3 MJS401D, accurate audio measurements. from -110 to + 40dBm with a readouts of both frequency and 1RJ. EWW 220 on reply card. Standard functions allow claimed accuracy of better than level. Distortion and crosstalk measurement of level, noise, 0.1dB. Distortion measurements is measurements are fully automatic. frequency, distortion and crosstalk. possible down to 0.0008% Technical Projects Ltd, Unit 2, Plug -in options include extra filters, ( - 102dB). The dual -range meter Samuel Whites Industrial Estate, IEEE interface, IMD, wow and display enabled rapid calibration of Medina Road, Cowes, Isle -of -Wight Charge -coupled flutter. The unit incorporates an the equipment under test. The P031 7LP. EWW 219 on reply character reader MD404B twin -tone oscillator, but meter automatically switches card.

A 256 -photodiode linear c.c.d. image sensor (TH 7806) is suitable for small optical - character High -resolution recognition systems and desk -top computer interfacing. Each monitors photoelement is 13µm square and is optimized for an even response in the 400 to 1100nm spectral range. Colour monitors for data and The maximum data rate is 2MHz. graphics displays are built around A noise dynamic range of 6000:1 a compact c.r.t. driver board only allows sufficient grey -scale depth to 140 by 178mm. Miniaturization enable the easy and reliable has been achieved by the use of discrimination of smudges, etc, thick -film hybrid circuits allowing from the printed matter. the video amplifiers to be mounted on the c.r.t. baseboard. By separating the power supply, the driver circuit and baseboard are Torodial transformers and chokes made suitable for use by equipment manufacturers who can A range of toroidal transformers screen between primary and obtain the c.r.ts directly and includes 87 different standard secondary windings. The range supply their own power supplies. configurations of from 15 to meets the requirements of most Kent Modular Electronics have 990VA. Any other configuration is international standards. Various based their marketing on a similar available to order. The options for mounting the system for o.e.m. monochrome Transduktor range has been transformers are provided. monitors and have found it to be designed to maximize the Computerized design allows the successful; they are now advantages of toroids; lower company to respond to almost any transferring their expertise in weight, smaller size, low no-load request with an optimized thick -film applications to the The sensor comes in a ten -pin d.i.l. losses, and less acoustic hum and transformer design. Samples can colour monitor. They also package and can have a guaranteed magnetic interference. Earthed be provided very rapidly. manufacture complete monitors accuracy to within 50µm. The option copper foil is used to prevent The range is complemented by a and produce a range of of a Z -type epitaxial substrate electrostatic interference and a set of toroidal chokes for switch - monochrome sets in both prevents the deterioration which Mu -metal screen around the mode power supplies. These are landscape and portrait format. may be caused by infra -red outside of the transformer designed to run at 40kHz with a They recently launched a loin components in the illumination minimizes electromagnetic ripple current of 10%. They are colour monitor for use in such source and ensures high interference. To reduce this even wound on powder cores having a applications as bank dealer rooms performance whatever the source. further the design maintains a distributed air gap and offer where space is at a premium. Thomson -CSF Components and constant number of amp -turns per similar advantages to the Kent Modular Electronics Ltd, Materials Ltd, Ringway House, Bell unit circumference of the toroid. transformer range. Transduktor Maidstone Road, Rochester, Kent Road, Basingstoke, Hants RG24 This requires the placing of Mylar Ltd, 443B Holloway Road, London MEl 3QL. EWW 208 on reply OQG. EWW 221 on reply card. insulation and earthed copper N7. EWW 207 on reply card. card. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 87

www.americanradiohistory.com NEW PRODUCTS

New 68000 with MMU

An addition to the 6800 family memory associated with a specific was introduced at the Paris task are kept separate from any component show by Philips. others. Direct memory access Known as the SCC68070, the allows blocks of memory to be device includes the same central transferred between the on -board processor as the 68000 but also memory and peripherals. The has a memory management unit inter -i.c. (I2C) bus relieves the (m.m.u.) and direct memory access parallel bus from routine (d.m.a.) control as well as a serial communications tasks where speed communications bus (hC bus), is not critical; similarly the RS -232C interface and three RS -232C interface reduces the counter -timers all on the same load on the parallel bus as well as chip. reducing the external chip- count. Off -air frequency standard The processor is fully software Internally the single chip has the compatible with the 68000 family equivalent of 100 000 transistors Computer -aided design has been certification of frequency meters, and is claimed to be the first and is built using 2- micron used for the circuitry of the p.c.b. counters, timers, signal sources processor to include d.m.a. and geometry. With an internal in the Quartzlock frequency and generators and radiotelephone m.m.0 in a single package. The maximum clock frequency of standard. The design will operate test equipment. c.mos device is likely to replace 10MHz the device has a on the current frequency The set uses an internal ferrite the 68000 in many applications surprisingly low power transmissions of the BBC as well aerial and a socket for an external Where the reduction in component consumption of 1W. as those to come into operation in aerial is also provided. The p.c.b. count with the associated lower Designed and manufactured 1988. Outputs of 1MHz and can be retro- fitted to earlier Gould cost would be advantageous. It jointly by Philips and Signetics, 10MHz are accurate to 2 parts in Advance and Quartzlock receivers. also uses less power. the SCC68070 is to be marketed in 1011 long -term and 1 in 1010 in the Dartington Frequency Standards, Memory management is used to the UK by Mullard Ltd, Mullard medium term application. Uses Moor Road, Staverton, Devon organise the memory during multi- House, Torrington Place, London include calibration, audit and TQ9 6PB. EWW 212. tasking where the blocks of WC1E 7HD. EWW 205.

