Journal of the Odio Sodé

journal of the odio Sodé

REVIEWED IN THIS ISSUE

The Heathkit SB-104 all-solid-state hf bands

Photo I. Front vie w transceiver

Photo 3. Illustrating Photo 2. Interior vie w use of outrigger board RADIO COMMUNICATION July 1977 AMATEUR ELECTRONICS UK M AIN ATLAS SOLE dk--î PLUS AGENT R A DI O IN C. AGENT ELECTR ONICS YOUR BEST BUY FOR YAESU MUSEN ! AS DIRECT IMPORTERS W E OFFER YAESU YOU ...

1. KEENEST PRICES 2. LARGEST RANGE 3. HIGHEST STOCKS FT-101E 4. TOP AFTER-SALES SERVICE FT-221R 5. BEST DEMONSTRATION FRG-7 FACILITIES FT-223 AN D MU C H M ORE —EX STOC K! HO W TO REACH US (EASY PRIVATE PARKING ON OUR 70 ft FORECOURT) FROM SOUTH AND EAST. We are located approximately two miles from Junction 5 of the M6 from which follow signposts to Birmingham. Within k mile turn right at Clock Garage and proceed towards city. After one mile look for traffic lights at Fox & Goosu and immediately over the lights take minor left fork into Alum Rock Road. We are located one mile from this point. FROM NORTH. Leave M6 at Junction 6 (Spaghetti) and follow left fork down to traffic island beneath motorway complex. Take third turning off to Lichfield. One mile further on follow A4040 to the right and within 100 yards vare again to the right, approximately one mile further on brings you to the Fox & Goose. Turn right and see preceding directions. FROM THE WEST AND SOUTH/WEST. Follow M5 then M6 to Spaghetti Junction (see above). Alternatively, leave M5 at Junction 4 or 3 and proceed to inner ring road. Turn South on ring road and leave on A47 (East). We are located three miles from this point. HOURS: 9.30-5.30 continuous including Saturdays—Early closing Wednesday 1pm, or, if you can't make It, we will gladly ship by Securicor at no extra cost.

-4SensationalATLAS-210/215X NO W AT THE NEW LOW PRICE OF £395 VAT £2.50 for 25 pence!

25 pence brings the latest Yaesu catalogue with our Credit Voucher for £2.50 against eventual purchase. A couple of stamps brings the Atlas leaflet or our used equip ment list.

BRANCH: AMATEUR ELECTRONICS UK- COASTAL, CLIFTON VILLE, KEN T. KEN McINNES, G3FTE, THAN ET (0843) 291297 BRANCH AMATEUR ELECTRONICS UK SCOTLAN D 287 MAIN STREET, WISHA W, LANARKSHIRE, GORDON McCALLU M, GM3UCI, TEL: WISHA W 71382. (BR A N C HE S AT YO U R SER VICE DURIN G NO R M AL BU SINES S HOU R S) AGENT: W ALES & WEST—ROSS CLARE, GW3N WS, CAERLEON 422232

508-514 ALU M ROCK ROAD 1497 021-327 BIR MING H A M 8 Telex337045 6313 EDITORIAL STAFF ISSN 0033-7110

Editor A. W. Hutchinson

Book Editor R. J. Eckersley, G4FTJ radio

Editorial assistant V. Wyman communication Draughtsman D. E. Cole Editorial panel July 1977 J. P. Hawker, G3VA Volume 53 No7 R. F. Stevens, G2BVN CONTENTS

Advertising representative 515 What amateur radio is—Roger Sherland, G4EHE C. C. LIndsay 516 QTC RSGB NEWS BULLETIN SERVICE 518 The DSB1 Mk2. A simple sideband transmitter for the The RSGB news bulletin, callsign GB2RS, Is broadcast beginner—E. Elsley, G3YUQ every Sunday morning on tif and vhf, giving almost complete coverage of the British Isles. Its main purpose is to provide an outlet for amateur radio news items and 522 New product—Tester 50k announcements which, by virtue of their topicality or urgency, cannot wait for the next issue of Radio Com- 523 Equipment review—The Heathkit SB-104 all-solid-state munication. The bulletin Is prepared early on Thursday morning, hf bands transceiver—G. L. Mills, BSc (Eng) (ions), and news Items, marked "GB2RS news" should reach CEng, MIEE, M1ERE, G3EDM RSGB HQ by first post that day (telephoned items can also be accepted unt1110am). No guarantee can be given of Inclusion in part or whole of any Item submitted and, 529 Book reviews—Radio, TV & Audio Technical Reference once broadcast, items are not usually repeated. Book. The International VHF-FM Guide

SCHEDULE 530 Technical Topics—Pat Hawker, G3VA Time MHz Location and coverage (hf) or beam heading (vhf) of station 536 4-2-70—Graham Knight, GM8FFX 0930 3.65 G2MI, Bromley, Kent (SE England) 1000 3-65 G8ML, Cheltenham (SW England) 144.50 GM3UAG, ElIon, Aberdeenshire 539 Oscar news (NN W) 144-50 G8GGK, Croydon, Surrey (NE) 1015 3-65 Gl3GAL. Belfast (N Ireland) 540 Microwaves— Dain Evans, G3RPE 144-50 GI3TLT, Bangor, Co Down (N) 1030 3-65 G2CVV, Derby (N Midlands) 542 The month on the air—John Allaway, G3FK M 144.50 GM3UAG, ElIon, Aberdeenshire (SW) 144-50 G3P WJ, Brierley Hill (NW) 545 Propagation predictions. HF propagation study 1045 144.50 G8CDP, Middlesbrough (NW) 144-50 G8GGK, Croydon. Surrey (SW) 546 Your opinion. Obituaries 144.50 G3SMT, Stockport (NN W) 1100 3-65 G5VO, Bridlington (NE England) 1115 3.65 G3LEQ, Knutsford (NW England) 547 Contest news 1130 3-65 GM3TC W, Wishaw, Lanarkshire (S Scotland) 1145 3.65 GM3HGA, Aberdeen (NE Scotland) 548 Special event stations. Looking ahead Mobile rallies calendar. Contests calendar An rtty news bulletin, calisign GB2ATG, Is also transmitted every Sunday at 1200 and 1900 on 3.590MHz and at 1230 and 1245 on 144-6M1-Ix. This bulletin carries items of 549 Club news interest to rtty enthusiasts. 554 Members' Ads

Radio Communication is published by The Radio Society of Great Britain as its official journal on the first Thursday of each month and is sent free and post paid to all members of the Society 20,432 copies Contributions and all correspondence concerning the content of Radio Communication should be per issue addressed to: The Editor, Radio Communication, 35 Doughty Street, London WC1N 2AE. Tel ABC average 01-837 8688. (Circulation queries should be addressed to: The Subscriptions Department, RSGB).

w pm p AVM, circulation Closing date for contributions unless otherwise notified: 4th of month preceding month of C. N.41.9 . in 1976 publication. © RADIO SOCIETY OF Advertising, other than Me mbers' Ads, should be sent to the above address marked for GREAT BRITAIN 1977 the attention of Mr C. C. Lindsay. Tel 01488 5839 (ADVERTISING ONLY). \e/ YAESU MUSEN Yu MOBILE/BASE HF TRANSCEIVER

THE FTIOIE

Yaesu's top to ten transceiver whose design, reliability

and construction (quality and techniques (modular plug-

in boards etc.)) set new standards thus establishing the

'101 as a world beater, w th over 200,000 now In use.

A complete device-packed hybrid station, offering

FT-101E (EE-E X) "built ins" that either are not available elsewhere

or come as costly extras.

FT 101 E FEATURES 160-10 metre inclusive coverage Semi break in with sidetone Fully adjustable carrier level Multi mode, USB, LSB, CW, AM 3 models E, EE and EX Heater conservation/low power links Mains 234V and 12V DC Rs on MSF (10MHz) and CB Clarifier with Indicator LED 11-(133") 6' > 13 .1 30 lbs Front Panel microphone gain SSB and CW filter bandwidths Silky smooth precision VFO drive Indicator LED for VFO operation Valve PA and driver tube Readout to better than lkHz Eight Pole sharp sided filter 100/25kHz crystal calibrator 2 Fix channels per band segment RF speech processor (In IF) Switchable adjustable noise blanker

FT101 E SPECIFICATIONS

Frequency range Sensitivity Input power 160-10 metres transceive -; for 10dB N — SiN (4) 14MHz >260W PIP A31 M.S.F. and CB receive >180W DC Al (50%:duly) Selectivity >80W A3 Modes SSB 2-4Hz at 6dB (1-67:SF) USB, LSB, CW, AM AM* as SSB Audio response Frequency stability CW*61)0Hz at 6dB (2:1SF) 0.35-2-7Hz ±3dB FSK as CW >1001-IzaH (A.W.U.) Carrier suppression <100Hz for 10% line change Spurious responses < —50 dB Backlash Image < —50dB Sideband suppression 50Hz or better Internal spurious <1pV > —50dEl Antenna impedance Audio output Spurious radiation 50 ohms, nominal 3W (int. or ext. speaker) > —40dB Power requirements 234V AC 350W Audio distortion Dimensions 13-5V DC 0-515-0;20A <10% at 3W output 11- (131) x 6 x 13 " & nibs

AT YAESU MUSEN :A MATEUR RADIO EQUIP MEN T IS NOT A SIDELINE, BUT THE ONLY BUSINESS. OVER 130 LICENSED AMATEURS PROUDLY PRODU CE THE MOST DIVERSE AVAILABLE AMATEUR PRODUCT LINE SSE, CW, AM, FM OR FSK FOR MOBILE, PORTABLE OR BASE USE.

W RITE TO ONE OF OUR DISTRIBUTORS FOR A FREE CATALOGUE.

498 RADIO COMMUNICATION July 1917 YAESU MUSEN

MOBILE/BASE VHF TRANSCEIVER r

THE FT22I R

YAESU's state of the art, fully modular, plug in board, multimode, 2 metre transceiver renders over the board

"rats' nest" wiring obsolete. A 134MHz, VCO, automatic varicap tuning of transmitter and receiver, gives you an exceedingly clean signal, and a sensitive receiver having outstanding strong signal handling capabilities. FT221R

FT22 I R FEATURES

144-148MHz Inclusive coverage Semi break-in with sidetone 600kHz and repeat shifts Multi mode AM-FM-USB-LSEI-C W Unique automatic tone burst 'S/centre zero/output meter 234V AC or 12V DC working P.T.T. microphone supplied Clarifier (IRT also RT i TT) 114' (14') x 5- x 11}", and 22Ib Front panel adjustable VOX 2-4kHz SSB 12kHz FM bandwidth Dual speed smooth VFO drive Front panel microphone gain Adjustable sensitive squelch Readout to better than 1kHz A LC external phono socket 100kHz crystal calibrator 44 fix channels (4 x 11) (2MHz) 70W dissipation PA device Switchable noise blanker

FT22 I R SPECIFICATIONS

Frequency range Sensitivity Output power 144-149MHz 0.5mV for 10dB SiN at 145MHz >14 W PEP A3i 600kHz + 1 other shift >10 W F3, Al Selectivity >2.5W A3 Modes SSB 2.4kHz at 6dB (1.7:1 SF USB, LSB, CW, AM AM as SSB Audio response Frequency stability FM 12kHz at 6dB (2:1 SF) 0-3-2-7kHz ±3dB CW as SSB >100Hz 1;FI (A.W.U). Carrier suppression <100Hz for 10% line change Spurious responses > -50dB Backlash Image > -60d8 Sideband suppression >50Hz Internal spurious 1inV > -50c113 Antenna impedance Audio output Spurious radiation 50 ohms unbalanced 3W (int. or ext. speaker) > -60dB Power requirements 234V AC 30W RX, 90W TX Audio Distortion Dimensions 12V DC 06A RX, 3A TX <10% at 2W 14(14") >, 5' 111', 22Ib

OUR AGENTS

A mateur Electronics, South Midlands Co m munications Ltd, W estern Electronics (UK) Ltd, 508-514 Alu m Rock Road, S. M. House, Osborne Road, Totton, Fairfield Estate, Alu m Rock, Birmingha m B8 3HX Southa mpton, Ha mpshire S O4 4DN Louth, Lincolnshire LN11 OJH

RADIO COM MUNICATION July 1977 499 South Midlands TOTT ON, HAN TS (HQ), LEEDS, DERBYSHIRE, YIESII 2 YEAR GUARANTEE °INou SMC FREE SECU RIC O R '24 H O U R' DELIVER Y for Ya m, Items over 551bs (B service) over £5 post free. T HE LARGES T RA N GE EX-S T O C K IN THE U.K. FR O M SM C THE FT221R, COMPLETE 2M STATION Ex-Stock Tho FT221R. Tho multimodo USO. LSB, A.M., F.M., CW, (with semi -breakiiin and side tone), 2m transceiver offering the choice of phase locked VFO or 44 crystal channels, simplex or repeater (600Hz up and down shifts). with unique 'double push' auto tono burst, mains or 12V (IA) operation, excellent selectivity. SSG 2.4kHz (1'7: S.F.) or FM 12kHz. Front panel adjustable VOX and mle gain, a calibrator (1MHz 10), lkHz readout and linearity. sensitive squelch, clarifier with IRT and IRT with ITT (makes F.S.K. easy), swlichable "S" and contra zero tuning meter, noise blanker, serviceable plug in boards all contained In 1 tr (14") u gu 111-.U1b. rigid package. 600kHz and 1.6MHz shUts over 4MHz. 111111111119 mIl m oli mIll fflui Y0221 DIGITAL READOUT UNIT Available around mid July. Price about £70 + VAT The FT101E (EE-EX)-ex stock. New Service manual £12 Tho FTIOIE. A complete mains or 12v, DC station cOntalned Irla compact 30Ib. package, 260W, PIP of SSB (with In.bulit RF speech processor) 180W, CW and 80W or AM 10 to 160m (inc. 10 MHz RX). The sensitive and selective (Permeability tuned RF stages and 8 polo crystal Oiler) receiver offers: threshold adjustable noise blanker, switch. chie 25 and 100 kHz calibrator. d 51. Mariner (with separate onfoll switch), etc., etc. Tho VFO is stable and linear (readout to 1 kHz), external VFO or crystal control can be selected, with LED Ind'. cabers illuminated accordingly. Cruder level Is adjustable for: tuno up, AM and for CW operation, whose performance with the semi break-in keying ,with side tone, end the optional 600 Hz filter Installed is of high order. Linear and transverter provisions are mode with sockets for: relay contacts. ALC output, all Internal HT supplies, low level OF, heater links and switches, etc.. etc. 111 FTIOIE THE FRG7, general coverage receiver Ex-Stock Tho FRG7 is a general coverage solid state receiver with specifications unparalleled in its price range. It uses a Barlow Wadley Tripla-mie, drill cancelling loop for continuous, spin-tuned Inclusive coverage of 0.5 to 30MHz with calibration accuracy better than 5kHz. Frequency selection is accomplished by • the RF (pre-Selector and tango switch), dialling up the required number of mepahertz. then I1 tuning the VFO knob as normal. The receiver in sensitive (0.5 e for 1003, S + NIN (SSB)) and stable (within 50011: for goy 30 mlnutim - -:-. - after warm uP) with A.M.. SSB and CW modes catered for. A 3 position audio filler. RF attenuator. • dial lamp conservation switch, recorder and phone sockets aro fitted. It Is mains powered, but should , - • the supply fall, or portable operation be required, 8 dry cells are automatically switched in. YH55 HEADPHONES Available around end August. Price about £9.00 + VAT TRY US FOR — BANTEX, CUSHCRAFT, GEM QUAD, GOTHAM, G WHIPS, HY GAIN, KLM, JAYBEAM, MINI BEAMS, MOSLEY, SMC, SMCHS, TAVASU, HZP, CDE, STOLLE, PLEMMI, HILLS, STRUMECH, HOND A, SOMMER, AEC, BURNS, COAX, ELECTRONIC DEVELOPMENTS, ICE, JD, KW, LEADER, MICRO WAVE MODULES, OMEGA, TECHNICAL ASSOCIATES, SEIWA ATLAS, BELCOM, C1R, ICOM, FDK, KEN, KYOKUTO, HOLDINGS, KATSUM1, NAIGAI, SPECTRONICS, LESON, MAEDEN SOUND, NANA, SHURE, HI MOUND, JUNKER, SAMSON, MODULAR ELECTRONICS, AMPERE, TEMPO, TTE, NAGASA WA, ROCKET and many, many more. 4 VHF HANDHELD VHF MONITOR RECEIVER KEN KP202 TRANSCEIVER SEIWA MR2 AND 8052 VAT prices) 144MHz, FM, 2W of RF and ¡W of audio. Ideal for the SWL, the YL or even the XYL Immunity to Image and IF breakthrough and as the monitor receiver to keep you In touch performance to rival all walkie-talkies and Tiny (2e x le x 4e) and light (8 ozs.) slip many mobile sets. Into your pocket or onto your belt with the C/w F plug, leather handle/whip case and optional case. Sensitive double conversion telescopic whip. superhet with 12kHz, band width, auto Fitted 6 channels S20 á S22 + Any 4 of S squelch, and generous audio output c/w (0, 21, 23, 24), R (3, 4, 5, 6, 7) £109.50. Nicads, Mains Charger. Earpiece, Antenna R channel only crystal tone burst £10.00. MR2(4) 70MHz. 12 switched channels £53 Flexible stubby ant. £5.80 Case £4.90. MFt2 144MHz. 12 switched channels £53 MS2 Base charger KCP2 £11.75 NI cads £8.50. MS2 144MHz. 4 scanning channels D u F to UHF adaptor £1.65 (all + VAT). Leather Case £1.90 Crystals each £2.00

SOUTH MIDLANDS COMMUNICATIONS LTD. EVEN INGS — AGEN TS —QT H R Head Office, Showrooms G3ZUL Stourbridge (03843) 5917 Brien Kennedy 1 OS BO R N E ROA D, T O TT O N ..,,iia t e „._ Cables: Aerial Southampton GMBDOX B. of Allan (078083) 3223 Ian McItechnlo SO U T HA MP T O N, 90 4 4 DN ,•Í', _.5.)y., Telex: 471151 SMCOMM G G W3TMP Pontybodkln (035287) 846 Howarth Jones Te I : Totten (04216)7333 (3 linos) G13W WY Tandragee (0763)840658 Men•Tn Anderenn Hours of business: 9-5.30; 9-12.30 Saturday 'i: ''''', ...L.,

500 RADIO COM MUNICATION July 1977 Communications Ltd \e/ LIN CS., BIR MING H A M. Agents: N.I., SCOTLAN D, W ALES YAE INTRODUCES UK MAIN DISTRIBUTOR SOME NEW LINES THE NEW REVOLUTIONARY ASTRO 200 Full digital synthesis Solid State 200W HF Transceiver

,111.11111 xa o To pock an entirely modular construction, 10-80m., digital readout transceiver in a box Li 2 2 2.e 2-8' o 12-3' ie remarkable enough, but with a 0.2µV sensitivity and 10OW output from ..n transistors with the boast of:—stabllity better than MHz hour, from an electronically tuned (biased toggle switches with no other moving parts) IODHz. Step digital synthesise ,. good R X front end filtering, TX TVI proofing, unwanted sideband at —WEI, carrier at --50c113. RIT clarifier (±50Hz), Inbuilt SWR bridge, semi break in CW with ldetones, etc., etc. Is almost unbollevablo.

SNIC EST A BLIS HE S A NE W PLA TE A U OF SO P HIS TIC A TIO N — DE M O M O DELS IN T O T T O N!

AN ALL SOLID STATE MOBILE KILO WATT!!

Tho MA1900 produces up to 600W output, with 10dB gain, across 82 to 30MHz from 4 hybridised push pull striplino linear translator paIrs.No tuning is required but 5, 5 section tchbycheff L.P.F. may by manually or remotely switched In. Thy und uses devices rated to welhstond infmile VSWR. a large healsink. a high speed magnetic circuit breaker. best quality components, reverse polarity proteCtlon and a thermostatic "switch through" control.

HIGH QUALITY LOW PRICE SMC—HS VHF ANTENNAS (Vat 12t % Carr 95p)

250 (29 or 145MHz) ik effective, DC short, snap mount, matching transformer, shock spring tapered whip c.'w 12' cable 8, PL259 ONLY £11.75 GDX1 80 to 480MHz Discone, omnidirectional, 3dBk. Excellent VS WA £37.50 260 (70 or (45MHz) High gain, gutter mount, tapered coil and whip, 90 sprung fold over £17.15 25 Trunk lip mount for snap bases £2.95

LA R GE RA N GE OF AN TE N N A S & AC CES S O RIE S, BO T H HF & VHF 260 250

FOUR NEW POST-FREE BARGAINS! (FOR JULY ONLY)

Power, VS WR, Field Boom Microphone 'Headset' Strength-meter 600 ohms magnetic light- Frequency independent (1.8-150 weight boom mic (only) MHz) 50 ohms 10 6 100W F.S.D. MD35 complete £14.75 S0239 connectors ..1D11 O (-1- VAT Microphone only £9.75 8%) £8.45 Footswitch only £5.95

Extended crystal Filter range Stabilised 12 Volt Power For the FT101 Range ( i 124% Supply VAT) YF3OFC1 350Hz 6 pole £18.00 YF300HC1 350Hz 8 pole £20.75 12VDC from 240VAC 3 Amps .e.ottir YF3OFC W 600Hz 6 pole £18.00 (5A peak) 3f lbs x 41' 6' YF30F12 12kHz 6 pole £18.00 ODR123C ( 8/34 VAT) £12.55 tee, e

SEND LARGE SAE FOR FREE 22 PAGE CATALOGUE PRICE STOCK LIST, YAESU CATALOGUE, SECOND HAN D LIST, FURTHER INFOR MA TION.

NORT HE RN (LEE DS) BRANC H A MATE UR RA DIO S.M.C. (Jack Tweedy) LT D Tiro Chambers, No. 8 The Parade (Chas 14. Young Ltd.) Roger Baine,, G3Y BO Jack Tweedy. G3ZY 79 Chatsworth Rd, Ham Shack, Roue hton Lane North Lane. HeadIngley, Leeds 170.172 Corporation St. Bermingham Chesterfield. Derby Wood hall Spa, Linos Tel: Leeds (0532) 782326 Tel: 'Brum'1021) 236 1535. Open Mon -Sut. 9.5.30 Chstrfld (0246) 34992 Wdhl Spa, (0526)52793 Open 9.5prn Tues-Soturday 9.8pm Thur,. Multl-storey Car Park at Rear of shop. 9.5 Tues -Sat 9.5 Tues -Sat ( I- appt)

RADIO COM MUNICATION July 1977 501 LOWE ELECTRONICS LTD

nu n, Jeatexec S,pecificatiarie Following area few of the TS-820s ninny FREQUENCY RANGE:1.8.30MHz r ei r \ exciting features. (160.10 metres) MODES: USO, LSO, CW, FSK INPUT PO WER: 200W PEP on SSB SPEECH PROCESSOR o An HF 160W DC on CW circuit provides quick Ione constant 100W DC on FSK Efa. e* •• m». ••• compression using a true RF ANTENNA IMPEDANCE: 50.15 ohms. compressor as opposed to an IF clipper. u4 ondba lanced Amount ol compression is adjustable CARRIER SUPPRESSION: Better than to the desired level by a convenient e front panel control. SIDEBAND SUPPRESSION: Better Um.. 50dB SPURIOUS RADIATION: Greater than IF SHIFT e The IF SHIFT control 0 260dvEl (Harmonics more than —40dB) vares the IF passband without changing RECEIVER SENSITIVITY: Better than the receive frequency. Enables the 5„ operator to eliminate unwanted signals RECEIVER SELECTIVITY: by moving them out of the passband of The ultimate transceiver ... TRIO's TS-820. No matter what SOB 2.4kHz ( • 6dB) the receiver. This feature alone makes 4.4kHz ( 60dB) you own now, a move to the TS-820 is your best move. It offers the TS-820 the pacesetter that it is. C W • 0•5kHz —6dB) a degree of quality and dependability second to none, and 1•8kHz ( —50dB) as the owner of this superb unit, you will have at your finger- PLL e The TS-820 employs the latest • With optional CW filter Installed. phase lock loop circuitry. The single IMAGE RATIO: 160.15 metres: Better tips the combination of controls and features that, even conversion receiver section than 60dB Performance oRers superb protection under the toughest operating conditions, make the TS-829 10 metres: Better against unwanted cross.modulation. than 50dB the leader that it is. And now, PLL allows tho frequency to IF REJECTION:Better than 50dB remain the same when switching PO WER REQUIREMENTS: 1201220 Unprecedented demand plus the painstaking care TRIO sidebands(USB, LSB, CW) and VAC, 5060Hz, 13.8 VDC(with optional eliminates having to recalibrate each lavishes on each TS-820 has created a back-log of orders, DS-1A 0C-DC converter) time. but rest assured, it's well worth waiting for. Once you have PO WER CONSUMPTION:Transmit: 280W. Receive: 26W (healers oft) operated the TS•820 you will not be satisfied with anything DIMENSIONS: 14'w • 6'h • 13,-;-'d TS-820 £625 inc. VAT else. WEIGHT, 35.21b(16kg) £126 inc. VAT 1:10.1. digital readout optional

TS-520 £432 inc. VAT

S P.520 £18 inc. VAT

V F0-520 £72 inc. VAT

TV.502 £171 inc. VAT

SP-520 TS-520 VFO-520 TV-502 As a TS-520 owner, you go on the air with a sense of pride and MODES: USB, LSB. CW SELECTIVITY: SSE12•4kHz ( — 6dB), confidence. Thousands of these precision-built beauties are PO WER: 200W PEP input on SSB, 160W 4 4111z(— 60d81. CW 0• 51.Hz ( —60B). 1-51iFix ( — 60dB)(wIth accessory filter) in operation all over the world ... in ham shacks, field day DC input on CW ANTENNA IMPEDANCE: 50-75 ohms. FREQUENCY STABILITY:100Hz per 30 sites, in DX and contest stations and in countless mobile unbalanced minutes after warm-up installations. No other rig has ever offered the performance, CARRIER SUPPRESSION: Better than IMAGE RATIO: Better than 50dB 45dB dependability, versatility and value that is built into every IF REJECTION: Better than 50dB UN WANTED SIDEBAND TRIO TS-520. TUBE AND SEMI-CONDUCTOR SUPPRESSION: Better than - 40dB COMPLEMENT: 3 tubes (2 • S-2001, HARMONIC RADIATION: Better tiran You have certainly heard the TS-520s clean signal on the air 1213Y7A). I IC. 18 FET, 44 transistors. 84 - 40dB diodes and have probably heard a lot of glowing praise by other AF RESPONSE. 400 lo 2,600Hz ( 6dE1) hams. So if you don't already own a 520, maybe it's time you AUDIO INPUT SENSITIVITY. 0.25i/V DIMENSIONS: 13-1' w • 5.9 h 132' d did. for 105810 • N)11k1 WEIGHT: 35.2Ib

STOP PRESS TS 520 NO W AVAILABLE WITH OUT I2V INVERTER AT ONLY £405 Inc. VAT

For those who want a good low cost 2 metre FM receiver, we are delighted to offer a much up-dated version of the Lowe Monitor. Made for us in Japan (where else), the ASV 1515 can take up to 12 xtal controlled channels, has a proper 15 kHz filter, a mains/12 volt power supply and loudspeaker built in and a new FET front end for higher sensitivity. Price? £39.50 inc. VAT. Crystals ex stock at £2.40 each. Use a good 70 cm converter in front of it to keep in touch with the increasing activity on that band. Full details on request. Is it a sign of the times that we sold out of 2 metre SSB gear on the first day at Alexandra Palace and had to rush more TR7010 from Matlock ? The idea of real DX is catching on, and with tlie TR7010 still costing only £175 including VAT, it's the best way to get in on the action. Rallies. Must congratulate the organisers at Drayton Manor and Belle Vue for first class arrangements. Regret we will not be at Woburn this year but will be covering most other events including Preston—at which the charge for the whole rally is exactly the same as the hire cost for one table at Woburn? ??? Congratulations on a timely story from Pat Hawker in June Technical Topics. It may seem odd that a purveyor of sophisticated (or should one say complicated) equipment should welcome such a warning, but the sad truth is that fewer and fewer amateurs understand what is going on inside their equipment and it would be pleasant to see some simplified equipment around instead of more and more complex boxes. If any club needs a talk on current equipment techniques as distinct from a show of black boxes, we will do our best to oblige.

502 RADIO COM M UNICATION July 1977 LOWE ELECTRONICS LTD

TS700G £392.62 INCL VAT The standard by which all others are judged. Full 2 metre coverage, VFO or •..,-,., i‘...___,V6.r . — crystal controlled. All modes AM, FM, USB, LSB, and CW. Mains or battery operation. Normal and reverse repeater facilities. Trio exclusive tuning fork -,•• -..... access tone generator. Plus, of course, Trio quality and reliability backed by i ' C's•i' -." Lowe Electronics service. If you haven't seen it yet, go to one of our branches 's. and be prepared to be impressed...... ,:.,>.•..7- ••••• i'. CN, 15 Watts output. 0.25 microvolt sensitivity. European standard FM selectivity. . ... This rig has all others beaten...... , , . , * This special price includes a free inalchino VOX3 unit *

_ --,...- - e L , .. TR7200G £175.00 INCL VAT The TR7200G has set all 2 rector FM operators talking about its outstanding performance on both transmit and receive. Not only is it the best engineered transceiver on the market, but it's also the most sensitive at 0.3;.V for 15dB : quieting and has the cleanest transmitted signal both in and out of band (the .1t '' economy transceivers simply lack the interstage filtering to ensure that the _ ..... , C • ' ••-•• owner is not put off the air by the Home Office.) Supplied complete with microphone, mobile mount, power leads, spare fuses oo • li and incorporating the TRIO exclusive tuning fork access tone generator. the . TR7200G includes ten fitted channels. normally R3, R4, R5, R6. R7, S20, 21, 22, 23, 24.

TR3200 £171.00 INCL var The newest FM handy transceiver from the TRIO range. Superb performance for the 70cm. operator, 12 channel capability In the range 432,136MHz with three channels fitted (SU8, SU18, SU20). Transmitter output switched 2W/ 400mW and incorporating the TRIO exclusive 1750hz tuning fork access tone generator. i-wave detachable antenna for high gain performances on both e' ,s transmit and receive. '4: .' ..,..,...... Supplied complete with all accessories as the TR2200GX and with the new li L...... , ,,,,,,,, ••'41!.. ,, miniature handy microphone...... ‘ t • * The price includes the all.Important battery charger for the optional re-charpe•ble battery pack. The battery pack costs £9.72 incl. VAT *

TR7010 Join the SSB revival for only £175.00 INCL VA T Following the worldwide success of the TS700, Trio have taken the TS700 basic design and packaged it for 2 metres SSB mobile use. o The TR7010 sets new standards in receiver sensitivity and low spurious emission on transmit. Operating C W and SSB from 144.1-144.335MHz, the • ,ib' i!z•- — 7-- . TR7010 covers CW SSB and beacon activity. 48 5kHZ channels plus VXO and 0 . :* • RIT provide continous coverage. Single conversion using an IF of 10.7MHz with a superb crystal filter provides outstanding selectivity. Wide range amplified AGC and newly developed FET 1.- devices in RF amplifier and mixer stages allow maximum sensitivity to be used , • with freedom from overload due to adjacent signals. Single conversion transmitter with fully balanced mixer system generates a beautifully clean signal with crisp audio quality.

HE A D OFFICE 119 Cavendish Road, Matlock, Derbyshire. Tel (0629) 2817 or 2430, 9 a.m. to 9 p.m. BR A N C H OFFICES Com munications House, 20 Wallington Square, Wallington, Surrey. Tel. 01-669 6700 Soho House, 362-4 Soho Road, Handsworth, Birmingham, Tel. 021-554 0708 27 Cookridge Street, Leeds. Tel. 0532 452657 A GE N T S Alan GW3YSA.35 Pen-Y- Waun, Efail lsaf, Nr. Pontypridd. Tel. Newtown Llantwit 3809 EVE NIN G S AN D WEE KE N D S John G3JYG. 16 Harvard Road, Ringrner, Lewes, Sussex. Tel. Ringmer 812071 Sim GM3S AN. 19 Ellismuir Road, Baillieston, Nr. Glasgow. Tel. 041-771 0364 OPENING HOURS: 9-5.30 TUESD AY TO SATURD AY INCLUSIVE

SEND 48p IN STA MPS FOR FULL CATALOGUE, PRICE LISTS AN D OUR ANTENN A BOO KLET

RADIO COM MUNICATION July 1977 503 PAUL G3VJF CND ICO M

You could pay up to £30 less for a 2-metre rig but is it worth it when an IC-240 offers so much more

£198 INC VAT

DIMENSIONS 156mm wide 58rnm high 218nen deep

IC-240 THE WORLDBEATER FOR FM MOBILE

THERE ARE SEVERAL CHEAPER ALTERNATIVES BUT IF YOU LOO K CAREFULLY INTO IT YOU WILL FIND THAT TO BUY ONE IS FALSE ECONO MY

* Can be easlly program med to any channel of your choice. The 1C-240 contains * Excellent modulation and clipping. The modulation and clipping on the IC-240 a synthesiser instead of banks of crystals. This contains a programmable divider are designed to provide a high quality, easy to read, signal without over deviating. which can be programmed by YOU for each of the 22 channel positions merely Many sets neglect this point with the resuitthat you either have to turn up the mod by putting diodes in the appropriate places as indicated by e chart provided in the to be read at all, and then find that you over-devlate on peaks, or you keep the handbook. deviation down and are accused of mumbling! The ICOM quOtity of modulation is well known and la hard to beet. * Quick, easy selection of channels. The IC-240 has a single knob. 22 position, channel selector. Anyone who drives In traffic and wants to change from ono popular channel to another knows the problems of channel changing when this * Really solid construction. There Is nothing cheap and nasty about the IC-240. involves leveret knobs or even a single one when it has to be used in conjunction It is a really solidly built piece of gear which is highly reliable, Of the hundreds with a digital display which requires peering at. already sold very few had to come back for repair under warranty, their record in * Instant facility for listening on all repeater input channels at the flick of a this respect being much better than many crystal controlled sets. switch. I/ is a tremendous advantage to be able to listen on the INPUT channel of a repeater in order to determine whether a direct DSO Is possible. With the IC-240 this is possible merely by flicking the control switch on the front panel from * Automatic PA protection. Thu PA has a continuously variable PA protection DUP to SIM. system which gradually cuts down the output power as the sot is fed into a worse VS WR. * Built In tone burst which can be completely •utomatIc. The tone burst is easily made automatic so that the tone Is placed at the beginning of each transmission when on Duplex. Thin is a necessary feature while some UK repeaters need feeding * Very adaptable for adding a cheaply constructed scanner to cover the whole with a fono nt the beginning of each over rather than only for initial opening as 1m band. The greatest asset of the IC-240 Is the way it lends Itself to the experi- recommended by the RSGB. We this mod for you if you buy from a THANET do menter in digital logic. It is easy to design periteral equipment to do Interesting agent or shop. things such as scan the band or provide other frequencies which are nol pro- * Second-to-none receiver. The receiver on the IC-240 is really sensitive. Simply grammed Into the set already. Several circuits for scanners will no doubt be comparing maker's specs will not give you the true picture. The re-designed published shortly and we hope to be able lo offer a kit for a scanner with six digit discriminator circuit makes the 240 by far one of the best receivers on the market. frequency display for something in the region el £20. You can soon spend this on Ask someone who has one! crystalst IT WILL HAVE TO BE AN IC-240 FROM THANET - YOUR ICO M SUPPLIERS

FOR DETAILS LEAVE YOUR NAME AND ADDRESS OR CALLSIGN ON OUR ANSAFONE (02273 63850) DURING THE EVENING WHEN CALLS ARE CHEAP HP TERMS NO W AVAILABLE

YOUR SOLE AUTHORISED UK IMPORTER FOR ICOM Au THANET ELECTRONICS A n k 143 Reculver Road, Beltinge, Herne Bay, Kent (02273 63859)

504 RADIO COMMUNICATION July 1977 DAVE IC OM G4ELP

T WO LITTLE QS0 GRABBERS

THE PORTABLE PAIR THAT ARE A PLEASURE TO HAN DLE— AND HARD TO BEAT

IC-202 SSB IC-2I5 FM

T WO RELIABLE LITTLE PORTABLES WITH SENSIBLE BATTERIES AND A USEFUL OUTPUT PO WER.

Both the IC-202 and its FM brother the IC-215 give a useful 3 Watts output and run from C type cells, which are about 4 times bigger than the penlight cells used In other portables and give correspondingly longer life. Both exhibit the high quality found In other ICOM equipment both in construction and In excellent transmission. Ask anyone who has one and he will tell you just how good they really are.

THE IC-211E —KING OF THE BLACK BOXES (even if it is really dark grey). The news is getting around how good they are. We dare not do more than just show a picture as we cannot get enough!

DIMENSIONS 9}in wide slin high 10!,in deep HOT NE WS! A Thanet Shop will be in the North before long

Why not see and buy the excellent ICOM range at your nearest Thane agent—phone for an evening or weekend demonstration.

LONDON —Terry G8BAM (01-5569366) W ALES—Tony GW3F KO (0222 T02982) THANET NORTHERN SCOTLAND—Ian GM8DOX (073683 3223) MIDLANDS—Tony G8AVH (021 329 2305) 64 High Street, Wombwell pew 756229 DEVON—Bob G3POH 5th, NORTH WEST—Gordon G3LE0 (Knutslord (0565)4040)

RADIO COMMUNICATION July 1977 505

B • • FIRST WITH - -STILL IN FRONT

Never mind the pretty PICTURES (you can see them on other ads.) YAESU FT101 E —just take a look at our The latest of a long line of successful PRICES ... transceivers, unbeatable value at our that's what counts! price of—

£448.87 VINC AT . FT301 D FREE SECURICOR DELIVERY —as pioneered by us- The "Rolls Royce" of solid-statetransceivers. 200W. p.e.p. input, digital readout, all options -still the "only way to go" for—

INC. £606.37 VAT FT22I R

There's a lot of 'em about, and with good reason. Join the multimode set on 2m. GUARANTEED DESPATCH of "in-stock" for— items on day order received (Monday-Friday)

£336.37 VATINC . FRG-7 CAST-IRON 1 YEAR GUARANTEE includes You want accurate general coverage? This is the best value for money we know. PARTS, LABOUR, CARRIAGE Only—

. £162.00 VINC AT FIRST - CLASS AFTER - SALES SERVICE at our centralised service facility

FM{ Multi 8 with VFO £101.25 NDK200 SWR meter £27.110 Drake SPR4 (with NB end extra Bolcom 12r. PSU Ica Liner or SECOND crystals) £421.138 sirallol .. 2 at £14.63 Carriage extra Yaeau RF1010—as new £295.00 Standard SY200 synthesizer— HAND Standard C430, 70em FM .. £140.63 details available .. 2 at £34.37 i• Securicor £4.86 EC10 Mk.1. AC PSU £100.13 Ya m FR5OB receiver £44.37 EQUIP MENT Drake SSR-1 £126.56 Collins KWM-2, VFO and mains Roadline £2.16 Hemr,F4W202 • PSU .. £1110.00 PSU(240v.) £400.00 — ALL PRICES INCLUDE VAT —

* SOUTH A MPT O N HOLIDAY CLOSURE -28 June to 12 July inclusive* * LOUTH HOLIDAY CLOSURE -23 July to 8 August inclusive*

506 RADIO COMMUNICATION July 1977 MEET THE

NEW EMOTATOR

FAMILY

Posing lor you (left to right) are:

103LBX -for lighter HF and medium to large VHF arrays.