Superfast 16132 -bit processor

Claimed to be an inexpensive Special instructions have been alternative to the multi -chip bit -slice included to speed the execution of processor, the GI DSP32010 is a digital signal processing algorithms. second source for the TMS32010. It High -speed applications include is said to combine the flexibility of a speech recognition and synthesis, high -speed controller with the radar and optical sensing, and servo - numerical capability of an array loop computations; particularly in processor and can execute five robotics. The device operates from a million instruction /s. single + 5V. supply and is housed in The èfficiency of this 'single -chip a 40 -pin d.i.l. package. Available computer' is the result of a through Campbell Collins Ltd, 162 "comprehensive and easily High Street, Stevenage, Herts. programmed instruction set and of EWW 218 on reply card. highly pipelined architecture."

again when retrieved. The drive is in Super-fast floppy one box and the interface unit in another. The price is quoted as A new flexible -disc drive from "somewhere in the region of Epson has a formatted capacity of £1,000." Epson (UK) Ltd, Dorland Speech recognition on chips 4.8megabytes. BM -5 is a mains - House, High Road, Wembley, operated 5.25in unit operating at a Middlesex HA9 6UH. EWW 216 A p.c.b. with speech -recognition The system features a 'learning speed comparable to that of a hard on reply card. l.s.i. circuits comes from NEC. The and training' mode, whereby disc drive. It can act as a back -up MC4760 analogue interface carries extracted features of a voice are unit for hard discs and has the out equalization, amplification and stored in a reference memory. When advantage over tape streamers of analogue -to- digital conversion. a degree of simularity is established random access to the files. It also There is a signal processor which between the input and the stored has an advantage over hard discs by Test sockets performs spectral analysis of the reference, the results of the being a removeable medium. It is digitized voice input and systems comparison are transmitted. A 98% possible to have an unlimited A series of low- insertion -force controller to communicate with a recognition rate is claimed. With a number of 5Mbyte floppies sockets has been produced by host system. This can receive high- 64Kbyte memory the system has a compared with a fixed 10Mbyte Aries. Called the Eject -a -dip range level commands and transmit the vocabulary of 128 words; 512 word disc. Interface cards enable the they are available in 14, 16, 24, results. The board is designed for can be registered with a 64Kbyte drive to interface with Epson's own 28, and 40 -pin versions. The isolated word recognition and is memory. The maximum length of range of computers or the IBM PC levers at each end of the socket based on the filter -bank technique utterance is two seconds and the and its compatibles. lock the i.c. into position when with dynamic programming average response time is 0.5s. The storage medium is a special inserted and also are used to eject matching. There is a digital Available (appropriately) through 6Mbyte double -sided high density it after the test. Aries Electronics attenuator to enable the easy Dialogue Distribution Ltd, 5.25in floppy disc. The drives (Europe), Alfred House, Oatlands detection of the beginnings and ends Watchmoor Road, Camberley, internal firmware 'compresses' the Drive, Weybridge, Surrey KT13 of words. Surrey GU15 3AQ. EWW 217. data to be stored and expands it 9LB. EWW 206 on reply card. 88 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

www.americanradiohistory.com I CO IJ METE S0NGLE JQ. ®ARD CO IN/1 .1 SUPPORT Now you can weald the power of the 8051 using BASIC.

Based on the Intel 8052AH single component Microcontroller the CPU comes complete with a unique implementation of the BASIC language enabling direct access to the special function registers, timers and interrupts available on the 8051 device.

The new Cavendish Automation 7030 CPU is one of a complete range of Eurocards providing complete systems capability to OEMs. Support includes static MOS RAM boards (to 128K), Power - Down Control boards, Decoder boards, providing further address line decoding, watchdog, real time

clock /calendar plus additional output flags and I /O. Mass storage devices. Backplaines. PSU and battery packs. Drive boards offering power output, signal conditioning and externally gated outputs. Multi channel DAC /ADC. Remote switch modules for power switching, sound or V.I.S. of vision.

Comprehensive documention is supplied with each CPU and the 7030 CPU card requires only a +5v supply and dumb terminal for operation. Many unique features are incorporated and the system allows very fast interactive development of user software for super easy deployment in the target system. CPU Card Advantages: On card EPROM programming with single instruction & auto -start option 16K User EPROM /ROM plus 8K User RAM on card

" Twin Serial ports independently configurable (300 - 19,200 baud) * 9 x 8 bit parallel I/O ports on card Full floating point arithmetic

" BASIC utilities may be called from Assembler * Interrupts handled by BASIC or Assembler * Very fast tokenised interpreter drastically reduces software development time * 11 MHz operation as standard * low cost * customised options on low quantity ROBOTECS..ENVEROMMENTAL CONTEOL., PAOCESS CCNTR01 For further information on the CA 7000 Series Controller contact:

Cavendish Automation Limited. 45 High Street,St Neots,Cambs, PEI9 1BN. Tele(0480) 219457 Telex 32681 CAVCOM G. CIRCLE 75 FOR FURTHER DETAILS.

It's easy to complain about an advertisement. Once you know how:

One of the ways we keep a check on the advertising that appears in the press, on posters and in the cinema is by responding to consumers' complaints. Any complaint sent to us is considered carefully and, if there's a case to answer, a full investigation is made. If you think you've got good reason to complain about an advertisement, send off for a copy of our free leaflet. It will tell you all you need to know to help us process your complaint as quickly as possible. The Advertising Standards Authority. If an advertisement is wrong,were here to put it right.