502CXX-the really new boy for mednim HF and larger VHF UHF arrays.

1102MXX - for the largest trlbonders and monobanders.

ALSO . . the powerlul 1103MXX (not shownI-a nnared down 1102-i-unarm torque. slower rotation for the really big slut]

. . . AND TO MAKE THEM EASIER TO LIVE WITH. • • •

MB300 1213 BRACKET

MAST BEARING A unique 3-piece mounting bracket lor fixing your rotor to a mast or for The beat answer to your rotary exact centring ol antenna stub Masts. mast problems. Robust, ball- An stainless hardware-takes masts bearing Riled unit with stainless Irom 40 to ramm. dia -fits 502CXX hardware. Complete with 4 hies and 1102/1103MXX rotors. Standard as for guying rotary masts up to top bracket on 502CXX. 62mm. dia.-or can be bolted to gat tower plate as an alionment 1211 BRACKET available For mut- ton mounting of 1031.55. same as tela bearing. bracket (see photo).

PRICES 450 FLEXIBLE COUPLER 451 FLEXIBLE COUPLER 103LBX • • £78.75 Fits between 103LBX and lower mounting plate or Fits between tower mounting plate or mast bracket mast bracket 11211) to compensate for slight mis- 502CXX.. . • £111.38 (1213) to provide same facility as 450 flexible coupler

alignment bearing. 1102M XX £163.13 -but to lit 502CXX or 1102:1103MXX type rotors. A worth-while Rotor "floats" in the 1103MXX £168.75 adjunct to 450 and thus allows the 450 .. , • £5.63 . your system the ironer stub mast to 451 .. £10.69 lo avoid wear align within bearing. to 1213 .. £14.06 r' and tear ••• 4 avoid excessive wear 1211 .. £8.44 through slight and possible rotor MB300 £14.06 bearing 1mis. alignment. demon, All include carriage/ VAT

Agents . LES LYSKE, GI3CDF, NEWTO WNARDS (0247) 812449 ALAN CAMERON. GM3OGJ, ALL A (0259) 214653 Western Electronic/ (UH) Ud DAVID SMITH, G4DAX, WATFORD 42619 HEAD OFFICE(All Mall/Enquiries) OPENING HOURS :- LOUTH : Open 812.1 4 p.m. Mon-Fri. Sat, by appointnlent. SOUTHA MPTON st WEST PARK ROAD, Tel 0703 2764. Open FAIRFIELD ESTATE Tues. -Fri. 9-1. 2-5.30 p.m. Sat. 9-4 p.m. LEICESTER : MAY'S HI-Fl. CHURCHGATE. Tel. 58662. Open LOUTH, LIN CS, LN11 OJEI,To. Looth o m 4gssi3). Mon-Sat 9-6 ans. Closed Thurs.

RADIO COMMUNICATION July 1977 507 k9 WATERS & STANTON TELEPHONE HOCKLEY (03 704) 6835 (2 LINES)

JUBILEE CASH BONANZA FDK LISO TO BE WON

Here's a Ornai chance to make a blo saving with your next FEW purchase.Yes It's true, you can save up to £100 on each item you purchase. This offer applies to every transceiver, receiver, vfo and power supply manufactured by FDK for the UK market, and purchased between fat July and 3151 October by UK customers. With every FIX Item mentioned you will find in the carton a Jubilee Cash Bonanza card. Simply write your full name and address on the back of the card and return to us to enter this exciting draw. As well as flrst pace of £100, second and third prizes of £30 and £20 will also be awarded. The draw will take place on 31st October at the ARRA exhibition in Leicester. The winners will be notified in writing and the results published in our advertisement immediately alter the draw.

for 70 cms Multi-Ull for 2 metres Multi-II This lop Selling FM transceiver has the finest front end on FDK 70cms inn has opened up a completely new era in Mt mobile FDK the marbet. Add to this its 4 channel auto-scan facility. operation. II you haven't yet tried It then send an SAE for full punchy 12 watts output and a host of other features, and you details of the transceiver that over? one is using:70cms FM— have today's most advanced 2 metre fm mobile. SAE for the place to meet a lot of nice peopiel £249.9 cha fitted. leaflet. £299. 7 ch's fitted.

FDK XTALS FOK ACCESSORIES U-11 reverse repeat Pair £5.90. AC PSU with switched voltage outputs. 4 amps capacity and short circuit protected. 119111 s s • IiI M-I I S21122/23 sets 6 £10.00. £63.50. M-11 repeat input ea. £2.45. Sound box for fitting beneath MI1 for TM5813 repeat sets 5 £9.00. deflecting sound forward. £10.50. M-1I S24 pair £4.90. Desk lop aerial fits most monitor receivers and transceivers £2.50. 1.6MHz 2700 shift ea. £2.45. M11 VFO Full frequency coverage of 2m with repeater shift. £81.00. NOTE Ail the above crystals are high Mobile mounting brackets (ono supplied stability FIX types. Specials to order. with each transceiver) £13.00. DC power leads £1.115.

FDK TM56-B VHF Monitor FDK Multi-2700 Mk II FDK QU ARTZ 16

A complete 230V/I2V VHF FM monitor receiver. 12 fixed A complete station inc. vox, toneburst. OSCAR This is the 2 metre FM transceiver tor the man who wants channels end 4 auto-scan. 10 channels supplied. Amazing re.. variable power control, speech processor, functional transceiver without any frills. Supplied Com- 61:4/Hz 6 1.6MHz repeater shift, dual vlo, 15 watts plete with 10 channels, toneburst and all accessories no Performance al an amazing price. £84, 10 eh's fitted. output. SAE for leaflet. £481 incl. carriage. other transceiver can match Its price. £169. 10 eh's fitted.

508 RADIO COMMUNICATION July 1977 S FAST ELECTRONIC MAIL ORDER SERVICE FDK TELEX 897406

A SHOP FULL OF HAM RADIO -BUT A LOT OF CUSTO MERS NEVER VISIT US!

Many of our customers we never see. That's because our reputation for fast. ailment and above all, helpful mall order service Is second to none. Some people even send us open cheouesl That's how good our reputation Is. But it occurred to us that although you mop never visit us you might like lo see who you are dealing with! The photo on the right will show that we do not lo fact operate tram a telephone kiosk but from purpose built modern premises with s large customer car park. So now you know that when you place your order by post or telephone, you are dealing with one of the UK's largest ham radio outlets. Since 1972 we have been serving the ameteur and short wave listener. Our success rests on your trust and satisfactIon-we intend to keep

It that way! 31 SPA ROAD, HOCK LEY, ESSEX. 10 mins. from Southend Airport

JUST PART OF OUR EXTENSIVE STOCKS

MICRO WAVE MODULES 5Y)2M 5 element yogi .. £6.98 (£1.001 "V" brackets, Strec,n1 protected MMC 2rn. conv.IF 2-4 4-6 28-30 .. £20.25 (36p) 8YI2M 8 element yogi .. £9.10 (£1.00) copper wire, etc. . £27.00 (n.c.) MMC 75MHz conv.28-30 £22.50 (36p) 10Y/2M 10 element yagi £19.35 (£1.50) Q-Trap compact 80'40 dipole kit MMMC 70MHz cony. 28-30 fiscal PBMI0/2M 10 ale. parabeam £23.00 (£1.50) £14.82 (£1.001 osc. .. £22.50 (38P) PBMI4/2M 14 ale. parabeam £28.35 (£1.75) Q-Trap coils only .. £7.98 (50P) MMC 2m. conv.28-30 + local est. £22.50 (360) 5XY/2M 5 eta, crossed yogi.. £14.50 (£1.25) MINI- PRODUCTS MMC 70cm. cony. 28-30 or 144-146 £IA.00 (36p) 8XY/2M Belo. crossed yogi.. £18.10 (£1.50) HO-I 10-20m. compact12kW yogi £84.37 (£2.00) MMC 12961144 or 28-30 .. £28.12 (38p) IOXY/2M 10 ele. crossed yogi £23.95 (£1.75) C410-20m. compact 1•2kW vort.cal £38.25 (£1.50) MMDO 50 50/0Hz counter .. £66.95 (36p) 0412M 4 ale. quad £14.85 (£1.50) MMD 500P 500MHz pre-scaler .. £27.00 (36p) 06/2M 6 eh). quad .. £19.80 (£1.75) ROTATORS MMT 432/28 70cm. transverter £109.00 (36p) 05/2M 5 ele. slot fed £12.35 (£1.25) A930 antenna rotator £44.40 (£1.50) MMT 432/144 2m. transverter £149.62 (36P) D8/2M 8 elo. slot fed £16.55 (£1.50) AR4() antenna rotator £51.70 (£1.50) MMT 144/28 2m. transverter .. £88.67 (36p) X012M crossed dipoles .. £6.40 (£1.00) C044 antenna rotator £106.85 (£1.75) NIHON DENOTE) U GP/2M ground plane vertical £6.95 (£1.00) Horn II antenna rotator £145.00 (£2 .00) Liner-2 Mk. II 2m. sob Icor. 12v. DC £184.50 (1.2.50) H0/2M Mobile halo head only £3.55 (50o) CO bearing £4.21 (500 LIner-43070crn. sob lear. 12v. DC £296.25 (£2.50) HM/2M Mobile halo with mast .. £3.09 (£2.75) Stolle 2010 antenna rotator £48.50 (£1.50) RUSE reg. p.s.u. for Oner-2 4430 £31.50 (£2.50) PM1-1/2C 2 way phasing harness for Stolle 2030 antenna rotator £S1.05 (£1.50) SOLID STATE MODULES circular polarisation £4.60 (75o) Stolle alignment bearing .. £11.23 (50p) Oro. or On, Europa transverter 2COW HY.GA IN ANTENNAS £109.15 (n.c.) NEW £39.90 (£1.50) 2 or 4m. converters IF 2-414-8128-30 £te.o0 (n.c.) 70cms base aerial, 8db gain .. £36.50 (£.2 00) 12AVO 10-20m. vertical 2kW. £55.60 (ei.so) 70cm. converter IF 144-146 £18.00 (n.c.) 1296MHz Yogi, 15db gain .. £20.90 (Li 00) 14AVO 10-40m. vertical 2kW. 2m. boxed pre-amp £8.72 (n.c.) 18A YTIWB 10-80m. vertical 2kW. £75.90 (£2.00) TH3 JNR 10-20m. yagl 600W. .. £108.00 (£2.00) PAS 2m. miniature pre-amp board £6.27 (n.c.) UHF ANTENNAS BY JAY BEAM TH3 Mk3 10-20m. yagi 2kW £165.00 (£2.50) SSM Z-Match 18-80m £31.50 (1.00> 08f7Ocrn. 8 ele, slot fed £14.05 (1.i. 25) W ATERS PBM18,70cm.113ele. parabeam £16.95 (£1 50) SHOO belon 2kW. £13.50 (50p) Stable tone-burst modules 1750Hz £3.93 (25p) MBM48/70cm. 48 ele. mu)tibeam .. £19.65 (£1.50) STATION ACCESSORIES POLAR ELECTRONIC DEVELOPMENTS MBM88/70cm. 88 eta. Multi beam .. £26.30 (£1.75) Shure 526T table microphone £25.50 ((.00) Magnum 2m. transvorter £151.90 (£1.50) 12)(Y/70cm. 12 ele, crossed yogi .. £27.00 (£1.50) Shure 444 table microphone £21.95 (£1.00) Wavemeter 65-230MHz .. £19.00 (50p) PMH2/70cm. 2 way phasing harness £5.30 ((5p) Shure 201 hand microphone £9.95 (50p) 432MHz linear 230Y AC £151.90 (£1.50) PMH4/70cm. 4 way phasing harness £11.10 (£1 00) SWR single meter .. £9.85 (50p) Magnum 2m linear 230V AC £151.90 (£1.50) SWR dual meter .. £12.65 (50p) QM70 PRODUCTS MOBILE ANTENNAS BY JAYBEAM TAS 2m. 518th glass fibre whip Telegraph key £9.75 (5013) 2 & 4m. converters 28-30 .. £18.00 (36p) Drake low pees filter • . £18.00 (75P) with 4m.of cable £11.80 (£1 00) 70cm. convertors 28-30 IF .. £19.50 (36p) Ferrite rings Ir for a.1.1. 30p (8P) U5 70cm. colinear 5.6013 gain and 1296MHz converters £14.00 (36p) £2.53 (150 4m. of cable £18.90 (£1 00) HP3A high pans tv filters .. Cobra 70cm. transverter £86.00 (75P) HP? ni-cads (Ever-Ready) £1.10 (100) Solid state amplifier £49.50 (500) LF ANTENNA SYSTEMS HPII ni-cads (Ever-Ready) .. - £1.90 ((0p) VHF ANTENNAS BY JAY BEA M EL4OX compact 80/40 dipole de Baran Insulator 50 ohm (beams or 4Y/IM 4 element yagl £11.45 (£1.75) luxe with balen, hard-ware, inc. dipole) 2kW £9.90 (50p)

MAIL ORDER & HEAD OFFICE: HOCKLEY AUDIO, 31 SPA ROAD, HOC KLEY. ESSEX. TEL. 03 -704 6835 (2 lines) ALL PRICES INCLUDE VAT CARRIAGE AT COST AGENTS -G3XTX J.R. Electronics, 148 Collier Row Lane, Rornford, Essex. Tel. Romlord (0708) 68956. [BARCLAYCARD' G3OOT Bredhurst E)ectronics., Willowbrook. School Lane. Bunbury, Cheshire. Tel. Banbury (0829) 260708 GM3GRX Eric Simpeon, 6 Mosel. Road, Fekirk, Stirlingshire. Te). 0324-24428 MOND AY TO SATURDAY 9 A.M. TO 5.90 P.M. EARLY CLOSING WEDNESDAY

RADIO COM MUNICATION July 1977 509 William Munro (Invergordon) Limited

distributors for NEC Amateur Radio Equip ment

FOR SCOTLA ND, NORTHER N ENGLA ND & NORTHER N IRELA ND

.3116

NEC 14 NEC

C61110E Transceiver (Ex Stock) £645 plus VAT £80.63, Total £725.63

(Price includes Securicor Delivery)

Frequency Range 10m-15m -20m -40m -80m -160m and 11m and WWV 15MHz on receive only. Mode LSB—USB—C W—AM —FSK—FAX/SSTV Power Requirements 100/1101117!200/2201234 Volts AC or 13.5 Volts DC Input Power 280 watts PEP (240 watts on 28MHz)

Digital Readout—Separate Crystal Filters for each of LSB, USB, and CW. AC and DC power units are built in. Switched metering for "S" meter, Relative Output, Plate Current, and ALC for setting MIC Gain, The following accessories are supplied with the Transceiver-Microphone, DC Power Cable, AC Power Cable, 5 RCA Plugs, 2 Spare Fuses, 2 Jack Plugs, 2 Allen Keys and a 60 page instruction book. Built-in speaker with 3 watts output. A hybrid design utilising the best features of valves and semiconductors is used to give a high performance. 7 Valves-49 Transistors-19 FETs-128 Diodes-25 ICs. The use of the RCA low noise beam deflection valve (7360) as receiver mixer gives the CQ110E high sensitivity combined with remarkable crossmodulation characteristics.

CQ 301 2KW Linear Amplifier—I0 to 160m with built-in power supply and 2 EIMAC 3-500Z Valves Ex-stock. £760 plus VAT £95, Total £855. (Price includes delivery)

Available soon CO 201 External Digital VFO CO-P-2200 12 channel portable /mobile 2m FM transceiver

We also stock Antennas and Accessories—Microwave Modules—Modular Communication Systems—Solid State Modules—Antex Products Components etc. SELECTION OF USED EQUIPMENT

100 HIGH STREET, INVERGORDON, ROSS-SHIRE IV18 ODN. Telephone 0349 852351 Telex 75265

HIRE PURCHASE INSURANCE

510 RADIO COMMUNICATION July 1977 antenna specialists

"THE ULTIMATE CHOICE"

ASP655 ASP659UK FOR AMATEURS W HO 130-174MHz Iv/ 3dB 425•440MHz 5dB Gain Gain. DC Grounded. Base Station Collnear DEMAND THE BEST Base Station Ant, Power capability 100W Power Capability 100W. Termination Female 'N' ASPA680UK Termination SO-239. Tyne connector. Complete with mount- Complete with mount- 144-148MHz edB gain ing brackets for matte ing brackets (or matte DC Grounded Base up to ir 0.0. up to li• 0.1). Station Collnear. Available now. Available now, £15.49 Power capability 350W, £14.44 plus £1.00 plus 75p car,. Length: approx. 12' carrlag• Weight: approx. 41b. Rated wind velocity: 118 11 NE W! mph. HELICALS FOR THE FOLLO WING Termination: Male 'N' PORTABLES Type Connector. Trio TR2200GX Available now. Trio TR3200 £47.25 plus £2.50 car- icon, IC-215 riage. (p & p lor hellcats 405) NE W I I 111› ASP 700UK 430•440MHz. 9dB gain • OC grounded baso station collnear. Power capability 250W. Length approx 12'. Rated wind velocity, 103mph. MOBILE ACCESSORIES Termination male 'N' typo connector AS P332 K•203 AVAILABLE NO W Gutter mount suitable No hole boot mount. £57.75 plus £2.50 card - for use with ASP629. suitable for r hole snap aile. ASP393 complete with in mount, easily adapt- 10' RG.58U cable and able tor other mounts ASPN701UK PL-259 connector £3.09 £3,70 plus 50p Peat and plus 50p post and pecking. 430-440MHz 12dB Gain. Packing. DC Grounded Base Station Colinear. ASPR132 Now Magnetic Mount 11›. Power Capability 250W, Gutter mount suitable Shown with ASP629. Length approx. 18'. for use with ASP677. but also Pitt ASP393, Veiglit approx. 25/be. ASPE667, easily adapt- ASP677 and ASPE667. Rated wind velocity 122 k,..• able for use with other Complete with 10' 0G- mph. antennas. Complete 53U cable. Termination Male 'N' with 10 RG-58U cable £9.19 plus 500 Post and TYPe Connector. and PL-259 connector. OaCkInct. Available now. £8.09 plus 500 Post and £135.00 plus £2.50 Packing. carriage.

V AT of 14 % to be added to above prices. Please send SAE for catalogue of complete range. ‘waalier:7". FOR M OBILE ANTEN N AS PLEASE SEE PREVIOU S ISSUES. 0 "Stripe, of Quality"

AV AILA B LE FR O M

LON DON AVO N CHESHIRE Lee Electronics Ltd. 01-723 5521 D. G. Smith, G3UUR. 0225 833433 Bredhurst Electronics. 0829 260708 A mateur Radio Exchange. 01-579 YOR KSHIRE SCOTLAN D 5311 The A mateur Radio Shop. 0484 Ian Mckechnie, GM8D OX. 078683 Terry Barnett, G8B A M. 01-556 9366 20774 3223 KEN T Leeds Amateur Radio. 0532 452657 Thanet Electronics. 02273 63859 Nick Sheard, G4GCP 0943 78239 SOU TH W ALES BEDFORDSHIRE J. J. Doyle, GW4F01. 0639 2942 Alan R. Morris, G4ENS. 0582 414179 N. IRELAN D NORFOLK G.I. A mateur Supplies. Ennis- NORTH W ALES Ted Rule, G3FE W, Surlingharn 632 killen 2955 Bill Davies, GW8AHI, QTHR

J. YU, 21 Langley Avenue, Surbiton, Surrey KT6 6QN SOLE DISTRIBUTOR TO THE AMATEUR TRADE

RADIO COMMUNICATION July 1977 511 MODULAR ELECTRONICS PROPRIETOR: P. J. CRAIG, G8CQS 95, HIGH STREET, SELSEY, NR CHICHESTER, WEST SUSSEX. P0200QL. Telephone: Selsey (024-361) 2916.

SOLE DISTRIBUTOR TO THE AMATEUR RADIO 8E190 £1.60. Bd -19 8p112.5%). CILIOS 8P112.5%). HIGH QUALITY FINISHED UNITS MARKET FOR THE PRODUCTS OF SOLID STATE 945130 WIRE END VARACTOR. 7p1(4V) 5w input Transverter M.E.T. 432.28-10 compatible with the FT101 SCIENTIFIC INC. suitable for Mull service. Only 55p 8%. on Similar. Full 10w output with low Inteirnodulation MANUFACTURER OF R.F. PO WER TRANSISTORS Dual Mixer VHFrUHF FETS Type E420 (dual E300) products £704- VAT 12.5%. Transveiter M.E.T. USING ADVANCED ALUMINIUM NICHROME Ideal for mixers. 432-50-10 as above but with 50MHz IF £72 VAT. Both fAETALLISATION FOR RUGGED RELIABLE With oata only E1.00.4 8% marked W0383 (Pyo) above have better N.F. than 2,7dB with 28dB AX pain. OPERATION UHF Antenna Changeover Relays. Magnetic M E, FM15-1. Better than 13w out when driven with the 2200g or similar 1w FM equipment. £33+ VAT. ALL PRICES EXCLUDE VAT AT 8% Devices 951-110-12V 50 ohm good VSWR to 1296MHz. Direct cable entry for RG43 or similar cable. Reduced M.E. FM15-2. Better than 14w out when driven with tire Price £5.09 +VAT 8% 2200GX or similar 2w FM equipment. £33 r VAT. Type Specification Frequency Price M.E.L. 202-25 Typ 25w clean SSS from the ICOM IC202 2N4427 1w 161B 12.5V 175MHz £0.84 Heatsinks suitable for Transistor amplifiers. Single fully automatic changeover. Also suitable for Ille ICOM 2N3866 1w 10dB 28V 175MHz £0.78 sided types. FiEDPOINT TYPES. Prices Reduced. VAT at 8% IC215 on FM £35+ VAT. 2N5913 2w 7dB 12.5V 470MHz £1.40 2143553 2-5w 9dB 28V 175MHz £0.95 411 4.5 deg. C por W 2.36' with mounting area M.E.L. 40. 40w Linear amplifier. Made to your drive level 2N6080 4w 12dB 12-5V 175MHz £3.90 1.26' £0.70. of from 9 to 1 3w. You specify the drive level. £14 -r-VAT. SDI 143 10w 10dB 12.5V 220MHz £5.56 6M1 2.6 dog. C per W 6.. 3.69' with mounting area M.E.L. U4 300Mw for full aw output at 432MHz. No 1•37 £1.10 2N6081 15w 63,15 12-5V 175MHz £5.32 Switching. BNC connectors £22+ VAT. DAU 4.5 deg. C per W52. 120mrn £0.55. 2N6082 25w 6.2dB 12 .5V 175MHz £7.50 M.E.L. U10 2.5ve for lull lOw output at 432MHz. No Due to weight, postage. is 25p on EACH Heatsink. No 2N6083 30w 5.7dB 12 .5V 175MHz £8.40 switching. BNC. £28 • VAT. other goods under this postage charge. 2146084 40w 4.5dB 12 .5V 175MHz £11,10 Components. VAT el 12•5% unless mocked otherwise. 8E2127 70w 6.5dB 12-5V 175MHz £23.60 PREA MPLIFIERS FOR 141 AND 132MHz DAU Superior Quality PTFE Files Trim mers. 2145044 2yr 9dB 12.5V 410MHz £5.22 PA1. 50 ohrn in and out. Uses latest 3N204 device. Type 7r.nrn 1.5.90-18p. 7145845 4W 848 12.5V 470MHz £7.51 N.F. 2dB gain al 18 to 26:10. 1-1- square fits most gear. 7rnm 2.0.18pf -18p. 2N55146 10w 6dB 12.5V 470MHz £9.48 Only £5.00 • VAT. Liner 2 Model avallable to order. 501136 10w 5.5dB 12.5V 470MHz £6.10 100,0e 3.5-35p1-15p. PA.U1 for 432N1Hz. Gain 11,1B N.F. 2.4dB. 55mrn SD1088 25w 6.8dEl 12.5V 410MHz £16.45 Mullard 7mrn 1.60 1-151, square. U M: VAT. The Ut has been parnmetered SC11089 40w 4-3dB 12.5V 470MHz £1111.17 Surplus lOrrun 2.5.250 -81, Mica Compression Trim mer.. Very suitable tom the for compromise N.F. and has improved intermod 2N5590 10w 5.2dB 13 .6V 175MHz £1.60 Performance. Use the U2 for min N.F. but be warned it 2N559I 25w 4-4,16 136V 175MHz £8.50 Collector tuned circuit of Power amplifiers. Clydon. 10.600-15P, Handles 50w. has poorer interrnod performance. 21'45179 Gen, purpose amp. F.T.- 900MHz TO72 £0.72 2N5031 UHF arnp. ti.F.- 2.5d8 at 450MHz 1072 £2.13 Radlospares. 4-40pf -17p. Handles 70w. PA.U2. Gain 10dB N.F. 2dB. The best low noise RADIO FREQUENCY CHOKES performance. Uses the TRW TP491. Only £7.50+ VAT. TR W. Very Low Noise. 3GHz F.T. "T" Pack (Pin 12 uH. 622 irH. 0.33 sift 068 pH. 33 pH. 20 pH, Both 01 the UHF preamplifiers can be supplied, bored layout same as EIFFI9691) Interchangeable Improved 1000 pH. All at 12p+VAT. end tuned with BNC connectors for additional £4.50. low cost replacements for same In most circuits. FERRITES. Only genuine Mollard with correct As supplied to the Ministry. (470MHz applications). characteristics. VAT 8% TP390 2.7dB N.F. at 450MHz £1.10 FX1115 single hole 4p. FX1898 6 hole 10p. FX2049 NE WI NE WI NE WI RF PO WER M ODULES. TP393 2.0dB N.F. at 500MHz £2.00 double aperture transformer core Lie- 200 lap. Complete tuned and tested, ready to install in your TP491 1.6dB N.F. at 500MHz £3.10 PLUGS AND SOCKETS by COLINE. VAT at 8% horne.mode rig. Low cost units. 92 55nun Tuned to MU LLA RD. 5GHz F.T. "T" Pack for 1296MHz 50 ohm lueut. BER90 3.2:10 N.F. at 1250MHz £3.50 BNC single hole Socket 50p. PM2-10 10w out 13 .5d8 gain only 40(M1W drive £15 ,- ElF1491 2 5r113 N.F. al 1250MHz £4.00 BNC 50 ohm Plug UR43 type 55p. VAT. Amphenol UHF Socket 4 hole fixing S0239 Silver Plato NE W 19p. PM2-15 15w out 10.5dB gain only 1.3w drive £16+ VAT. The very latest FANTASTIC PERFORMANCE "0" UHF PL2.59 PLUGS, make unknown, OK 52p. PM2-25 25w out 8.5dB gain only 3.5w drive £17.50,-- MOS DUAL GATE MOSFETS. UNBELIEVABLE Reducers for above RG43 15p. VAT. INTERM00 AND CROSS MOD PERFORMANCE INTEGRATED CIRCUITS VAT 8% The above aro tor 144MHz use with 13 .8V sunPlY• WITH TYPICAL NOISE FIGURES AT 144MHz OF MOTOROLA MCI2013 Prescaler with MTTL output. PM70.4 Cis out 10dB gain only 400m W drive £16.75 - 1.5dB. Not a misprint 1.5c18 SIGNETICS 50306 Divides by 10 or II typical toggle frequency 600MHz. VAT. with data only £2.00-8%VAT. 5V supply. Easy to use with datacopy. £10.50. P6170-10 10w out 5.7‘113 gain only 2.7w delve £16.75 -- SURPLUS RF PO WER. Small quanlitles Only. NEW, NEW. NEW. PRESCALER KIT. PCB MC12013 VAT. Check availability before ordering. all components to build complete with 2 stage Input PM70-10a 10w out 8dB gnIn only 1.6w drive £17.75 - PT2125E 0w in for 15w out at 144MHz 13 -8V £3.604 VAT amplifier using 3GHz "T" pack transistors. All corn- VAT. STRIPLINE STUD RF CATV TRANSISTOR. ponents excluding box. Sensitivity typ. 30Nly at 432. Tho above are for 432MHz use with 13SV supply. Sire 2145947. 5W Diss. FT 1.2GHz at 75rna. High gain. £18 - VAT 8% Only 805 • 8%. In•houSe coded. Specials can be made for 384MHz for use as Injection M OTOROLA MC11951.. Uses: Multiplier. Bal Modu- Source for 1296MHz equipment. VARACTOR BOLT TYPE ITT VBC75A lator. Phase 0v-t. etc. With Datacopy. £1.75 VAT 8% Sre in at 384MHz more than 2-5w out at 1,152MHz Only MOS SCL4001AE 18p VAT 8% NE W! NE W! NE W! Complete boxed tested PRE. £3.170 CERA MIC CAPACITORS. VAT 12.5% SCALER. Input requirement only Typ 30mV. Boxed HP5082-3080 UHF pin diodes, 65p .4 VAT (8%) Disc Erie type 1000pf -2.5p. Disc Erie type 203Pf-2.59. 2N-I429 1w out at IGHZ 28v only £1.00 - with BNC infout. 5V supply. Adequate output to drive Feedthrough Solder in type: 1000pf Erie-8p. 50p1 Erie- soy 50MHz counter. Divides by 10 up to min 500MHz Small Signal Transistors and MOSFETS. • El% 7p. Typ. 600MHz, and you don't have to leed the rig in to 40573-60p. 40341-60p. 3N204 Third Generation SPERRY BECK MAN •55' Displays. Set of 4 Malts pet a measurement. Only £26 t- VAT al 8%. MOSFET-£1.20. BES28-9017, 2N2359-15p. BC107- end three seven scontent numerals. Only £2.00 12p. BFII 5-30p. BFX89-90p. -- VAT 85i Also available as a tested board (unboxeri) 01 £22 -- POSTAGE: SMALL COMPONENTS 25p. HEATSINKS SEE LIST. PREAMPLIFIERS 40p. LINEARS,TRANSVERTERS 90p. MINIMUM ORDER: £1.50 U.K. VAT FREE EXPORT MINIMUM £10 COMING SOUTH? VISIT US AT SELSEY. SHOP OPEN FREE HELP WITH YOUR PROJECTS. SPECIALIST COMPONENTS, DEMONSTRATIONS ETC. PLEASE NOTE: CLOSED ON MONDAYS DURING THE RALLY Access SEASON. ALSO CLOSED DURING MAJOR CONVENTIONS BARCLAYCARD 1 BARCLAYCARD OR ACCESS OVER Et() L

512 RADIO COMMUNICATION July 1977 (M) DRAKE Radio Shack Ltd

CGT-144 2m Collnear with mount £.36.1» LONDON'S ONLY IOO 58-144A 2m Collneer for base station £51.75 RM-805 80m high power resonator £19.00 A M ATEUR RADIO STORE 4BTV 10-40m Vertical •. £75.15 r3D-1 Quick disconnect .. • • £10.23 PRICES INCLUDE VAT 5105 top section only of above .. • • £13.84 Above models filled with Noise Blani.ér £516.33 • • £12.87 R. L. DRAKE PRODUCTS 220-CS Console and AC Power Supp:y £118.12 HLM Trunk Lip mount with coax .. MM-1 Mount £5.62 RECEIVERS 8. ACCESSORIES 200-PS AC Power Supply .. £74.25 RSS•2 Spring • . • • £4.95 R-4C Receiver-SSB. AM. SW„ RTTY £450.00 DMK De luxe Mobile Mount .. £36.00 SSM-3 Spring £10.35 FL250 Filter for R-4C (0.250kHr) £40.50 DCC DC cable.. £8.45 MBK Mobile bracket kit £3.38 F1.5041 Filler for R-4C £40.50 MICRO WAVE MODULES FL1500 Filter for R-4C(1.5kHz) £40.50 MT-1 Mobile antenna matching trans- TRANSVERTERS FL4000 Filter for R-4C(4.0kHz) £40.50 £18.00 MMT 432128 .. £109.13 F16000 Filter for R-4C(11.0kHz) £40.50 PC-120 Plug-In Noise Blanker .. £40.50 MMT 432144 .. £149.03 £54.00 10X Crystal Oscillator £42.75 4-NB Noise Blanker for R-4C NWT 144/28 .. MS-4 Matching Speaker for R-4C £20.25 DD-613 Digital dial .. £180.00 VX.5 VOX accessory £38.00 FS-4 Frequency Synthesizer for R-4C/T- CONVERTERS 4XC/SPR-4 .• £191.25 £20.25 YAESU MMC 144fany IF Interface Kit To mod. FS-4 for use with £22.50 FT-101E Transceiver .. MMC 144128 10 SPR-4 . . £7.43 £20.25 FV-101B Remote V.F.O. MMC 70/any IF.. .. SPR-4 Receiver-general Pureorie £472.50 lii £22.50 FT-200B Transceiver and Power Supply.. MMC 70(28 LO AL-4 Loop Antenna for SPR-4 only (150- £24.75 FT-221R 2m Transceiver .. MMC 432/any IF .. £23.63 I:co MMC 1296/any IF .. £28.12 5-NB Noise Blanker for SP11-4 £54.00 FR-10I LI Receiver u SCC-4 100kHz Calibrator for SPR-4 £15.75 FR-101130 Digital Receiver.. FREQUENCY.COUNTERS FL-101 Transmitier tu- TA-4 Transcelve adaptor for SPR-4. T- arc MMO 050 . £66.86 FL-2100B Linear Amplifier .. £85.32 £27.00 Ect• MMD 0501503 DC Power Cord for SPR-4 £1.05 SP-101B Speaker console .. • • .. o Amateur Bands Crystal Kit for SPR-4 £21.75 YO-100 Monitorscope VARIOUS £14.63 Time 6 freq. Crystal Kit for SPR-4.. £20.25 YC•601 Digital readout unit for101 and 401 MMA 144 2m preamp. Y0-848 Hand-held microphone MMD 500-500MHz protrude* .. £28.13 MARS Crystal Kit for SPR-4 £20.25 FRG-7 Receiver general coverage .. MMV 1296 70cm-2.3cm 'retractor triplet £33.75 Teletype Commercial Kit for SPR.4 £15.75 Aeronautical Crystal Kit for SPR-4.. £28.58 NYE KEYS (Straight Morse Keys) VERSATO WERS Marine Crystal Killer SPR-4 £44.55 Model 312-001 .. £8.75 W25 Wall-mounting Tower £115.00 Tropical Bands Crystal Kit for SPR-4 £12.38 Model 312.002 £7.81 W40 Wall-mountlng Tower £169.58 RY-4 Teletype adaptor for SPR-4 £15.75 Model 3124103 £3.43 WOO Wall-mounting Tower .. £214.92 DSR-2 Digital Receiver .. £2227.50 Model 312-004 .• £8.33 P25 Post-mounting Tower £169.00 SSR-1 Recelver-general purpose £184.50 Model 322-001 .. £8.43 P40 Post-mounting Tower .. £223.58 HS-1 Headphones for SSR-1 .. £7.88 Model 322-003 .. £9.84 P60 Post-mounting Tower .. £268.92 Model 454-002 .. £18.22 Carriage on the above will be charged at cost TRANSCEIVER & ACCESSORIES G-WHIP PRESTEL TR-4C Transcelver-SSB £150.00 Tribander helical . £18.11 MC-16 Transistorised field strength meter 34-PNB Noise Blanker for TR-4C £49.75 additional coils for 40m, 80m. 1613m each £5.48 UHF/VHF/FM £216.00 AC-4 1151240v P.S.U. for TIE-IC, T-4XC.. £93.38 Multimoblie 77...... £21.38 DC-4 12v P.S.U. for 7R-4C, 7-4)(C, R-4C £103.50 additional colts for 40m, 80m, 160m, each £5•48 MMK-3 Mobile mounting kit for TR-4C .. £5.15 MFJ CWF-2BX CW filter el m Telescopic whip .. .. £2.08 RV-4C Remote V.F.O. tor TIE-IC.. £93.38 Base mount single hole fixing £2.47 FF-1 Crystal Control for TIE-IC £37.13 CSP-520BX Super logarithmic Speech Processor .. £30.25 base thread adaptor .. £0.73 CSP-5208X2 De luxe version of above .. £45.00 Extendarod 40 booster for Multlmoblle 77 £9.21 TRANSMITTER & ACCESSORIES BAN TEX T-4)(C Transmitter SSS £450.00 S WRIPO WER METERS £8 .00 B5 144MHz fibreglass whip .. £8.44 L-4B Linear Amplifier á Power Supply .. £697.50 SWR-10 Single meter £12.10 BOA 144MHz stainless whip £7.43 MN-4 Antenna Match Network .. £85.50 SWR•50 Twin meter .. Magnetic Base Mount for either of tho £171.00 MN-2000 Antenna Much Network.. above £10.80 W-4 RF wattmeter 2-30MHz £54.00 COPAL CLOCKS WV-4 RF wattmeter 20-200MHz .. £82.64 Model 225 24 hr motor-driven digital £6.75 JAYBEAM ANTENNAS-Full range HAM RADIO PUBLICATIONS 1-1 Y•G AIN £205.60 ADDITIONAL ACCESSORIES Novice Radio Guido .. £2.50 billower £38.80 TV42LP Low Pass Filter 100w £10.13 Ham Notebook Vol. 1 £2.50 12AVO £53.43 TV3300LP Low Pass Filter £18.00 Ham Notebook Vol. 2 £3.50 14AVO £19.90 RP-500 Receiver protector .. £58.50 14RMQ . £27.58 7072 Hand Microphone £14.18 HUSTLER I8V MO-1/2 Foldover mast £13.84 £76.21 7075 Desk Microphone £21.13 18AVT £10.35 £109.66 Accessory Crystals for R-1C, 7-1%C, BM-1 Bumper mount TH2MK3 C-32 Bell mount .. £5.06 £112-43 SPR-4 £4.50 TH3Jr . £7.75 £156.08 Fixed Frequency Crystals £7.88 C-29 Stainless steel spring • • TH3MK3 £9.34 £188.43 Spare Operating Manuals £3.94 RM-10 10m Resonator TH6DXX £10.17 £172.96 Spare DSR-2 Operating Manuals .. £15.75 RM-15 15m Resonator HY Quad £11.14 £117.84 RCS-4 Remote Control Antenna Swlich £90.00 RM-20 20m Resonator DB-10-15 RM-40 40m Resonator £13.84 103B', . £51.20 RM-90 80m Resonator £14.73 153BA . £63.00 ATLAS SF-2 2m I whip .. 203BA . £117.56 210X 10-80m SSB Transceiver .. £444.38 OCL Olscone 80-500MHz £20.47 215X 15-160m SSB Transceiver £444.38 CG-144 2n1Colinear £25.25 LARGE SAE FOR DETAILS

BARCLAYCARD DRAKE SALES SERVICE ACCESS 188 BRO AD H URST GARDENS RADIO SHACK LTD. LON D O N, N W6 3AY Giro Account No. 588 7151 Telephone: 01-624 7174 Cables: Radio Shack, London, N W6. Telex: 23718

RADIO COMMUNICATION July 1977 513 SEM

P.O. BOX 6, CASTLETO WN, ISLE OF M AN Tel. PORT ERIN (0624) 833714

NEW! The only one available THE SENTINEL STAN DARD 2 METRE PRE-AMPLIFIER Same circuit as the one above but without the RF switching. Price: £7.75 VAT = £8.72. IN ST OCK. SENTINEL TOP BAN D CONVERTER Top Band (Marine Band) to 20 metre converter. If you miss being THE PA3 able to listen on 160 metres this provides the answer. 1.8MHz- 2-3MHz In, 14-14.5MHz out. Price £18.00 + VAT = £20.25. IN Size only about 1 cubic inch to fit Inside your transceiver. N.F. STOCK. 2dB gain 18dB. Price: £5.57 VAT £6.27. IN STOCK.

2 METRE CON VERTERS SENTINEL H.F.P RE-A MPLIFIER. These are wideband pre- Sentinel D. G. Mosfet converters. These provide a perfor- amplifiers from 1-40MHz. N.F. ldB, gain 15dB. Input and output mance that cannot be beaten. N.F. 2dB, Gain 30dB. Supply Impedances 50/75 Ohms. Size: 2r • ir e. Price £7.00 ••- 12V(9-15) 15mA. Size is 21" ir x ar. IFs: 28-30MHz, VAT - £7.87. 4-6MHz, 2-4MHz. These are also In stock for Marine Band to 28-30MHz and Satellite Band to 20-22MHz. 4 metres to 28- SEN TINEL H.F. PRE-A MPLIFIER with change over relay. 28.7MHz. Price: £18.00 + VAT - £20.25. IN ST OC K. Same specification as above but including a change over relay for switching straight through. This can be operated by your SENTINEL 2 METRE CON VER TER KIT IF 28-30MHz. transceiver for direct connection in your aerial co-ax. Price: £9.00 • VAT - £10.12. IN STOCK. Performance as above converters. Complete unit with box, connectors etc. Price: £11.50 -,- VAT - £12.94. We will get them going If you have trouble for £2.50, so you can't go wrong. SEM "Z" MATCH IN STOCK. A compact and attractive A.T.U. 80-10 metres tested at 1kW into 50 ohms. Slow motion calibrated dials. Size only sr x 4" SENTINEL 2 METRE CON VERTER • 7e. 50239 and screw terminals for co-ax fed or wire aerials. Containing a mains power unit and RF gain control. Specifica- Balanced or unbalanced. Price: £28.00 VAT - £31.50. IN tion as above. Size: 5" x 2" front panel by 5" deep. Price: ST OCK. £22.00 + VAT = £24.75. IN STOCK. SEM EUR OP A C 70cms CON VERTERS Now Includes a relay controlled by the ON/OFF switch for The most economical method of listening on 70cms is our switching the H.F. equipment between the Europa or your 70cm to 2 metre FET converter. N.F. 3dB, Gain 30dB. Price: H.F. aerial. I.E. NO PLUG CHANGING. £18.00 + VAT••=.- £20.25. Size: 2r x W 3. IN STOCK. • Receive converter-2dB N.F. 30dB gain with MOSFETS. • Transmit converter 200M W drive for 200W input. SENTINEL 70 • Spurious output-80dBI 70cms to 28-30MHz, N.F. 3dB, gain 30dB. Size ar • ir • e. • Size only 9- - ar front panel, 4" deep. Price: £20.00 + VAT = £22.50. Price only £100 -, VAT £112.50. IN STOCK. Complete to plug into Yaesu equipment. PRE-A MPLI FIERS Complete power supply for Europa £45.00 - VAT £50.62. IN These must be the most cost-effective items being advertised STOC K. in these pages. EUROPA SS All solid state Europa. THE SENTINEL AUT O M ATIC 2 METRE PRE-AMPLIFIER • Receive converter 2dB N.F. 30dB gain. Contains an RF operated relay for connecting straight into your • Transmit converter 200M W input for 10W output, capable of transceiving aerial co-ax. Performance: 1dB N.F., 18dB gain operating into o/c and sic loads. from selected FETS. Supply 12V nominal. Price: £13.00 i• VAT • Front panel meter reads P.A. collector current. = £14.82. BL sockets standard, S0239s £1.50 , VAT - £1.69 • Contains rectifier and smoothing circuits for operation off extra. 12V a.c, or d.c. Price: £80.00 ± VAT - £90.00.

ALL OU R PR O D U C TS C A R RY 12 MO N T H GU A R A N TEE

To order: C.W.O. or credit card. We take credit card orders from anywhere in the world, just send or phone your card number for same day service. We welco me trade enquiries from anywhere in the world. If you require more detailed information or help do not hesitate to ring or write.

514 RADIO COM MUNICATION July 1977 COUNCIL

President RADIO SOCIETY OF GREAT BRITAIN Lord Wallace of Coslany 35 Doughty Street, London WC1N 2AE Executive Vice-President Telephone 01-837 8688 D. S. Evans, G3RPE, PhD, BSc, MIM Immediate Past-President Founded 1913 Member society, International E. J. Allaway, MB, ChB, MRCS, LRCP, Incorporated 1926 Amateur Radio Union G3FKM Honorary Treasurer J. O. Brown, LLB, FCA, G3DVV PATRON: HRH The Prince Philip, Duke of Edinburgh, KG Teleco m munications Liaison Officer R. F. Stevens, G2BVN The national society representing all UK radio amateurs Ordinary members P. Balestnnii TEng(CIE), MITE, G3BPT J. Bazley, G3HCT Membership is open to all those with an active interest in radio experimentation and C. H. Parsons, GW8NP communication as a hobby. Applications for membership should be made to the general D. M. Pratt, BTech, MICE, MIERE, G3KEP manager, from whom full details of Society services may also be obtained R. F. Stevens, G2BVN G. M. C. Stone, G3FZL C. J. Thomas, G3PSM GENERAL MAN AGER AN D SECRETARY EDIT OR Zonal members G R. Jessop, CEng, MIERE, G6JP A. W. Hutchinson Zone A. B. O'Brien, G2AMV Zone B. J. Anthony, G3KOF Zone C. D. J. Andrews, G3MXJ Zone D. W. A. Scarr, G2WS, MA, FBIS Zone E. D. M. Thomas, GW3R WX Zone F. W. F. McGonigle, GI3GXP Zone G. A. M. Allan, GM3ZBE

REGION AL REPRESENTA TIVES ANNUAL SUBSCRIPTION RATES Region 1—W. M. Furness. G3SM M Region 2—R. C, Andreang, G4CMT UK corporate: £8, including VAT Overseas: LB. Region 3—H. S. Pinchin, G3VPE Region 4—T. Darn, G3FGY Associates under 18: £3. Students aged 18 to 21: £4.50. Region 5—P. F. Chilcott, G4BBA Region 6—F.S.G. Rose, G2DRT OAPs with 15 years' membership: £4.50. Affiliated societies: £6.50 (including Region 7—N. A. Smith, G3HFO Region 8—D. N. T. Williams. G3MDO Radio Communication)- £3.25 (excluding Radio Communication). Region 9—H. W. Leonard, G4UZ Region 10—R. G. Barrett, GW8HEZ Region 11—P. H. Hudson, GW3IED Region 12—F, Hall, GM8BZX Region 13—A. B. Givens, GM3YOR Region 14—A. J. Mitchell, GM3UDL Region 15—H. J. Campbell, GI8FOK Region 16—R. E. G. Kendall, G8BNE Region 17—L. Hawkyarci, G5HD Region 18—P. J. Fay. G3AKG Region 19—D. S. Smith, G4DAX WHAT AMATEUR RADIO IS Region 20—G. Mather, G3GKA

The following foreword to the programme of the Longleaf Mobile Rally held on 12 HON ORARY OFFICERS June is reproduced by courtesy of the Chairman, RSGB—Bristol Group Awards managers hf—C. R. Emery, G5GH vhf—Jack Hum, G5U M Amateur radio offers an opportunity for free speech and unlimited communi- Emergency com munications manager cation. It is essentially a hobby of communication and it should be encouraged P. Balestrini, G3BPT more now than at any other titile, for in this age of mass communication there is Intruder Watch organizer often little opportunity for man to communicate with his fellow man. S. A. G. Cook, G5XB Microwaves manager Mankind has created many artificial barriers which turn man against man, D. S. Evans, G3RPE woman against woman, and child against child. There arc no barriers in amateur QSL Bureau manager radio. Russians talk to Americans. Catholics talk to Protestants, man talks to A. O. Milne, G2MI man. Amateurs talk to amateurs, they talk radio, they talk, they communicate. Slow morse organizer M. A. C. MacBrayne, G3KGU There have been many changes since the early days. from crystal to valve and Taped lecture library curator back again, and there are still many changes ahead. There is an exciting future, S. W. Coursey, G3JJC new bands. new techniques, a whole new era of communication. But do beware Trophies manager of anyone, any nation that tries to silence the talking, the communication, for it P. A. Miles, G3KDB could be that once the talking stops the fighting begins. VHF manager: D. A. Evans, G3OUF Roger Sharland, G4EfIE Correspondence to RRs and honorary officers Chairman, RSGB —Bristol Group should be addressed directly to them (QTHR).

RADIO COMMUNICATION July 1977 515 The demand for the circuit diagrams has been such that a • third printing has now been made, but because of increased QTC printing and postage costs the price has had to be increased. The 10-page set now costs 60p including postage and packing and can be obtained by sending a remittance for that amount • amateur radio news to: The Editor, RSGB, 35 Doughty Street, London WC1N 2AE. Photocopies of the article can similarly be supplied at a Channel Islands subscriptions cost of 80p including postage and packing. Council decided at iis meeting on 9 November 1976 to increase the overseas subscription rate to £8 with effect from Woburn Abbey Rally, 7 August January 1977; this increase being forced upon the Society by Details and information for trade stands available from the extra cost of overseas postage. Norman Miller, G3MVV, "Avon", Gardiners Lane, Crays However, the increase is not justified in respect of members Hill, Billericay, Essex. in the Channel Islands who have the same postage rates as the UK. Region 6 Regional Representative As a measure of redress, therefore, the Society will, if At its meeting on 18 June the RSGB Council approved the required, make an annual refund to any Channel Islands appointment of Mr F. S. G. Rose, G2DRT, as represent- member of a proportion of his subscription equal to the ative for Region 6. Mr Rose was the sole nominee for this amount of Value Added Tax charged in the UK. This office. amount is at present 24p. Any member requiring a refund should send a claim, The Appleton Laboratory together with a self-addressed envelope, to HQ marking it in Dr Frederick Homer, DSc, CEng, FIEE, Deputy Director the top left hand corner "Channel Islands refund". Members of the Appleton Laboratory, Slough, Bcrks, succeeded Dr making refund requests should bear in mind the admini- J. A. Saxton, CBE, DSc, PhD, CEng, FLEE, FInstP, as strative cost involved. Director with effect from 1 July 1977, following Dr Saxton's G3DVV retirement. Dr Homer joined the Radio Division of the National Postage increases Physical Laboratory in 1941. After the war this became a As a result of postage increases effective from 13 June, the separate organization and evolved into the present Appleton publication price list on the inside back cover has had to be Laboratory of which he became Deputy Director in 1969. revised. Always check the current price list before ordering Dr Homer's research has been concerned mainly with books and other items from RSGB HQ. radio direction finding and with the study of radio emissions from thunderstorms. He has been active in international Raynet affairs in radio science since 1950, holding various offices in The Raynet Committee discussed at length the RBO, RB8 international organizations. situation at the meeting on 14 May 1977. The view was expressed that owing to the large number of amateurs HM The Queen's Silver Jubilee Birthday Honours currently using SU8 as a simplex channel, the best interests The Society offers its congratulations to the following radio of Raynet and the amateur population at large would be for amateurs who received awards in HM The Queen's Silver RBO to remain allocated as a Raynet repeater frequency. Jubilee Birthday Honours List: The view was also expressed that this would avoid Raynet Mr. R. B. Peters, G3ZUF, who was appointed an MBE; causing difficulty to SU8 users on a wide scale. Mr C. E. Godsmark, G31WL, who was awarded the Queen's A ballot was taken for "move to RB8" for Raynet Jubilee Medal for services to Great Britain. repeater use or "RBO to remain allocated for Raynet repeater use". With one abstention a motion was carried, Who has the cup "That in view of the stated problem, RBO should remain Peterborough was noted in the past for its df contests (they allocated as a Raynet repeater channel". A rider was made were at national level) and a challenge cup was presented that this should not preclude the use by Raynet of other for annual competition by the late G3GCK. There are signs channels for simplex purposes. of renewed interest in this side of amateur radio at Peter- borough, and efforts are being made to locate the lost cup. Facts and figures It was last known to have been won by an amateur in the The Home Office advises that the following numbers of Midlands but there is no record of his name or callsign. It amateur licences were in force at 31 May 1977: is possible that he was unaware that it was a challenge cup Class A 16,078 Class B 6,385 and could not be won outright. Should this note catch his At the same date the latest callsigns issued in the 04 and eye, will he kindly communicate with Leslie Critchley, G8 series were G4GCA and G8NJM respectively. G3EEL, 36 Waterloo Road, Peterborough, who is hon sec of Peterborough Radio & Electronics Society. Storno Viscount circuit diagrams In the April 1974 issue of Radio Communication, an article Walsall Amateur Radio Club "Conversion of Storno Viscount vhf radiotelephones for The above club was formed on 3 May and will meet at amateur service" was published. For those wishing to carry 8.30pm at the "Hamemaker Inn", Blue Lane, Walsall, at out this conversion, a 10-page set of circuit diagrams was fortnightly intervals from the above date. Details from Mr printed and offered for sale. K. Boucher, G8KML, 2 Emery Close, Walsall, W Midlands.

RADIO COMMUNICATION July 1977 516 RSGB NATIONAL MOBILE RALLY Woburn Abbey, Bedfordshire (Coach Park Site) Sunday 7 August 1977 From 11 am

Attractions will include a large trade exhibition, RSGB bookstall and enquiries stand, grand raffle, Raynet stand, BARTG stand, and a bring-and-buy stand. All will be under cover. Bring-and-buy this year will be charged at £1 per table per hour, which will enable members to sell direct. Tables will be offered on a first-come first-served basis. The RSGB makes no charge for entrance to the rally but all visitors must pay for entrance to Woburn Park, in which the rally takes place, at 50p per car irrespective of the number of passengers. All the normal Woburn attractions will be available at small extra charges. Various bars and cafes are available nearby. How to get there: From the south via the M1—Leave the M1 at intersection 13, not 12 as signposted. Turn left off motorway and follow signposts through Husborne Crawley to Woburn Abbey. From the south via the A5—Turn right at Hockliffe and follow the A50 to Woburn. From the north via the M1—Leave the M1 at intersection 14 and follow the A50 to Woburn. From the north via the A5—Turn left at A418, five miles south of Fenny Stratford, and follow to Woburn. From other directions make for the points indicated above and proceed as indicated. Avoid routes signposted to "The Wild Animal Kingdom" or "Game Reserve". The rally takes place in Woburn Park and correct routes are signposted to -Woburn Park" or The Abbey". Also watch for RSGB signs. Usual talk-in facilities will be in operation by Dunstable Downs RC on 1-8, 70, 144 and 432MHz.

Teleprinter Handbook Amateur Radio Techniques by J. G. Denny, G3N TT, and D. J. Goacher, G3LLZ by Pat Hawker, G3V A

This book is the most comprehensive guide to the "Experiment or die" might well be the rallying call of the theory and practice of amateur rtty available, and is a radio amateur. No matter how much equipment he or she "must" for anyone interested in this mode. possesses, no matter how well it performs, there always Essential theory is thoroughly dealt with, and has to be a better way of doing things just around the corner. separate chapters are devoted to rtty signalling, keying, demodulation, and control systems. And that is why Amateur Radio Techniques is so useful. It A particularly useful feature of the book is the 131- brings together a very large selection of stimulating ideas page chapter on teleprinters, which gives system and circuits, together with many constructional and fault- descriptions and servicing information for all popular finding hints and tips, gathered in by the author during 16 European and American machines. Other essential years of writing the Technical Topics feature in Radio Com- rtty equipment, including test gear, is described in Municalion. similar detall elsewhere in the book and, although much commercial equipment is featured, many Some of the ideas are sophisticated, others very simple, designs for home construction are given where appro- but whatever the complexity the subject matter is always priate. dealt with in a practical and highly readable way. This hardbound book is fully illustrated with hun- Chapter titles are: Semiconductors; Components and dreds of line diagrams, some in pull-out form, and Construction; Receiver topics; Oscillator topics; Trans- many close-up photographs illustrate particular mitter topics; Audio and modulation; Power supplies; features of equipment. Aerial topics; Fault-finding and test units, Chapter titles are: Aspects of signalling; Tele- printers; Other rtty machines; Power supplies; Demodulators; Auxiliary equipment; Keying methods; 304 pages Fifth edition £3.55 inc p 8, p Filters; Test equipment; Control systems; Operating procedures; Glossary of commercial equipment; Obtainable from RSGB Publications (Sales) Terminology. See inside back cover for full list of RSGB publications 358 + xiv pages First edition £8.89 inc p&p

RADIO COMMUNICATION July 1977 517 indeed it is. Anyone who has built one of the popular IOW The DSB 1 Mk 2. 1-8/3-5MHz a.m. rigs will find most of the circuitry and construction familiar. The signal is received as ssb by modem transceivers and selective sideband receivers and A simple sideband most operators do not realize that the signal is not ssb. The Mk 1 version and, more recently, the Mk2 have been in use at G3YUQ for about five years (with a break when the transmitter for the Home Office declared it illegal). While the output from the rig may seem low (12W p.e.p.) by today's general acceptance of linears, it is more than adequate to get around Europe and beginner Scandinavia on 3-5MHz using a modest antenna. Cost is kept to a minimum; most of the components are ex-junk-box, no crystals or filters are required and the rig by E. ELSLEY, G3YUQ* needs only a simple unstabilized power supply. Valves have been used throughout; all are readily available types and many substitutes are possible. Total cost if some parts can S a tutor of amateur radio the author is often asked how be obtained from a junk box should be under £5; the author's Ait is possible to start the hobby cheaply, as many begin- cost less than 50p. ners are faced with the high cost of modem ssb equipment or, alternatively, building an ssb rig. The majority will already be listeners and have a receiver, leaving the transmitter as the The circuit main problem —most amateurs will agree that building an The rf side. VI is the vfo using an EF91 in a "standard" Clapp oscillator ssb rig is not a project for the beginner, indeed it would not tuning 1-75 to 2-0MHz. An alternative valve would be an be attempted by many experienced amateurs. There is, EF80 (B9A base). Output from the anode is via a 100pF therefore, a need for a simple sideband transmitter which could be built by almost anyone using simple tools and capacitor to V2, the buffer amplifier/frequency multiplier, easily obtainable components, and the equipment to be again a "standard" circuit using an EF80. The band required is selected by L2, S2. An alternative valve here is the EF91 described will fill that need. To keep the rig simple and the cost as low as possible, but the EF80 specified seems to provide better isolation. A link coupling from L2 is connected to L3, the pa grid coil, via double sideband suppressed carrier (dsb) has been adopted. a short length of coaxial cable earthed at one end. C17 across This is often described as a step between a.m. and ssb, and the pa grid coil tunes 3-5MHz at near minimum capacitance and I-8MHz at near maximum capacitance. The rf now in push 14 Studley Road. Wootton, Beds. pull is passed on to the grids via 200pF capac itors. The pa valves

2000 CIO ,« 0' 10000 CIO .200,I 02 03 lot statical 47. L2 04 0 -100fol. R9 5763 1.0 Coaxial 220 Lanni C. C22 100. 10000 I '." 0°*. > 2 RFC] ; VI 0.1 1 518 2.5enn AA OAMOSWITC>I1 C23 Le • RFCZ •i• 1.3

net /.• ..C17 C26 CO Cti PA 3008 — k 5 -1 —/ 500 0.01 0.01 GRID IIIIVE obt o sib I , z toInsang 7- 7" 5000 RIO 1 : ; g1 = op IPA %/NEI '1Fr771.

— 1 9 . '— jS2 , .01/ LT —ve k c, 2'0 Cll I ; - ,, 220f iLlt„,po:T-0 T00 Tool T0.o ee.

620 R12 Rli C32 1000p 101 100. 'FUNCTION SWITCH n un ,rlay

4.3 C3I Ref fiver 4508 100. 0.01 antenna

6 26 Antenna Atcro vo , e

70 " ?Fel4LA2 5 To roclovor mutt

, o ale Ott 111 4701 470 508 transformer •••, Tnv

Fig 1. Circuit diagram

518 RADIO COMMUNICATION July 1977 are 5763s, although any small receiving-type output valves should suit, cg EL84, 6BW6, 6V6 etc. For higher power the L2 But ferlanode coil 6146, 807s etc could be tried. The anodes of the pa valves are connected together and pass via the tank network and relay 5 turn 34 swg wire link 7/16"dia x 1" long to the antenna. coil former with HT one iron-dust core The audio side. Main winding V5 is the speech amplifier using a 12AX7 twin triode, again 36 turns of 34 swg wire All windings are in another "standard" circuit. Input is suitable for a crystal closewound microphone. The output from V5b is via a 1,000pF capacitor To V2 pin 7 to provide a little speech tailoring to the modulator, a (buffer anode) 12AT7 (although a 12AU7 is also suitable). The modulator valve is connected in parallel to provide a more "beefy" valve. Output is passed through the primary of a 1-to-l+ 1 L3... PA grid coil driver transformer, although any ratio up to I-to-2+2 will To V4 pins 8 and 9 be suitable. A small mains transformer, 250 in to 250-0-250 (PA grid) via Clel out, may be suitable but has not been tried. The outputs of main winding the transformer now in push pull are corrected to the screen 36 plus 36 turns of 34 swg wire grids of the pa valves, which in turn are decoupled to earth 8 turn 34 swg via 1,000pF capacitors—do not increase the value of these. wire link Centre tap of wound over centre .- main winding to The audio output provides the only voltage on the pa screen of main earth via PFC2 grids, and a good whistle into the microphone will produce winding about 200V at that point. The result of the rf and af in push pull is that the pa acts 7/16"cha x 11/2 " long as a power-balanced modulator and phases out the carrier. coil former To V3 Pins 8 and g (PA grid) via C19 The output to the pi-tank is double sideband suppressed carrier (dsb). The transmitter is controlled by a four-pole three-way function switch and a toggle switch for ht on/off. 2 iron-dust cores screwed-in to meet in the centre Operation Net Fig. 2. Coil details, L2 and L3. L1, vfo coil, is 96t 34swg fin dia HT is applied to the vfo and ha via the ht switch. The relay former plus core; note that a longer-than-average former is required to accom modate all the turns (closewound ono is not energized and so leaves the receiver on and the layer). L4, PA pi-tank coil, is 39t1Bswg closewound on 1.5in dia antenna connected to the receiver. former, tap at 19t for 3.5M Hz

Fig 3. Front panel layout

5 6 e inches 9 o 2 3 4 (

RADIO COMMUNICATION July 1977 519 BA bandswitch FIT switch PA grid tune Function switch Microphone

52 54

To Tf tank Screen Si Screen RFC3 Fig 4. Chassis underside

( C17 r Coaxial link • 0 Mod transformer terminals

Tag strip

Chassis 9" x 5"x 2"deeP To PSU 3-way terminal block 0 1 2 3 4 8 inches

Tune chassis before the vfo is fitted. Keep all leads short and All stages except one pa valve are operational when ht is direct. Do not omit any of the screening, or cans on the vfo, switched on. The pa valve has ht applied to its screen grid ba or speech amplifier. A screen lead must be used between via a 10k 1W resistor. The rig can then be tuned in the the microphone socket and the speech amplifier. Earth the normal way with the pi-tank network. The relay is energized screen at one end only. If this is not done the speech amplifier and so the receiver is muted and the antenna is connected to may oscillate as it is a very high gain stage. the transmitter. Alignment DSB The rig may be aligned in two ways: The transmit standby position. All stages are operational I. Alignment using a grid dip oscillator when ht is switched on. The ht switch is used as a transmit/ Adjust LI to tune 1-75MHz with CI vfo tune at maximum receive switch. capacitance. Power requirements are also simple; 400V de at about Check that the vfo covers 1.75MHz to 2-0MHz. 80mA maximum and 6-3V for the heaters. A 350-0-350V L2: set S2 bandwidth to 3-5MHz and C17 pa grid tune at transformer gives 400V when smoothed. The circuit can be minimum capacitance. any of the types shown [1] using either valve or silicon diode Adjust the core of L2 to tune 3-8MHz. Next set S2 band- rectifier circuit. No stabilization has been found necessary. switch to 1-8MHz and C17 pa grid tune to maximum capacitance. Adjust the value of C12 (365pF) until L2 tunes Constructional details 1.75MHz—do not adjust the core of L2 as this will alter the The chassis used by the author was 9 by 5 by 2in deep. It is 3-511,1Hz setting. best to get all the components together first and, using the If L3 is wound correctly with two cores screwed fully in to layout as a guide, adjust the size as necessary. Do not try to meet in the centre, the coil will tune to 3.8MHz with C17 pa make it any smaller as it may be difficult to wire up. grid tune at near minimum capacitance and S2 bandswitch The front panel is bent round at each end and fixed to the at 3.5MHz, and I-8MHz with C17 pa grid tune at near side of the chassis. This produces a strong neat job. The maximum capacitance and S2 bandswitch at 1-8MHz. panel can be finished with cellulose paint spray and lettered Check that it does so by using the gdo near L3. up using Letraset or similar transfers. L4, the pa tank coil, requires no alignment at this stage. Commence by building the vfo; the author used a 3 by 3 by 2M deep box. All components are inside, except the valve Alignment without test equipment which is mounted on top and to which a screening can must With this method the rig is LIVE and care must be taken to be fitted. The unit is mounted on top of the chassis with avoid shock. leads brought out underneath for ht, It and output. The vfo The vfo can be set up by listening on the station receiver. is adjusted by the slug on Li and the 3-30pF trimmer to Set function switch SI to NET. Switch on ht, S4. cover 1 -75-2-0MHz. Adjust the core of Ll and trimmer C2 until the vfo covers The buffer anode coil L2 must be mounted on the main 1-75MHz to 2-0MHz. The vfo is now set up.

520 RADIO COMMUNICATION July 1977 Connect a 15W lamp to the antenna socket to act as a If difficulty is experienced in obtaining a good output at dummy load. 1-8MHz it may be necessary to alter the value of C12. Set GRID TUNE to near maximum capacitance and alter the value Alignment for 3.5MHz of C12 by experiment until the rig is giving a good output at Set controls as follows: 1.8MHz and the pa meter reads about 40mA—do not adjust BANDS WITCHES to 3.5MHz the core of L2 as this will disturb the setting for .3..5"MHz. VIO TUNE to 3.8MHz Next, set FUNCTION switch to dsb and check as before. PA GIGO TUNE to minimum capacitance If all is well the rig is set up for 1-8MHz. FUNCTION to TUNE PA TUNE to maximum capacitance Operation PA LOAD to maximum capacitance If using an atu, tune this for maximum strength of signal received on the required band, and it will be set up just about Switch on ht. Quickly adjust PA TUNE for maximum dip. right for the transmitter. Connect the main antenna to the This should be quite low. Continue by adjusting the pi-tank transmitter via the atu, and the receiver mute and receiver network (PA 'TUNE/PA LOAD) in the normal way until the pa antenna connections as required. meter reads about 40mA. Next adjust the core of L2 for Set BANDSWITCHFS to required band; PA TUNE and PA LOAD maximum output. The lamp should be glowing quite to maximum capacitance; PA Gnu) TUNE to minimum for brightly by now. 3.5MHz or maximum for 1.8MHz. Next, set FuNc-riox switch to dsb. If all is well the meter To net on to another station: set FUNCTION switch to NET; will read zero but kick up to over 30mA, and the lamps will switch on ht; tune the vfo to zero beat with the other station; light, when speaking into the microphone. Monitor on the switch off ht. station receiver; the audio should sound clear with no hum, To tune the transmitter (this will be necessary when if so the rig is set up for 3.5MHz. changing bands or moving more than 75k Hz or so): set FUNCTION switch to TUNE; switch on ht; quickly adjust the pa Alignment for 143MHz tune for maximum dip in the pa meter reading; adjust the Set controls as follows: pa grid tuning to improve the dip in the pa meter reading; BANDS WITCHES to 1.8MHz continue to tune the pa tune and pa load in the normal way VIO TUNE to 1.8MHz for pi-tank networks until the pa meter reads about 40mA; PA GRID TUNE to maximum capacitance check that the pa grid tune is set to give the best dip in the pa FUNCTION to TUNE meter; adjust the atu if required to improve the output from PA TUNE to maximum capacitance the rig; switch off ht. PA LOAD to maximum capacitance Once the atu and lx settings are found they should be noted Switch on ht. Quickly adjust PA TUNE C24 for maximum for future use. dip. Next, adjust PA GRID 'rum to improve dip. Antenna socket PA bandswitch Continue by adjusting the Relay mounted on pi-tank as before until the front panel return pa meter reads about 40mA.

Speech Slow. motion drive amp \ / C26 PA load

Mod valve

Screen to full panel re,ght Modulation PA valves L3 under transformer Fig 5. Chassis top layout BA/Freq X Mute control valve from relay

Power input Coaxial cable to receiver Mute 3 way terminal block antenna socket Ii To receiver antenna o 2 4 5 6 inches 9

RADIO COMMUNICATION July 1977 521 Components list (a) Run the pa valves at a higher voltage. The author has run 5763s with 600V on the anodes with good results. Output 121 68k0 }W R11 IW is then about 25W p.e.p. If one tries this, keep the tuning of Ft2, R4, R9, RIO 22k0 4W R13, R14 100kft 4W the rig down to periods not exceeding lOs or so. R3 47ks-2 R15 1k0 4W RS, R12 10kft R16, R17 470kt-1 4W (b) By using higher power valves in the pa, cg 6146s. This R6 270k11 4W R18 1500 3W would require some re-designing of the chassis. R7 2200 4W R19 10ka 1W (c) By using the rig to drive a linear—there is plenty of R8 low 3W R20 Wirewound to suit power to do this. relay RLA The author suggests that the rig be tried "barefoot" first: Cl 75pF variable (VFO TUNE) he will be pleased to hear from anyone building and using the C2 30pF trim mer (vFo TRIM) rig and the results they get. C3, C28 50pF silver mica C4, CH 100pF silver mica C5, C6, C7, Reference C16, C20, C21, C22, C32 1.000pF silver mica [1] Radio Communication Handbook, 3rd edition, page 333. C8, CIO, C11, C14, CIS, C29, C31, C33 0.01mF disc ceramic C12 365pF silver mica (see text) C13 150pF silver mica C17 300pF twin gang variable (PA GRID TUNE) NEW PRODUCT C18, C19 200pF silver mica C23 2,000pF silver mica-1.000V type C24 500pF variable. (PA TUNE) C25 300pF silver mica Tester 50k multimeter C26 1,000pF variable (500pF + 500pF) (PA LOAD) A further instrument in the range offered by Alcon is a high C27 8gF 450V electrolytic impedance multimeter designed with the electronic tech- C30 25xF 25V electrolytic C34 1e4F paper 150V nician/engineer in mind. The Tester 50k offers 50kO/V input impedance on both dc and ac. Thirty-nine ranges cover up V1 EF91 1 V2 EF80 to 1,000V and 3A on ac and dc. Four resistance ranges V3, V4 5763 See text for substitute types extend from 10ka fsd to tomn fsd, and there are five power V5 12AX7 ranges covering from —10dB to +6IdB. An optional extra V6 12AU7 is the universal signal injector providing harmonics detect- S1 4-pole 3-way able up to 500MHz and particularly useful for radio and tv S2, S4 1-pole 2-way toggle S3 2-pole 2-way toggle servicing. The meter is of modular construction thus providing easy replacement of circuit boards or other sections. M1 0-100mA fsd moving-coil meter Size is 105 by 130 by 35mm and the weight (without bat- RFC1, RFC2, teries) is 300g. RFC3 2-5mH TI 1:1 -i- 1 driver transformer, valve type, see text for substitute types RLA 2-pole change-over relay Valve bases: 1 off B7G with screening can; 3 off 89A with screening can; 2 off B9A ceramic (PA valve bases). Sundries: 1 off sm drive and dial for vfo; 3 off coaxial sockets (mic, rx antenna, tx antenna); 1 off phono socket (rx mute); 4 off medium knobs; 1 off large knob; 1 off panel light Chassis 9 by 5 by 2in deep aluminium

Panel 13 by 64in aluminium for front panel

Sundry offcuts for screens as:required

To transmit: switch to dsb; use ht switch as a transmit/ receive switch, je switch on to transmit and off to receive. PA meter will read zero but will kick up to about 30mA when speaking into the microphone. The author uses a 90ft end-fed antenna at a height of 25ft with a modest earth system consisting of about 50ft buried around the garden, and has had good results around Europe.

Alternatives One-off price with test leads, instruction manual and The rig can be modified for other bands by changing LI, carrying case is £39.20 including VAT. Further information L2, L3 and L4. may be obtained from Alcon Instruments Ltd, 19 Mulberry Higher power is possible in a number of ways. Walk, London SW3 6DZ. Tel 01-352 1897.

522 RADIO COMMUNICATION July 1977 necessitates the use of a 5 to 180V dc-dc converter, operating at approximately 25k Hz, to provide the ht for these tubes. However, their use is well worthwhile because of their EQUIPMENT REVIEW clarity. The digital counting devices are largely 74 series ttl. A stable crystal oscillator operating at 1MHz provides the reference frequency for the time base, and six ics form a divider string with outputs at 100, 50, 25 and 12-5Hz. The function of the counter is to count the premix signal (the The Heathkit SB-104 difference frequency of the mixed hfo and vfo signals) and to produce the correct format for display. This is ingeniously achieved by using a false zero of 10,000.0kHz. The decade all-solid-state hf counters are preset to 10,000.0 minus the bfo frequency. The action is perhaps best understood from the example bands transceiver below shown for a signal frequency of 3.750MHz. HFO for 3.5MHz band 12,395.0kHz VFO 5,251.4 by G. L. MILLS, BSc(Eng)(Hons), CEng, Premix 7,143-6kHz MIEE, MIERE, G3EDM* False zero 10,000-0kHz BFO for lsb 3,393.6 rr HE transceiver which is the subject of this article was ordered in kit form, together with its associated electronic- 6,606.4kHz ally regulated mains power supply type HP1144, from the Gloucester factory of Heath Ltd in December 1974. Delivery Preset frequency 6,606.4kHz was made early in February 1975. Approximately 100 hours Counted frequency (Premix) 7,143.6 were spent on a start-stop basis assembling the kit of the SB-104 and it was ready for testing in mid-March 1975. 13,750.0 The reviewer has also been able to test an SB-104 owned by Colin Howard, G3WFB, and his help is acknowledged. The signal frequency will be displayed as 3,750.0kHz as the "1" is suppressed because there are insufficient devices to General description display it. On the 14, 21 and 28MHz bands the initial digit is This transceiver is completely solid-state except for the use of controlled directly by the single-wafer bandswitch (SIB). an antenna-changeover relay which is necessary to switch the The band selection is controlled by a wafer switch which high rf power from the output stage. The SB-104 is of an selects the bandswitching diodes to be forward biassed at advanced design and contains some 2,800 parts, including the input and output of the various broadband stages 31 lc's, 75 transistors and 171 diodes. These devices are throughout the transceiver—a single wafer is used for this mounted mainly on 15 glass epoxy printed circuit boards. purpose, while a second wafer is used to switch in mechanic- ally the appropriate harmonic filter between the pa, or driver, Eleven of the PCBS plug in, and seven of these may be extended out of the chassis while the transceiver is opera- and the antenna socket. The transceiver operates from a tional by means of the extender circuit board. This is useful nominal 13.8V de supply (although see the results of the test). and necessary for fault-finding, and for checking signal and The manufacturer claims that it can operate directly from a voltage levels. Circuit boards are particularly useful when 1-12V car electrical system (je negative of battery earthed). another SB-104 is available, for this enables any trouble to Optional extras are the noise blanker to reduce effects of be quickly pin-pointed by interchanging boards (unless the impulse interference (not tested here) and the 400Hz crystal problem exists with both transceivers). It is also an advantage filter for cw working. Several auxiliary equipments are when advances in the state-of-the-art are made and it then offered for use in conjunction with the SB-104; they are the becomes convenient to change just a circuit board rather than SB104 loudspeaker, S13644 remote vfo, SB634 station buy a whole new transceiver. console, SB614 station monitor and SB230 linear. The re- Instant QSY is possible, especially if one has a broadband viewer has used only the SB200 linear in conjunction with antenna such as a cubical quad, since none of the more the S13-104 and it may be adequately driven from the common preselector, load and tune controls exist. This is transceiver. achieved by broadbanding for both transmit and receive The pa stage consisted of two push-pull amplifiers operated functions. A useful feature is the digital readout of fre- in parallel using four TRW transistors type 2N6456. In the quency which achieves a 100Hz resolution using a maximum reviewer's model alternative devices manufactured by CTC of six figures (only five figures are, of course, required for this have now been fitted by the Gloucester factory after dis- resolution on the 3.5 and 7MHz bands); it indicates both tortion problems were encountered after the factory fitted a transmit and receive frequencies which are always the saine second set of TRW devices. The pa is broadbanded and no unless an external vfo is being used. There is no facility for tuning is required. Hybrid dividing and combining trans- independent tune of the receiver. The use of flat seven-seg- formers are used to divide the input drive power between ment gas-discharge display tubes for the frequency readout the push-pull pairs and to combine the output powers. The vfo is a fairly conventional fet circuit and basically similar to fet VFOS used in earlier Heath valve transceivers (cg the • Tanglewood, The Ridge. Little Baddow, Chelmsford, Essex. H W 100).