ASA Ltd, Dept 1 Brook House,Tomngton Place, London WC1E 7HN

This space is donated in the interests of high standards of advertising. ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 l

www.americanradiohistory.com Appointments

DISPLAYED APPOINTMENTS VACANT: £21 per single col. centimetre (min. 3cm). Advertisements LINE advertisements (run on): £4.50 per line, minimum £30 (prepayable). BOX NUMBERS: extra. accepted up to 12 noon £10 (Replies should be addressed to the Box Number in the advertisement, c/o Quadrant House, The Quadrant. Sutton, 5 February for March Surrey SM2 4AS). PHONE: SUSAN PLATTS, 01 661 3033 (DIRECT LINE) issue 15% VALUE ADDED TAX NOT INCLUDED Cheques and Postal Orders payable to BUSINESS PRESS INTERNATIONALLTD. and crossed.,"

THE BESTAPPROACH

£7,000- £30,000 + CAR * Where does your interest lie: Graphics; CAD; Robotics; Simulation; Image and Signal Processing; Medical; Automation; Avionics; Acoustics; Weapons; Comms; Radar; Opto and Laser? * Experienced in: VLSI; Microprocessor Hardware or Software; Digital and Analogue circuitry; RF and Microwave techniques? * There are hundreds of opportunities in: Design; Test; Sales and Service for Engineers and Managers * For free professional guidance: Call: 0638 742244 (till 8pm most evenings) or write (no stamp needed) to ELECTRONIC COMPUTER ANO MANAGEMENT APPOINTMENTS LIMITED FREEPOST, The Maltings, Burwell, Cambridge, CB5 8BR.

CLIYEDEN Electronic Engineers - 1. SERVICE ENGINEER Point of sale, multi user What you want, where you want! microprocessor system. To £10,000 + Car. Herts. TJB Electrotechnical Personnel Services is a specialised appointments 2. TECHNICAL SUPPORT ENGINEER service for electrical and electronic engineers. We have clients throughout Mini and micro based office automation equipment. c. the UK who urgently need technical staff at all levels from Junior Technician £ 10,000 + Car. Berks. 3. TEST ENGINEER to Senior Management. Vacancies exist in all branches of electronics and Analog and Digital experience to work on radar /microwave allied disciplines - right through from design to marketing - at salary systems. levels from around £20,000. £10,500. Essex. £6,000- 4. SERVICE ENGINEER If Repair and fault find a range of you wish to make the most of your qualifications and experience and mini and micro based information systems. move another rung or two up the ladder we will be pleased to help you. £8,000 +. Hants. TEST ENGINEER All applications are treated in strict confidence and there is no danger of Fault find a range of microwave your present and electronic assemblies. employer (or other companies you specify) being made aware To £ 10,000. Surrey. of you' application. 6. CHIEF TEST ENGINEER Digital, A n a l o g a n d NNNNMNNNNNNrNNNN microprocessor systems. Test of PCB's for broadcast equipment. TJB ELECTROTECHNICAL Please send me a TJB Appointments Registration form L11,000. Berks. Hundreds of other Electronic PERSONNEL SERVICES, and Computer vacancies to Name £15,000 12 Mount Ephraim, Phone or write: Tunbridge Wells, Roger Howard C.Eng. M.I.E.E. M.I.E.R.E. Kent. TN4 8AS. Address CLIVEDEN RECRUITMENT 92 Broadway, Bracknell, Berkshire RG12 1AR Tel: 0344 489489 (25981 Tel: 0892 39388 (861) (24 Hour Answering Service)

90 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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r -1 Telecommunications I for your classified I Engineering I adverts ring Technicians 101 661 3033 Openings in Servicing and Maintenance 07. Up to ,£9,317 ELECTRONICS .., _-« TECHNICIAN GRADE 7 PHYSICS DEPARTMENT Our business is to install and . THE CITY OF LONDON maintain the communications POLYTECHNIC invites equipment used by the Police applications for the above post in and Fire Brigades in England its Physics Department, located in Jewry Street, EC3 close to and Wales - some of the latest Some LIVERPOOL STREET and you will find in operation anywhere. travelling FENCHURCH STREET We have a number of vacancies will normally STATIONS and ALDGATE at our Service Centres in various parts be involved. UNDERGROUND. of the country for Telecommunications Registered disabled persons can of The successful candidate will Engineering Technicians with practical course apply. assist in the provision of an electronics service to all sections skills in locating and diagnosing faults The Home Office is an equal of the Department and will be in a wide range of radio equipment opportunities employer. r e s p o n s i b l e to t h e including AM, FM and computer based Salary will be on a scale £6,810 Superintendent of Laboratories data transmission systems. to £9,317 a year with generous leave for the overall operation and maintenance of electronics The work provides excellent allowance and pension scheme. Starting services, the design, opportunities for extending your salary may be above the minimum and development, construction, technical expertise, with specialised relocation expenses may be payable for modification and repair of courses and training to keep you up to some of the posts. electronic equipment and date on developments and new Good prospects for promotion. occasional training of other technical experience is equipment. There are also opportunities If you are interested in work- expected. for day release to gain higher ing with us, please write for further Salary on a scale from £10,617 qualifications. details and application forms quoting p.a. to £11,757 p.a. (including Applicants, male or female, reference EWW /1 to: Miss M London Weighting of £1,365 must be qualified to at least City & Andrews, Home Office, Directorate p.a.). Guilds Intermediate Telecommuni- of Telecommunications, Horse- For further particulars and an application form please write, on cations standard and possess a ferry House, Dean Ryle Street, a postcard, to the Staff Records current driving licence. London SW1 P 2AW. Officer, City of London 1144) Polytechnic, 117 Hounsditch, London EC3, quoting reference Directorate of no. 86/2. Home Office Telecommunications 1148

LRT BUS ENGINEERING LIMITED BRITISH ANTARCTIC SURVEY MOBILE RADIO REPAIR PERSON Engineer This vacancy is in the Radio Repair Workshops of our Electronic ad maintain a computer and Bus Engineering The Survey requires an Electronic Engineer to operate Works at Chiswick, West London. microprocessor controlled HF radar, known as the Advanced Ionospheric Sounder, at for the system hardware and The successful applicant should have a thorough Halley 76 °S 27 °W in the Antarctic. He will be responsible be able, with training, to modify the system software necessary. knowledge of Radio Communications principles, should The appointment will be for a period of 38 months, commencing in April 1 986 and the specifically VHF -UHF transmission and reception successful candidate will sail for Antarctica in October, returning to the UK in May 1989. using AM -FM -PM and Data Modulation Modes and Qualifications: Degree or equivalent in electronica, electrical engineering or other will be required to work on various types of appropriate subject. Some relevant experience preferred. equipment, including hand -held units, and should Applicants, to work mainly overseas, must be physically fit. single. male and aged between 21 and 35. therefore be well experienced in this field. A good Salary: Grom £6252 per annum plus an allowance of 946 per annum for periods south understanding of general electronics is also required. of Montevideo. For futher details an an application form, please contact: - A City and Guilds Certificate or ONC in a relevant The Establishment Officer, discipline is desirable, though not essential. British Antarctic Survey, Madingley Road, We offer an attractive benefits package, which Cambridge CB3 OET Telephone: Cambridge (0223) 61 188, Ext. 235 includes FREE TRAVEL on LRT bus and underground Please quote reference: AS 4/86 services and a contributory pension scheme. Closing date for applications: 10 February 1986 Interested? The phone Ann Clark on 01 -994 3641, Ext 182 or write to the Personnel Director (Bus Natural Engineering Limited), 566 Chiswick High Road, Environment Chiswick, London W4 5RR quoting reference Research BELW /1 /WW. Council

1149 1141' EI.I?ChRU\1CH \V'OR1.1) ITIIRL_AR1' 1986

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Field Service JUST THE TICKET! Clipping this advert could be your ticket to a better career. We have a wide selection of the best appointments in Digital, Analogue, RE Microwave, Micro-processor, Engineer Computer, Data Comms and Medical Electronics, and we're here to serve your interests. £NEG Company Car Call us now for posts in Design, Test, Sales or Field Service, at all levels from £6,000 - £18,000. SONY BROADCAST LTD is well established as one of the world leaders in the professional broadcast television industry, with branches throughout Europe, the Middle East and Africa. Our wide range cTechnomar&Engineering & Technical Recruitment of sophisticated products includes Cameras, 11 Westbourne Grove, London W2. Tel: 01 -229 9239. VTRs /VCRs, Camcorders, Editors and the new (1935) High Definition Video System. Applications are now invited from experienced engineers to join our Field Service team based at our international headquarters in North Hampshire. ELECTRONIC ENGINEER Responsibilities will include the commissioning, Samuelson Communications are leaders in audio and video service and repair of our full range of video rental in the UK. Our expanding Technical Services products. This will involve overseas travel Department which provides technical support in all areas of throughout our market area and extensive customer our operation, require both bench and field engineers. contact at all levels. Candidates should possess a Your duties will include the maintenance or operation of a formal electronics qualification, together with a wide range of Monitors, VCR's, Video Projectors and minimum of 2 years experience gained either in associated equipment. Ideally you should be qualified to operational television or its allied manufacturing HNC level with serveral years practical experience, specific industry. product training will be provided, salary by negotiation. Full product training will be provided and If you like to join our team, please contact Janet Smith, generous relocation assistance where appropriate. Samuelson Communications Ltd. We offer an excellent benefits package including an 120 Cricklewood Lane, London NW2. attractive salary, Company car, free private medical Tel: -01-2080011 cover and a Company Pension /Life Assurance A SAMUELSONGROUPPLC COMPANY Scheme. (142) If you are interested please write to, or telephone: David Parry, Personnel Officer.