RADIO COMMUNICATION July 1977 523 Wanted signal °dB BEEBE • W à ds lgn Man = OdB a. 111•111111111 Horizontal scale- -10 Horizontal scale..... 1kHz per division 1 kHz per division B M M U U M -20 Suppressed Unwanted -20 carrier -55dB 2nd audio -Generated in balanced MMUMMUMMIUMM -30 harmonic mixer (and within filter 40 passband) MIMMIU MMWMUM -40 Unwanted LSB MMI MIRM MAIMM -50 " HUBER -60 m u muu moram -60 BUIWW WIMMUFM M MUS 111 -70 • muumuu. -70 Fig 1. Output spectrum from driver stage 1W using 1,000Hz Fig 4. Spectrum of pa stage being overdriven (pwr at 12 on signal of 11m V at mic socket. Unwanted (Isb) at -70dB meter) and level control too high. Input at 2,000Hz at mic referred to wanted signal. Carrier level 55dB. Other spurii• socket was 11mV. The worst in-band product is seen to be -50dB. (Co mpare Heath specification - 55dB, -50dB and only 10dB down, and out-of-band products are considerably -50dB ( r 3MHz of carrier) respectively). All figures are within increased over those shown in Fig 3 for correct level control specification-although admittedly the specification refers to adjustment. This would result in poor speech quality and pa stage output. Wanted signal frequency 14.128M Hz. much adjacent-channel QRM • (Except for 2nd audio harmonic at 32dB)

a WantedsignaI...lU U U od8 B M Wanted • od 9 3 .1111 , 1 1111 U M = _10 Horizontal scale-. ▪ signal M U M . -10 Horizontal scale-. Unwanted 1kHz per division 1 MHz per division Suppressed Ii -20 carrier - 50dB 2nd audio harmonic -30 ...... 111111 rn. -320 0 7 : 7 M•.7111 7 -40 111111111111• iiiTula.. -4050 Unwanted M M . M U M. _50 L S B 6 m u m , upiumm_ , is um qmil o • um II ILIU M • ." " I I/ " le g7- 0 u

Fig 2. Output spectrum from pa stage 100W using 1,000Hz Fig 5. PA stage at full output when driven by 11mV at 2,000Hz signal of 11m V at mic socket. Unwanted (Isb) at -62dB. at mic socket. Spurli within ±3MHz are > -50dB. Except for Carrier level - 50dB. Other spurii > -50dB except for 2nd one at just above +3MHz the other spurii greater than 2_3MHz audio harmonic (in-band) are > -60dB. Thus all are within specification except that one just above -l-3M Hz

BIZEMIIM MI MMIUMIMMUM M OdB Wanted OdB signal 2nd harmonic Horizontal scale._ -10 Horizontal scale -10 » muumuu M UM 1 kHZ per division MIUMMUMMI MM -20 1 kHz per division 3relharrnorlic -20 Suppressed Position of Carrier -30 suppressed MMIMME -30 carrier WWMIMMM -40 -40 M UM MMIUMM MU M -50 -50 M O N' A M MO M alin M U M » -60 -60 ORPRNU MMVIII U M, k -70 -70

Fig 3. Spectrum of pa stage at full output (level Control 91 Fig 6. Output spectrum of balanced mixer measured at T601. o'clock) with 2,000Hz drive at mic socket (input 11mV). Spuri- Input to mic socket was 10mV at 500Hz. Note that 2nd, 3rd and ous responses better than - 45dB 4th in-band harmonics are significant. Carrier suppression at -45dB is good and since the filter follows it will be further attenuated there

Bench tests 1. Tests of the 1st balanced modulator, which uses FH1100 spurii, with levels measured relative to the wanted 1,000Hz hot-carrier diodes, shows the production of significant audio side frequency (lsb), were found. in-band harmonics, the 2nd and 3rd being respectively 17 and 26dB down on the wanted single-tone at 500Hz. No Level relative to 1,000Hz specification for such harmonics is given by Heath but good Frequency (approx) MHz side frequency commercial practice would not accept a 2nd harmonic only 0.8 —50dB 17dB down. Fig 6 shows the spectrum of the modulator 2.8 —48 output for a single-tone test as measured using an HP8552/3B 5-7 —50 analyser. 8-2 —32 2. Initial tests before the pa transistors were changed for the 11.6 —50 first time showed considerable numbers of spurii out of band 13.6 —14 when the transceiver was tested at 4.00MHz. The following 16-8 —38

524 RADIO COMMUNICATION July 1977 — 1000 __---- -{ 1 1 80

3.7437 MHz 1.513 Hignieowsz f 1600 Hw100 tort zit 10/2 tic ace 70 3 7437 MHz LSO Low paver Level control at 12o clock

1400 1OrnV audio Into microphone I I I I 60 socket usa 1.4100 N I -power (at 1000Hz power reading s 1.5) peoo 1200 50104 Serla No 00450 E 50 Driver only 2 500 000 6dEl a i. -608 M -6dB at 2 62508 - ... tE)1 1 247514 L511 58104 2500 ,48 540 s /4 Fullizioumz "e 400 two ./...... \ 30

i4 300 60 -5d6 / -6413 -6dB -6413 1 E 20 li 200 400

10 100 200 o 9 9 i \ \ • e o / • 300 500 1000 1500 2500 2500 300 500 800 1000 1500 2000 2 Audio MOO. oCY Audio frequency (Hz)

Fig 7. SB-104 rf output response (speech band only) when Fig 9. SB-104 rf output response (speech band only) from trouble was experienced with distortion of transmitted side- driver stage band. Believed due to instability. Cured by Heath changing pa transistors and adding decoupling (see manufacturer's modifications). H W100 response shown for comparison adjusted and working correctly. The 6dB frequencies are now as specified. Fig 9 shows the output response of the driver stage only. This stage is used as the final stage when When the third set of pa transistors was fitted by Heath, subsequent tests on the CTC pa transistors into a 50CI running low power output and it too has an excellent response. Cantenna load produced spectrum under single-tone of 1,000Hz shown in Fig 2. Results of frequency drift measurements on 8B-104 3. A frequency plot of the transceiver response was made by using a TF1417/2 frequency counter (Table 1) injecting approximately 10mV of audio frequency tone into The figures in brackets are values after the factory modified the mie socket and monitoring the voltage across part of a the vfo because of its excessive drift. There is sufficient back- 50f1 rf load with the transmitter pa stage operating at full lash in the tuning mechanism to shift the count by 200Hz. power. The response showed that the If audio figure of The absolute frequency change has not been measured 350 -!--75Hz at —6dB was not up to the Heath specification although it is sufficient to modify the received voice signal in the transmit mode (see Fig 7). Comparison there is made when it becomes necessary to follow a slightly unstable against a similar plot for the older HWI00 transceiver which incoming frequency. uses a broader crystal filter. After the CTC pa transistors The measurements show that in the first half-hour of the were fitted the test was repeated and Fig 8 shows what a non-transmitting test the vfo before modification drifted superb response is possible with everything in the transceiver +530Hz, and after factory overhaul (in which several components were changed) the drift was reduced to a com- 80 mendable +8Hz. Heath do not specify drift in the first half- hour, but for those who operate their rigs for short periods it may not always be convenient to switch-on the rig 30min o 50 3•7437 MHZ LES High power before use. The above figures show that the next 60min drift o Level control at 1 o'c I oc k was reduced from +182 to —14Hz. At first the figure was E›.413 10mV audio into microphone socket (at 1000Hz power reading 12)

o Serial Na 00450 Table 1 50104 E 30 L Elapsed time Counter (T F1417i2) SB-104 readout

6aB a (minutes) reading (MHz) (MHz) 360 Hz 2: eg; 0 (Start) (0) 14.186570 (14.128045) 14.1858 (141271) 20 2.5 (7) 660 ( 008) 58 ( 71) 6 (12) 780 (14.127990) 59 ( 71) 10 (17) 850 ( 989) 60 71 E 10 15 (24) 940 (14.128039) 61 ( 72) / 21 (29) 14.187040 ( 053) 62 ( 72) 26 (39) 110 ( 058) 63 ( 72) o 31 (50) 160 ( 060) 63 ( 72) 300 500 1000 1500 2000 250 0 Audio frequency (Hz) 35 (57) 195 ( 054) 64 ( 72) 45 (66) 256 ( 042) 65 ( 72) Fig 8. SB-104 rf output response (speech band only) after CTC 60 (75) 302 ( 048) 65 ( 72) pa transistors and further decouplIng installed to cure distor- 77 (83) 330 ( 055) 66 ( 72) tion of transmitted sideband experienced earlier (cf Fig 7) 90 (86) 342 ( 039) 66 (14.1273)

RADIO COMMUNICATION July 1977 525 Table 2 Table 4 Before After 3.7380MHz SI} Spurious carrier 28-9554 3-6520 S3) Spurious carrier 28 -9996 Input (0,J) S-meter Input (A/) S-meter 7-0744 29-0216 1 0 14 0-5 7.0647 Carrier audible 29-0440 2 0 18 1 14 -0143 29-0639 4 0 25 2 14 .0656 29-0743 8 1.5 32 3 14-0775 29 -0850 16 4.8 43 4 14-1992 29-2306 32 9.0 54 5 14 .2404 S1 29-2584 64 9 — 20dB 75 6 14 -2966 29 .2829 128 9 -,- 30dB 110 7 21 -0644 29.3842 Morse 256 9 - 38dB 165 8 21-1997 S1 breakthrough 512 9 --- 45dB 256 9 21 -2590 29-4130 Morse 21-4258 breakthrough 28 -04.32 29-4299 Morse outside the Heath specification of less than 100llz per hour 28-3886 breakthrough but again the final drift achieved is very low. 28.3943 29 .4621 28-4337 29-6432 The S-meter readings (Table 2) were taken before and 28-5440 29-6524 St) after the sensitivity modifications to the front-end of the re- 28.8096 29-6616 ceiver (a Heath modification). The input voltage is that at 28-8201 Teleprinter 29 .6712 the receiver antenna terminals, at a frequency of 14.280MHz. breakthrough 29-7283 28.8381 29.7304 Morse Fig 10 shows the test circuit and the voltage measured. Note 28-8457 breakthrough that the lower S-meter readings taken after the modifications 28 -8728 Morse 29-8448 Morse do not necessarily indicate a lower sensitivity but simply that breakthrough breakthrough 28-9127 Morse 29-8736 Morse the S-meter calibration was re-adjusted. breakthrough breakthrough 28 -9325 29-9794 Note: where no S-meter reading is shown the spurii were insufficient in level to produce a reading, but were nonetheless audible. Signai generator• Rld Receiver

Table 4 shows frequencies at which spurious signals were Fig 10. Circuit arrangement for S-meter calibration (see Table detectable. Some of these are products of the digital counter 2) and others are due to pick-up other than through the antenna (a screened dummy load was used to terminate the antenna socket throughout these measurements). On-the-air use has shown that the S-meter calibration of Table 5 gives the readings of output rf power measured the final two columns of Table 2 compares favourably with using a Bird Model 43 Thru Line wattmeter into a 500 the reports received at the reviewer's station for his own dummy load. signals when comparable power and antennas at each end are in use. However, this is at the expense of the S-meter moving hardly at all on quite readable signals on a quiet Table 5 band. This appears to be a characteristic of transceivers of Fra- Hi Lo Fra- Hi Lo all types at the many dx stations contacted using the SB- quency power power quency power power 104. The readings between S2 and S9 are approximately (MHz) (W) (W) (MHz) (W) (W) 28-7493 100 1-9 14-2489 110 2-2 logarithmic and average around 3dB per S-point. 28-2497 98 1.8 7-0500 95 2-0 Table 3 shows the power output into a 40 resistor. AF gain 29-2497 105 2.0 3-5482 50 1-3 at 12 o'clock and rf gain control fully clockwise. The noise 29-7505 98 2-0 3-7500 92 1-6 output was 2mW into the loudspeaker with no signal. AGC 21-2502 100 1.8 in now position. Note: 1 he low reading at the bottom end of the 3.5MHz band was due to the adjustment of L321, the 3-395MHz trap, and was subsequently corrected by re-adjustment. Table 3 Power into On-the-air-tests Input (5V) loudspeaker (mW) 1. After Heath fitted the second set of pa transistors much 1 10 2 40 Overall gain. The specification adverse criticism of the audio quality was made. At first this 4 120 quotes less than 14V, for 0-5W was thought to be entirely due to the Heath G1-1-12A micro- 8 220 audio output. With gains flat out phone being used despite a statement by Heath that it was (af and ri) 0.62e.V produced 16 280 suitable. Two separate GH-12As were tested to ensure this 32 320 0-75W audio plus noise so that 64 350 the receiver was well within was not a characteristic of a single microphone. Reports 128 370 specification. when using this microphone were described variously as 256 390 Intermodulation distortion. harsh and nasal sounding. Use of a Philips type N8210 512 410 With a 5-6.d.V signal at 14-304MHz 1,024 420 a signal in excess of 100mV at microphone (as supplied with their N2203 and N2204 2,000 440 14-280MHz was required to pro- cassette recorders) proved more acceptable although quality 4,000 450 duce a detectable signal at was still not good. The Heath OH-12A is a piezo-ceramic 14-256MHz of —85dB. Hence the 8,000 470 microphone and is unsuitable for the input impedance of the 16,000 480 claim of —60dB is very reason- 32,000 460 able. SB-104 and if so used will result in severe attenuation of the

526 RADIO COMMUNICATION July 1977 lower frequencies. Its unsuitability was confirmed in con- rf output power. Heath have now changed R254 to 750f1 versation with Angus McKenzie, G3OSS, a well-known from the original 680O in order to raise the nominal 11V rail audio consultant (but it is entirely suitable for use with the voltage. The ic controlling this rail voltage is a Motorola HWI00 transceiver with which it has been used here for MFC 6030A which was unable to work with the manu- many years). facturer's specified 3V differential between input and output In May 1976 the transceiver was returned to Heath for until the reviewer raised the transceiver supply to 14-50V the second time to determine the cause of the harsh audio originally (later 14V). It was this increased supply voltage quality when transmitting. It was then that the pa transistors which led to the excellent regulation figures quoted above. were changed for the second time, that is to say to the third Having to keep the supply voltage at this level would seem to set, and this time the CTC devices were fitted. Heath said the suggest a problem in connection with mobile operation when pa transistors were changed although they were not proven the car battery is not on charge. To date the SB-I04 has not to be at fault. However, this together with the following been tried from a 12V battery supply. modifications affected a cure to the distortion. R954 and The WWV crystal in the SB-104 failed to oscillate, and R956 were changed to ferrite beads. L952 and L953 were changing the crystal did not make the circuit oscillate; only reduced from five to four turns. 001F capacitors were when the value of R414 was reduced from 15kft to 47kû added to pins C4 and C5, and ferrite beads to the lead from did it do so. Some added difficulty in finding this fault was K5 to lug 8 of the relay. To prevent pa oscillations when due to the fact that the HFO/PRE MIXER schematic (fold- using CTC transistors a 390f1 resistor was fitted across out from p 294) has a drafting error that has been perpetuated RFC902. in the second issue of the Operations Manual. The designa- 2. Very careful adjustment of the mic/cw level control is tions Y403 and Y404 together with the crystal frequencies required and also very much care must be exercised in have been interchanged, as have circuit board outlets 12 and keeping the voice at the correct level so that the transmitter 13 (with their respective labels WWV and 14-0). The labelling is not overdriven (see Fig 4). It is recommended that the of D419 and D420 should also be interchanged, as is obvious meter with the switch in the P WR position is driven to if the X-ray view (fold-out from p294) is consulted. between the 3-6 marks; the operations manual (p258) Criticism of the Operations Manual may also be made recommends ale meter reading should not increase by more when it comes to fault-finding because insufficient test volt- than six units, but the reviewer's ale reading moves only very ages, particularly for ac levels, are given. It is believed that occasionally. Before the CTC devices and the modifications Troubleshooting Guides are available on request and some mentioned above had been carried out, tests over some 4-5 were obtained by G3WFB on direct request to Benton miles gave the distinct impression that the transmission was Harbor, Michigan. wider than when using a HWI 00 transceiver. Now, with the In the reviewer's transceiver some lack of drive on the above modifications, the quality and spread is indistinguish- 28MHz band was corrected when the bandpass filter able from the HW100 transceiver at this station. components were checked and C472 was replaced. The overall response of output versus frequency was Experiences and problems encountered in commis- checked by plotting the voltage obtained across a Cantenna sioning the SB-104 for operation dummy 5012 load when an audio signal into the microphone The SB-104 under review had the serial number 00450 and is socket was varied across the passband. The response, so an early model. In working and speaking to several dx stations obtained, in the Lo P WR position is shown in Fig 9 and as the reviewer concludes that his experiences are not unique such has a reasonably flat top. The response when the pa and hence describes these so that they may be of value to stage was tested produced the curve shown in Fig 7 and was other amateurs. Other kit-builders have experienced differ- far from flat for the TRW transistors. Heath were unable to ent problems which the reviewer did not encounter. The comment on this response even though copies were sent to standard of soldering required must be high since there arc Benton Harbor and Gloucester, but it is thought to have well over 6,000 soldered connections, any one of which been due to instability and oscillations occurring. A similar could cause an incipient fault. test carried out on the HW100 at this station produced a very The most serious difficulty initially was the considerable good flat-topped response shown in Fig 8. The responses frequency modulation experienced, and almost as soon as the were also tested using a pseudo-random noise generator and reviewer had diagnosed the problem the first of the many a spectrum analyser which verified the hand-plotted re- modifications for the SB-104 arrived. The trouble was mainly ponses. Adjustment of the hfo oscillator coils posed some in the lack of voltage stability with the vfo dc supply which difficulties as the adjustment of L403 of one turn clockwise itself was derived from the nominal I1V rail. Zener diode from the peak voltage position only resulted in the oscilla- (ZD1201) was originally a 10-1V zener and was first changed tion stopping. The table listing these adjustment is on p237 to a 9-1V zener to be later changed to one working at of the Operation Manual and it was found that the coil slug 7-5V. However, before this latter modification had been for L403 could only be turned a quarter turn from the peaked received the reviewer had raised the dc input to the trans- position. The output from the oscillators varied between ceiver from the recommended value of 13-80V to a value of 0.25V and 0-15V when measured at the tp near Q402 (as 14-50V to get the electronic stabilizer within the transceiver described on p236). The lower voltage is below the value working correctly. When Heath subsequently modified required in the manual of 0-2V dc. R254 and R255 from 10 to 5 per cent components this The alignment of the upper and lower sideband fre- allowed the reviewer to reduce the transceiver supply to 14V. quencies readout posed some problems in getting the read- It was found essential to use a digital voltmeter to measure ings to be similar but the vfo modifications seemed to have these voltages, and when so measured the 11 and 5V rails overcome this (except that from cold the discrepancy may be remained stable to four significant figures no matter what the as high as 600Hz difference on the digital display).

RADIO COMMUNICATION July 1977 527 Appearance and general construction* Photo 4 shows a typical circuit board with the connection Photo 1 shows the frontal appearance of the SB-I04 with the sockets which mate with male plugs fixed to the chassis. There tuning control centrally placed. The knob may be spun are 24 of these on each of the main boards. The board shown quickly using the finger-hole. No conventional tuning scale is is that for the carrier generator and contains the crystal provided as the digital display takes its place. It is useful to filters. At the time the photograph was taken only the ssb have the vox gain and delay controls brought out on the filter was fitted. Plastic straps at each top corner of each front panel although it is the reviewer's experience that they board enable it to be withdrawn from its compartment using are less frequently adjusted than the corresponding controls a screwdriver through each strap. Each board fits into a on a valve transceiver. AGC may be switched off altogether pair of guides attached to the sides of its compartment, also or operated in a slew or FAST position. In each of the opera- serving to earth the board effectively. Where extra earthing tional positions the attack time is 1 ms and the release time is necessary, such as on the TX I.F. PREDRIVER circuit board, is respectively is or 100ms. FAST or OFF positions are pre- then the appropriate screening cover on the board is earthed ferable for cw operation according to the preferences of the directly to its adjacent compartment wall using a spring clip. operator and the quality of the incoming signal. Photo 2 shows how each of the main circuit boards, housed in its own compartment, is completely screened Conclusions from the others. The vfo box can be seen immediately behind Clearly this transceiver is conceptually ahead of its time and the main tuning knob which is on the right-hand side of this a pleasure to use. It has been in use at this amateur station photograph. The pass transistors for the 11V and SV sup- for well over 18 months although not without major problems plies can be seen at bottom right. Their corresponding during that time. However, it has now worked consistently integrated circuits are on the second circuit board behind (to for the last 10 months with only one integrated circuit the left of) the vfo. The integrated circuits driving the digital driver failing in the digital display. This resulted in one seg- display are mounted immediately behind the flat seven- ment of one digit lighting permanently, and some care had segment gas-discharge display tubes and can be seen at the to be taken during the time a replacement was awaited in top right of the photograph. The long spindle is that of order to interpret the frequency display correctly. the wavechange switch and this spindle passes through the Should the output stage see a mismatch into the antenna screened compartment containing the 5 to 180V dc to dc or other load a control voltage is automatically generated converter supplying the display tubes. The converter itself is which reduces the drive level. Experience has shown that in another screened box which is well decoupled to prevent the transistor output stage is less tolerant of mismatch than the 25kHz and harmonic hash from its oscillator getting valve stages but so long as the output stage sees a vswr of no into the receiver section. The DRIVER circuit board is mounted more than 1.2 : 1 it seems perfectly happy. Such a vswr has in the next compartment (top left) and on its own heatsink been achieved on the reviewer's cubical quad, even at the which is fixed to the main chassis wall by the metal stand-off band edges, so that the instant QSY facility is truly available. pillars. The pa stage hybrid transformers are visible to the The ability to switch out the pa stage and to use only the left-hand side of this compartment, and the pa transistors are driver with its 1W p.e.p. is very useful, since it reduces soldered to this circuit board and their lugs are bolted to the QRM to others, when conditions are such that propagation large heatsink seen on the extreme left. Also fixed to this allows the use of the lower power—this is more often than heatsink is the biassing diode (D1)—its connection can just the reviewer is sure most operators realize. The ability to be seen in the rearmost compartment behind the main switch all tuned circuits using just a single-wafer switch must circuit boards. in the long term reduce the failures often associated with Photo 3 shows how the outrigger board enables each of the mechanical switches carrying many wafers. There is no main circuit boards to be positioned so that measurements independent tune facility on this transceiver, but to the re- may be made when fault-finding or adjusting. The trans- viewer this is no disadvantage since he is inclined to the ceiver works more or less normally with a board in the opinion that the independent tune facility leads to poor outrigger. netting. Admittedly the facility does allow one to follow a • See front cover for Photos 1, 2 and 3 drifting received signal, but then this uses more than one

Photo 4. Typical circuit board

528 RADIO COMMUNICATION July 1977 channel for two-way communication and no-one should use more bandwidth than necessary. For those wishing the facility, an external vfo is available, and additionally this ( BOOK REVIEWS allows split-frequency working which is perhaps a "must" for those working dx on 3-5MHz etc. • Since the CTC transistors and other modifications have been incorporated the audio quality has invoked much Radio, TV & Audio Technical Reference Book, edited by S. W. favourable comment from both local and dx stations. The Amos. 145 by 222mm; hard bound; price £24. Published by receiver sensitivity is adequate for use with the antennas at Newnes-Butterworths, Borough Green, Sevenoaks, Kent, this station but is outside the Heath specification. A signal TN15 8PH. of 1-8µV was required across the input terminals to produce This is the fifth edition of this book, which was first published in a 10dB signal plus noise-to-noise ratio in the ssb mode. It 1954. It is intended to give an essentially practical account of would be a pity to have to introduce a pre-selector control to modern developments in radio, audio and television. It Is directed tune the receiver front-end but at times it is felt that it may to the technical assistant, service engineer, radio amateur or audio enthusiast. be the only way to improve the sensitivity. The initial vfo The material has been compiled with the help of 31 contributors, drift was cured by the Gloucester factory changing many of Including B. J. Arnold, G3RH1, and three members of the Society's the components, although when it was returned from the Technical and Publications Committee, le Pat Hawker, G3 VA; factory there was a discrepancy of some 600Hz when Robin Hewes, G3TDR; and Phil Horwood, G3FRB: all of them specialists in their particular fields. The 35 chapters cover the switching sidebands. This was cured by adjustment of the vfo subjects indicated in the title, beginning from fundamentals. The after warm-up but even now the discrepancy can be 400Hz editor, S. W. Amos, is well known for the books and articles he at switch-on in certain parts of the bands (it is not possible to has written over a period of many years. Until his retirement in 1973 he was head of the Technical Publications Section of the BBC. compensate entirely with the present circuitry). Unlike As one might expect from a book of this pedigree the layout and previous•SB-series transceivers the vfo is assembled by the presentation of both text and diagrams are clear. The subject kit-builder. The dial backlash although specified at 50Hz coverage is wide, and the book, within the limitation imposed by is often as much as twice this value. the price, will undoubtedly find a place on many bookshelves. The reviewer would criticize the lack of rf, ac and dc voltages available on the diagrams and in the handbook when The International VHF-FM Guide by Julian Baldwin, fault-finding, but he understands that more information has G3UHK, and Kris Partridge, G8AUU. been made available in the handbooks for such later trans- Limp bound, saddle stitched, A5 size. Obtainable from ceivers as the HW-104. Also there has been no automatic the compilers at 41 Castle Drive, Maidenhead, Berks follow up to advise purchasers of the modifications necessary SL6 6DB. Price 90p including p and p. For European to make the transceiver function correctly. addresses the cost is nine IRCs, and outside Europe, 14 IRCs. Many of the modifications only came to notice when The new 1977 edition of this handy reference book runs to 65 pages. speaking on the air to other amateurs. Even now the reviewer The format is basically the same as previous editions comprising a is not completely sure that the list of modifications he has wealth of information regarding repeaters and reciprocal licensing. compiled is exhaustive'. Having said that, whenever he A problem experienced in the compilation of such a book is the constantly changing information but the editors have managed to requested the components to carry out these modifications produce a book that is up to date at this time. they were always sent free of charge, so in that respect the Heath service remains as good as ever. Some of the minor "mods" have not yet been incorporated, such as the cure for the vox hang-up, since they have only recently been brought to the reviewer's attention. Having had a series-pass transistor go short-circuit in the HP1I44 •power supply, which caused that rail voltage to go high, the reviewer can vouch that the transceiver will stand an over-voltage for a short period. Naturally he was quick to switch off when that happened. If the vox gain is set too high then parasitics can occur on the tx audio board output. When the vox gain is set to a level compatible with the input signal the parasitics are not present. About 300mV p-p unclipped is required at terminal BI I for satisfactory audio. Much dx is consistently worked with this transceiver and its cross-modulation performance has proved adequate under busy band conditions. A project of this nature must not be undertaken lightly even by the experienced kit or homebrew expert unless he has rather more facilities available than average.

Acknowledgement The author wishes to thank Mr E. Bell for taking the photographs used in this review. Very effective, Fred... but I don't think you will get the • Obtainable from the editor at RSGB HQ. CBers to accept it

RADIO COMMUNICATION July 1977 529 had led him to investigate the use of consumer ics incorporat- e ing limiting amplifiers and intended for use in domestic technical fm broadcast receivers. Like the Dutch listener this had drawn him to the TBA120 series of devices: as described with circuit details by J. R. Hey, G3TDZ, in Radio Conununica- topics tion (September 1972, pages 592-594), these devices incorporate a series of high-gain limiting amplifiers based on long-tail pairs followed by a balanced coincidence detector. • Pat Hawker, G3VA Available types include the TBA120A Siemens devices and the Mullard TBA120S series which have the advantage of extra limiting stages. He confirms the Dutch work that such nNE of the fascinations of radio and electronics is that, devices will successfully process the signals and allow them ‘-/even now, almost a hundred years after it all began, it is to be used as a frequency standard. very dangerous to be too certain or too dogmatic about The important thing is to make sure that the tuned circuit almost any facet of design technique or mode of transmis- is really tuned to Droitwich (and not, for example, the strong sion. When 1 hear or read somebody laying down the law Allouis French long-wave station on 164kHz). His receiver that such and such is the right way to do something or other I uses a preliminary rf stage in front of the TBA120 and uses a usually cringe. For it reminds me of those over-simplified ferrite-rod taken from an old portable radio with the mf beliefs of times past—"double-conversion superhets are winding removed and a miniature ift padded up with a 500pF better than single conversion" (nowadays you can be fixed capacitor to provide the coupling between the rf stage equally dogmatic in putting it the other way round), "you had and the TBA120. In initial setting up it is useful (but not better get your swr down or otherwise most of your rf essential) to use a 200kHz signal generator or to use a diode power goes back into the transmitter" (what does it do detector probe with af amplifier to tune to Droitwich. At there?), "fm or ssb or a.m, is better than a.m. or fm or ssb", low signal levels audio appears at the output of the TBA120 "a frequency synthesizer is better than a free-running vfo" although severe distortion will be noticed as soon as the etcetera. limiters really begin to take effect. Whether an rf stage is Even in the less controversial areas it is usually essential to likely to be needed probably depends mainly on the efficiency qualify the statements—better than what? better for what? of the ferrite rod as an If antenna and the location (it would, better at what cost? and better for how long? New devices of course, be possible though less convenient to use a tuned and components can quickly swing the technical debates circuit with an external wire antenna). from one side to the other. What really matters is "does it In his original plans, G3VTJ had intended to have a local work well under present-day conditions?"—and if so, why ? marker oscillator at 10MHz by using a phase-locked-loop The only thing certain in life is death; the only thing certain ic (NE562B), dividing the 10MHz output by 50 to 200kHz in radio is that we live in an age of uncertainty. And long by using two SN7490 devices and then comparing this with may it remain so. the 200kHz Droitwich signal: with a further divide-by-two device so that he could have outputs at 100kHz, 1MHz and 10MHz. He considers that a hf marker is often an asset More on the Droitwich standard when setting up the clock of a digital frequency meter etc. The March Ti' presented a precision frequency standard However, his efforts to obtain a solid lock at 10MHz using an extremely simple 200kHz receiver and signal proved unsuccessful despite the investigation of possible processor, as described by G. van den Brock in the Dutch earth loops and the incorporation of isolation, decoupling journal Electron. This design has attracted considerable etc. He soon realized that an alternative approach would be interest and although it appears that there were some errors to extract the fifth or third- harmonic of the output of in the diagrams of the electronic switch (March Fig 2) and TBA120 in successive operations, using further TBA120 the divider chain (March Fig 3), the stunning simplicity of devices and modified Toko irrs for coupling, and so obtain- the receiver section (March Fig 1) remains unchallenged. ing 1, 5 and 15MHz outputs. The TBA120 incorporates an However, it is felt that the very brief description in March "af amplifier" stage and this was found to provide gain at may have left some readers wondering how such a simple 200kHz; the IFS'S for 5 and 15MHz were based on 10.7MHz arrangement can not only receive Droitwich but can also transformers. Of course, for some applications the direct perform the much more difficult task of stripping off the 200kHz output, as in Fig 1 of the March issue, is all that is modulation so as to provide an effective, harmonic-rich, needed to provide markers, so that even the simplest unit pulsed output. can provide the most accurate checkpoints ever likely to be This month, thanks to Harry Bradshaw, G3VTJ, some of needed! the missing details can be filled in. For it so happens that On the general subject of precision frequency standards, G3VTJ has for some time been working along similar lines interest is being shown both by professionals and amateurs and had originally intended to "write-up" this work in detail, in the USA in using television oscillators controlled by the although this task was delayed by business commitments. bursts of colour sub-carrier of broadcast television signals, He now feels that the Dutch unit is sufficiently close to his which in the USA are based on an atomic standard; for own work as to make a full-length article redundant, but example see Electronics (11 November 1976, pages 114-115), that readers may be interested in some explanatory notes. 73 (February 1977) or the April issue of the Cheltenham He stresses that much of the complexity in earlier Droit- RSGB Group Newsletter. I feel it should be said that in the wich frequency standards stemmed from the need for some UK (where the sub-carrier frequency is 4.43361875MHz and tricky signal processing to eliminate as much as possible is maintained to better than ±IHz except during relays of of the original modulation on the broadcast station. This programme material from overseas) this technique is less

530 RADIO COMMUNICATION July 1977 +5V November 1976 TT. One error was of my creating, the other appears in the original Electronics write-up and also affects 220 the diagram. Briefly the connections for divide-by-eight should be: Pin 12 to 1; 11 to 2 and 3 and not Pin 12 to 1 and 2; 11 to 2 and 3. The divide-by-eight connections are LED2 7400 correctly shown in the calibrator in the March 1976 issue. Droitwich 2 However, the divide-by-seven arrangement in both the table and diagram of the Electronics article is wrong, as 7400 BRS33339 discovered by accident. What is shown as divide- 100kHz by-seven is in fact an alternative arrangement for divide-by- six. BRS33339 gives the divide by seven connections as: input pin 1; output pin 11; pin 1 1 to 14; pin 12 to 2; and pin 8 to 3. Local oscillator Mono output 15 115 LED1 And more on that Russian mixer 220 In the April TT, attention was drawn to a novel mixer/ product detector arrangement for use in direct-conversion receivers, originally described by V. Polyakov (Pliakov), Fig 1. BRS37312 suggests this modified logic circuit for switching in the local 100kHz oscillator when Droitwich is off the air RA3AAE, in Radio (December 1976). At the time I men- (see March TT). LED1 lights when output is from Droitwich; tioned the problem presented by the Russian text and made LED2 when output is derived from local oscillator it clear that my brief comments were written in more than the usual fog, relying on the circuit diagrams to tell the attractive than using Droitwich. This is partly because it is story. my understanding that the BBC use Droitwich to keep their Thanks to the valiant efforts of two RSGB members, Sid sub-carrier accurate; so it is surely better to go straight to the Dunn and J. Lekesys, G4BYW, I now have before me two original source without the need for a colour tv receiver, excellent translations of this article. These make it clear that locked by bursts, from which to extract the signal! It is, of the operation of the circuit and its aim is by no means in course, a valid system for those not having access to Droit- accordance with my initial impressions. On the other hand, wich. they do fully justify my belief that the Russian amateur has It was mentioned earlier that Figs 2 and 3 of the March 77', come up with a useful circuit that well merits further investi- although reproduced as in the original Dutch article, appear gation, not only for its application as a product detector for to contain errors. C. J. Bristow, BRS37312, writes: direct-conversion receivers but also (as RA3AAE points out) "I think there must be some confusion over the logic as a mixer for vhf receivers (where the halving of the fre- elements in the electronic switch. In the presence of the quency of the local oscillator is particularly attractive) or 200kHz signal the gated mono output will be logic 0, ignoring possibly as a substitute for a balanced modulator in an ssb positive spikes due to gate delay. Thus the upper NAND exciter. gate will be enabled via the inverter and the lower NAND RA3AAE considers that direct conversion receivers are gate will be inhibited and thus its output will be logic 1. extremely attractive for amateur use but have three main However, this logic 1 will force the output of the NOR gate disadvantages: (1) double-sideband receiver (unless an ssb to logic 0 and the 100kHz signal will not be transmitted. phasing demodulator is used); (2) direct envelope demodula- The two led displays show slips of the pen. May I suggest tion of powerful signals (often particularly troublesome on the Fig 1 as a means of overcoming the shortcomings and also 7MHz band); and (3) local oscillator radiation unless an reducing the pack count. The 74123 is re-triggerable, hence the rf stage is used. Both (2) and (3) can be minimized by the 151.es output enables the Droitwich signal to be transmitted use of a good balanced or double-balanced mixer/product normally. Loss of signal allows the mono to relax, switching detector, but there are many factors that make it difficult for the local 100kHz oscillator to the output." home constructors to achieve good balance over a wide John Young, BRS33339, points out that in the divider frequency range (packaged double-balanced mixers of good chain of Fig 3 (March) the counter/dividers shown are used performance are increasingly available as complete units with the divide-by-five section preceding the divide-by-two but are still quite expensive in terms of direct-conversion section. Although the final result (1Hz) is the same, the inter- receiver costs). mediate outputs should be as shown in Fig 2. RA3AAE's detector then is intended to provide an On the subject of divide-by-n use of 7490 devices, BRS- alternative to a balanced mixer by using diodes providing the 33339 has also unearthed two errors in the table given in voltage-current characteristic shown by the solid line in April's Fig 1. This is, in effect, a symmetrical cubical para- lop SN7490 bola and can be achieved with two diodes, preferably kHz —110" BD A BD A BD BD A BD A selected for matching, connected back-to-back. Rather surprisingly RA3AAE uses silicon diodes, though as Sid Dunn points out this is odd at low signal levels unless the switching action of the local oscillator effectively removes 10 2 200 100 20 10 2 1 the "dead" zone near the origin of a silicon diode charac- kHz Hz teristic. The operation of the mixer is described by RA3AAE as Fig 2. Corrected divider chain for precision frequency standard used with "huff and puff" stabilizer etc follows: "When the local oscillator voltage goes through