Sony Broadcast Ltd. Betgrave House Basing View. Basingstoke SONY Hampshire RG21 2LA j:ìs)° Broadcast United Kingdom Telephone (0256) 55 011 11331 £30,000 p.a. 6i As the UK's leading specialist sales and technical recruitment consultancy, we provide a FREE service to engineers seeking a career move. If you have experience in Microprocessors AIR TRAFFIC ENGINEER - GRADE 2 (H /W or S/W), Digital or Analogue Applications are invited from persons aged 25 years or over who hold a minimum of ONC (Eng i. technologies, ideally with a recognised City and Guilds Telecommunications Technician (Course 270/271) up to and including T3, TEC qualification, we have hundreds of vacancies Certificate /Diploma in Telecommunications or equivalent technical qualifications, for the post of Air Traffic Engineer Grade 2 on the staff of the Isle of Man Airports Board. Candidates should throughout the UK in R & D, Design, have a sound knowledge of electronics and be experienced in the maintenance of Airport Communications, Radar, Nan. Aids, CCTV or data processing systems. Manufacturing, Test, Service and Sales. The post is permanent and pensionable on a non -contributory basis (save for a contribution of Call your nearest branch for more information 1 }% towards family benefits) and has a salary scale of £8.070- f9,462 per annum. The post involves shift work including some Saturday and Sunday working for which an additional allowance is payable. A grant of up to E1,500 towards the cost of removal and relocation Bishop's Stortford (0279) 506464 expenses is available to applicants not resident in the Isle of Man and arrangements exist for the Bristol (0272) 211035 Leeds (0532) 580510 transfer of certain pension rights. (021) The duties of the post include the installation, maintenance, repair and calibration of electronic Bracknell (0344) 481808 Birmingham 6431994 equipment and systems concerned with Air Traffic Control and Operations at Ronaldsway Milton Keynes (0908) 666872 Crawley (0293) 514071 Airport. Further details can be obtained from the Airport Director (Tel: 0624 82331 11. (061) London (01) 637 0781 Application forms and further details of the post can be obtained from the Secretary, Manchester 832 5856 Civil Service Commission, Central Government Offices, Douglas (Tel: 0624 26262 Edinburgh (031) 226 5381 Leicester (0533) 544193 Ext. 2835) by whom applications should be received within two weeks of the date of this advertisement. or send a comprehensive C.V. (no stamp required) to:- (1!,- ISLE OF MflÑ A Division of ATA Selection and Management Services Ltd CMLSERVICfi `FREEPOST, Bishop's Stortford, Herts. CM23 2BR. (115 43 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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HUMPHRIES VIDEO SERVICES LTD. Video Engineer Opportunities in Professiona Humphries Video Services is a leading Broadcast Engineering V i d e o c a s s e t t e Established 8 years ago as a part of the highly successful Sony Corporation, Sony duplication and video Broadcast Limited is now recognised as a world leader in the professional broadcast facilities plant. We industry. Our Hampshire headquarters and overseas branches provide sales, currently have a vacancy distribution and engineering support to a marketing area that extends to Europe, the for a video engineer with Middle East and Africa. Our innovative product range incorporates state -of- the -art experience in the electronics and includes some of the most sophisticated broadcast equipment maintenance of all VCR available, such as Betacam, a High Definition Video System and the Digital audio range. formats, e.g. VMS, Applications are now invited from experienced engineers who are looking for a fresh challenge in their BETAMIX etc; and also a career. working knowledge of Principal Project Engineer 1 1 " cformat, BUVect The successful candidate will join an engineering team responsible for the design and would be useful. project management of static studio and mobile television broadcast systems. Aged 30 Applicants should ideally plus, applicants should possess a formal electronics qualification together with a proven track record in manufacture. be qualified to BTEC ONC broadcast systems Some overseas travel will be required. level or equivalent. Senior Sales Engineer Salary in the range To join our UK sales team, the person appointed will be responsible for our full range of £8000 to £10,000 professional video products. UK and some overseas travel will be required. Candidates - have p.a. Please telephone or should significant sales experience gained in a broadcast environment. write for application Senior Engineer Technical Operations form. The successful applicant will be responsible for the technical support of our complex video products, such as the new Sony studio camera. Key activities will also include the HUMPHRIES VIDEO optimisation and evaluation of performance, and the conducting of customer SERVICES LTD., acceptance tests. A minimum of 3 years broadcast experience and the ability to 42 Station Road, effectively maintain customer interface is essential. Merton Abbey, Demonstration Equipment Engineer London SW19 To join a small engineering team responsible for the provision of a product Tel: 01.542 5661 demonstration facility to our customers in the UK and Overseas. Responsibilities will also 1134) include the provision of support at exhibitions. Candidates should have a track record in the broadcast industry, VTR and editing experience would be an advantage, together with a formal electronics qualification. There will be a requirement for overseas travel. Graduate Engineer We are looking for a newly qualified University of Aberdeen graduate electronics engineer to join the Research and Development within DEPARTMENT OF PSYCHOLOGY department Sony Broadcast Limited. The post requires a good Departmental Superintendent honours degree with a bias towards communication theory. The variety of work undertaken offers a stimulating challenge with the opportunity to apply recently acquired Technician (Grade 81 academic knowledge to reality. required for the Department of practical Physchology to supervise technical Senior Engineer Systems Production staff in various research and The successful candidate will join teaching laboratories and our Systems Group and supervise a small team workshops and be responsible for responsible for the acceptance of vendor equipment, test and repair of equipment built the design, development and use of in -house and the development of "black box" units - primarily interfaces. Applicants electronic instrumentation in the should have experience of sound and television principles together with a recognised Department's teaching and research electronics qualification. Previous supervisory and microprocessor experience would programmes. The Department has a be an advantage. range of mini and micro computers as well as video, audio and We offer attractive salaries together with first class conditions of employment, including physiological instrumentation. free private medical cover, and Company Life Assurance /Pension Scheme. Experience in computer interfacing and programming and in designing If you are interested please write with details of your career to date and current salary to digital and analogue circuitry is David Parry, Personnel Officer, Sony Broadcast Limited, Betgrave House, Basing View required. Basingstoke, RG212LA, or alternatively telephone our 24 hour answerphone for an Applicants should have a degree or HNC in electronics and normally application form, on 0256 59583. have had a minimum of 15 years' Sony Broadcast Ltd. relevant experience. Salary on scale £10,315 - Betgrave House £ 1 1 , 21 7 per annum, with Basing View, appropriate placing. Basingstoke Application form and further Hampshire RG21 2LA particulars from The Personnel SONY Kingdom United Officer, University Office, Regent Telephone Walk, Aberdeen AB9 1 FX (Tel Broadcast (0256) 55 011 40241 Extn 5351), to whom the 11 461 completed form should be returned by 31 January 1986. (Ref T437)

11 351

ELECTRONICS & WIRELESS WORLD FEBRUARY 1986 93

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THE START 11 CAPITAL APPOINTMENTS LTD ,il_II OF THE UK's No. 1 ELECTRONICS AGENCY If you have HNC /TEC or higher qualifications and are looking for a job in design, test, customer service, technical SOMETHING I sales or similar fields: i Telephone now for our free fobs list NEW We have vacancies in all areas of the UK If you are leaving College and planning a career in modern i Salaries to £15,000 pa communications or if your present job lacks interest and I challenge why not join us in GCHQ? 01808 3050 We are recruiting I I (24hours) RADIO OFFICERS I CAPITAL APPOINTMENTS LTD who are after initial training will become members of an 76 WILLOUGHBY LANE, LONDON N17 OSF organisation that is in the forefront of communications I 12911 technology. Government Communications Headquarters a. can offer you a satisfying and rewarding career in the wide ------field of communications. Training involves a 32 week course (38 weeks if you come straight from Nautical College) which will fit you for appointment to RADIO The independent local radio station for South Wales has a vacancy for an OFFICER. Engineer, Grade ILR 2, based in Cardiff. enjoy a wide variety of work including project Not only will you find the work as an R extremely The successful applicant will 0 maintenance and Studio and Outside interesting but there are also good prospects for design and development, technical Broadcast operations. promotion opportunities for overseas travel and a good Electronics and have salary. Add to this the security of working for an important Applicants should be qualified to Degree /HND level in or a related field. A clean driving licence is have experience in broadcasting Government Department and you could really the essential. start of something new. Salary is in accordance with current ACTT rates. Apply in writing, including a The basic requirement for the job is 2 years radio operating full C.V. to:- experience or hold a PMG, MPT or MRGC or be about to obtain a MRGC. Registered disabled people are welcome to DAVE COCKRAM, CHIEF ENGINEER, apply. RED ROSE RADIO PLC, P.O. BOX 301, Salaries start at £4,988 at age 19 to £6,028 at age 25 and ST. PAULS SQUARE, PRESTON, PRIIYE over during training and then £6,832 at 19 to £8,915 at 25 1i451 and over as a Radio Officer. Increments then follow annually to £12,328 inclusive of shift and weekend working allowances. application form phone 0242 32912/3 The Recruitment Office A/1108 On instructions from Roger H. Pearson Esq. Liquidator of Priors Road Gintel Communications Systems Ltd. CHELTENHAM (2806) Glos GL52 5AJ FOR SALE BY TENDER The stock of Mobile Radios and Spares. Test Equipment. ARTICLES FOR SALE Answerphones. Telephone Equipment and Telephones. P.A. Equipment. Telex's, Printers and Facsimile's. 2 x Olivetti M20 GOLLEDGE LOTS) Tool Cases Toolwallets Computers etc. (IN Viewing - 23rd and 24th January 1986 for the Professional ELECTRONICS Closing date - 28 January 1986 QUARTZ CRYSTALS Tender Forms available from the Liquidators Agents OSCILLATORS AND FILTERS of all types. Large stocks of standard items. NOEL D. ABEL Specials supplied to order. Personal and 32 NORWICH ROAD, WATTON, NORFOLK export orders welcomed - SAE for lists TEL. (0953) 881204 TELEX. 975326 please. OEM support thru:- design advice, prototype quantities, production Also at HUNTINGDON, CAMBS and ST. ALBANS. HERTS. (147 schedules. Golledge Electronics. Merriott, STOCK CLEARANCE COPPER Somerset TA16 5NS. Tel: 0460 73718 Marconi continuously variable portable WIRE Soft tint .315mm diameter 300 x (2472) filter 0- 1OKc /s, twelve calibrated points E25.Avo portable valve tester £18. High 60oz reels. £1 per reel + vat? Also large power lamps, suitable audio modulation, quantity of Miltac 230 volt 10 amp micro INFRA -RED REMOTE CONTROL signalling etc., El 5. Sig -gen 95 -180 Mc /s switches. Tel. 0773 760661. (38) VIF -KI To fit Grundig 2 x 4 Super Video £12. Marconi Noise generator £25. £5.95 with Tele Pilot TPY355 £12.95 Foster AC Mains Bridge Impedance Test PAL EPLD FPLA IFL PROGRAMMING SER- £20. IDC Process Timer £20. P &P £2. Stan Willets, 37 High Street, Set VICE. Anything from circuit diagram through Chronotron Period Timer E25. Marconi logic equations to fuse plots accepted to produce West Bromwich, West Midlands. Tel. Testmeter, 39 ranges including centre programmed devices. Send for details. Tel: 021 553 0186. (40) zero (galvo) and negative ranges, AC to (0438) 727364 for sample pricing. Kostadin 1.5Gc /s E75. Tensometer £39. Hydraulic Limited, 57 Hardwick Road, Reading Berks RG3 pump, valves, actuators, pipes £79. TEL 4LF. 11061 G. TEK ELECTRONICS LTD Autograph Transcriber (X -Y) £79. Teloman Products Burrows Chambers, Stabilised Power Supplies, Ignition Exporting to U.K.? Send us a sample Analyser £39. Auto/Manual SLR camera to produce to East Burrows Road, board and all components 213 Abhotts Ripton Road, E69. Paint for re- finishing vinyl surfaces your reuirements here at home base. Swansea. SA1 1 RF. £1 /tin. Pneumatic Power Stapler (crates, Huntingdon, Cambs Wave soldering etc.,same applies to U.K. Tel: 0792 475522 Tlx: 48206 Entlr fencing, cabinets etc) E89. Ratchet Interested? 2716 3.00 8085 2.20 stocks /dies £29. Flow meters. Komag Mainland companies. Telephone: 10480) 57758 Telephone: -on- Thames (0932) 2732A -2 3.50 80085 3.50 grinder £ 1 5. Chart recorders. LCR Bridge. Walton WAVEGUIDE, Flanges and dishes. All standard 2764 -25 2.90 8155 2.50 Infra -Red Analyser. Pye Megohhmeter 220612 24 hour telephone answering. 1391 27128 -25 3.10 8251 2.70 £45. h -P 1750.8. dual channel plug -in sizes and alloys (new material only) from stock. machine. Special sizes to order. Earth Stations, 01 -228 27256 -25 7.10 8255 2.65 £35. Film processing QUARTZ CRYSTALS OSCILLATORS AND 4164 -15 Characteristic Curve 7876, 22 Howie Street, London SW 114AR. (2099) 0.99 Z80A 2.10 Semiconductor FILTERS of all types. Large stocks of standard 6116LP -3 1.90 Z8OB 5.00 Tracer £79. 040 -376236. items. Specials supplied to order. Personal and CLEARANCE SALE - Very good 6264LP -15 4.00 74L500 0.20 (2016) mains transformers: 6V 1A, 9V export orders welcomed - SAE for lists please. quality LM324 0.43 4001 0.20 OEM support thnt:- design advice. prototype ¡A, 12V }A 50p - 12V 1A, 15V 1A, 75p LM311 0.50 NE555 0.20 nuantities, production schedules. -8 +8V }A, 18V 1A, 24V IA, £1 - 12V Plus many many more. BRIDGES waveform /transistor analys- Golledge Electronics. Merriott, Somerset TA16 5A, 15V 4A, 24V 2A, £2 - 24V 4A £4 - Please add 50p post and packaging and ers. Calibrators, Standards. Millivoltme- 5NS. Tel: 0460 73718 (2472) V.A.T. to total. ters. Dynamometers. KW meters. Oscillo- 24V l0A £10 - 230/115V 100W auto £2. Export: No V.A.T. Min order £25 J. Bull 34 America Lane, Orders from government dept and colleges scopes. Recorders. Signal generators - TELEQUIPMENT SCOPES, spares, manuals, sweep, low distortion, true RMS, audio, Ochre Mill Technical Services Ltd. Stone (0785) Haywards heath, Sussex RH16 3QU. etc. welcome. 11 371 Phone 0444 454563. (125) RM, deviation. Tel. 040 376236. 814643. (121 94 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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SERVICES WANTED CIRCOLEC WE USE THE COMPLETE ELECTRONIC SERVICE Test equipment, receivers, Artwork, Circuit Design, PCB Assembly, Test & Repair Service, Q.A. ONLY 10% valves, transmitters, corn - Consultancy, Prototypes, Final Assembly. Full PCB Flow Soldering OF OUR ponents, cable and Service. electronic scrap and quan- Quality workmanship by professionals at economic prices. MENTAL tity. Prompt service and 5686 for advice or further details. Please telephone 01- 646 POTENTIALS cash. Member of A.R.R.A. TAMWORTH MANOR 302 -310 COMMONSIDE EAST, MITCHAM 11391) These are the words of Albert Einstein, the M &B RADIO greatest physicist of recent times. 86 Bishopsgate Street L. Ron Hubbard's discoveries in the field of the mind prove today that Einstein was right. Leeds LS1 4BB TO MANUFACTURERS, WHOLESALERS In his book "DIANETICS; The Modern 435649 Science of Mental Health" L. Ron Hubbard 0532 ETC. takes one more giant step in this direction. 19956) BULK BUYERS. He reveals how anyone can use his discoveries to isolate the exact barriers that have so far prevented people from using their LARGE QUANTITIES OF RADIO. TV AND m ental potentials to the full. STEINART OF READING More and more people from all walks of life WYKEHAM ROAD ELECTRONIC COMPONENTS FOR DISPOSAL use Dianetics technology today. 110 The many written reports on their success READING RG6 1 PL SEMICONDUCTORS, all types, INTEGRATED CIRCUITS, TRANSISTORS, are the best proof of the quality of this book. your copy of this 68041 C M /W, Find out for yourself. Order TEL NO: 0734 DIODES, RECTIFIERS, THYRISTORS, etc. RESISTORS, /F, /F, W etc. remarkable book today. CAPACITORS, SILVER MICA, POLYSTYRENE, C280, C296, DISC Price E3.95 paperback E17.50 hardback. FOR flake cheques and P.O.s payable to S.H.F. TOP PRICES PAID Hill CERAMICS, PLATE CERAMICS, etc. Send to -. Church of Scientology Saint ALL TYPES OF SURPLUS Foundation, FREEPOST IWW1I East Grinstead. ELECTROLYTIC CONDENSERS, SPEAKERS, CONNECTING WIRE, CABLES, Sussex nil i a v.JA (no stamp required). 170 TEST EQUIPMENT, SCREENED WIRE, SCREWS, NUTS, CHOKES, TRANSFORMERS, etc. COMPUTER EQUIPMENT, ALL AT KNOCKOUT PRICES Come and pay us a visit ALADDIN'S CAVE COMPONENTS etc. - When replying to classified ANY QUANTITY. 1103) TELEPHONE: 445 0749/445 2713 advertisements, readers are R. HENSON LTD. recommended to take steps to 21 Lodge Lane, North Finchley, London, N.12 protect their interest before (5 minutes from Tally Ho Corner) (1613) sending money 125191 WANTED ELECTRONIC SCRAP I'.C.B.'s produced from your artwork. Prototypes, small/large batch produc- WANTED with precious metal content. PCB's tion. P.T.H., screen printing; labels, etc. Valves, Cable, Plugs and Sockets, Photography: englargements, reduc- Components, Speakers, Chips to tions. Fast turnaround. Quotations: Or- complete computers etc. bitechnic, 38 Torquay Gardens, Red- E C COMPONENTS IC TESTERS bridge, Essex. 01 -550 3610. (95) STEINBECK REFINERIES large and small parcels Two cards to plug into your Apple II We buy (UK) LTD computer. Type I tests over 500 74TTL and of surplus I /C, transistors, capa- i.cs transistors £99. Type 2 tests all common Anchor Road, Eastwood, TURN YOUR SURPLUS citors and related electronic 4000 series, etc. into cash, immediate settlement. We RAM and tests/programs EPROMS, PROMS, Notts. (07731760661 welcome the opportunity to quote for stock. Immediate settlement. £ 129. Add 15% VAT, £3 carriage. also ERIC HENDERSON complete factory clearance. Contact Tel: 01 -208 0766 PEANUT COMPUTER (Tel: 0924 499366) COLES -HARDING & CO, 103 South Telex: 8814998 FREEPOST, DEWSBURY WFI3 IBR. (82) You will get a better price at Brink, Wisbech, Cambs. 0945 (2491) Steinbeck! 584188. 192) Telex 377494 MK LEIN.G. 198)