RADIO COMMUNICATION July 1977 531 zero both diodes are open circuit, and the circuit current vanishes. At the peaks of both positive and negative half- waves of this voltage, one or other of the diodes conducts and the signal source is connected to the load. "In this way the mixer works like a switch closing the circuit at a frequency equal to twice that of the local oscillator. When the switching frequency (2110) is close to that Ti of the signal frequency (fs), a beat appears in the circuit of the difference frequency (2fLo -fs) when the signal frequency is less than twice the local oscillator frequency; or (f,2f10 ) when the signal frequency is higher. This represents the (a) lower and upper sidebands respectively. "For mixers with cubic characteristics, two significant properties emerge: first, the local oscillator must be tuned to a frequency one half that of the signal; second, in the load circuit there is no direct current (ie signals from powerful interfering stations are not detected and consequently produce no noise). This clearly is only true for a strictly symmetrical characteristic ... nevertheless in practice it appears simpler to guarantee 'ideal' characteristics for two back-to-back diodes than to achieve an accurate balance of a mixer having several elements. Radiation of the local oscillator voltage from a mixer is much attenuated with an input circuit tuned to twice the frequency of the local oscillator (although second harmonic content will not be Fig 3. Basics of harmonic mixing: (a) shows the conventional similarly attenuated). diode :mixer while (b) shows an anti-parallel diode pair mixer RA3AAE points out that the advantage of his Fig 3 (April) over the simpler scheme of Fig 2 (April) is that it (4) Inherent self-protection against large peak inverse overcomes the loss of signal power in the coupling to voltage burnout. the local oscillator: this drawback is avoided by using the These results are obtained at microwaves without the use "balanced" arrangement using two cubic elements (je of either filters or balanced circuits employing hybrid the four diodes). junctions. It is shown that conversion loss of this typa of mixer can be approximately the same as when the same diodes Yet a further practical advantage of having the oscillator are used for a conventional fundamental mixer. Schottky operating at half the signal frequency is that the receiver input GaAs diodes are used in the experimental mixers and, for circuit does not "pull" the oscillator frequency when it is example, an 8dB total conversion loss was achieved at tuned: stability of the oscillator can be improved by the use 12GHz, comparable to that obtained by fundamental of larger tuning capacitance, and in turn this will improve mixing. These figures suggest, it seems to me, that this the note of cw signals and the reception of ssb stations. approach could not only be well worth investigating for amateur 10 or 24GHz receivers but also for the 12GHz Background to harmonic mixing receivers that one day may be part of the ordinary domestic It has also become clear that the RA3AAE form of third- scene for the direct reception of television programmes from order, second-harmonic mixer/demodulator is not new— synchronous satellites (in Europe these are planned to be in fact readers have supplied references to harmonic mixing located in the band 11-7-12.5GHz). stretching back to a 1958 Russian article and provided evi- G. Franklin Montgomery, W3FQB, also draws attention dence of current, very lively interest in this approach, to a number of early references to harmonic mixers but particularly for microwave applications. For example, Tony notes that relatively small attention has been paid to them. Goacher, G3YBJ, has sent along a copy of a paper "Har- He considers the principal idea is that by arranging pairs of monic mixing with an antiparallel diode pair" by M. Cohn, diode rectifiers properly, and by controlling the diode J. E. Degenford and B. A. Newman (IEEE Trans on Micro- conduction angle at the heterodyne reference frequency, it wave Theory and Techniques, Vol M1T-23, No 8, August is possible to emphasize the response to a signal at any 1975, pp667-673), which not only provides a detailed mathe- chosen integral multiple of the reference frequency while matical analysis of this interesting circuit configuration suppressing responses to signals at other multiples. For but also reports on experimental microwave mixers for 4 and instance, the circuit used by RA3AAE is responsive only to 12GHz. Fig 3 shows the basic principle. Apart from the even multiples of the reference frequency; similar but useful feature that the local oscillator source for second balanced diode circuits can be made similarly responsive harmonic mixing need be at only about half the signal only to odd multiples of the reference, including the multiple frequency, the following features of this mixer are under- unity. A mathematical analysis is given in "Phase-sensitive lined: detection with multiple frequencies" by B. O. Pederson, (1) Reduced conversion loss to other harmonic mixers by IRE Trans on Instrumentation, vol 1-9, No 3, December 1960, suppressing the fundamental mixing products. pp 349-355. (2) Lower noise figure through suppression of local oscil- He mentions that for a time in 1961 he used successfully lator noise sidebands. a 7MHz direct-conversion receiver consisting of a demodu- (3) Suppression of direct detection. lator essentially the same as Fig 2 (April) operating directly

532 RADIO COMMUNICATION July 1977 from the antenna tuned circuit and followed by a three-stage chip layout; in fact the LM555 from National Semicon- valve amplifier with headphones. Particular advantages ductor appears to incorporate this change but apparently were a relatively small oscillator voltage appearing in the those from other manufacturers do not. antenna circuit at 3.5MHz and, relatedly, little or no "The recommended cure by the makers was to put a diode reaction on the reference frequency when making antenna or high-value resistor in series with the connection to pin 2 adjustments, tuning the signal frequency circuit or from of the 8-lead dil pack. Although the timing error drift of the strong signals. No buffer was used between the local (refer- basic 555 is quoted as 5OppmrC, adding such a diode ruins ence) oscillator and demodulator. However, he adds: the otherwise good temperature stability; not the most "I see in the RA3AAE diagrams no direct-current loads helpful of suggestions! for the diode rectifiers. In general, each diode needs a by- "To retain the good stability and yet ensure a ready start, I passed resistor in series with it to accommodate the steady have devised the circuit shown in Fig 4. To ensure that the back-bias generated in response to oscillator drive. This oscillator starts every time, R2 and R3 are chosen so that the provision will make the circuit behaviour less sensitive to potential at pins 2 and 6 exceeds t3-5V even when the tran- changes in reference level and probably less sensitive to sistor connected to pin 7 is saturated. The formulae for small differences in diode characteristics (the dc loads also frequency of oscillation and duty ratio are, however, rather affect conduction angle in the event that one is trying to more involved than the simple ones quoted for the conven- optimize for a particular frequency multiple as discussed by tional circuit." Pedersen). It is worth noting that if we had ideal diodes in the sense of their having zero forward resistance and zero Receiver imd and crystal filters reverse conductance, then omitting dc loads would make all Peter E. Chadwick, G3RZP, who has spent several years such circuits completely inoperative." working on the design of high-performance professional The RA3AAE circuits also attracted the attention of receivers, adds some pertinent comment to the general Brian F. Rose, G3ULR, who promptly quizzed an English- question of dynamic range and mixers (see 77 May 1977, speaking Russian amateur by rtty for further details of the pp 374-375). He points out that these days it is fairly easy original article, and one result was that he quickly modified a to achieve the sort of intermodulation distortion (imd) 7MHz direct-conversion receiver for the tl4MHz band, performance you want—until you add a crystal filter. achieving a receiver in every way as sensitive as the original, He writes: "We all like to think that quartz crystal filters and attractive enough to be kept for portable QRP opera- are passive, linear, reciprocal, two-port networks. In practice tion. In effect the receiver consists of the Fig 3 (April) they are two-port and passive; but they are far from linear demodulator followed by a CA3002 at low current, second or reciprocal! Typically an hf ssb crystal filter will have an CA3002 and CA3030 output ic. However, if no antenna intercept point of +15 to +18dBm. Turning it round will filter is used he does find 7MHz signals are sometimes often alter the intercept point. The imd products in the demodulated, although this can be overcome by using a pre- passband are more of a problem than those removed by selector in front of the receiver. 10 or 20kHz. About 15 to 18dBm is typical for a well-known 9MHz ssb filter at this spacing. One well-known manufac- Oscillators using 555 devices turer has found it necessary to select his roofing filters Many circuits have been published using the well-known (about 30MHz) for their imd performance. It may be 555 timer ic as an oscillator, but Richard J. Harris, G3OTIC, necessary to pay around £70, even in bulk quantities, for a points out that nowhere has he seen any mention of the filter with a specified imd performance. fact that under certain conditions 555 oscillators do not! "This means that it is not too difficult for a designer to He writes: end up with the filters (rather than the mixer or rf stage) "Generally, this malfunction seems to occur when the proving a limiting factor for the overall imd performance. A supply is switched on, although once persuaded to oscillate they carry on quite happily. A couple of years ago, after a Ferranti ZC5800 colleague and I bad spent several days trying to get to the bottom of this problem, I telephoned the makers. They obviously knew about the problem, described the reason for the failure to oscillate, and suggested cures. lii III Output "The condition results from the design of one of the volt- ICI 1 son age comparators and could be changed by a single change in II

+Vcc

8-pin DIL pack

+27dBm 5o1 Output iocal oscillator Fig 5. G3RZP notes that a Schottky quad-diode mixer of this type can, with 27dB m oscillator drive, give a - 37dB m third- order input intercept for excellent imd performance. Any Schottky diode will work but G3RZP prefers the Ferranti ZC5800 devices. The transformers can consist of about five turns each winding marked 1 on FX2236 GEC M M621 red material or F8, although almost anything will work but might Fig 4. G3OTK's suggested "sure-start" 555 oscillator circuit make 1 or 2dB difference

RADIO COMMUNICATION July 1977 533 +12V would expect. My own HW101 has an input intercept point 90 (loaded) of about -I- 4dBm (incidentally very much better than some 40673 about 2k FT101 or Atlas transceivers) and a noise floor of about 3N200 —127dBm (-20dB on lu.V pd). 3N140 Input "For high-performance receivers one of the most important points after imd is the question of reciprocal mixing due to oscillator sideband noise, and here the trend towards frequency synthesizers does not help. I have heard one disillusioned developer refer to a synthesizer as 'a very powerful machine: produces all frequencies at least once, and generally more than twice—simultaneously'. So, for me, the phase-locked loop is treated with some suspicion and I seek from their advocates the answers to awkward questions such as their phase noise, noise floor, comparison frequency sideband levels and the like! i1Vpk-pk local oscillator "One final point I would stress—do not be so carried away by the 'broadband' concept as to do without signal Fig 6. Dual-gate fet mixer can have athird-orderinput intercept filtering at rf before the mixer. Some calculations by one point of about +25dBm, a gain of 0 to ldB and a noise factor of around 6dB. However, it is very susceptible to a.m. noise on firm indicated that a rhombic pointing towards Europe the local oscillator drive could provide 1 W output during the night! That figure comes from summing all the strong signals from 1 to 30MHz. good-quality Schottky-diode mixer such as that in Fig 5 Two or more tuned signal frequency circuits are still a good can, with +27dBm of oscillastor drive, provide a -I- 37dBm idea. Put some selectivity in front of Fig 4." third-order input intercept point. Even a dual-gate mosfet As we mentioned in May, there is still a lot of controversy mixer (Fig 6) can give about +25dBm intercept but is very in the area of receiver design and G3RZP's comments are susceptible to amplitude-modulation noise on the output well calculated to stir up some strong feelings! But from my of the local oscillator. reading of the situation they deserve to be taken very "From my own experience I would recommend a low- seriously indeed. I suspect that part of the problem with noise bipolar transistor of the type developed for catv (wire- crystal filters are the ferrites used in the transformers of distribution television systems) as an rf amplifier: such as half-lattice filters. the 2N5019 or BFW17 or BFW17A. If this is run with about 20mA collector current, with some un-bypassed emitter resistance (about 22L1) you can get adequate gain to allow Up the cycle you to use a Schottky-diode mixer, as in Fig 7. Few people listening on 21 and 28MHz during the latter part "I have tried a quad-fet mixer basically similar to that of May can have been left in much doubt that we are now at used by ex-G3VBZ (May TT) and was unimpressed. One of last heading quite rapidly towards the next sunspot maximum. my engineers spent two months working on it and we found What is still exercising many people is just how high that it possible to get a good noise/gain figure or good imd maximum is likely to be. In the April TT it was noted that performance, but not both at the same time. We did achieve after many pessimistic forecasts predicting a pretty low about 2dB of conversion gain, 25dBm intercept point with maximum for Cycle 21 an increasing number of experts are about 7dB noise figure as a practical arrangement. The taking the opposite view and talking of a peak that could measurements reported by G3VBZ are a little better than 1 approach that of 1958. Michael Faulkner, G3IZJ, has noticed that the "pre- +18V 8.2k dicted" sunspot numbers issued by the American National Bureau of Standards have changed during the past few months (confirming my long-held view that predictions based on extrapolation of past data need constant up-dating and BFW17,BFW17A should always be taken with a pinch of salt). For example, in or 2N5109 with heatslnk July 1976 the predicted sunspot number for January 1977 0.01 was given as 6.2 as shown as part of Cycle 20. But the February 1977 predictions gave the January figure as 15-2 and placed it firmly in Cycle 21. This bulletin indicates that Input Z we may reach a smoothed sunspot number of 50 by Septem- abOut 30 ber this year and indicates a maximum of 141.4 by July 1979 to 10011 (compared with a Cycle 20 maximum of 110 during 1968-9). One result of these changes, as G3IZJ comments, is that many published predictions, including those in Radio Communication, are tending to underestimate significantly the number of openings per month and the duration of the dx Fig 7. RF amplifier of wide dynamic range using a CATV-type if power bipolar transistor which will provide enough gain to openings on the higher hf bands. Certainly if you have taken allow the use of a Schottky diode mixer without loss of sensi- your 28MHz antenna down in despair in recent years, tivity on the higher hf bands. Increasing the unbypassed 22D now is the time to get busy. This autumn may well see 28MHz emitter resistor decreases gain but improves the imd charac- truly open and give us a taste of American cb activity these teristics. Note the requirement to use a heatsink since a collector current of around 25mA Is desirable days on 27MHz.

534 RADIO COMMUNICATION July 1977 Double-delta array +5V The April 1977 issue of Old Man reprints from CQ Magazine a short note by J. B. W. Jackman, ZF1MA, on a "ZFIMA Special" or double-delta beam. The antenna consists of two similar triangular loops each 69ft 9in in overall length: see Fig 8. It is stated that "both loops are coupled very closely by passing the loop of the driven side through the undriven side... The support boom can be made from any type of material: wood, bamboo, aluminium, pvc tubing etc. Nylon fishline was used for guying... On 28, 21 and 14M Hz 750 cable provides a good match; however, on 7 and 3.5MHz a *transmatch' is recommended." ZFI MA makes strong claims for the effectiveness of this system. However, I am a little puzzled at his "boom" dimension of 20ft, as with the other dimensions indicated oneiwould expect this to be 25ft, as shown in the redrawn diagram. o to =" soot 600 kHz 25ft support boom

Fig 9. Subtractive (difference) digital mixer (SN7474) used as basis for a calibration read-out from an existing receiver in conjunction with a simple digital counter. This arrangement is suitable for use with receivers having a one-range vfo with reverse tuning

Is there any way in which an external frequency counter, now found in many shacks, can be connected up to one of these receivers and induced to provide a direct display of the Nylon line guy* kilohertz calibration in each band? The answer, according to F. H. Flanter, ZSIFX, (Radio- L ...... 22ft 41/2 In ZS, March 1977, p8), who in turn acknowledges CQ-DL Li 251t as his source of inspiration, is in the affirmative—at the cost X.... Insulator only of two ttl integrated circuits, a crystal and a few resistors and capacitors. It is usually possible to obtain a Mast few rnilliamps at a reasonably stable 5V from an existing 75 ohm supply, either directly or from a voltage-dropping resistor coaxial cable and suitable zener diode. Fig 8. The "ZF Special"—a double-delta arrangement used by To put together the digital adaptor, which is in effect ZF1 MA. See note in text on boom dimensions a subtractive digital mixer, it is necessary to know the vfo tuning range and to confirm that this is reverse tuned. For example, many Trio equipments use a reverse-tuning range Counters with receivers of 5,955 to 5,3551cHz or 5,500 to 4,900kHz; some Yaesu While some of us have certain reservations on whether receivers use 8,900 to 8,400kHz and some 9,200 to 8,700kHz amateurs really need digital displays built into their receivers, etc. The essential requirement is a crystal for the frequency there is no doubt that the technique is proving an attractive of the vfo which tunes the receiver to 7,000, 14,000, 21,000- sales feature—and does have real value; for example, for kHz etc. those who listen on the hf broadcast bands. Of course what One input to the digital mixer is taken from the vfo in the most of these digital displays indicate is the frequency to receiver; the other is provided by the crystal oscillator. which the receiver is tuned, and it should be appreciated When the two inputs are identical the subtractive mixer that for ssb and cw reception that is not quite the same thing produces zero frequency output; tuning the receiver. up the as the frequency of the transmission; to arrive at this you band results in an output from the digital mixer steadily need to take into account the question of usbilsb or the beat increasing in frequency in step with the decreasing vfo note of the cw signal. For this reason there is little point in frequency. If the vfo is tuned to receive on 14,3001cHz the providing calibration displays with less than lIcHz digital mixer provides a square-wave output of 300kHz steps. which is fed to the counter to provide a display of 300 (the When it comes to providing such displays the usual megahertz being indicated by the band to which the technique is to measure the frequency of the vfo, applying the receiver is tuned). neringary correction for the intermediate frequency. This is Fig 9 shows the circuit arrangement. Two gates of a stan- fine where the vfo tunes in the same direction as the signal dard 7400 ic are used in a familiar crystal oscillator arrange- frequency. But with many of the current generation of ment with the output passed through a third gate for double-conversion receivers with crystal-controlled hf shaping and isolation. This output then goes to the Cl oscillator, reverse tuning is used; that is to say that as one tunes up the band, the vfo is in fact tuning down in frequency. (Continued on p541 )

RAM COMMUNICATION July 1977 535 Club, and Ian McKenzie, GM4DXV, the club secretary, reports on many a.m. contacts. Recent QS0s from Scotland 4-2-70 on a.m. include G4ATI/P in QTH square XI( in Cornwall and several LA and PAO stations. John Tye, G4BYV, in Norfolk has worked 868 different Graham Knight, GM8FFX* stations on 144MHz using 15W of a.m. from the "2N4" transmitter described in the Radio Communication Handbook. Proof indeed that a.m. is still alive and still being used as a "Firsts" and "Iongests" dx mode. The request for information under the above heading to be Repeaters sent to G5UM did not go unheeded. From the Isle of Man Four new proposals for 144MHz repeaters have been GD2HDZ has come up with a list of no fewer than 40 firsts received by the RSGB and are presently being vetted by the from the island, including the believed first-ever 144MHz Repeater Working Group and the VHF Committee. The contact made by GD3DA/P with G3GM X as long ago as callsigns requested are: GB3AR (Arfon, North Wales); July 1951. Of special interest are the uhf claims by GD2HDZ GB3FR (Mavis Enderby, Lincolnshire); GB3HS (Humber- with GI, 1-E13 and PA in July 1976 and October 1975. Arthur side); and GB3WH (Abingdon, Oxfordshire). A further modestly does not provide any news of "firsts" on 70MHz of 144MHz proposal is awaited from the Perth & District which he must surely hold several; G5U M is writing for Group. further information in respect of that band. The Grampian Repeater Group received the licence for Who, during last year's phenomenal lifts, was the first to GB3GN at the beginning of May. The repeater which will work Malta on 144MHz? Can anyone better the claim of have an output frequency of 145.775MHz is expected to be G3CHN who worked 9H1CD on 23 June 1976? It is on the air soon from the IBA site just south of Aberdeen. believed that GC8AAZ was the first Channel Islands station The Grampian Group has recently doubled its member- to work Malta (again 9H1CD) in the same month. Members ship and further details about GB3GN can be obtained from who worked the super dx last year are asked to check logs in the project manager GM3HAT. GB3GN is licensed for 40W case they may have established either a "first" or a "longest". erp to an omni-directional antenna. G3CHN is believed to have established the European Graham Smith, GM3SNO, sends details of improvements record for an auroral contact (YK to LP locator squares) made to GB3CS—the Central Scotland 144MHz repeater. when he worked UP2BBC on 23 March 1976 at a distance of Experiments were carried out with a preamplifier in the over 1,900km. repeater receiver using an SD306 transistor (as previously All claims for any mode on any band above 70MHz to recommended by 4-2-70). A 15V wner across the supply Jack Hum, G5UM, QTHR. takes care of any spikes on the line and the rf input is diode protected. Tests showed a considerable increase in receiver Amplitude modulation for sporadic-E sensitivity but also some slight interrnodulation from strong A sporadic-E opening was noticed by GM8FVX in local signals on 145.45MHz (third order). Extremely strong Aberdeen at noon on 26 May when stations from Portugal signals on 145.55MHz also caused some problem (fifth were heard on the 100MHz fm broadcast band. No 144MHz order). The level of the GB3CS carrier at the pre-amplifier sporadic-E signals were heard in Scotland but DC1XC in output was 25e and the intermodulation was occurring in Hamburg worked RB5EHT in QTH locator RI45D at the receiver mixer. This meant that notch filtering was not 1649gmt. DKIKO worked UY5RQ (also in square RI) on required before the preamplifier, only between it and the cw at 1700gmt. DC1XC also monitored YO2IS calling receiver; much more convenient as the filter could be fitted SM3AK W at 1400gmt. Hartmut, DC1XC, says he was glad at ground level saving GM3SNO another 400ft climb! to be able to transmit on a.m. as this was the only mode Chris Morcom, G3VEH, gave a talk at Alexandra Palace available to RB5EHT in the Ukraine. Convention entitled "Repeaters—where are we going?"; surprisingly, only 27 enthusiasts attended. A lively and Amplitude modulation and the all-mode section interesting discussion took place with emphasis being put on Many people have been forecasting the death of a.m. as a rtty and microwave repeaters. One operator spoke eloquently mode for 144MHz for a few years now, but judging from the of future mobiles having video display units fitted to cars. number of correspondents who mention a.m. activity the Perhaps this is a trend as the "Data transmission at vhf" mode refuses to die. If anything, the number of stations on lecture attracted 90 people. a.m. is increasing—many are operating in the all-mode section between 144.525MHz and 144-900MHz. Malcolm Simplex fm frequencies Cummings, G8KPN, in Ealing agrees wholeheartedly with As a calling frequency, 145.0MHz has been used for a long the VHF Committee recommendation that fixed stations use time, but with international agreement this is now a repeater this section of the band. He mentions that there arc over input frequency and is widely used on the Continent. 500 G8 stations in the London area alone and he hopes that Recently there have been extended periods of lift conditions many of them will sometimes QSY into the all-mode section. There is a great deal of a.m. operation in the Edinburgh area with more than 30 operators equipped for the mode. GM4- This diagram shows the frequency bands that are allocated FFI is the caIlsign of the George Heriot's School Radio to the amateur service above 70MHz in the countries forming part of the Region 1 division of the IARU. In most cases the information has been provided by the national society of the country concerned. It should be noted that the only exclusive • PO Box 49, Aberdeen AB9 8JA. amateur bands are those at 144MHz and 24.0 -24.05GHz

536 RADIO COMMUNICATION July 1977 AALI, 1 — 1 . o -. .. , .= L. o ,=. ...,,.. “, Ln 0 0 Ln ,=,..-.. 0 0 0 LO Ln _, C, 0 0 .- 0 0 - c. .., __,. ...., ,—. P C o o on on r un in --, -, ,-, N., N-1 an ._„, en O ,_ ,_. ._, Lit 3UU 3UU Lit un Lc, Lc> on en en .., -.., ...e. ,_ ,_ ,_ N. N. N. — 2400 — — 2400 — — 24250 24250 — 2450 — — 24000 T 24000 — _inçnn I ?lnn _ —i — I ' 1 I r — I t r I r I r r "mu • ' ri • imal ARI I 1 I ARM 3A G mu! G t I I r um ' 1 II mr I m CARS 56 1 r r r r r r r t ' CRCB LZ 1 r r a r rm. l 'i CRCC OK r r j I )mml au -S 1 OARC DL tn." r ¡ imr r EOR OZ r r 1 t r I FRA OY r r 1 I r m ' i FRR YO 1 r t 1 r . GARS 9G 1 1 t i I I 1 I 1 , LB Irri morl Iml t GI AA RR CS 4X4 r )• IRA TF r r mu mmi 1 3 1 IRTS El ' . r III I l MARL 9H I r • MRAS HA I t o t ¡ ' ml . NRRL LA r I I cc al ill IM I OE I t I I I I °VPZ SV K SP I I Il , I I j g I r s ' RAAG SV I I 4 r I 1 I r , I i RAL 00 r. r 1 mil ' REF 1 . t "( r 1 1 I r r i • REP CT r r r s r RKODR DM r 1 r r r I I r imil 1 1 LX I RL I I I I i UA . I RSF I I M IO ISMI M M I i RSGB G I I ) 1 M I SRAL OH M M i I

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RADIO COMMUNICATION July 1977 537 and both mobile and fixed stations in the UK have caused Tropo conditions problems to a number of European repeaters. British An extended period of lift conditions occurred between 17 operators are advised by the VHF Committee that 145.0MHz May and 29 May. During these 12 days an area of high should not be used as a simplex frequency. All of the fixed pressure hovered around the North Sea between the UK and station contacts taking place on this frequency could easily Norway, sometimes moving slightly to the north and then move into the all-mode section. back to the south. The 432MHz band was open from An extremely popular fm simplex frequency in the UK is Scotland to the Continent every day during this period. 433.2MHz, in particular many Raynet groups advocate the Unfortunately on 18 and 19 May the 432MHz band was use of this frequency for local exercises and real emergencies. completely unusable as the whole band was being wiped It may be allocated to transportable Raynet uhf repeaters, out by radar interference. This pulse type transmission always assuming these can ultimately be licensed. The VHF affected most of the European countries adjoining the North Committee reminds all fm operators that the section 433.400 Sea. By checking and comparing beam headings, G3OSS, to 433.575MHz is allocated for simplex fm use. The calling G4CVI, G3N WU, G3LQR, DB1X1, DC1XC and PAOVV frequency of 433.500MHz is used internationally and during came to the conclusion the interference was coming from the the recent period of good conditions many operators were middle of the North Sea. The university station at SK6AB able to establish long-distance contacts on this frequency. used their gigantic beam of eight bayed 46-element arrays to Max Hanaghan, G8HPW, in Sunderland, noted the high confirm the df bearings and noted on a spectrum analyser level of activity from Holland on 433.550MHz. that the 7001.N signal extended from 431 to 435MHz. Further checks with the Swedish authorities revealed that Aurora they were aware of the problem but could take no action. It An auroral event which took place on 2 May was reported seems the interference was due to long distance radar being briefly last month. Richard Diamond, G4CVI, operating used on a warship. from the home of GM8FFX (YR801) stayed exclusively on Despite the interference, Harold Meezra, BRS34348, at Chatham in Kent, using an 11-element antenna at 21 ft, cw to work a total of 14 countries from 70 contacts. The first phase lasted from 1625gmt to 1945gmt and a second phase found the band good for dx. The OZ2UHF beacon on 432- lasted from 2105gmt to 0225gmt. The beam heading was 050° 450MHz has been an extremely strong signal at Chatham, for all contacts. DL7QY, Clause Neie, Berlin, was active as has PAOFMK on 432.950MHz which runs just 1W from during this event working many SM and LA stations. Clause QTH locator CM551. SK6UHF on 432.925MHz, which runs writes that all signals faded out with him at 1700gmt, except 10W to a simple clover-leaf antenna, is another of the GM4CV1 who could be heard until 1830gmt. GM3JFG indicators used by Harold to forecast dx on 432MHz. (XR40C) worked several European stations but also remarks Among the dx stations heard, PAODBQ (CM72D), PAOTJD that GM4CVI could be heard working stations which could (CN69C), DB1XI (EN33C), F1DBJ (3102E), DC8TK not be heard properly at Fortrose. Graham Kimbell, (EN64G) and DCOLY (E018H) were all outstanding signals G3TCT, at Aldershot, worked GM4CXP on 70.2MHz cw well over S9. Harold also received a QSL which brings his during the same event but heard no other 70MHz signals. confirmed score on 432MHz to 47 counties—a feat many Graham's G3LTF auroral monitor receiver warned of another of the transmitting members would like to equal. aurora on 11 May at 1840gmt. Several other operators also During the extended period of the opening, G6NB, noticed signs of this aurora but signals were weak at Aber- G3MCS, G3VPK, G8G ML, G8BTX, G8FUF, G4CVI and deen although DLOPR was monitored for more than two GW8CFQ were all heard working stations at more than hours from 1900grnt. 6001cm. G8BTX had a long QS0 with LA1FH for his first Norwegian station on 432MHz. Unfortunately the 432MHz Open Contest took place Expeditions earlier in May before the good conditions, nevertheless many A group from the Chalmers University station SK6AB hope stations still did well with several scores of more than 100 to be in the Faroe Islands from 29 July to 14 August. The contacts being heard towards the end of the event. The callsign will be SK6JF/OY and operation will be on 144MHz 144MHz event on the weekend of 28 May did coincide with and 432MHz with high power and good antennas. As the the lift and many of the entrants worked SM7AED, SM6XV, Glenrothes group will be using GM3YOR and GM3OLK/P OZ3SW, LA8UU and many French stations. The team at from the Shetland Islands from 12 to 29 July it will be GW8BHH were heard giving serial numbers in the 600 interesting to see if contact can be made from GM to OY on region some time before the end of the event. 29 July. During the lift many G 144MHz stations worked Norway The Milton Keynes Group will be on 144MHz from the and Sweden for the first time. Nigel Roberts, G8JEF, at Isle of Man during the period 24 July to 4 August, using the Prescot, Merseyside, mentions the consistent signals from callsign GD8MKC from Laxey. This includes the period of LA6HL, LA3EQ and LA8UU, all of whom were working G the QRP contest on 31 July. Between 30 July and 7 August stations at a rate of about one per minute. It is significant the following stations will be portable from Powys, Clwyd that during the lift, conditions on 144MHz never equalled and Gwynedd: 70MHz—G W4EQF/P and GW4EQK/P, those on 432MHz. The ducting was definitely favouring the 144MHz—GW8KPA and GW8KPB, 432MHz—G W8GDZ higher frequencies, and the large number of PAO stations and GW8KOS. For skeds contact G8KPA, QTHR. monitored on 432MHz working crossband to 1,296MHz The Oxford University Group will be in the Isles of Scilly confirms the fact. A further example is GM8CBQ/M driving from 24 August to 6 September. Callsigns to be used are around Aberdeen with a Liner 432 working Continental G3YGF/P on 70.240MHz, G3OUR/P on 144-280MHz, and stations with ease with just a dipole on the roof while G8HDR/P on 432.220MHz. Skeds can be arranged by similar contacts were impossible on the lower band of contacting G8HDR/P, QTHR. 144MHz.

538 RADIO COMMUNICATION July 1977 REAL DX 1977 oscar news 70MHz G4CVI-GM3ZBE 6.50km 144MHz GW4CQT-S M2CK R 1,920km 432MHz G3DAH-SM6HYG 1,090km Oscar 6 The battery in Oscar 6 has deteriorated further and the end of the useful life of the satellite must now be imminent. Launched on 15 October 1972 it has long exceeded its planned Maps and lists lifetime. This is mainly due to the efforts of the command Harold Mcezra writes about his new wall decorations. stations, including the University of Surrey, who have First is a relief map of the British Isles (99p from W. H. controlled the equipment on board, ensuring the best use of Smith) which has the hills and mountains pushed up in available resources. plastic. He notices a distinct groove between Kent and the Isle of Man, which helps to explain the loud signals from A-0-D launch GD2HDZ. Second is the large RSGB QTH locator map in Due to problems with the launch vehicle the lift-off has been soft ply—he uses different coloured mapping pins to show put back until late February or early March 1978. However, at a glance the squares he has heard on the different bands. A-0-D will probably be available before the Russian Oscar Completing the decoration are what Harold describes as about which there is considerable speculation and little "the marvellous RSGB computer read-outs"—RSGB definite news. The Russian magazine has carried some news beacons, IARU beacons, and RSGB repeater licences and of ground tests of the transponder which will be of the proposals. Very keen vhf enthusiasts will want to get the Oscar 6 and Oscar 7 mode A type, je 145MHz uplink and updated read-outs about every three months at 19p each 29MHz downlink. from RSGB HQ. Oscar nets The grapevine For latest news of satellite activity there is an AMSAT-UK Much Pandemonium on MP when a GM station accessed it net on Sunday mornings at 1015 (local) on 3,780kHz with and GB3CS and LA5SR with one tone during the recent G3R WL as net control. The AMSAT international net is on lift ... Most interesting theories about auroras and eclipses Sundays at 1730ut on 14,280kHz. Between 1730 and 1800 from Ed Tilton, W1HDQ, at Alexandra Palace ... G8FUF there is an interchange of information between Oscar users, getting ready for moonbounce G8JUK, G8BTX and and at 1800 the AMSAT hq station radiates a news bulletin. their father, G3RXF, all operate on 432MHz from the same house in Lowestoft, and in a recent multi-way QS0 with AMSAT-U K GM8FFX each claimed he owned a piece of equipment Details of membership and other services can be obtained vital to the QS0. G3RJV claimed he owned the bottom from G4EZN, QTHR, by sending an sae. lJ third of the pump up mast, G8JUK owned the transverter, G8BTX owned the prime mover—an IC201 .. To add further to this family venture at Lowestoft the cw expert at reading LAI UHF and SK6UHF was an unlicensed brother ... Heard during lift on GB3HH "Will the mobiles go QRT and let the dx stations through" ... With such a multiplicity of antennas no wonder G3OSS has crow trouble ... G4CRC/P, the Cornish Radio Club, an outstanding signal in the 144- Gi4.13L1.- MHz contest.

Late news GW4CQT and G4DGU both worked CT1W W on single sideband via meteor scatter—both contacts are possible firsts. G3P01 and G3SEK are assisting the Society in preparing a paper on meteor scatter QS° procedure for the up-coming IARU conference; suggestions would be welcomed by both operators who arc QTHR. Julian Moss operated G8ILO/P near Lancaster in the recent 144MHz Portable Contest; using 25W he worked 315 stations including PAO, F, ON and GU8IRF. GM3ZEM/P worked SP5ZN in square KM in the same event. ON6UG/C31 will be operating from Andorra during the first week of August; for further details write to 12 Olmstr, B9910, Mariakerke, Oost Vanderen. Finally, thanks for the huge amount of mail this month. Please send all your news of 4-2-70 to Aberdeen, and all "Antenna here is a collapsible quad" (With apologies to "The 1,296MHz and above items to G3RPE. GUNN Instant beam", Radio Communication April 1976)

RADIO COMMUNICATION July 1977 539 LA8TO, from the Akademisk Radioklubb in Trondheim, writes to say that there is growing interest in lOGHz locally and that they hope to get a special licence to operate. At pre- microwaves sent the Norwegians have to have special permission to operate at frequencies above 1,215MHz. A rough measurement shows that the shortest distance between the UK and p Doin Evans, G3R PE * Norway to be a mere 450km, which is an exciting prospect. Trondheim itself, unfortunately, is nearly as far as it is possible to get from the UK while still remaining in Norway. WI CF reports that great interest has been shown, especially The Sheffield microwave round table in Germany and the USA, in the Microwave Associates The microwave round table held in Sheffield on 30 April Gunnplexer which he has been responsible for developing. This transceiver was shown at the recent Alexandra Palace attracted 21 amateurs, including two GMs. The main dis- exhibition and attracted much attention. In the USA the cussion of the afternoon centred around a review of activity interest in lOGHz so far seems mainly with tv and radio links and equipment for the bands 1.3 to lOGHz. SSB equipment for the 1.3 and 2.3GHz bands using the parametric upcon- to repeaters, whereas in the UK the emphasis has been verter principle was shown by G3ZIV, and this stimulated a mainly concentrated on the dx potential of the band. Early long discussion on the relative merits of this system and the in May W1CF used a crystal-controlled version of the more common high- and low-level mixing techniques. Gunnplexer for a 80km contact, which is a respectable GM3FYB and GM8CSE then showed their crystal- "blooding" of the gear. Visitors to the exhibition will have appreciated the controlled gear for the 2.3, 34 and 5.6GHz bands. This demonstration of lOGHz tv put on by members of the transmits on fm only, but can receive on all mcides. G8AGN Havering Club. Despite the difficulty of having to pipe-in described the 3.4GHz beacon GB3U0S which is now lOGHz signals via 100ft of flexible waveguide with all its operational from a site near Sheffield, and discussed the associated losses, pictures of reasonable quality were design of a crystal-controlled harmonic mixer monitor received over the 14km grazing path from Ilford throughout receiver. Wide-band equipment for 3.4GHz based on the the exhibition. The transmitter used a standard Gunnplexer polaplexer principle was shown by G8HAJ and G4DRX. An example of the latter equipment is also described in the as referred to above, the video being applied directly to the varactor tuner/modulator built into the Gunn oscillator. current edition of the VHF/UHF Manual. A bandwidth of 18MHz was used. The tv receiver, which was Wideband gear for lOGHz using either klystrons or Gunn diodes was described by G8HAJ, G8CZO and G3TQF. due to G8IXC, used a home-made balanced mixer with a Gunn oscillator as the local oscillator, the If. being a This was followed by a discussion on Gunn oscillator cavity designs and on crystal-controlled equipment for this band. standard tv receiver except that an fm detector was fitted. Although no gear was shown for 24GHz, several people Dishes of 0.5m diameter were used at both ends. Special mention must be made of the efforts of G8LLB are busy collecting piece. It was agreed to hold another meeting in Sheffield, pro- and G8FJG who throughout the exhibition provided 22h of continuous lively tv pictures. These included views of bably in the early autumn, and this will be well publicised Ilford, its railway and its traffic jams, dog fights using model in advance. The main topics for discussion suggested are aircraft against a live background of Ilford (which were antennas and path checking. surprisingly realistic) videotapes of lOGHz mobile tv, and even some glove puppetry. Well, you try generating lively pictures for 22h! lOGHz news PAOKKZ is also active on lOGHz tv, and can operate What may prove to be yet another significant step forward on not only /P but also /M. Best dx for the former so far is 2km, this band comes from recent systematic tests by G8DEK for the latter, 800m. Members of the Havering club and and G3WDG. In these, attempts have been made deliberately PAOKKZ hope to exchange tv signals between G and PAO to use the tropospheric scatter propagation mode to cover this summer by super-refraction. the 100km path between Winchester and Bristol, a path which has four to six obstructions depending on the value of K taken. In the transmitter, G8DEK is using a crystal- PAO lOGHz beacon controlled driver to a twt which produces 3W of output on Since the beginning of March a lOGHz beacon has been 10,368MHz, and this feeds a dish 4ft in diameter. On the operating from Zaandam, which is a few kilometres NW of receive side, G3WDG uses a standard 1N23 mixer fed from a Amsterdam. The beacon consists of an 80mW Gunn oscillator dish also 4ft in diameter, with the local oscillator either on 10,100MHz which feeds four horns of I6dB gain via a Gunn or a crystal-controlled oscillator. An ECIO is the three magic tees. The horns are mounted 52m agi (which is tunable if. Out of 10 attempts so far, they have been suc- about the same as asl!) and are beamed, perhaps optimistic- cessful on eight. On the two other occasions, there was rain ally, at London and Scotland, and into Belgium and Ger- about, and this might have had an effect. We look forward many. The signals are tone modulated and keyed once per to the results of other tests. minute with the callsign PAOHSM. PAOKKZ would welcome G8DKU in Hartlepool is anxious to contact other lOGHz reports. enthusiasts and potential enthusiasts in that area. The construction of a high-power crystal-controlled beacon generating a few watts is understood to be well in hand. This will be sited at Noordwijk on the coast and will • 4 Upper Sa, Chaude, Hemel Hempstead, Harts. beam towards the UK.