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www.americanradiohistory.com ALL -TIME CP /M MICROCOMPUTER SYSTEM BARGAIN! Fantastic bulk purchase of a major European manufacturer's entire stock of this top -quality machine enables us to retail it at far below its manufacturing cost. ALL FEATURES LISTED are INCLUDED as STANDARD: COMPLETE with EITHER single or double (as Exceptionally high quality styled keyboard with illustrated) TEAC half- height 51/4' double- sided, numeric keypad & 6 function keys double- density floppy disc drives. Formatted capacity: 320Kb per drive. Centronics parallel interface RS232N24 4 MHz Z80A CPU serial interface selectable 300 -9600 Baud 64Kb RAM (in 4164 chips) UHF Modulator for TV & composite video output 28Kb EPROM containing monitor & MICROSOFT BASIC ROM port. (A Word- Processor ROM is available at f59 + VAT) PRICES (monitor £69 + VAT): CP /M Version 2.2 With DUAL floppy: £1 00.00 (E 288.85 inc. VATI 6 month full guarantee With SINGLE floppy: £135.00 (£155.25 incl. VATI 80 x 24 display with colour block -mode graphics Carriage: £9.50 (incl. VAT) Visa & Access accepted

Available ONLY from:COMPUTER APPRECIATION, 111 Northgate, Canterbury, Kent CT1 1 BH. (0227) 470512 MATMOS Ltd., 1 Church Street, Cuckfield, W. Sussex RH17 5JZ. (0444) 414484 454377 (0444) 73830 124921 CIRCLE 22 FOR FURTHER DETAILS.