540 RADIO COMMUNICATION July 1977 Checking microwave receiver performance 100 At a recent microwave round table, G3WDG demon- 80 strated a simple way for checking the performance of 60 receivers. This method tends to work rather better at the higher microwave frequencies, which is fortunate because 40 conventional noise sources (for example, discharge tubes mounted across waveguide) are not usually part of the 30 average amateur's test equipment. The principle of the method involves recognizing that all 5 20 poor conductors such as earth, trees and buildings, produce noise. The amount emitted is determined by their temperature and therefore they can be used as a "standard" noise o source. By contrast, the level of noise coming in from space is .o 10 virtually zero. So if a receiver antenna is pointed at a e building, the noise output from the receiver will correspond 6 to that from the receiver itself plus the "hot-body" noise, while only receiver noise should be heard when the antenna e 4 is pointing at the sky. If the ratio of the two can be measured, then the absolute value for the receiver noise can be calcu- 3 lated. 2

0A81 or other Ge diode

0 2 4 6 8 10 12 " 14 16 18 0-25V_ Noise factor (dB) To receiver 2okalv Fig 2. Conversion between noise increase and noise factor

Loudspeaker the hot body to avoid spurious effects such as due to reflec- transformer tion of stray local oscillator signals. Fig 1. Simple noise level indicator (d) If the receiver has no image suppression, noise can be picked up equally well via the second channel. In this case In applying these principles practically there are many the noise factor will appear to be 3dB lower than the correct potential qualifications but nevertheless the method is so single channel value. obviously attractive that it is well worth exploring. A Preliminary tests suggest that the noise factor estimated simple method for measuring the noise output is to use a using this method with lOGHz equipment is consistent with circuit such as that shown in Fig I, the af gain being set to measurement made by more formal techniques. G3WDG produce an output of 10-20V. The antenna is first pointed at will be pleased to hear of others' experience. At the same the sky and the mean voltage reading taken. Being careful meeting he also demonstrated the use of the sun as a stan- not to change anything else, the antenna is then pointed at dard noise source which, in principle, can be used to check the ground or a building, when a significant increase in the overall performance of both receiver and antenna. He is output voltage should be detected. This process should be currently looking at this in more detail and will report at a repeated until constant differences are determined. The later date. D output voltage fluctuates by an amount which depends on the bandwidth of the receiver and the time constants of the Technical Topics indicating circuits, but with practice small percentage changes (Continued from p535) should be easily detected. This percentage increase can be input of a 7474 device which forms the subtractive mixer. converted to noise factor directly from Fig 2. The signal from the vfo passes through the fourth gate of the This method has the obvious advantages that it requires 7400 device for shaping and then, as a near square wave very little in the way of test equipment, it does not require passes to the D1 input of the 7474. Output from the mixer well-matched components, and it can be used to check appears at QI as a square wave, ideal for feeding to a simple receivers actually on site. However, a few points need to be frequency counter. made: ZS1FD reports that the adaptor unit can be built on a (a) If the receiver is fitted with an fm detector, it is import- small piece of Veroboard (about 5cm by 7cm) and then ant that this does not limit on receiver noise. Nan rf gain con- usually readily accommodated either inside the receiver or trol is fitted, this can be turned down to check that the same the counter. To bring the system into operation, first check percentage difference is obtained. the band-edge receiver calibration with an internal or exter- (b) The measurements do not depend on antenna gain, but nal calibrator; switch off the calibrator; observe the read- one of moderate gain makes it easier to ensure that it sees out of the counter which should be 000; if this is not quite only the hot body or only the cold sky and not something in right adjust the crystal oscillator trimmer. Then, says between. ZSIFD, sit back and watch the digits flash past you as you (c) The antenna should be kept at least a few metres from tune the receiver.

RADIO COMMUNICATION July 1977 541 the month on the air r John Allaway, G3FKM*

RECENT study revealed that Radio Communication is now Abeing distributed to more than 120 countries, including the Chinese People's Republic. This is an excellent example of the true international aspect of our service and its unique ability to promote understanding and friendship. In the writer's opinion there is no other interest available to so many which does so much to bring together the peoples of the world and show them that language and politics are unimportant. The announcement of the appointment of an IARU Information Officer appeared in Radio Communication a little while ago. It should perhaps be pointed out that IARU is synonymous with international amateur radio and not just the cold statistics of the administrative side of the OK1DDL, Dagmar, has now contacted 32 countries on top subject. G3HCT will of course be pleased to hear from those band, and only Oceania is needed for WAC, which she hopes who would like to locate speakers on the subject. to complete this year. (W1BB photo) G3FKM would like to trace the operator of VS9ASC who amateur at the time of John's visit. He had been there 31 was active during 1967 and whose name was Steve. Many years but is not hopeful that he will be able to renew his enquiries are being received from those looking for confir- licence. mations for contacts with VS9 in the past and it would be Medical readers will be interested to learn that there is a very helpful if those readers who operated from Aden and net of German doctors, organized by Peter Hipp, DJ3FK, are still able to supply QSLs would please supply details for which meets on 3,705kHz at 2200 on Fridays and at 1000 on reference purposes. Sundays. Please note that the AGC W-Bulletin is transmitted Mike Rogers, ZSIRZ/G3VOG, reports from Capctown, every first Sunday in the month in English on 7,030kHz at where he has been for the past three years, that his G3VOG 0900 on cw at about 14wpm. callsign, which he still retains, is being pirated. Please note that all times given in MOTA are gmt. DX news It seems likely that there will be activity from the Kermadec News from overseas Is in the early autumn, possibly coinciding with either the In a letter to your scribe, WA9YNE says that he acted as VK/ZL or CQWWDX contests. ZLls AIC, AJL, AMN, QSL manager for ZB2A for the period June 1970 to Septem- AVR, BKL and BKX have been mentioned as possible ber 1972 only. At that time the operator was Gordon Kelly, participants but final details will not be available until next who was with the RAF. He has received a large number of month. Government permission is awaited and, if given, the QSL requests and says that all those which he is able to operation should last for about two weeks. answer will be sent out by August. WA9YNE's address is: ZK1BA is reported to be erecting an antenna for 7MHz. K. Vanarsdall, 17 W 151 White Pine Rd, Bensenville, Ill, There is a chance that he will visit Manihiki Is again some- 60106, USA. time this month. In the same area 5W1AT may repeat his John Knight, W6YY, has returned home from a month's earlier visit to the Tokelau Is and be on the air again as visit to Africa and he has sent along his observations on the ZM7AT for a two-week period during July/August. current amateur radio situation in that area. He says that The expected operation from Pitcairn Is by W6YO/VR6 there are about 40 stations active in Kenya—mostly on was considerably curtailed and it is believed that he was only 144MHz. 5Z4ERR has now retired and is not very active, on the air for one day. However, en route for Pitcairn the but 5Z4LW and 5Z4RT (DK8RT) are often on the hf ship called at Easter Is and new Atlas equipment was bands. There is only one amateur on the air from Uganda— delivered to CEOAE. this is 5X5NK who is only occasionally to be heard (QSL to A35DG is in Tonga and using an FT301D and dipole DL1Y W). In Egypt SUIIM is now recovering from surgery antenna. He has been heard on 14MHz ssb and should be on and has received the Swan 500 sent by the N California DX the islands for 18 months or so. The recent activity by Foundation, but is unable to use it at present. SU1MI is WA7VVU/K W6 seems to have been not valid for DXCC Ibrahim's daughter. SU1MA is also fairly active. ET3FF credit as all operation took place from on board the container (ex-ET3AH) was the only active and licensed Ethiopian ship American Charger. However, the ship calls at Wake Is several times a year and in future the transmitter will be set

• 10 Knighdow Road, Birmingham BI7 8QB. up on land.

542 RADIO COMMUNICATION July 1977 VK9ZM was believed to be due to leave Willis Is at the Englewood, Fla, 33533, USA. VP9BA-Alan was informed end of June. According to the West Coast DX Bulletin, recently that this would be returning to the air on its old VK2AKG and VK2BKE are located on Lord Howe Is, and frequency of 28,165kHz, but no reports of its operation have there is currently a station on Cocos Keeling Is using the been received. callsign VK9CW. Mention is made of possible activity from The moving of the beacon sub-band decided at the War- Heard Is in November. saw Region 1 conference is now taking place and new XT2AS is PAOLUB who is working with the Netherlands frequencies will be "mirror images" of the old ones with Volunteer Corps in Upper Volta until the end of August. He 28,200kHz as the centre frequency. Spacing of 2.5kHz is is said to look for contacts with PA at 1630 on 14,320kHz. now being adopted. EA20JZ has been heard on 28,247.5kHz Harry, ex-VQ9HCS, now lives in Swaziland and has the but no information is available. callsign 3D6BP. 6W8FP has left Senegal and is in Sierra Leone but still awaiting a 9L1 licence. Awards Activity from Bangladesh by S21AB has been noted. He is Flanders Fields Award JA6GDQ, and is crystal controlled on 14,198kHz and active European applicants require three contacts with ON7FF after 1100. (the Ypres RC station) and other members of the club on hf, VE1BFV has now left Sable Is for Western Canada and or 10 contacts on vhf. Send QSLs and 10 mcs to: ON7FF, his replacement on the island is not an amateur operator. BP 32, Ypres 8900, Belgium. The Stratford ARC and Palmerston & District ARC (of Diploma Jadran Ontario) are making an expedition to Pelee Is in Lake Erie For contacts with 10 stations in at least five different places for the period 23 July to 4 August. This will be the most on the coast of (or on islands in) the Adriatic. They must have southerly amateur station in Canada, and its callsign will be been made since 1 January 1970. Send list and QSLs plus VE3PEL. Equipment will consist of Drake T4X and R2C and eight 1RCS to: Radio Klub "Ante Jonic", YU2AKL, PO operation will be from the boat. Contacts with the UK will Box 89, 58001 Split, Yugoslavia. be specially welcomed and readers are advised to check the Worked YUDXC Members vicinity of 14,150kHz and 14,025kHz for the expedition. For eight confirmed contacts with members of the YU DX G4EGZ advises that Canadian amateurs located in Club since 1 Janaury 1970. Send certified list of contacts and Newfoundland and Labrador have been authorized to use seven mes to: YUDXC, PO Box 82, 62259 Ptuj, Yugoslavia. the prefixes X01 and X02 respectively during the period of The Rubens Award the Canada Summer Games between 1 and 31 August. For contacts with six Antwerp stations between 1 July and 30 XOICSG will operate at the site of the games in St Johns, September. Any mode/band. Send certified log extract and Nfd. five mes to: ON6KC, Van Riet Robert, Beukenshofstraat 47, Readers are asked to note that the information on the B 2060 Merkscm, Belgium. Listeners may also apply. This Gibraltar net given in June MOTA is no longer applicable. celebrates the anniversary of Paul Rubens and special QSLs The net now meets only at 2100 on 3,770kHz on the first will be used. Saturday of each month. Most activity at present comes from ZB2BL and ZB2CF. The WAGM Award F6CWB will be visiting Andorra for the second week in Issued by the Aberdeen RC on receipt of proof of two-way July and will be active on 14 and 144MHz from QRA communication with Scottish stations on any band. Contacts locator AC48C with the callsign C31NQ. QSLs should be are required with one GM2, 15 GM3s, one GM4, one GM5, sent to the address in "QTH Corner". one GM6 and one GM8. Applications to the club secretary, FM7W0 is at present in Reunion and using the callsign GM4BKV, S. Sutherland, 67 Greenfern Rd, Aberdeen AB2 FRODGP. He is using a dipole aerial and is expected to be 6TP. Applicants outside the UK do not need to send QSLs- found around 14,025kHz and 7,020kHz, as well as in the ssb a certified list will suffice. Cost to UK applicants is 60p and 10 part of both bands. mes to others. The Sherlock Holmes Award Issued by the International Police Association RC, German Welcome section, for contacts with members (since I March 1976). The following overseas amateurs joined the Society during For basic award 50 points are needed. Contacts with May: CT4FB, DK4VW, EAI ME, EA1LQ, EA9FF, members in one's own country count two points, in other F1AAG, F1BYU, F1DPT, K3ZDK, N3DF, K4GMJ, countries in same continent five points, and elsewhere 10 N6N W, SMOAVK, SM5CCY, VE3HSY, WA4FTJ, WB- points. IPARC club stations count twice on each band, and 2DWP, 5Z4IX, 6Y5HJ and 6Y5MR. members can be worked once on each band. Send certified list of contacts and eight mes to: Adolf Vogel, DL3SZ, International beacons Ritter-von-Eyb-str.2, D8800 Ansbach, W Germany. Latest information about 28MHz beacons has been supplied (DL3SZ will supply a membership list etc in exchange for by the IARU beacon co-ordinator, G3DME. 5B4CY changed sae and an irc). frequency from 28,180kHz to 28,220kHz at 0900 on 6 June. Reports should be sent to 5B4AP, PO Box 1267, Limassol, Contests Cyprus. A9XC is now operating on 28,207.5kHz from the The European DX Contest (WAE) location of A9XBD with restricted hours (to avoid tvi)-2100 0000 13 August to 2400 14 August (cw). to 1400 approximately. Reports should be sent to Geoff 0000 10 September to 2400 11 September (phone). Smith, A9XBD, c/o Cable & Wireless, PO Box 14, Bahrain. 0000 12 November to 2400 13 November (rtty). N4RD (ex-K4BRD) is operating on 28,207.5kHz and reports All bands 3.5 to 28MHz. Single-operator-all band. Multi- should be sent to R. W. Davis, 2845 North Beach Rd, operator single transmitter. Only 36 hours' operation by

RADIO COMMUNICATION July 1977 543 single operators is allowed. The 12 hours rest may be taken QTH Corner A35CR in not more than three periods. Europeans contact non- Box 147, Nukualofa, Tonga. A3500 Europeans and each contact counts one point. Exchanges C31190 via RC M, J. J. Bernard. 87 Route de Corbel', 91350 Grigny, France. consist of RS/T plus serial number (from 001), and a station EJOA J. Casey. 91505, 10 Derravarragh Rd, Cakerclavin, Limerick, Eire. [P211( via GW3IRK, A. C. Whitehlli, Cwrt, Penrhyncoch, Aberystwyth. may be worked on each band for credit. The multiplier for FGOST via F6C WB (see C31NC) Europeans is ARRL DXCC countries worked, with the FMOBAH BP 619 Fort de France, Martinique. FRIDGP via K5KEZ. Dr, V. Thompson, John Hopkins Hospital-Boa 234, 601 addition that each call area in JA, PY, VE, VO, VK, W/K, N Broadway, Baltimore, Md, 21205, USA. ZL, ZS and UA9, and UAO also counts. In addition the FYOST via F6C WEI (see C31N0)- H142MC Box 501, Port au Prince, Haiti. multipliers on 3.5, 7, and 14/21/28MHz may be multiplied KP6AL } vie KOECE, H. D. %Vibe'. 5115 Delaware Av, Fort Wayne, Ind. 46805, by four, three and two respectively. Final score is total QS0 RP M) USA, S2IAB vis JAOZGII. Y. Moriyama, 3-18-9-306. Flonmmanuma, Suglnaml, points plus QTC points multiplied by the sum total multi- Tokyo 167, Japan. pliers from all bands. QTCs are details of a previous QS° ST2JJ/STO via W4JBZ, 5912 Barbados Way W. W Palm Beach, Fla. 33407. USA. with a European passed by a non-European and consisting m i. vis DO WD, D. Surmann, Olbersstr 6, 1000 Berlin 10,W Germany of time, call and number received. They may only be passed TT8SM WB500E, G. C. Fogg, Box 626, Allen, Texas. 75602. USA. VEIBFV W3HNK, Box 73, Edgemont, Pa, 19028, USA, once and not back to the originating station. A maximum of VPIO W G4DSC. D. Bonitace, 11 Holmelleld Rd, Ripon, N Yorks HG41 IRZ. 10 may be passed at one time, but more may be passed XT2AS J. H. Deklus, Hemonystmat 40 II. Amsterdam. Netherlands. ZDIIRD via G3ZIY, 28 Hound Rd, Nelley Abbey, Southampton 503 5FX during later QS0s (which do not count for QS0 points of 2F2AA Box 688, Grand Cayman. course). DARC log sheets and summary sheets are available ZP2AB Box 697, Grand Cayman. ZF2AN via W5UFF, B. A. Thompson, 6607 Pebble Beach Cr, Houston, (large sae and IRCS please) from: WAEDC Committee, Texas, 771169, USA. Postbox 262, D-895 Kaufbeuren, W Germany. Logs must 3V1113Z via DARC. 5N2QIR W A70IR. 261 N Hill St, Mesa, Ariz, 85203. USA. reach this address by 15 September, 15 October and 1 9G1JX via DL7SI, Benekendorfistr 13, 1000 Berlin 28, W Germany. December respectively. Note that in the rtty section other 9L1MD via G3TEJ, M. C. Dighton, 7 The Close, Godmanchester. Hunting- don. stations in the same continent may be worked, and countries include those peculiar to the WAE list as well as the DXCC RSGB QSL Bureau, G2MI, Bromley, Kent, BR2 7NH (GM Shetland, Bear Is, Sicily). In accordance with IARU recommendations DARC suggests no contest activity above 3,550, 14,075, 21,100 and 28,100kHz in the cw section, and in the sections 3,650-3,750, 14,300-14,350, 21,400-21,450 and posted before 16 October to TTARS, PO Box 1167, Port of Spain, Trinidad. 28,700-29,700kHz in the phone contest. SEANET 'NW DX Contest Ten-metre Activity Contest 0001 9 July-2359 10 July (cw). Results of the contest held on 1 May have been received from 0001 20 August-2359 21 August (phone). David Whitaker. There were 15 cw entries-the first three 1.13 to 28MHz. Single- or multi-band single-operator, and of whom were G2ADZ (40 points), G2PT (37) and G3ICH multi-band single- and multi-operator sections. No cross- (28). Twenty entries were submitted in the phone section band/mode contacts allowed. Exchange RS/T plus serial and the leading stations were G3OZF (103 points), G3UDR number (starting from 001 on each band). Stations may be (71) and G3LBS (54). Twelve listeners sent in logs-BRS worked on each band, and the multiplier is three for each 32525 (114 points), BRS34348 (89), and BRS29909 (74) had country in the SEANET area contacted. The final score is the highest scores. Fifty-five reports were received but it was the total of QSO points multiplied by the total of multipliers noted that over 460 different UK stations were active. from each band added together. SEANET countries are: A4, Static seems to have been a problem in northern Britain, A51, A6, Al, A9, AC3, AP, BV, CR9, DU, EP, HL/HM, and most activity centred on the Midlands and southern HS, JA, JD1, JY, KA, KC6, KG6, KX6, P29, S21, S79, VK, counties. The most interesting time was around 1730 when VQ9, VS5, VS6, VS9K, VS9M/8Q6, VU, VU (Islands), XU, there was a limited opening to the Middle East, the XV, XW, YB, YJ8, ZL, 3B6, 3B8, 3D2, 4S7, 4W1, 524, skip then moved into Africa (5Z4JE, EL7F, ZD8RR, 9K2, 9M2, 9M6, 9M8, 9N1 and 9V1. Contacts count as 5T5CJ and SM2HLSJ4U all being noted). From 1930 the follows: 10 points on 1-8MHz (double if with HS, YB, DU, band opened into S America (CE, CX, LU, PY and ZP). 9V, 9M), five on 3.5 or 7MHz (ditto), and two on 14/21/ ZC4I0 worked 15 UK stations as well as ZS, ZD7, ZD8, HA, 28MHz (ditto). Submit separate log for each band and UB, EA, PY and LU, and heard VK6HD and 9M8HG. include summary sheet showing QS° total, points, countries David would like to thank all who took part and reminds us and multipliers on each band, plus the usual signed declara- all that the 28MHz band is often open if we would only try tion. Entries must reach SEANET Contest Committee, Ismail calling "CQ" occasionally. It is hoped to continue these Razak "Eshee", 9M2FK, 281-C, Jalan Peketiling, Bukit tests. Glugor, Penang, Malaysia, before 31 October.

Trinidad & Tobago 1st Anniversary QS0 Party Band reports 0000 27 August-2400 28 August. The severe interference originating from the Soviet Union 1.8 to 28MHz (plus Osrr). Phone and cw. Exchange RS/T appears to have been less troublesome on amateur fre- plus serial number (from 001). A certificate will be awarded quencies during the past month, although it has continued to those working at least five 9Y4 stations on the same mode. to play havoc with other legal occupants of the spectrum. A certificate with endorsement sticker and QSL cards for Conditions on the hf bands have greatly improved and 14 contacts will be awarded to those contacting 9Y4 on five MHz has been open 24 hours daily. On 21MHz propagation bands on the same mode. Logs should give time, number seems to have been better than predicted and openings into sent and received, and QSLs must be submitted for the five- Japan (which were not predicted) have occurred. Very good band award. $1 or eight IRCS should be included and entries conditions have also existed on 7MHz in the early mornings.

54•1 RADIO COMMUNICATION July 1977 Many thanks to the following contributors to this column: 141,4142 JULY 1977 G2s DHV, HKU; G4RZ; G5JL; G3s HCT, KDB, OKA, RCA, RZI; GM3LYY; GM4CHX; G4s DSE, EAN, FAM; USA•East W1-4 S Min S IA /A l CIE G8KLO; BRSs 17567, 31301, 35608, 36928, 38280, 38709, US A- West W6.7 5_41_,..1 38876, and A8961. Caribbean 6Y5 FM.TI ami =ism Stations listed in italics were using cw. Brazil PY S Wz:1, I . CFZE) , ilIZ MI M ' U M = 1.8MHz. 0000 EA3TJ, F8EX, K1PBW, PT2C W, PYIRO, South Africa ZS S S O ZelIM M:= PY9D M, VEI MX, ZP9A Y. 2300 ISOLYN, 5Z4L W. SE Asia HS.9 M2 1 , 3.5MHz. 0000 HBOBLC, 9K2 DR. 2100 UA9, UAO, 2200 : : = I, CIV8AD, V P8PL. 2300 EL2FY (QSL to JA I NSA), 9Q5BG. Australia V K 7MHz. 0500 8P6GN. 0600 HC5EE,KH6AT, VKs, VKOAC, L : ; : S ! 1 r-F7) M r7-7777, ?7,7 ", — . ZF2AB, WI-WO, ZL. 0700 YV4TI. 1700 VU2 DU. 1800 JA. Japan JA i 2100 ZS6ME. 2200 FMOBAH, TU2DD, VS5MC. 2300 : 1 M I BS, TF5TP, VP2KF, Z D8RR, 9Q5QR. Time (GMT) 00 02 04 06 08 10 12 14 16 18 20 22 24 14MHz. 0100 WD4CQH/C6A, JY25HH, 0300 HH2MC. 0600 K H6, W6-W7. 0700 A357T, AP5HQ, FO8E1, HKOCLS 21 h4H2 JULY 1977 i I I I KL7, VC9U M, VE7A XH (2W input), ZK1DA, ZK1DR, US A-East W1-4 S , , I- 1- 1 ZL30G/C, ZM7AT, 3D2DN. 0800 A35CR, FK8KAA, C arib be a n 6Y5, FM. TI S : r 7,4 -1 FO8AQ, ZK IBA, 3D2GA. 0900 5WIAU. 1000 VP2GCS Brazil PY S : : I . r/w w,ie I (Box 447, St Georges, Grenada). 1100 KH6IJ, VS6HJ. 1200 South Africa ZS s I KM6FC. 1300 CR9AJ. 1400JTIAN,JTIBF, YB8ACK. 1500 SE Asia HS. 9M2 S SUI MA, VS5 MC, XT2AE, 5V7AR. 1600 YB3AB, 9M6KT. Australia VS S

1700 HS1AKT (Mondays, 14,170k Hz), VS5PM, 5Z4QC Time (GMT) 00 02 04 06 08 10 12 14 16 18 20 22 24 (QSL to SMOH WM). 1800 UAOYAD. 1900 VP8PL. 2000 HZITA, TT8SM, VP1APC, VP8HZ, 3D6A (QSL to Short path = 1- 5 days 1222222Z3 6-20 days

W3HNK). 2100 JWISO (Bear Is), VK3MR, ZFI MA (QSL Long path Openings on more than 20 days in the montn to VE3BWY), 3V8BD (QSL to DARC), 9A1AD. 2200 JA, ST2SA. 2300 CEOAE. 21MHz. 0000 WI-W4. 0800 JA, P29JS, ZS. 0900 TR8WR. HF Propagation Study 1000 JA. 1100 EA9FH, HM3LR, JA, VS5MC, WA6EGL1 Predicted HPFs (MHz 10) for July 1977 VQ9, 3B8CV, 3D6BP (QSL to K1AGB), 7P8BC. 1200 GMT — 00 02 04 06 08 10 12 14 16 18 20 22 24 ZD8EW (BBC, Ascension Is). 1300 JA, JY25YJ, KG6J1H. Aden 136 139 172 223 268 253 255 260 261 270 168 145 138 Ascension 143 119 117 117 252 248 256 261 267 271 291 172 143 1400 D4CBC, VP8PL. 1500 CE, VP8OL, KH6JJD/VQ9, Bahrain 159 149 177 220 255 230 234 224 242 270 211 186 159 VU2LQA. 9V1SA. 1600 KOWIQ1DU2, JA, ZD7SD, 9X5TM. Bangkok 150 144 177 208 211 201 213 209 206 167 168 149 150 Barbados 199 153 145 133 143 204 214 215 215 215 242 251 199 1700 A9XBD, KC4AAC, TR8VE. 1800 HZI HZ. 1900 Bermuda 191 147 138 120 133 187 205 204 205 205 208 208 191 SMOFHY/4U (QSL SM Bureau). 2000 CE3BF, PI'. 2100 Bogota 199 154 144 131 148 153 208 213 211 214 220 244 199 Buenos Aires 183 152 149 139 119 177 237 235 239 227 275 252 183 W6CPL, SMIFPEI4U (QSL SM Bureau). 2200 CE, HP, TI, Cape Town 120 101 96 210 266 256 261 274 276 238 153 144 120 W, ZF2A N. Colombo 138 147 180 219 244 220 228 220 238 263 221 195 138 28MHz. Europeans between 0700 and 2300. 1200 A9XC. Cyprus 162 140 161 202 235 Z29 218 210 224 251 232 196 162 Dakar 162 154 143 159 252 248 255 261 263 271 291 202 162 1300 C31NG, JW9FD, 3B8CU. 1500 D2AFW, PP5A.I. 1600 Denver 163 150 135 124 110 134 162 180 176 191 183 194 163 Fairbanks 157 161 157 159 163 191 181 181 181 181 132 177 157 CE8AA, 0Y5NS, ST2SA, ZD8TM, 5N2NAS, 9H! CH. 1700 Falklands 141 129 118 108 107 152 244 241 244 248 251 174 141 EA8, EL, PY1ZAE, TU2FW, 9G IJX. 1800 LU, PY, UK9- Gibraltar 124 101 100 120 162 162 152 152 155 152 186 164 124 Hongkong 147 143 174 200 194 195 205 201 196 196 154 172 147 AAN, UL7, W4DHZ, 5Z4L W, 6W8EX, 9Q5QR. 1900 Honolulu 167 155 152 159 163 181 144 141 147 181 185 177 157 WB8FAG, ZD8RR, 5T5CJ. 2000 CX, LU, ZP. 2100 CE, Iceland 114 102 116 124 138 139 139 143 144 144 140 141 114 Jamaica 196 149 141 130 144 158 205 205 205 206 213 230 196 PY. 2200 YV1NX. 2300 to 0100 WI-W4, W8KPL, VEICD. Lagos 150 139 133 200 263 252 261 272 275 270 257 183 150 Acknowledgements to the authors of the following for Las Palmas 163 136 138 144 216 221 213 214 219 209 256 227 163 Lima 194 157 147 134 141 131 216 219 219 218 251 251 104 items extracted from their publications: The Ex-G Radio Los Angeles 155 147 135 138 108 105 135 176 178 191 188 188 155 Club (W3HQ0), the 29 DX Club Bulletin (VK6RV), Long Malta 140 117 122 161 195 195 181 177 188 195 215 173 148 Skip (VE1AL/3), the West Coast DX Bulletin (WA6AUD), MaurIllus 108 107 172 223 266 256 255 261 261 204 172 15$ 100 Mexico 186 148 133 138 148 129 182 165 197 204 192 204 186 DX'press (PAOTO), and CQ Magazine (W1WY). Moscow 124 121 144 168 172 168 177 174 181 185 169 158 124 Nairobi 125 122 164 220 267 257 255 263 263 277 169 144 125 Please send all items for August issue to reach G3FKM by 7 New Delhi 153 144 178 213 220 210 216 214 229 205 192 161 153 July and for September by 6 August. New York 188 150 139 115 135 164 190 188 192 200 191 205 186 Osaka 154 162 172 188 190 192 191 190 172 168 167 164 154 Perth 162 147 180 218 243 219 194 144 140 136 119 102 162 Rio de Janeiro 178 153 126 120 116 237 244 241 240 243 281 251 178 Salisbury 140 124 125 216 268 267 261 271 274 285 218 178 140 Seychelles 139 130 172 225 255 249 249 249 257 237 168 152 139 SIngnpore 153 144 178 213 220 210 218 214 185 161 159 141 153 Propagation predictions Suva (s) 162 169 164 173 181 182 161 140 121 138 179 172 162 Suva (1) 167 157 150 190 136 131 122 129 122 115 214 230 107 Sydney (s) 147 143 174 200 194 176 145 140 141 122 112 173 147 Conditions this month will be much as those given for the previous Sydney(I) 191 154 147 139 126 111 107 114 105 103 115 218 191 month and all predictions given for June will hold good for July. Teheran 163 147 180 219 244 220 228 220 238 263 215 192 163 Users of the tables will have noticed repeatedly that stations in the Vancouver 159 155 145 153 144 150 181 172 163 174 17/ 177 159 area indicated are not audible. This Is especially the case when the Wellington (s) 162 161 168 163 178 143 139 143 136 121 183 163 162 time given does not correspond to the main working period of WellIngten(1) 174 171 155 121 103 97 100 108 102 102 163 213 174 the dx countries. Contacts will be at their best if the time given in the For Information on !he use of thla table, see page 284, Radio Communkallon April predictions coincides with the main operating time of overseas 1976. Please send reports to Mr J. Spurting, GIAQI, 15 Tibbs Hill Road, Abbate stations. This particularly applies to countries with few amateurs. Langley. Watford, Hertz W056E5.

RADIO COMMUNICATION July 1977 545 PHA NTO M AT ALLY PALLY The Editor Radio Com munication gour opinion Sir—I would be obliged if you could publicise that a "phantom" G4BBH has been active in the London area recently, both via GB3L0 and .A or In fact I was unable to make it to "Ally Pally" this year, but I hear a "G4BBH" was talked in and listed as being present at the exhibition on 7 May. I wish I had known I was there, and I hope I enjoyed myself! If anyone is unsure, please contact me and I will be pleased to confirm whether any call was genuine or riot. GE FOR EVER! R. C. Ferryman, G4BBH The Editor 249 Folkstone Road, Radio Communication Dover, Kent CT17 9LL Sir—The various countries which make up the UK are all equal partners, and should be seen to be so, not least within our hobby of amateur radio. To assist towards this end, I would propose that the STUCK simple "G" prefix for England be discontinued, and the prefix "GE" The Editor be substituted. Radio Communication The use of "G" with GM, GW etc for the rest of the UK seems to Sir— With reference to GM30XX's letter in your April issue. While Imply that Scotland, Wales etc are English dependencies, a situation he has my deepest sympathies I cannot let the matter go without perhaps true in the distant past but now no longer so. The changes to "GE" as the English prefix would, I ant sure, be saying "What about MY PROBLEM ?" I am part of a family team (om and xyl) but as the label on the welcomed by most of us, as a legitimate rationalization of UK Radio Com munication wrapper does not extend the courtesy of my prefixes. existence, being addressed only to my husband, I can but assume Do any other amateurs think as I do ? that the RSGB do not want to acknowledge the existence of xyl Brian Jenkinson, G(E)3JHC operators or members! Potential grounds for divorce loom on the horizon! CON TES TS To enable me to purchase books at a discount from the RSGB. The Editor do I have to ask the orne permission or do I lighten the house- Radio Communication keeping still more ? Sir—I am in favour of avoiding unnecessary and useless work. As a Can't I sell my gear by advertising in Radio Communication? small contribution to this, could we abolish the mandatory dec- May I claim an RSGB Award ? laration in RSGB and many other contests ? Those who cheat are Isn't there a law about such things ? unlikely to be inhibited from signing a declaration that they have Ruth Uwins, G3TNN obeyed the rules, and it is superfluous to the vast majority. The legal reservation of decision to the organizers can be met by a general rule on the lines: "Submission of an entry, whether valid or accepted or not, means that the entrant agrees that the decision of the Council of the RSGB is final in all cases of dispute". Perhaps others who enter contests would care to com ment. A. A. H. Moss, G8VF

The Editor obituaries Radio Communication Sir— Would it be wrong to asume that the majority of amateur radio operators are unable to operate during daytime hours on weekdays due to their absence at work? If this assumption is correct, It follows that the weekend is their only opportunity, apart from holidays—and there is the rub. Practically every weekend brings a The Society records will? regret the deaths of the following radio chaotic state of affairs on the bands due to contest traffic, which amateurs: leaves no room for the ordinary individual who wishes lust to Mr J. Chapman, G3NUT com municate and does not regard the exchange of serial numbers Jack Chapman died in a car accident at the age of 42 on 28 May. accompanied by an inevitable 59(9) report as being communication. His main interest lay in construction, dxing and cw operation; and Even if a contact is established, it often happens that contest some years ago he made slow morse transmissions front the stations disrupt the QS0, calling a dx station while he is trans- Wirral. mitting. operating key down or switching-in a powerful linear to drown out the non-contest operator until he, or the dx station, gives Mr J. Court, G3K KF up in disgust. I have almost reached the conclusion that weekend Jack Court died in early April aged 64. He was first licensed in 1955 operation with fairly modest equipment and simple antenna systems and was well known on all bands, particularly the early-morning is becoming quite Impossible. I am sure that very few non-contest "Shaving Club". His interest in radio started with war service, and operators have the space, or the depth of pocket, to be heard amidst he was a telecommunications technical officer with British Rail for contest shambles. 30 years. However, unlike some of the contest operators I do not wish to spoil their enjoyment of our hobby as they are spoiling mine. I Mr P. R. Solder, GSFA would propose an extension of existing band planning so that Percy Solder died on 9 April. He was first licensed In 1921 as 6JS contest operation is limited to a sector of each band, leaving the and had held G5FA since 1937, He was a keen member of Southgate rest of the bands free for other operators to compete only with the RC, and G5FA ,P had been in almost full use for NFD since 1947 in normal hazards of our limited frequency allocations. Surely it is not which year the club won the event using that call. He was also a beyond the wits of the various national societies to reach some member of FOC, RSARS and RAOTA, and held many awards. such agreement? Furthermore, If international contest rules were amended so that It became obligatory to give names and locations The Society has also been advised of the deaths of: as well as serial numbers and RST reports, I would not be surprised if more operators took part. At least such exchanges could be Mr R. Cave, G2K QI, on 17 May; regarded as com munication with a fellow human-being and not Mr A. G. Cole, GJ3GS; with an automatic device which bellows 59(9)099999, when it Is not Mr A. D. George, ex VP2LG, on 30 May; engaged in yelling ''CQ Contest" on top of an established QS01 Mr W. F. Howlett, G3VU A, on 29 April; Although I believe that the RSGB is predominately contest- Mr N. C. Kirby, G6FV; orientated. I would venture to suggest that this may not be true of Mr J. A. North, 62K0; the majority of its members and I would not be surprised If quite a Mr "Siggi" Mansnerus, OHONI: large number of overseas amateurs shared this opinion. Mr J. Scholefield, GJ2TR; and C. J. Teece, G4DBR Col Bader Zaza, JYI B.

546 RADIO COM MUNICATION July 1977 High Wycombe DF Qualifying Event results Twenty-one teams assembled at Maidenhead Thicket on 1 May, to contest news compete in the first df qualifying event to be organized by the newly-formed Mid-Thames Radio Direction Finding Club (RS38663) on OS map No 175—Reading and Windsor. Transmitter "A", situated in a heavily-camouflaged hide in a beech wood near Beaconsfield (NGR 944877) and manned by Paul Hawes, G4CK W, assisted by Mike Moore, was seven miles from the starting point (NGR 055815). April 1977 144NIHz CW Contest results Transmitter "B" was located only 2.5 miles away at Shottesbrooke This contest was held under poor-to-average conditions but (NGR 835783) but Chris Marsden, G3XSO, and Graham Dore were nevertheless a very good entry was recorded. A check log from well hidden in one of the thickest bramble patches ever seen by dt RSGB member ON5UN contained a potential score, subject to fanatics. The excellence of the concealment, however, did not checking, of 731 and he could well have been the winner had he prevent Mike Hawkins, G3WM M, from locating both stations in th entered. It is worth reminding other RSGB members outside the 27min to win the event, the High Wycombe Cup, and to become the UK that they can enter our contests unless a specific rule limiting first to qualify for the 1977 National Final. entries to the British Isles only is included. One reminder is, however, that as a general rule RSGB vhf contests require an exchange Time of arrival of 0TH as well as OTH locator, which is not common practice Peen Name Club Station "A" Station "B.' outside the UK. This was a point on which several entrants com- 1 M. P. Hawkins Chelmsford 1420 1457 1418 1510 mented, preferring a 0TH locator-only exchange. 2 I. Batson Chelmsford 3 P. M. Lisle Mid-Thames 1416 15101 Certificates will be awarded to the overall winner, and to G3P01 as 4 A. Simmons Mid-Thames 1419 1511 leading fixed station. G3FZL 5 C. M. Wells Mid-Thames 1415 1545 8 G. Whenham Coventry 1548 14585 7 P. T. Tyler Mid-Thames 1550 1451 a 8. M. Bristow Mid-Thames 1550k 1506 Posn CallsIgn Points QS0a Best do Km 9 E. L. Mellott Mid-Thames 1552 14491 1 GMIDMZ/P 727 56 G3DAH 540 10 R. Parsons Oxford 1554 1500 2 G W3 WRA,'P 683 02 PAOCSL 11 C. D. Plummer Medway 1559 1511 3 G3P01 679 91 GM4CV1,'P 495 12 D. Nommas Rugby 1601 1449 4 GMICV1IP 661 55 PAOCSL 605 13 .1. R. Vickers Stratford 1431 1602 5 G3LCH/P 599 64 DK4TG 590 14 W. North Mid-Thames 1606 1458 6 G3CHN 585 55 G3XXO 540 15 D. Holland S Manchester 1509 1611 7 G3GQC/P 545 Ell DKITG 570 16 A. C. A. Newman Salisbury 1432 1617 8 G3WSN 499 77 GM4CXP 483 17 O. W. Sergeant Bracknell 1503 9 GJUDAIP 475 65 ON5UN 470 18 E. Treloggen Oxford 1506 10 G4CZP 443 51 G3CHN 440 19 C. T. Oliver Dertlord Heath 1611 11 G4ERPIP 434 74 PAOLSC 443 20 M. Wright Salisbury 12 03600 389 69 G4CZP 412 21 A. R. Davis Bridgwater 13 03.JE0iP 346 78 GIAIDMZ/P 525 14 G3JXN 338 66 0.155V 520 M. P. kfawkins and I. Butson qualify tor the National Flnal event In September. 15 G3FJEiP 335 75 GMICIMZJP 414 16 G3YYFIP 326 56 G3CHN 320 17 030A0 323 41 DJ5BV 530 18 G4DZ W 319 51 GM4CVI 475 Region 1 (RSGB) VHF Contest rules 19 G4APL 283 64 GM4DMZ/P 485 0900-1700gmt 14 August 1977 20 G WIEAI 216 34 ON5UN 475 Bands. 70, 144 and 432MHz. 21 G4BBA 211 35 GMICIMZ/P 380 Section 1. Multi-operator, fixed or /P. Separate callsIgn on each 22 G3YMDIA 202 30 DJ5BV 402 band, simultaneous operation. 23 jr 03110 191 41 ONSUN 385 -. Section 2. Single-operator, fixed or iP. Any or all bands. IP L 0361.1 191 JI G3CHN 365 25 G3GGL/P 186 25 ON5UN 420 entrants may go up to 20 miles outside the region. ALL 26 G4FDX 176 43 GM4CVI'P 420 operators must say that they are in or from Region 1. 27 G2BLA 171 53 PAOW WM 308 Section 3. Operators outside Region 1 are invited to enter logs. 28 G5HD 158 36 G3LCHIP 240 Score ONLY for Region 1 QS0s. 29 G3YHG 143 39 GM4CVI/P 468 Rules. The following general rules, published in the January 1977 30 G3PBA 134 25 GM4DMZ 31 G3JEI 124 27 G3CHN issue of Radio Communication, will apply : 2, 3, 5a, 6a, 9a, 10e, 11 to 16, 18, 19. 32 {G4EVIIP 120 26 G3DAH 260 G W3VKLIA. 120 24 ONSLIN 475 Scoring. A As above rules No 7a followed by B, C and D in that 34 G2h111 102 21 G3rIF,P order. 35 G3GC 78 sa ON5UN 275 B Multiply 70MHz score by 3, and 432MHz score by 4. 36 G3BTO 65 17 G3CHN 220 C According to aerial height asl. Multiply band totals as 37 G4ATV 34 11 G3CHN below: 0-100ft by 2, 100-200ft by 1-8, 200-300ft by 1.6. 300-400tt by 1.4, 400-500ft by 1.2, 500-600ft by 1.1. 600ft and over DF Qualifying Event, Stratford-upon-Avon by 1. D Add 10 points bonus for each contact with a Region 1 Date: 24 July 1977. station. Map: OS Sheet 150, Worcester and The Maiceros, Logs. Separate sheets for each band. On 70MHz, national open Assembly: 1300bst for start at 1320bst. Location: Lay-by on A4104 at Upton-on-Severn NGR 849402. contest serial numbers may be used. One cover sheet to include NGR and aerial heights asl. Intending competitors requiring tea are asked to notify Mr G. Awards. 1, the G3SM M Shield; 2, the G2CIP Shield; both to be held Foster, 6 Halford Road, Stratford-upon-Avon, Warwickshire CV37 for a year. Certificates of merit to band leaders in 1 and 2, 9B0 (Tel 0789 66402—recorded answering service) not later than 14 and best log in 3. July. Entries to G2CUZ, 34 Sandbrook Road, Ainsdale, Southport PR8 3JE.

DF Qualifying Event, Chelmsford Date: 7 August 1977. Errata Map: OS Sheet 167 Chelmsford and Harlow, 7MHz Contest 1977 An error occurred in the rules for this contest published in the Assembly: 1300bst for start at 1320bst. June issue. The date of the cw contest is 5-6 November, not 15-16 Location: Lay-by on A130 between Ford End and Howe St NGR 689162. November as shown. Intending competitors requiring tea are asked to notify Mr W. RSGB 21/28MHz Telephone Contest 1977 Petchey, Forge Cottage, Good Easter, Chelmsford CMI 4RS (Tel The time of this contest is from 0700 to 1900gmt, not to 1800gmt 024531 612) not later than 28 July. as published in the rules in the June issue,

RADIO COMMUNICATION July 1977 547 Special event station

16 July, Sutton Manor High School Silver Jubilee Fete This station will be operated by the school's curateur radio and electronics society. On 3.5 and 21MHz, G4AVViA and G4B WG -A; on 144 and 432MHz, G8LZ A.A and G8JUGiA. Special 0SL cards. 16 July, Joseph Rowntree School, New Earswick The station will be operated by York ARS using G31-1W W, A. 12-14 July, Great Yorkshire Show, Harrogate This station will also be operated by York ARS using G3H W W;A. 21-24 July Teignbridge Council Jubilee Trade Fair The Torbay ARS will operate this station at Newton Abbot racecourse on all bands 3.5 to 28MHz using the callsign G3NJA,,A. 27 July-5 August, Welsh Scout Jamboree This will be held at Llanover. near Abergavenny, when it is expected that up to 5,000 Scouts from 16 nations will be in the camp. Opera- Bert Grayson, G3EVP, and Miles Salmon, G2CK M, try their tion under callsign GW3KAF P will be on bands 3.5-28MHz ssb, sstv luck at the White Rose Rally club raffle stand manned by and 144MHz lm. Details from G3KAF, QTHR. tel 061-439 4952. Geoff Denby, G3FC W and his xyl Margaret 13 August, Tollerton Show The station will be operated by York ARS using G3H W W : A. 14 August Pembroke RSGBG Bucket and Spade Party, 27-29 August, National Town 8. Country Festival Regency Hall, Saundersfoot. Details from To be held at the National Agricultural Centre, Stonleigh, Warwick- G W3XJQ. shire. The station will be organized and operated by nine Midlands 21 August Preston ARS Mobile Rally, Walton le Dale amateur radio societies. G3GEIIA on 1.8MHz, G3UV W/A on 3.5 County Secondary School, Barnber Bridge, MHz, G2ASF,A on 14MHz, and G3UDN'A on 144MHz. Talk-in on Preston (one mile from junction 29 on the M6). 1.8 and 144MHz. Special QSL cards. It is hoped to demonstrate fast Talk-in on 2m. Trade stands, raffle, bring and and slow scan Iv, rtty, radio astronomy and aurora, and a microwave buy stall, plenty of parking space. Doors open repeater on the amateur radio stand. Details from G8HRH, QTHR. at 11.30am. Details from G8KTM, QTHR. tel 0926 24465. 28 August Torbay ARS Mobile Rally, Haldon Racecourse, on A38 near Exeter. Talk-in on 3-774MHz G3NJA: A, 145-00MHz fm S22 G8NJAIA from 9.30am. Usual attractions. Used (not junk) equipment stall. Demonstration by Brixham Coastguard. Details from G3UIQ, QTHR. 18 September Peterborough Mobile Rally, Walton Secondary Looking ahead School, Mountsteven Avenue, Peterborough. Talk-in station G3DQW on 2m. Details from 10 September—Scottish Amateur Radio Convention, Adam G3EEL, QTHR, tel Peterborough 6288165423. Harlow & D ARS Rally, Netteswell Comprehen- Smith Centre, Kirkcaldy. 25 September sive School, Harlow. Details from G3WUX, 17-18 September—N W Amateur Radio Convention, University of G8FRG, G3YDI, QTHR Lancaster. 25 September— Welsh Amateur Radio Convention Oakdale Com munity College, Blackwood, Gwent. 15-16 October—Jamboree on the Air. 27-29 October—ARRA Exhibition, Granby Halls, Leicester. 2 December—RSGB AGM, IEE, Savoy Place, London WC2. Contests calendar

10 July DF Qualifying Event Salisbury (Rules In June issue) 17 July 3•5MHz FD (Rules in June issue) 17 July lOGHz Cumulative (Rules in May issue) 24 July DF Qualifying Event Stratford (Rules in July Mobile rallies calendar issue) 31 July 144MHz QRP (Rules in June issue) 10 July Upton Radio Rally, Hill High School, Upton-on- 7 August DF Qualifying Event Chelmsford (Rules in July Severn. Details from G8ASO. issue) 16 July Hornsea ARS Mobile Rally, Hornsea School and 13-14 August 70MHz Open (trophy) and SWL (Rules in June Hall Garth Park, Hornsea, N Humberside. Held issue) in association with Hornsea Carnival. Details 14 August Region 1 (RSGB) VHF (Rules in July Issue) from G4CHH, QTHR. 21 August DF Qualifying Event Slade (Birmingham) 17 July Cornish RAC Mobile Rally, Truro Rugby Club 21 August lOGHz Cumulative (Rules in May issue) Ground. Details from G3NKE, QTHR. 3-4 September SSB FD (Rules in April issue) 24 July Anglian Mobile Rally, gam to 6pm, StanwaY 3-4 September 144MHz Open (trophy) and SWL (Rules in June School. Colchester. Talk-in on 2 and 80m, issue) G3CRC and G4CRA. Usual attractions. Details 18 September DF Final South Manchester from G3YAI, tel 0255-21664. 18 September 10GHz Cumulative (Rules in May issue) 7 August RSGB National Mobile Rally, Woburn 1-2 October UHF (432MHz-2•3GHz) Abbey. 8-9 October 21;28MHz (Rules in June issue) 14 August Derby Mobile Rally, Lower Bemrose School 15-16 October 7MHz Phone (Rules in June issue) (Rykneld School), Bedford Street, Derby. Talk- 23 October 70MHz Fixed in on 144MHz by G3ERD;A and G2DJiA. Gates October.- open noon. Free admission and parking. Usual November 432MHz Cumulative attractions. Grand prize draw (over 40 prizes) 5-6 November 7MHz CW (Rules in June July issue) 3.30pm. Flea market. Brass band concert. 5-6 November 144MHz CW Children's competitions. Details from G3FGY, 12-13 November 2nd 1•8MHz QTHR. 4 December 144MHz Fixed

548 RADIO COMMUNICATION July 1977 Leyland (LHARG)-Second Monday In each month, 7.30pm. "Rose & Crown", IJInes Walton. Leyland. Details from G3XII. Liverpool (L&DARS)-Tuesdays, 8pm. Conservative Association club news Rooms, Church Road, Wavertree. Sec G4EST. Liverpool (North Liverpool RC)-Tuesdays, 8.30prn. Informal meetings. "Nags Head", Thornton, Crosby. Liverpool 23. Visitors welcome. Sec R. Porter, 11 Craninore Avenue, Crosby, Liverpool L23 OC/D. Liverpool University (UoLARS)-Meeting at lunchtime and on RSGB affiliated societies and clubs, and RSGB groups, are Mondays, 5prn. Club shack, Reilly Building. The club is active on all invited to sub mit items for inclusion in "Club News" to their bands 80 2m-callsings G3OU LG8JUL. Details from hon sec, cio regional representatives (not direct to the editor). Students' Union or c"ci GW4FJK. Items of news and

The stand of Stockport RS, which won second prize in the club stand competition at the NRS A Convention in April, featured the 20ft long quad loop Vagi with which they have won several contests, including the 432MHz section of 1976 VHF NFD. Members of Stockport RS, XYLs and friends also manned the RSGB bookstall

RADIO COMMUNICATION July 1977 549 UK FM Group (Western)-7 July, 1 Sept (Informal meetings). Birmingham (South Birmingham RS)-Shack night Fridays, 8.30pm. Legh Arms, Knutsford. Visitors most welcome. 19 Sept 7.30pm. 3 Aug (Open discussion). 7 Sept. 8pm. Hampstead House, (AGM). 8pm. Wirral Mercury Motor Inn, Backford Cross, Chester. Fairfax Road, West Heath, Birmingham 1331 3QY. G8KPA. Details of group from sec G3LEQ, tel Knutsford 4040. Bromsgrove (B.Y.DARC)-12 Aug, 9 Sept (Surplus sale). 8pm. W arrington (W&D ARS)-Tuesdays, 7.45pm. Grappenhall Com- Avoncroft Art Centre, Bromsgrove. G8JTK. munity Centre, Bellhouse Lane, Grappenhall, Warrington. Sec R. E. Cannock Chase (CCARS)-First Thursday in each month .1. Staples, G3M MD, 3 Willow Close, Lymm, Cheshire, tel Lymm (Business meeting), other Thursdays (HF and vhf club stations, 3533. natter-nites, morse classes. talks etc.) Visitors welcome. eon). Wigan (W&DARS)--First and third Wednesdays of each month. Bridgtown Social Club, Walsall Road, Cannock. G4CHI. Poolstock Cricket Club, Keats Avenue, Poo!stock. Sec A. Cunliffe, Coventry (CARS)-Fridays, 8pm, Baden Powell House, 121 St G4E11, 50 Langholm Road, Garswood, Wigan. Nicholas Street, Radford, Coventry. G8DM1. Winsford (Mid•Cheshire ARC)- Wednesdays. Technical Activi- Coventry Technical College (CTCARS)-Mondays and Thurs- ties Centre, rear of Verdin Buildings. Verdin Comprehensive School, days, 7pm. Winlray Annexe of the College. G8ISJ. Grange Lane, Winsford, RAE class 7pm to 8pm. Morse class every Coventry (University of Warwick ARS)- Wednesdays during third Wednesday. Net nights 160m Mondays, 8pm, 2m (fm) Tuesdays term. Talk-in on 520. 7pm. Cryfield Farm, University of Warwick, 8pm. Sec G8HAV. Coventry. Vice-president G8MIA. Wirral (WARS)-First and third Wednesdays in each month, Hereford (HARS)-First and third Fridays in each month. 8pm. 7.45pm. Sports and Recreation Centre, Grange Road West, Civil Defence HQ, Gaol Street, Hereford. G4CNY. Claughton, Birkenhead. Sec G3DLF. Lichfield (LARS)-First Monday and third Tuesday in each month, Liverpool Luncheon Club -members wishing to attend should 8pm. Swan Hotel. Tuesday meetings are natter-rites. New members contact G3VQT or G2A MV. and swls welcome. Sunday net noon, 21-150MHz. Sec Ted Bowen, RS33003, Tel Tamworth 68756. REGION 1 VHF Contest. 0900-1700gmt 14 August-details on Lichfield (Chad RC)-Alternate Wednesdays, commencing 6 13547. July 8pm. The Naval Club, Burton Old Road, Lichfield. G4ESK. 1977 North West A mateur Radio Convention -17-18 September Mid-Warwickshire (M WARS)-First and third Mondays in each at Lancaster University. See advertisement in this issue. month. 8pm. 61 Enscote Road, Warwick. G8CXL. Redditch (RRC)-Second and fourth Thursdays in each month, 8pm. WRVS Centre, Salop Road, Redditch. G3EVT. Shrewsbury (Salop ARS)-Thursdays, 7.30pm. New members REGION 2-RR R. C. Andreang, G4C MT, 6 Beech Avenue, welcome. The Albert Hotel, Smithfield Road, Shrewsbury. Joint Bilton. Hull, Humberside. secs Bob Carter, 11 Ash Close, Sutton Farm, Shrewbury SY2 Barnsley (B&DARS)-Fourth Friday in each month, 7.30pm. 6Ht..1. and Dave Doody, 56 Ellesmere Road, Shrewsbury SY1 20P. King George Hotel, Peel Street, Barnsley. Sec G3LRP. Solihull (SARS)-19 July (Film show), 16 Aug (Lecture). 7.30pm. Denby Dale (DD& D ARS)- Wednesdays, 7.30pm. Pie Hall, Denby The Manor House, High Street, Solihull, G4EQF. Dale. Visitors always welcome. Sec G3FQH. Stourbridge (StARS)-Intormals on the first Tuesday in each Goole (G&D ARS)-Fridays, 7.30pm (during school term only). month, 9pm. "Shrubbery Cottage" public house, Heath Lane, Goole Grammar School. Details from chairman G3VBI. Oldswinford, Stourbridge. 18 July (Post-mortem on NFD and Halifax (Northern Heights ARS)-7.45pm. Peat Pitts Inn, Ogden, Jubilee), no formal meeting in Aug-a barbecue will be arranged- Halifax (four miles north of Halifax town hall). Sec G3MDW. see sec. 7.45pm. Longlands School, Brook Street, Stourbridge. Hornsea (HARS)- Wednesdays, 8pm. Rear of Victoria Hotel, G4CLX. Hornsea (facing Hornsea Mere). 16 July (Mobile rally, our first). Stoke-on-Trent (S-on-TARS)-Thursdays, 7.30pm. 2A Race- Details from sec G4CHH. course Road, Oakhill, Stoke-on-Trent, G4CWN. Hull (H& D ARS)-Fridays, 7.30pm. Dorchester Hotel, Beverley Stoke-on-Trent (North Staffs ARS)-First and third Mondays In Road, Hull. Sec G3LZQ. each month-lectures etc. Second, fourth and fifth Mondays in each Leeds (White Rose RR)- Wednesdays, 7.30pm. (Lectures start month-natter nites, Raynet and club station G4BEM. Newcomers 8pm). Sec G4DZI. welcome. 7.30pm. Harold Clowes Com munity Centre, off Dawlish Leeds (LUUARS)-Tuesdays, 8pm. Union Annexe (second floor), Drive, Bentilee, Stoke-on-Trent, G3YBY. Woodhouse Lane. All new students welcome. Sec G4CNG, QTHR, Sutton Coldfield (SCRS)-Second and fourth Mondays in each or at "E" block, Lupton Flats, Alma Road, Leeds 6, during term. month. 7.30pm. Central Youth HQ, Clifton Road, Sutton Coldfield. Otley (OR&ES)-Tuesdays, 8pm. 14 Back of Court House Street, Sec Mrs Liz Furness, 4 Goodere Drive, Polesworth, Tamworth, Otley. Sec G8DFZ. Staffs B78 1BZ. Scarborough (SARS)-Fridays, 7.30pm. Scarborough Technical Tam worth (TARS)-Second and fourth Mondays in each month. College, Corby Road, Scarborough. Sec G3RTN. PRO Charles Indoor Sports Centre, Corporation Street, Tamworth. New members Whitaker, 1 Ryefield Close, Eastfield, Scarborough. welcome. G4EUF. Sheffield (SU&PRS)-University- Wednesdays in ternn, 1pm. Telford (T&DARS)- Wednesdays. 7.30pm. Phoenix Centre, The "Red Deer", off Main Street. Details G4BXN. Webb Crescent, Da ,,vley. Visitors welcome. 13 July (Social outing Polytechnic-Thursdays in term. Details G4DHF/A, tel 303758. -trip by horse-drawn canal boat-see sec). G8MXS. Tel Much She ffield (Association of Sheffield ARCs)-Chairman G4EXK. Wenlock 357. Sec B. Flounders. All association meetings Room 3106, Sheffield Willenhall (W&DARS)-Alternate Wednesdays. Morse classes Polytechnic, 7.45pm. available at the end of each meeting. "The Three Crowns", Stafford Wakefield (W& D ARS)-7.30pm, Ines Road School, Wakefield, Street, Willenhall, G3YHN, XYL. Sec G3W WF. Wolverhampton (WARS)-11 July (Natter-nite), 18 July (Dis- York (YARS)-Fridays, 7.30pm (except for the third Friday in the cussion-df hunts on vhf), 1 Aug ("Early vhf experiences" by month). United Services Clubroom, 61 Micklegate, York. We would Bob Riding, G3JZG), 8 Aug (Natter-nite), 15 Aug (vhf uhf night on like to pass a vote of thanks to the RSGB for a fine exhibition at the air), 5 Sept ("Sporadic E-ht and vhf" by Martin Harrison, "Ally Pally" also to our Region 2 Rep for a fine evening visit to Hull G3USF). 8pm. Neachells Cottage, Danescourt Road, Stockwell College of Further Education, Marine Radio Radar Section. End, Tettenhall, Wolverhampton WV9 9PH. G8EDG. Worcester (W&DARC)-11 July ("VHF radio in the highlands and Note: Would all secs in the region please write to RR Region 2, islands" by Ron Payne, GM4A WA), 16 July (no meeting), 1 Aug QTHR, for inclusion in Sept "Club News". ("Teleprinters and their use with radio" by Brian Jones, G8ASO), 20 Aug ("The aerials available at the club shack" by Roger Avery, G3TQD), 5 Sept. 8pm, The Old Pheasant, New Street, Worcester. G4DXE. REGION 3-RR H. S. Pinchin, G3VPE, 61 Cole Bank Road, Hall Green, Birmingham B28 8EZ. Birmingha m (Birmingham University RS)-Every Tuesday REGION 4-RR T. Darn, G3FGY, Sandham Lane, Ripley. during term, 7pm. Students' Union. Gal UB. Sec G4CKK. Derbys. Birmingha m (Midland ARS)-26 July, 23 Aug. 8pm. Room 110, Derby (DA D ARS)- Wednesdays, 7.30pm. Morse classes Tues- University of Aston, Gosta Green, Birmingham. G3ZKQ. days and Fridays at 7pm when arranged. 119 Green Lane Derby. 14 Birmingha m (Slade RS)-Alternate Fridays, commencing 8 August from 12 noon: Derby Mobile Radio Rally, Lower Bemrose July. 8pm. The Committee Room, Church House, Erdington, School. St Albans Rd, Derby. All the usual attractions and a bigger Birmingham. G4FGF. and better flea market.

550 RADIO COM MUNICATION July 1977 Derby (NHARG)-Fridays, 7.30pm. Nunsffeld House, Boulton Lane. Alvaston, Derby. Grimsby (GARC)-First and third Thursdays in each month. 8pm. Alexandra Social Club, Cleethorpes. Leicester (LRS)-Mondays, 7.30pm. Club House, Gilrose Estate Cottage, off Groby Road Leicester. Mansfield (MARS)-First Friday in each month, 7.30pm. "The New Inn", Westgate, Mansfield. Melton Mowbray (MMARS)-7.30pm. St John Ambulance Hall, Asfordby Hill, Melton Mowbray. Nottingham (NURS)-Alternate Wednesdays during term time. Details from Roger Dixon, G4BVY, cío Students' Union, or QTHR. Nottingham (ARCON)-7 July (Forum), 14 July ("Logic" by G3WFV), 21 July ("Activity night"). 7.30pm. Sherwood Community Centre, Mansfield Road. Nottingham. 6, 7 Aug "Rail EX 1977" at Gregory's Rose Gardens, Stapleford; exhibition station on the air. Scunthorpe (SARC)-Tuesdays, 7.30pm. The Shack, Grange Farm Hobbies Centre, Franklin Crescent, Scunthorpe, South Hum berside.

L to r: G4FTA, G80 X, G3JLE and G2H MY

REGION 5-RR P. F. Chilcott, GOBBA, 258 Coneygree Road, Reading (RARC)-5 July ("WARC 1979" by G2BVN), 19 July Peterborough PE2 8LR. (TBA), 2 August (Demonstration of GB3BK), 23 August (Brewery Bedford (B&D ARC)-7 July (Treasure hunt), 14 July (Analysis of visit!), 6 Sept (Junk sale). 8pm. "White Horse", Emmer Green, VHF NFD), 21 July (Pub games), 28 July, 4, 11, 18 August (Informal), Reading. Sec G4CCC. 25 August (2m zif hunt). 8pm. United Services Club, Broadway. Sec G4FEV. Cambridge (C&DARC)-Fridays, 7.30pm. Corporation Yard, Victoria Road. Sec G4BAO. Cambridge University (CUWS)-Tuesdays during term. Sec REGION 7-RR N. A. Smith, G3HFO. 7 The Byeways, Surbiton Surrey KT5 BHT. G4EAG, St Catherine's College. Corby (CTCARG)-Mondays, 7.30pm. Corby Technical College. Addiscombe (AARC)-Tuesdays, 9prn, "Spreadeagle", Portland Road, Woodside. Sec G3SJX. Clubhouse and GB3CI in grounds. Dunstable (DDRC)-Fridays, 8pm. Chews House, 77 High St Ashford, Middlesex (Echelford ARS)-Second Monday and last South. Sec G3WXS. Thursday in each month. 7.30 for 8pm. St Martin's Court, Kingston Crescent, Ashford, Middlesex. Sec G3TDR, tel Staines 56513. March (M&DARS)-Tuesdays, 7.30pm. 2 Grays Lane. Sec G8GNE. Northampton (NRC)-Thursdays, 8pm. Spencer Dallington Bexley Heath (North Kent RS)-Second and fourth Thursdays, 8pm. St Mary's Institute, 2 North Cray Road, Bexley, Sec G4ARQ. Com munity Centre, Tintern Avenue, off Gladstone Road. Sec G8LHR. Coulsdon (CATS)-7 July (Activity night and club projects), 18 Peterborough (GPARC)-Fourth Thursday in each month, 7.30pm. July (Talk and film on Raynet by Sid Law, G3PAZ), 4 August (Surplus sale), 15 August (Activity night). 1 September (Construc- Southfields School. Sec G4BBA, tel 65213. Peterborough (PR&SS)-Third Friday in each month, 7.30pm. tion contest), 19 September (Inter-club quiz). First Thursday in each month, 8pm. 10th Purley Scout HQ, Chipstead Valley Road, Couls- Scout Hut, Occupation Road. Sec G3EEL. Shefford (S&DARS)-Thursclays, 8pm. Church Hall. Sec G8HHO. don. Third Monday in each month, 8pm. 1st Purley Scout HQ, Purley Park Road, Purley. Sec G4DLD, tel Burgh Heath 59956. Cray Valley (CVRS)-21 July (Natter nite), 4 August (To be arranged), 18 August (Natter nite), 1 September (Surplus sale). 8pm. Eltham United Reform Church Hall, 1 Court Road, Eltham, London SE9 (except 4 August when the meeting will be held at the REGION 6-RR F.S.G. Rose, G2DRT, 84 Cock Lane, High Christchurch Centre, High Street, Eitham, London SEO). Sec Wycombe, Bucks HP13 7EA. G3Y WO. Banbury (BARS)-Fridays, 7.30pm. 43 North Bar, Banbury. New Croydon (Surrey Radio Contact Club)-First and third Wednes- members and visitors welcome. Sec S. L. Terry, tel Banbury 4769. days in each month, 7.30 for 8pm. TS "Terra Nova", 34 The Waldrons, Bracknell (BARC)-First and third Mondays in each month, 8pm. Croydon. Sec G3FWR. tel 01-657 3258. Alternate Mondays, morse. Visitors welcome. Sec G3YMC. Crystal Palace (CP&ORS)-Third Saturday in each month, Burnham Beeches (BBRC)-First Monday in each month, 8pm. 7.30pm. Emmanuel Church Hall, Barry Road, London SE22. Sec Hedgerley Scout HO. Sec Peter Fynn, tel Farnham Common 2609. G4AVV, tel 01-653 4340. High Wycombe (Chiltern ARC)-Fourth Wednesday in each Guildford (G&DRS)-Second and fourth Fridays in each month. month, 8pm. 42 Castle Street, High Wycombe. Sec G4FRL. Model Engineers HQ. Stoke Park, Guildford. Sec G4BHQ, tel Maidenhead (M&DARC)-First Thursday and third Tuesday In Guildford 76375. each month, 7.30pm, British Red Cross Hall, The Crescent, Maiden- Kingston (K&DARS)-Second Wednesday in each month, head, Sec G4ALG. 8.15pm. Berrylands Scouts and Guides HQ, Stirling Walk, Raeburn Milton Keynes (MK&DRS)-11 July ("Slow scan television" by Avenue, Surbiton. Sec G4APG. G3ZPA), 8 August ("Tele -bashing" by G8HUH), 12 Sept(AGM). New Cross (Clifton ARS)-Fridays, 8pm. 225 Bew Cross Road, 8pm. Lovat Hall. Silver Street, Newport Pagnell, Milton Keynes. London SE14. Details from R. A. Hinton, 58 Camilla Road, Bermond- Sec G3THC, tel Milton Keynes 316730. sey, London SE16. Newbury (N&DARS)-First Monday In each month, 7.30pm. Reigate (RATS)-19 July (Talk on Repeater GB3SN by G4CTE). Newbury College of Further Education, Oxford Road, Newbury. First Tuesday, 8pm. (Natter nights), Marquis of Granby. Hooley Sec G4EEE. Lane, Redhill. Third Tuesday, 8pm. Constitutional Centre, Warwick Oxford (O& DARS)-Second and fourth Wednesdays In each Road, Recihill, Sec G3XSZ. month, 7.30pm. Civil Service Sports Club, Marston Road. Oxford. Sutton and Cheam (S&CRS)-Third Thursday in each month, Visitors welcome. Sec G4BHR. 7.30pm. Sutton College of Liberal Arts, Cheam Road, Sutton, Sec G2DMR. The annual construction contest of the Oxford and D ARS was held Thames Ditton (Thames Valley ARTS)-2 August (Natter on 27 April. The 12 entries ranged from an electronic egg-timer to night), 6 September (talk by representative of the UK FM Group). an oscilloscope and digital frequency meter. 8pm. Gig gs Hill Green Library, Giggs Hill Road. Thames Ditton. The winner was Jeff A. Jefferies, G8PX, chairman of the society, Sec G3ZN W. who received the Ben Farmer Cup from the president, Robin Pearce- Wimbledon (W6iDRAS)-Second and last Fridays in each month, Baby, G3JLE. There was a tie for second place between Tony 8pm. St John Ambulance HQ, 124 Kingston Road, Wimbledon Earle, G4FTA, and Dick Priday, G21-IMY. SW19. Sec G3XTC, tel 01-644 3698.

RADIO COM MUNICATION July 1977 551 REGION 8—RR D. N. T. Williams, G3MD O, "Seletar", New REGION 11—RR P. H. Hudson, G W3IEQ, "Silhill", Dinas House Lane, Thanington, Canterbury, Kent. Dinlle, Caernarvon LL54 5T W. Burgess Hill (Mid-Sussex ARS)-14 July ("My aerials" by (No information received—Ed) members), 28 July ("Modifying the Cambridge and Pocketfones" by Brian Fenwick, G8BTC). 7.45pm. Marie Place, Burgess Hill. Details from G3PEQ. Canterbury (East Kent RS)—As we have had to give up our REGION 12—RR Frank Hall, GM8BZX, 45 Priory Cottages, venue, details of future place and meetings from hon sec G8GHH, Lunanhead, Forfar, Angus DDB 3NR. QTHR, Aberdeen (ARS)—The club has now vacated the Crown Street Chichester (C&D ARC)—First Tuesday and third Thursday in premises and meets every Friday evening at the Covedray Club, 5 each month. Lancastrian Boys School. Details of future events Fonthill Road, Aberdeen. During the holiday period the club will from G4ETU, tel 0243 88069. be closed from 1 to 22 July. At a recent meeting a large number Crawley (CARC)—United Reform Church Hall, 'field, Crawley. attended from all over Zone G to discuss the Aberdeen vhf repeater Details of future events from G3MGL. project. This repeater, GB3GN, is now licensed but no date has yet Dartford (DHDFC)—Second Friday in each month, 8pm. The been fixed for commissioning. The Grampian Repeater Group Scout House, Broomfield Road, Dartford. chairman and project manager have thanked the club for their Dover (South East Kent Y MCA ARC)—Details of future events assistance. Sec GM4BKV. from G8KEN, 14 Victoria Rd, Capel-le-Ferne, Folkestone. Dundee (Kingsway Technical College ARC)— Wednesdays, Eastbourne (Southdown ARS)-4 July (Open-air meeting at 6.30pm. Kingsway Technical College. The club will be closed during Butts Brow, 4km NW of Eastbourne. Usual QTH if wet), 1 August the holiday period from June until mid-September. During the past (Quiz—more details later). All meetings at Chassely, South Cliff, year many talks have been given on all aspects of radio. Other Eastbourne. Details from sec G8CVV, pro G3LFZ. subjects have been photography, awards, and communications Gravesend (GRSGBG)—Mondays, 7.30pm. The Windmill Tavern, during the 1939-45 war. Speakers are required for the winter period. Shrubbery Road, Gravesend. Sec Robert Officer, 17 Broomwell Gardens, Monikie, BroughtY Hastings (HERC) (ITT(H)S&AC)—Detalls of future events for Ferry, Dundee DD5 3QP. both units from G8DNO, QTHR. Inverness (Technical College ARC)—Every second Wednesday Horsham (HARC)—First Wednesday in each month. Civil Defence 6.45prn. Room C30, Inverness Technical College. Sec John Reid, 37 HQ, Moons Lane, Brighton Road, Horsham. Details of future events MacEwen Drive, Inverness. from G3NPF. Lerwick (LRC)— Wednesday evenings. Annsbrae House, Ler- Maidstone (MYMCA ARS)—First and third Fridays devoted to the wick. Sec GM3HTH. beginner. RAE and morse tuition. 7.30pm. Melrose Close, Loose, Moray Firth (MFARS)— Wednesdays. 7.30pm. Elgin Technical Maidstone. Alternate Fridays, a wide range of lectures and use of College. Sec GM8LVG. the club shack. Details from Harry Poppy, G8KMX, tel Maidstone 61792. Medway (MARTS)—Fridays, 7.30pm. Aurora Hotel, Gillingham, Details from P. J. Poole, G4EVY, 5 River Drive, Strood, Rochester, REGION 13—RR A. B. Givens, GM3Y OR, 41 Veronica Crescent Kent. Kirkcaldy, Fife K Y1 2LH. Ramsgate (Kent Coast ARC)—Details of meetings from G4DTA, Berwick upon Tweed (Border ARS)—First and third Fridays in QTHR. each month, 7.30pm. Roxburgh Hotel, Berwick upon Tweed. Details Tunbridge Wells (West Kent ARS)—Details of future events from GM8I10. from G8LMV. Dunfermline (DARS)—Second Wednesday in each month, W orthing (W&DARC)—Details of future meetings from P. J. 7.30pm. CCTV Studio, Pittencreiff School, Maitland Street, Dun- Robinson, G8MSQ, QTHR. Tuesdays, 8pm. Adult Education Centre, fermline. Details GM3MGX, tel Limekilns 313. Union Place, Worthing. Edinburgh (E&DARC)—Tuesdays, 7.30pm. City Observatory. Kent Repeater Group—Details of membership and events from Calton Hill, Edinburgh. Details from GM4B WT, tel 031 668 1119. G3XDV, 5 Lambs Walk, Whitstable, Kent. Edinburgh (Lothians RS)—Second and fourth Thursdays in each Sussex Repeater Group—Information available from G8HVV, month, 7.30pm. Adult Education Centre, Riddles Court, High Street, QTHR. Edinburgh. Details from GM4BYF, tel 031 447 3201. Glenrothes (G&DARC)—First Sunday in each month and every Wednesday. 7.30pm. Old Primary School, Provosts Land, Leslie, REGION 9—RR H. W. Leonard, G4UZ, 4 Start Bay Park, Strete, Fife. Details from GM3YOR, tel Kirkcaldy 200335. Dartmouth TQ6 ORY. Camborne (Cornish RAC)-7 July ("Standard frequencies and time signals" by G2ABC), 17 July (Mobile rally at Truro), 4 Aug ("2m propagation" by G8HTE), 1 Sept ("An introduction to rtty" REGION 14—RR A. J. Mitchell, GM3UDL, 7 Limetree Crescent, by G4CVY). 7.30pm. SWEB Clubroom, Pool, Camborne. Cornish Newton Mearns, Glasgow 677 5BJ. net every Sunday 11am on 3.685MHz. Visitors to club meetings (No information received—Ed) most welcome. Full details from G3NKE, tel Camborne 2419.• Exeter (EARS)—Second Monday in each month, 7.30pm. Com- munity Centre, St Davids Hill, Exeter. Details from G3HMY. Newquay (N&DARS)—Alternative Wednesdays, 7.45pm. Trevi- glas School, Newquay. Details from G8GOR, tel Newquay 4168. REGION 15—RR H. J. Campbell, GI8FOK, 26 Kilcoole Park, North Devon (NDRC)—Second Wednesday in each month at Belfast BT14 81-13. QTH of G4CG, fourth Wednesday at QTH of G3FKO. Details from Ballymena (BRC)—Tuesdays, 8pm. 86 Old Cullybackey Road. G4CG. Ballymena. RAE and morse classes. Fridays. club night; Sundays, Ply mouth (PRC)-3 May (AGM). First and third Tuesdays in each special projects, 3pm. 2 Sept (AGM). Sec GI8LSF. month, 7.30pm. Virginia House, Bretonside, Plymouth. Visitors Bangor (B&DARS)—First Friday in each month, 8pm. Redcliffe most welcome. G4EJO. Hotel, Seacliff Road, Bangor. Sec GI4EMS. Saltash (S&DARC)—First and third Fridays in each month. 19 Belfast (QUoBRC)—Tuesdays, 8pm. Queen's University Radio Aug (River trip to Cal stock). 7.30pm Burraton Toc -H Hall, Saltash. Club, 37 Fitzwilliam Street, Belfast. All welcome. Sec G8LLR, tel Plymouth 771135. Belfast (CoBY MCARC)—The club is active on the air from Torbay (TARS)—Every Friday with special meeting on last Satur- 7.30pm on Tuesdays and 2.30pm on Saturdays. Meeting at same day of each month. 30 July (Come and see, night!), Aug 20 (Final times. 7 Wellington Place, Belfast. preparations for mobile rally). This meeting is a week early because Belfast (BRSGBG)—Third Wednesday in each month, 8pm. 90 of the rally on 28 August. 7.30pm, rear of 94, Belgrave Road, Torquay. Belmont Road, Belfast. Interesting spring programme arranged. Torbay net, weekdays on 3.765MHz, 10.30am. Visitors to club Visitors most welcome. 21 Sept (AGM). Further details from meetings always welcome. Full details from G3UIQ. GI8FOK. Carrickfergus (CY MC ARC)—Last Monday in each month, 8pm. Carrickfergus YMCA. New members very welcome. Sec C. Morrison REGION 10—RR R. G. Barrett, GW8HEZ, 23 Carshalton Road, GI8KZU, 3 Donegall Square, Carrickfergus, Co Antrim, Beddau, Pontypridd, Glam. Mid-Ulster RSGB Group—First Sunday in each month, 3pm. At (No information received—Ed) QTH of GI4BAC. 4 Sept (AGM). Sec GI3 W WY.