INDEX TO Wireless wóiid ADVERTISERS Appointments Vacant Advertisements appear on pages 90 -95

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Advertising Standards Authority 89 Flight Electronics Outside Back Cover Pantechnic 77 Airlink Transformers 10 Fulcrum (Europe) Ltd 46 Paxton Instruments 81 Armon Electronics 4 Phase Track Ltd 70 Aspen Electronics 58 GNC Design 2 Pineapple Software 46 Greenwood Electronics 71 P M Components Ltd 38/39 Barrie Electronics Ltd 71 Beckenham Peripherals 24 Happy Memories 70 Quadrant Picture Library 81 Harris Electronics(London) 46 Cambridge Microprocessor Systems 9 Harrison Electronics 58 Radiocode Clocks Ltd 2 Carston Electronics Loose Insert Hart Electronic Kits Ltd ' 85 Radio Components Specialists 4 Cavendish Automation 89 Henry's /Audio Electronics 96 Raedek Electronics 10 Colomor (Electronics Ltd) 77 Hilomast Ltd 46 Ralfe Electronics 24 Computer Source 24 Reprints 81 Conguin Software 12 IQD Ltd 37 RSD Connections 12 Connexions Satellite System 77 Control Universal Ltd 51 Jay Tee Electronics 85 Sarel Ltd 70 Co Star Ltd 23 JDR Sheetmetal 40 Service Trading Co. Ltd 16 Crofton Electronics 10 Johns Radio 58 Sherwood Data Systems 40 Sowter E A Ltd 2 Dataman Designs 5 Kestral Electronic Components 4 Stewart of Reading 85 Display Electronics 78/79 Surrey Electronics Ltd 24 D S Electronics 70 Langrex Supplies Ltd 57 Levell Electronics 3 Taylor Bros (Oldham) Ltd 52 Electronic Brokers IFC, 11, 13 Lowe Electronics 4 Technomatic Ltd 14/15 Electronics & Wireless World 86 Tektronix (UK) Ltd Inside Back Cover Electrovalue Ltd 40 MAP 80 Systems Ltd 58 Thorn EMI Instruments 45 EMS Mfg. Ltd 52 Micromake Electronics 51 Thurlby Electronics 80 ESP Services Ltd 52 Monolith Electronics 51 TIC Semiconductors 40 E &WW Answering Machine Offer 82 TK Electronics 9 Network Services Ltd 81 Triangle Digital Services 37, 71 Field Electric Ltd 9 Newnes Technical Book 16 Number One Systems 10 Valradio Power Ltd 37

Withers, R. Communication 12

OVERSEAS ADVERTISEMENT AGENTS Japan: Mr Inatsuki, Trade Media - IBPA (Japan), B.212. Azabu Jack Mantel, The Farley-Co., Suite 650, Ranna Building, France and Belgium: Pierre Mussard, 18 - 20 Place de la Heights, 1.5.10 Roppongi, Minato -ku 106. Cleveland, Ohio 4415 - Telephone (216) 621 1919. Madelaine, Paris 75008. Telephone: (03) 585 0581. Ray Rickles, Ray Rickles 8 Co., P.O. Box 2028, Miami Beach, Florida 33140 - Telephone (305) 532 7301. Hungary: Ms Edit, Bajusz, Hungexpo Advertising Agency, United States of America: Jay Feinnan, Business Press Tim Parks, Ray Rickles & Co., 3116 Maple Drive N.E., Atlanta, Budapest XIV, Varosliget. International Ltd, 205 East 42nd Street, New York, NY 10017 - Georgia 30305. Telephone (404) 237 7432. Telephone: 225 008 - Telex: Budapest 22-4525 Telephone (212) 867-2080 - Telex: 23827. Mike Loughlin Business Press International, 15055, memorial INTFOIRE Jack Farley Jnr., The Farley Coi. Suite 1584, 35 East Walker Ste 119, Houston, Texas - Telephone (713) 783 8673. Drive, Chicago, Illonois 60601 - Telephone (312) 63074. Canada: Colin H. MacCulloch, International Advertising Italy: Sig C. Epis, Etas -Kompass, S.p.a. - Servizio Estero, Via Victor A. Jauch, Elmatex International, P.O. Box 34607, Los Consultants Ltd., 915 Carlton Tower, 2 Carlton Street, Toronto 2 Mantegna 6, 20154 Milan. Angeles, Calif. 90034, USA - Telephone (213) 821 -8581 - - Telephone (416) 364 2269. Telephone: 347051 - Telex: 37342 Kompass. Telex: 18 -1059. 'Also subscription agents.

Printed in Great Britain by Ben Johnson Printers Ltd., 0141.41, Dunstable, and typeset by TypeFast Ltd., 2-6 Northburgh St., London ECI, for the proprietors, Business Press International, Quadrant House, The Quadrant, Sutton, Surrey SM2 5AS. (.Business Press International 1986. Wireless World can be obtained from the following: AUSTRALIA and NEW ZEALAND; Gordon & Gotch Ltd. INDIA: A.H. Wheeler & Co. CANADA: The Wm. Dawson Subscription Service Ltd., Gordon & Gotch Ltd. SOUTH AFRICA: Central News Agency Ltd; William Dawson & Sons (S.A.) Ltd. UNITED STATES: Eastern News Distribtuion Inc, 14th Floor, l i I Eighth Avenue, New York, N.Y. 10011.

96 ELECTRONICS & WIRELESS WORLD FEBRUARY 1986

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