552 RADIO COMMUNICATION July 1977 REGION 16-RR R. E. G. Kendall, G8BNE, "Wesley", Ran- Cheshunt (CDRC)-New premises-Church Room, Church Lane, worth Road, Hemblington Corner, Blofield, Norwich NR13 Wormly, Herts. Wednesdays, 8pm. 4PJ. Chingford (Silverton RC)-Fridays, 7.30pm. Friday Hill House, Chelmsford (CARS)-First Tuesday in each month 7.30pm. Simmonds Lane, Chingford E4. Visitors very welcome. Sec G4AJA, Marconi College, Arbour Lane, Chelmsford. Details from R. Brocks, tel 01-529 2282. 30 Rowan Drive, Heybridge, Ma'don. Ealing (EDARS)-Tuesdays, 8pm. Northfield Com munity Centre, Colchester (CRA)- Wednesdays, 7.30pm. 114 Ipswich Road, Northcroft Rd, London NW13. Newcomers and old-timers very Colchester (above Candor Motors). Details from G3YAI. welcome. Sec M. E. J. Cummings, G8KPN, tel 01-997 5947. Great Yarmouth (GYRS)-Last Thursday in each month, 67 East London RSGB Group -Summer break until September. Do Southdown Road, Great Yarmouth. Details from G3NHU. not forget "Small box of tricks competition". Build something into Harlow (H&DRS)-Tuesdays, 8pm Mark Hall Barn, First Ave, a 2oz tobacco tin. Rules from sec J. Bundock. G4CJQ. Harlow. Details from G3WUX. Edgware & District RS -14 July (Informal with club station on Ipswich (IRC)-Detalls from G4BAV. air). 28 July ("TTL logic" by Godfrey Manning). No meetings Loughton (L&DRS)-Second and fourth Fridays in each month, August. Slow cw under club call G3ASRIA now on 144.175MHz at 8pm. Loughton Hall, near Debden station. Details from G8DZI-I. 2030 on Mondays and 1930 local time on 1st and 3rd Thursdays. Lowestoft (L&DARC)-Fridays, 7.30pm. Morse class every Reports greatly appreciated. Sec P. Ling, G4BZY, tel 01-952 2495. Tuesday. YMCA. Park Road. Lowestoft. Harrow (RSH)-1 July (VHF NFD planning), 8 July (Astronomy Norwich (Norfolk ARC)- Wednesdays, 7.45pm. Crome Com- talk), 15 July (Practical), 22 July ("Transverter design" by G4AUF), munity Centre, Telegraph Lane East, Norwich. Details from G4E0L. 29 July (Practical), 5 August (Practical), 12 August (Practical), 19 Norwich (U of East Anglia R&EC)-Details from P. Gowen, August (Summer mobile ramble). 8pm. The Roxeth Community G3I0R. Centre, Scott Crescent, West Harrow, Middx. Sec G4FBK, tel 01-864 Stow market (S&D ARS)-First Monday in each month, Red 1412. Cross building near Stowmarket station. Details from G4ETC. Havering (H&DARC)- Wednesdays, 8pm. British Legion Club, Vange (VARS)-Thursdays, 8pm. Youth Hall, Barstable Tenants' Western Road, Romford. Com munity Association, Long Riding. Basildon. Details from Mrs Holloway (Grafton RS)-7.30pm. Holloway Institute, Archway D. Thompson, 10 Feering Row, Basildon SS14 1TE, Annexe, Highgate Hill, London N19. Sec G3ZKE. Ilford RSGB Group -Thursdays, 8pm. 50 Mortlake Road, Ilford. Details from D. T. Sapworth. G3YM W. Northolt (British Airways European Division ARS)-First REGION 17-RR L. Hawkyard, G5HD, 100 Shirley High Street, Monday in each month. Trident Club, Western Avenue. Northolt, Southampton, Hants. Middlesex. This club is open to non-BA employees by invitation. (No Information received-Ed) Contact G3OUF, tel Amersham 21573 for details. Civil Aviation Sunday net at 1100-1200gmt on 3.88MHz. listen for G3NAF or G3BEA. South Kensington (Baden Powell House Scout ARG)-Third REGION 18-RR P. J. Fay, G3AKG, 5 Harland Way, The Glebe, Tuesday in each month, 8pm. Baden Powell House, Queensgate, Washington, Tyne & Wear NE38 7RB. South Kensington. Durham (DU ARS)-Alternate Wednesdays during term. Physics Southgate (SRC)-Second Thursday in each month, 8pm. The Dept, Durham University. All local amateurs are welcome to join. Green, Winchmore Hill, London N21. Sec G4AEZ, tel 01-366 7166. Talk-in by G4DUR on R5 or 520 before all meetings. St Albans (Verulam ARC)-20 July ("Modern ri circuitry and Easington (AR&EC)--Tuesdays and Thursdays, 7.30pm. Easing- construction" by G8DKK), 25 August (Talk and slides by G2YS). ton Village Workman's Club. RAE and morse tuition if required 8pm. Market Hall, St Albans. Informal meetings at Salisbury Hall, (the club has a good RAE pass record). ATV can be received on London Colney, on 2nd Thursday in month. Congratulations to 625 lines. The club is now equipped with an hf transceiver as well G3TMA. Ian Buffan. as other gear. Sec G4C0I. Stevenage (S&D ARS)-First and third Thursdays in each month, Great Lumley (AR&ES)-Alternate Wednesdays 7.30pm. Great 8pm. Hawker Siddeley Dynamics Ltd., Gunnels Wood Road. Sec Lumley Community Centre. Assistance with RAE and morse if Trevor Tugwell, 11 The Dell, Stevenage. required. SWLs welcome. An excellent lecture on communication satellites was given on 12 April by Dr Triogga. It was suggested after the lecture that a course on satellites, including weather maps and Oscar, together with constructional work, be held in Newcastle at some later date. Anyone interested contact the sec G8JLQ. Hartlepool (HRC)-Mon days, 7.30pm. Methodist Church Hall, REGION 20-RR G. Mather, G3GKA, 8 Hills Close, Keynsham, Grange Road. Sec G3N WU, 73 Eamont Gardens, Hartlepool. Bristol. Middlesborough (POARC)-Sec G8CDP, 48 Grange Rd, Hartle- Bath (B& DRG)-Tuesdays, 8.30pm. The Crypt, Ascension Church, pool, Cleveland. 35a Claude Avenue, Oldfleld Park, Bath. Sec N. S. Cridland, Flat 3, Morpeth (Northu mbria RC)-Now meets Thursdays, British 30 Paragon, Bath BA1 5LY. Legion premises. Gambols, nr Blyth. Sec G4AVO. Bristol (BARC)-Tuesdays, 7.30pm. The University Settlement, Newcastle upon Tyne (Tyne and Wear Repeater Group)- Barton Hill, Bristol 5. Sec G8KGE. First Wednesday in each month. Arts Com mon Room, University Bristol (Shirehampton ARC)-Fridays, 7.30pm. Twyford House, of Newcastle. Open to all interested amateurs. Sec G3URE. Shirehampton. New members most welcome. G4B WB. South Shields (SS&DRS)-Fridays, 7.30pm. Trinity House, Old Bristol (BRSGBG)-25 July ("Amateur tv" by G8FNR, G8GLQ and new members welcome. Sec G8BQF, 67 Lauderdale Avenue, and G8KGH), 21 Aug (Bristol mobile picnic, Ashton Court), 22 Aug Kings Estate, Wallsend. (Home-constructed equipment). 25 Sept (Brains trust). 7-9.30pm. Teeside Repeater Group-Sec G8MBK. Group open to all amat- Small lecture theatre, Queen's Buildings, University Walk, Clifton, eurs. Bristol 8. Sec G4FRG. Tyneside (TRS)-Mondays, 8pm. The Community Centre, Vine Cheltenham (CRSGBG)-First Thursday in each month, 8pm. St, Wallsend. Sec Alex Frazer, 35 Percy St, Tynemouth. The Old Bakery, Chester Walk, Cheltenham. Sec G3KII. Cheltenham (CARS)- Wednesdays, 8pm, St Marks and Hestors Way Community Association, Brooklyn Road, Cheltenham. Visitors very welcome. Sec G8JAY. REGION 19-RR D. S. Smith G4D AX, 151 Hamper Mill Lane, Taunton (T& DA RS)-Fridays, 7.30pm. Jelalabad Barracks, The Oxhey, Watford, Herts. Mount, Taunton. Sec G. Swetman, "Little Copse", Monkton Heath- Acton, Brentford & Chiswick (ABCRC)-19 July ("My first field, Taunton. Tel West Monkton 298. contact as a G" by G5FVE/VE6CBN), 16 August("The disappearing Western-super-Mare (WsM RS)--Second Friday in each month, inductance", discussion on the article by L. A. Moxon). 7.30pm. 7.30pm. Room Lewis M2, Worle School, New Bristol Road, Worle. Chiswick Trades & Social Club, 66 High Road, Chiswick. Sec G3PQE. G3GEH. Yate (Y&DARC)-First Saturday in each month, 8pm. G3RQN Barking (BR&ES)-Mondays (Constructional), Wednesdays QTH. All welcome, including S WLs. Local chat channel S24, (CCTV techniques), Thursdays (Informal). Morse classes Tues- 145.6MHz, 2100 Wednesday and Saturday. Further info from G8LGC. days. 7.30pm. Westbury Recreation Centre, Westbury School, Yeovil (YARS)-Thursdays, 7.30pm. New venue: Hut 101, Hound- Ripple Road, Barking, Essex. Sec N. Dowsett, 44 St Anne's, Bark- stone Camp, three miles W of Yeovil, off A3088, info at main gate. ing. Sec G3NOF.

RADIO COM MUNICATION July 1977 553 Telford Tel°, showroom cond, £65. Buyer collects. G3EFP, QTHR. K W2000B, exc cond, ac power supply, spkr, 20 spare valves and four 6146. Just overhauled, £215. Datong rf clipper, hardly used, r members' ads perfect, £30. G3HCU. QTHR. Tel 0306-730 215. FTIOIE, £400. 2m Europa, £45. MMT 432/144 tx/tx, £115. 2m 54 whip and window clip, £5. 10m FIexiwhip with base and 80m coil, £8. Home-brew hf linear. Offers. G W4CBR, QTHR. Tel 064625534 evenings. These subsidized flat-rate advertisements are accepted as a service TR2200G with helical, S20, S22, R7, nicads, MB1A Modular Elec- to members of RSGB. They must be submitted on the Members' tronics FM15P amplifier, ASP 5.18 whip, magnetic base, 15 extra Ads order form printed in alternate issues of Radio Communication, channels, the lot for £180. Microwave Modules 432MHz converter, or on a postcard similarly laid out. Each must be accompanied 28MHz It., E18. T and T 144MHz preemie, £6. Coder dc psu, £10. by a recent Radio Communication wrapper addressed to the G3ZXF, QTHR. advertiser, as proof of membership, and a remittance by postal Standard C146A, 5ch fitted, toneburst, telescopic and helical order or cheque for 75p (stamps not accepted). They will not be whips, base charger, £95. FSM:audio monitor, £3. Last seven years acknowledged. Those not clearly worded or punctuated will Radio Communication, couple missing. Offers. Odds and ends. be returned. No correspondence concerning this service can G4BJM, QTHR. Tel 0908 72463. be entered into. Eddystone 770R vhf rx, exc cond. £120 or offer. G4E0G, QTHR. The closing date for each Issue is the 1st of the preceding month, Tel Lydd (0679) 20387. but no guarantee of inclusion in a specific issue can be given. K W2000A/B dc power supply, £25. Graham Down. 43 Cedar Drive. Valid advertisements not published in the issue following receipt Sutton-at-Hone. Dartford. Kent. Tel Farning ham (0322) 862736. will be held over until the next issue. BRT4OOK rx, 160kHz 30MHz. £40. U450E tx, fitted toneburst, RB4 Trade or business advertisements, even from members, will not and SU8, £30. Sentinel 70cm converter, if. 28MHz, as new. £14. be accepted for Members' Ads but should be submitted as classi- Cambridge U108, fitted 6ch, RB2, RB4, RB6, RB10, RB14 and SU8, fied or display advertisements in the usual way. Traders who are spare pa, £70. G8ABB. QTHR. Tel 0908 78102. members must enclose a signed declaration that the items for sale Ham marlund HQ180 rx, sell or exchange Hallicrafters SX122, or wanted are part of, or intended for, their own personal amateur HQ100, Sc828, Sc432, or why? G4A FY, QTHR. Tel Kidderminster station. 63358, The RSGB reserves the right to refuse advertisements, and 70cm 46-el Multibeam, immac, £10. R1155, 75kHz-18MHz continu- accepts no responsibility for errors or omissions or for the quality ous, with case, psu, audio amp and spkr, £15. JR500S. with matching of goods offered for sale. Advertisements may be edited or abbre- spkr and headphones, good cond. £45. Pye Cambridge, low band viated as necessary. comp, £6. G4CFA, QTHR. Tel Formby 77920. Russian C1-5 oscilloscope 10MHz bandwidth, little used, as new, Post to: ME MBERS ADS, "RA DIO CO M MUNICATION", spare valves, leads, manual, £40. Buyer must collect. Consider 35 DOUGHTY STREET, LON DON WC1N 2AE. exchange for 2m/70cm gear or rf sig gen. G8MES. Tel Sheffield 389229. QTH: end terrace, partially modernized, two receps, kitchen, two large beds, bath, spacious loft, front and 70ft rear gardens inc out- FOR SALE buildings, 400f1 sal, good amateur site, freehold, offers around Trio 7200G, 9ch fitted, first-class cond, not used mobile, comp £7,000. G4EUE, QTHR. Tel Tamworth 872159. with mic, power lead, car mount and manual, original carton, £140. 18AV r WB vertical, 9 months old, £40. G4FMZ. Tel Titchfield Buyer collects please. G3KZU, QTHR. Tel Oxford 63000 evenings. (Hants) 43410. Standard C146A, 5ch, toneburst, base-master, nicads. flexi-whip, KW Vespa mk2, tx, 160 to 10m ssb,cw/a.m., 6LQ6 pa, with spare mic. £120 ono. lcom IC21, 10ch, ac/dc, external vfo, £150 ono. KW valves, vgc, £85. IC202, vgc, £130. Preferably buyers inspect and 2m tx, a.m.itm, £15 ono. G8HEB, QTHR. Tel 021-357 1924. collect. G4EAX, Tel. Long Eaton 69238 evenings. AR88D with S-meter and handbook, recently overhauled, £50. Trio QR666 gen coy rx, good cond, £80. 2m 8-el XV with circular BC221 in table-top case with mains supply and calibrations. £25 phasing, harness, £10. 70cm Multibeam. £8. Joystick and 500W ono. RCA 807s, £3 pair. Five-pin UX ceramic bases, 5R4GYs, atu, new, £20 ono. G4FDR. Tel Albrighton 3793. 5U4Gs, 6V6. wide-range 6V octal valves. Tested. Any sensible H W17A with fm adapter; HG10B vfo; BC221E psu, charts, spare offers. Tel 024-05 2533. valves; CT471A electronic multimeter; Emsac 2m converter with Green and Davis psu, 20W, 2m and 70cm, fixed or mobile, £50. psu; U450L tx and rx on 70cm; AM25Bs, 2m. one fm, other a.m.; Marconi Marine receiver 3873B. 500kHz-30MHz comp with manual, Koyo tape recorder with fm. Reasonable offers, please. G4DEL, £50. G5SN, QTHR. Tel Southend 554846. QTHR. Liner 2 comp with mic, manual, leads, mobile mount, in original FTI01, little used, manual, 10-160m. fan, £275. G4EJV. QTHR. Tel carton, £110 ono. G4BFJ, QTHR. Tel Burgh Heath 55196. Worthing (0903) 65625. National Semiconductor SC! MP micro-processor introkit and Pye Cambridge U10B, ok 70cm mobile, £30. Technical Products keyboard kit, built and tested, £100. Univac terminal keyboard, 101 TE15 dip oscillator, 440kHz-280MHz. £20. AR30 rotator, brand new, keys, suitable for rtty. micro-processors, vdu etc, £30. No offers. does not fit my 2in mast, £35 or exchange for AR40 etc with cash G8LLB, QTHR. Tel 01-478 7557 daytime. 01-531 0716 evenings. adjustment. G8IXK, QTHR, Tel Luton 23827. Trio JR500S rx 80-10m, £40. Heathkit DX100U tx 160-10m, £30. Cosser 339 double-beam scope, £5. Various ht transformers. G3VOK, QTHR. Tel 0582 413909 after 5pm. Cameras: Minolta 16m m. £8; Halina Super 8. £8. Wanted: Coder TS 700G, £350, FRDX400, £165. Osker SWR-200 pwrIswr meter, T28, wkg but any cond considered. M. Lang, 9 Kinver Terrace, £15. IC22 12ch, in use daily, £125. All exc cond. MBM 46-70cm, £10. Burnham-on-Sea, Somerset. Tel Burnham 785976 most tea-times. G8ESK. Tel Bradford 45611. Property of deceased amateur: Ham marlund HQ180 gen coy rx. Pye base ta, a.m./fm cw, 6ch, in cabinet, 640A in final, £25 ono. BC221 freq meter. AR22 rotator. Coder PR30 rf pre-selector. Two Buyer collects or carr extra. G4FDQ, QTHR. Tel Lancing 63673. 811A valves. 36 Douglas Street, Motherwell, Lanarkshire. Tel Storno base station, 240V 12W stalled S20;SN;LO, control box, Motherwell 63732. ASP670, £45. Storno Viscount, stalled S20'21/22'SO,'SN LO, ASCII keyboard, data available. £10. AR20 rotator motor, new, control box, ASP670, £45. Storno Viscount, stalled 144.48, control £7.50. Wanted: 10-40 vertical (Atlas or similar), must be cheap. box, ASP670, £30 any trial. Storno base station 240V 12W, stalled G8HGO, QTHR. Tel Thatcham 65617. 70.48, complete with control box, seen wkg. G3PQC, QTHR. Tel Storno base station CQF13, 10W, 6ch, R5, R6, R7 (tx only), S20, Farnborough 44268. S21, S22, home-brew control unit, ptt mic, meter, vgc. £55 ono. KP202, as new, vgc, fully xtalled inc R6 and R7 toneburst, helical G4F0Y, Tel Alton (0420) 82855. telescopic whip, leather case, nicads, charger, antenna adapter, K W107, atu, swr. psu, 52f.) dummy load, £46. G3V WS, QTHR. Tel £120, or will exchange with cash adjustment for TR2200GX in similar Newark 2413. cond. G8JKA, G4FYA. QTHR. Tel after 6pm. HPZ3A psu with handbook, £25. Carr extra. Com mand rx 1-3-3MHz, Trio 9R-59DS all-bands com munication receiver, exc cond and £5. G3RB. QTHR. Tel Whitley Bay 530504. wkg order, voltage stabilized, handbook, £45. G3WMO. QTHR. Heathkit comp station. Factory built $8401 tx, $6301 rx with all Tel 01-363 5814. filters, Heath 2m converter, S8600 spkr. S8200 linear, SB610 Eddystone EC10 mk2, mint cond and in pert wkg order, mains and monitorscope. all perfect with manuals and many new spare valves. portable power packs, operating manual, Securicor delivery, £155 £495 comp. May consider separating. G2ABX, QTHR. Tel Sambrook ono. Phil Hodson, 43 Thorpe Road, Melton Mowbray, Leics. 531.

554 RADIO COMMUNICATION July 1977 K W2000B, vgc, fitted new 61468, about 50 spare valves incl two 2m 8-over-8 slot beam, £8. R1155B, internal psu, £12, 300(1 tubular, pairs 6146, sale to include ac psu, £195. no offers. Tel Hayling 30ft. £2. Ferris signal generator, 85kHz to 25MHz, £12. Pi tank, 3.5- Island 4013. MHz, to 30MHz, pa 807, £3. Xtals, filters, transformers etc. SAE for Trio JR599CS rx, exc cond, £150 ono. Yaesu FL50B, FV50B, exc list. G3CBU, QTHR. Tel 0256 58921. cond. £90 ono. Will not split Yaesu. G4EKS, QTHR. Tel Eastbourne Pye Vanguard fm tx, mic, control box, cables, plugs, S20 xtals, 32777. wkg well, £27 ono. R107, wkg. £6. R1392D with data, wks but needs Trio TS700 taira, fitted xtals 520, $21, S22, R6, £270. Belcom LA106 aligning, £6. R7, tx xtal, 8MHz, new, £1.50. G8NAQ, 48 Stonor Rd, 2m linear amplifier, 180W p.e.p., input power from 10W drive, £100, Hall Green, Birmingham. Tel 021 745 2750. near offers considered. G4FYS ex G8KME. OTHR. Tel Yeovil 4773. K W2000, vgc, ac/dc power supplies, service manual, Shure mic, Trio 7200 2m rx/rx, five repeater, six simplex channels fitted, mobile £110. No offers, buyer collects. G3NEP, QTHR. Tel 0246 823347. mount, mic etc., £135. Vibrotrol 2m 12V solid-state amplifier, 100W Calibrator Nol, £3. PR813s, £4. Murphy 4m base station, £3. o p version, £75. G3OUF, QTHR. Tel Arhersham 21573. BC221, charts, £12.50. Teletype station, comp, wkg, £40. Hammond FM1013 rx, comp. wkg R7, £25 ono. F450T tx, 5W, wkg, £25 ono. organ, £350. 2m and 4m beams, £3 each. G3PBQ, QTHR. 021 373 Cambridge solid-state osc boards tx;rx, 6eh, £3 each. Carr extra. 2282 evenings. G8HNN, QTHR. Tel Worcs (0905) 22704. Atlas 210 with de luxe mobile mount and antenna matching trans- 0S-2 scope, unused, £40. CT436, £70. Viscount 3 141 14W amp, former, few hours use only, £380. Hygain BN86 balun, £10. Drake exc cond. £17. 1025 deck, £8. APR4Y i.f. unit with tuning units, £100 TV3300LP low-pass filter, new, unused, £14. J. L. Barry. 13 Mill Rise, ono. Radiotelephones for spares, from £1. TCS tx, £6. Black 88 set, Bourton, Gillingham. Dorset. £3. N. Hammersley, 410 Liverpool Road, Rufford, Lancs. Hallicrafters Hurricane SR2000 tx/rx 80 to 10m, 2kW p.e.p. Icom Pye PF1 comp with deacs and wkg on 433.2, two sets, one with IC201 multimode 2m tx1rx, highest offers secure. Wanted: Drake charger, £35; one without, £30. S. Wheatley, tel Hurstpierpoint C-line, R4C, T4XC, L4B or SB220. Will sell SR2000 only on purchase (Sussex) (0273) 832435 after 6pm. of Drake Line. G3XVF, QTHR. Tel Norwich 56782. IC202 ssb/cw hand portable rig. covering 144.0 to 144.4MHz, 3W IC202, £128. TR2200G, 7ch. £80. MM 144MHz converter, 28MHz it., output, exc cond, £130. FT221 forces sale. G8JSK, 18 Mayfair Ave, £11.50. MM 432MHz converter, 28MHz if., £13. Belcom 12V psu, £14. 1pstones, S-o-T, Staffs ST10 2QE. Commercially-made 432MHz tripler. £9. BC221, charts, psu, £13. Single meter swr bridge SWR10, £5. Pair Eagle FR65 10W 8(1 Elderly HAD, works well, £14. G8DEE, QTHR. Tel Cambridge 64251. spkr chassis, £10. Microwave Modules 70cm converter. 28MHz 3BP1 crt, brand new, £8. CBM 7919D calculator, 29 functions, with if., £10 ono. QQZ06-40, Mullard, unused, with base, anode connec- case and mains adapter, £12. Buyers collect. Martin Berson, 31 tions and tuning sub-assembly, £4 ono. YL1130 driver, £1. G8KAX, Aldbourne Road, Burnham, Bucks, Tel Burnham 3756 after 4pm. QTHR, SB303, exc cond, swop for good value hf rig. Creed 75 mk3 printer. Yaesu FT200 with FP200 psu, exc cond, £200. Trio J R310 rx, boxed, £20. Lafayette 1-1E40, £20. Electronic flash gun, replaces flip-flash with spkr, a.m./ssb/ew 10Hz mach filter, £75. Eddystone 840C rx, bars, £7. Turner, 14 York Way, Thetford, Norfolk. Tel Thetford little used, no mods, £50. All fine cond with manuals.G4FQP, QTHR. 61648 after 6pm or Thetford 2484 ext 40 9am to 5pm. Tel Scunthorpe 720 794. 2m synthesizer, 5kHz steps. 144-148MHz, two independent selec- Heathkit H W32 20m ssb taira without spkr or psu, £50 or, with tors enable instant repeater/reverse or input listening, HW202, mic, HP23 mains psu, £65. Hudson AM108 4m radiotelephone with bracket, all documents. £130 ono. C146A, fitted R6, R7, SO, S20, 321, handset, £5. Pye Reporter PTC116 radiotelephone, rx on 70-375. helical whip, £85 ono. G8ITJ, QTHR. Tel Maidenhead 27460. no xtal in tx. without mic, £3. G3VSJ, QTHR. Tel Hodd (099-24) 68052 Teleton stereo cassette recorder, CR02, Dolby, counter, £40. Rank after 6pm. 300 slide projector, £12. Loudhailer, 10W, £15. Pye Westminster Wharfdale Golden spkr, 10in, 30, £3. Valves: 813. 2E26, £2 each. W15AM, tunes 144-146 a.m./fm, 3ch a.m. Ix. mic, spkr, manuals, £50. 5763, 6BW6, three for £1. Hundreds of unboxed valves, early and Carr extra. G3XKA, QTHR. Tel Woking 73620. late, some new, specials. G3MBL, QTHR. Tel 01-445 4321. Marconi mk3 tv studio camera, comp and wkg, viewfinder, monitor. 7261. press-button dialling telephones, £2.50. Wavemeter, £8. etc, £75. 14in monitor, very clean inside, good picture, £14. Camera R208 rx battery or mains, £10. Storno Viscount controls/spkr, £4. pan-and-tilt head with wedge plate, for cameras about 80Ib wt, £12. Microwave burglar alarm, £25. Variac transformer, £10. Valve volt- 44-In 10 yoke, £4. 3in 10 camera, transistorized, £25. G8GQS. Tel meter, £10. Radiovisor Ray burglar alarm £15. W. H. Joyce, 41 Gainsborough 3940. Rochdale Road, London Ell 8JF. Tel 01-539 5421, Yaesu FRG7 rx, vgc, £130 ono. Codar C70A rx, £28 ono. G8NHN, 10 M M T 432/28 transverter, over 10W output, low noise input, little Filey Road, St Annes-on-Sea, Lancs. Tel 0253 722652. used, £75 post paid. GW8A AP, QTHR. Tel 07456 2550 after 5pm. ACCU keyer, inc psu, case, latest Browns twin-lever paddle, solid- Atlas 210X tx, six months old, unused, mains power pack, G-whip state output, £25. Spare pcb with ic holders. £3. G3RUG. Tel mobile antenna, 10-80m Yaesu, mic, £425. Marconi TF1100 valve 061-439 7183 home, 061-483 2188 work. voltmeter, £30. Creed 75RO, silent cover, wkg and in exc cond, £40. K W Viceroy tx with psu, cct diagram, £40. Labgear Topbander James. Tel Dereham (Norfolk) 2437. with cct, modulator disconnected, £5. Incomplete vols of Radio Scorn IC22A 2m mobile tea. 11ch, mobile mount, good cond, Communication 1949-69, offers. Delivered 20 miles radius of Lough- surplus mains power supply, £140. Tel 061 431 3725. borough. G3XAZ. QTHR. Tel 0509 30957. Sensitive Collins TCS12 2w rx, SSM converter, S-meter. Q- BC221 with psu, charts,. £15. RAE course (31 lessons), £10. E-Zee multiplier, fm disc, noise limiter, remote spkr, psu, £25. AR20 match, £12. KW swr meter, £4. G4CZD, QTHR. Tel Gravesend rotator, 45ft cable, £25. Unused 70cm converter, 2m I.f., guarantee, 61252. £15. Gares 60W inverter psu, 250V, £3. AEC SWF(20 power/swr FT401 ORO rig, with cw filter, vgc, £230. Heath SE1.303 superb rx, meter, £4. Buyer collects or carr arranged. G8LKR, QTHR. Tel vgc, £135. Both ono. G4EGS, QTHR. Tel 051-427 1931. FT200 plus FP200, vgc, £230. Slow scan tv, com mercial pee. home- Hitchin 730 550. made case, spare 5FP7, £40. Buyer Inspects. 2m to mw converter, Heathkit SW717, Gen coy, Heath constructed, as new, exc cond, £4. 2m 51.8 antenna, £4. G4A WL, QTHR. Tel Cosham 79153. £50 ono. Bob Downing, 50 Woodfield Road, Solihull, W Midlands. Telford TC7 mk2. £45. Telford TL9, toneburst, £65. Withers Two- Tel 021 705 8451. mobile. a.m., £30. G8AEV converter, 4.8-6.8 1.1., £10. Pye Reporter 840A/320 bases, new, silver plated, ptfe inside, boxed, £1.75 each. tuneable rx, tx on 2, a.m., £12. Pye Hand Ranger, £10. G8G AZ, QTHR. Pair used 813s, useable bases, heater transformer, £5. Large eht Tel 021-357 1924. transformer 2-0-2kV under rated 400mA, buyer to collect, £5. MF455- Farflsa VIP345 electronic organ, home use only, hardly used, 1OCK, £10. HRO skeleton, 8 coils, psu, £7,50. G4AFS, 0TH R. comp with pedalboard, seven flute stops, piano and harpsichord Microwave Modules MMC 144/28 LO converter, BNC sockets, as presets, sustain, six percussion, syntheslalom, £280 ono or swap new, £14. MMC 14428 with 38.667MHz xtal, £8. G8AYY, QTHR. for 2m mobile or why? G3UZI, QTHR. Tel Horsham (0403) 66327. 14AVQ/WB with maker's 80m loading coil, used, £35. Heathkit Barlow Wadley XCR30, mk2, six months old, in original container, HFW1 tv generator, mint, £30. Vanguard AM25B, 6ch, 2m, some immac cond, white stick owner unable to tune bands accurately, xtals, internally excellent, £25. GW3G W A, QTHR. Tel 097 881 3891 £103. 136 South Street, Andover, Hants SP10 2BS. ext 231 wkg hours. Cossor 1035 scope with manuals, £15. Eagle FMT-640 fm tuner, £6. Trio TS520 txlrx, as new, £320. Cooper, 17 Castlepark Drive, Mullard type-C tape preamp, never used, with cct, £5. Triang 12V dc Fairlie, Largs, Ayrshire. transformer, £1.50. G8AZG, QTHR. Belcom Liner 2DX, later version of Liner 2, 144-05-144.625 ssb/cw, Eddystone 888A, vgc, tilt blocks, S-meter, manual, 985kHz xtals, -,5kHz shift to QSY, vxo. rit. af and rf gain, offers. Two MM 2m five new spare valves. Wanted: FL50B, FR5OB calibrator, mint cond, preamps. £10. MM 70cm/144 converter, as new with BNC, £16. manuals. Garex 2m xtal converter, original cond, not wkg. Voltage Lamb, 51/3 Vineyard Rd, Northfield, Birmingham B31 1PJ. Tel stabilizer, 190/260 in, 230 out, 150W. Offers please. G3FK, QTHR. 021-477 2029 after 5pm. Tel Breamore 436.

RADIO COM MUNICATION July 1977 555 Q M70 2m solid-state transverter plus linear, £48. UHF Cambridge Pye Vanguard FM25B, 520, S21, S22, S23, R6, R7, preamp, auto U10B, xtalled RB2•SU8, £35 ono. Starphone M5 multi-channel, fitted toneburst, exc cond, £50. Lowe Monitor 1420 rx, S20, S21, S22, R6, RB2;SU8, all solid state, approx 6W op. dashmount, £80. G3NPZ, R7, £20. BC221 with charts, £12. G4DTR, QTHR. Tel 061-439 8422. QTHR. Tel Titchfield (Hants) 43894. Trio QR666 gen coy rx 150kHz-30MHz (22-30MHz dual conversion) FT220 2m tx;rx, £220. Heathkit 5E1310 rx, gen coy, plus 80, 40, 20, a.m., ssb with bandspread, hardly used, £100 ono. Tel Buckland 15m, £130. Both items in exc cond. G8HVI, QTHR. Tel Stadhampton Newton (030 05) 223. 890910. K W107, mint, will exchange for 109 or similar with cash adjustment. FT200 FP200, exc cond. full 10m coverage, new pa tubes, £240 ono. G4GJ, QTHR. Tel Bingley (097 66) 2965. Swan rital table mic, £8. Delivery may be arranged to UK mainland, Subminiature 4-pole changeover relays, 70011, max current 1A my expense. Winch, Air Traffic Control, Belfast Aldergrove Airport, dc, pcb mounting, fitted with dust-proof covers and sockets. ex- Antrim, N Ireland. Tel Antrim 5611. equipment, exc cond, £1 each, postage 10p per relay. J. W. Hender- Eddystone 898 dial, unmarked, £8. MM 28:144 converter, oscillator son, 53 Dumyat Drive, Falkirk FK1 5PA. oip. £15. Jaybeam, 2m 10-el plus 39ft UR67, £14. Two QQV0640A, Trio TS520, virtually unused, mint cond, still under guarantee, £310. second-hand, good cond, £1.50 each. G3JDN, QTHR, Tel Reigate Midy VN 80-10m trap dipole, unused and boxed. £25. G3P0Q, 40646 alter 6pm. QTHR. Tel Hailsham (0323) 840379. IC22A, R3, Ra, R6, R7, RR7, SO, 520-S23, preamp mic, mobile mount, Xtals XF901, 1MHz, B7G, £1 each; wire-ended 80MHz. 72-687MHz, manual. £140. Liner 2, 1441-144-33, mic, mobile mount, manual, psu, 73MHz, 50p each; HCU, 30MHz, 40 MHz, 75p each; 2N3632, £1 each; £125. G3TCG, QTHR. Tel Fairseat 822043. BLY36, 50p each; SG1495D, £1 each; QC)V03-20A, £1.50 each: Atlas 180 comp with ac consul, £300. M. Giles, 9 Napier Close, R1475 rx, acidc psu, handbook, £15 ono. G4AJC, 21 Northcroft Fairstead Estate, Kings Lynn. Tel Terrington St John 401. Road, Ewell, Surrey. Tel 01-393 1876, Pye Cambridge, boot mount, 2m, 1m, 6ch, with control box and Solatron 513 scope, £35. Nombres sig gen, 220kHz to 230MHz, £7.50. cable, £25. Pye fm base, 6ch, £18, GW8HDH, QTHR. Tel 0792 22287 Carr can be arranged. G8LCO, QTHR, Tel 0783 842350. after 6pm. Microwave Modules 144•28 transverter, only few months old, £75 Heathkit SI3102 tx'rx wih power supply, spkr and manual, in mint ono. G4 FHX. Tel 01-428 7039 after 7pm. coml. £200. Firm, tel 051-677 5409. Stabilized mains power supplies, suitable for Liner 2 or Mt Tower BX1, two sections, £75. 7200G, mint, £150. IC22A, mint, equipment, adjustable from 8 to 18V dc, 3-5A, £20. New transformers A R88LF, £30. FT560, £215. KW160, £15. 10-el 2m beam, £6. Junkers oil filled, 1,185-0-0-1,185V, 360mA, £8.50. New mains transformer, key, £14. Heathkit power supply, HW101 etc, £30. ROR 2-el beams, 0-465V, 350mA, 50V, 50mA, 6-3V, 6A, £5. 813 base, 60p. SAE enquir- £8. KW103 swr meter. G4DYR, tel Wolverhampton 763504. ies. Carr extra. G4DFE, QTHR. Liner 2, fitted preamp, exc cond, £100. G4D UE, 18A Spencer Close, Trio 7200G, fitted SO, S20, 521, S22, R3, R6, R7, SUB xtals, SSM rf Potton, Sandy, Beds. Tel Potton (0767) 260552. amp, sial toneburst, performs well, £145. Matching VF0309, £35. H eathkit SW717, gen coy, well constructed, exc cond, manual, £35 Discount for both. G4DCQ, QTHR. ono. Jeff Jackson, 28 Church Rd, Newbury Park, Ilford, Essex. Tel 4CX250B valve, new, with uhf base, £7 ono. Will separate. G3V W0, 01-599 8852. QTHR. Tel Fencehouses 2301. Trio 9R59DS rx, fitted voltage stabilizer, 100kHz and 1MHz xtal Yaesu FR5OB communication rx, mint cond, amateur bands, xtal markers, manual, loudspeaker, vgc, £45. Microwave Modules calibrator, manual, £70. Lees, 450 Castle Lane West, Bournemouth, converter, 2m, 2 to 4MHz it., almost new, £12. Wanted: vhf and Tel 517200. audio sig gene. G8JTE, QTHR. Tel E Grinstead 22944. Property of deceased amateur. KW station comprising KW200E, Microwave Modules MMT144/28 transverter, works well, almost KW107. KW spkr and KW Q-multiplier units, £375 the lot. Prefer new, surplus, £60. G3REO. Tel Coniston 329. not to split. Buyer views and collects from A. H. Othen, G8FSZ, AV O Model 7, £14. AVO Multiminor, £5. A VO Minor with leather QTHR. Contact via RSGB HQ or tel Byfleet 48307 evenings. case, £3. Each instrument in exc cond and full wkg order, comp Two homebrew ATUs with roller coasters, etc, £4, £3. Aircooled with leads, prods and batteries. G8CCI, QTHR. Tel Oxford 880229 50(1 dummy, £4. Antenna switch. 6-way, S0239, £3. AEC swr meter, weekends or evenings alter 7pm. as new, £7. Joystick vfa. £5. Heathkit Mohican, vgc, mains psu, £40. Storno CQF614 25W 2m fm base station, 1,750Hz, control gear, G4EAQ, QTHR. Tel 01-327 5989. vgc, £110 ono. Storno COL600 4m fm mobile, vgc, £55. Pye MF5U 18AVG) with guys and insulators. Wanted: Bird 43 ht inserts for 70cm mobile, SUS, SU20, RB14, £85. Pye PF5UH 70cm handheld, 2-30MHz. G3SLI. Tel Reading 479850. £55. RCA R17M20 2m fin 20W amplifiers, £10 each. 0880Y, QTHR. Stolle semi-auto rotator, 8S-el Yagi, 2 by 2011 pole, 2 by 24in ASP655 base station antenna, brand new and unused, £12 inc brackets, buyer dismantles, very reasonable. Will exchange. carriage. G8EPQ, QTHR. Tel Kings Lynn (0553) 61554 after 6pm. G3E0F. Tel 01-650 5129. Liner 2 144-10-144-33, fitted with PA3 preamp, exc cond, plus R1155 rx, wkg order, with lash-up psu if required, fitted output stage, homebrew psu, £120. G810 X. QTHR. Tel 0909 2180. £17.50. Wanted: beam rotator suitable for 10m Monobander. G4FMO. 2000A, exc cond. £160. Honiebui It linear, from SW M Oct 68 design, Tel Ashby de la Zouch, (05304) 3973. £35 ono. Eddystone EC10 mains psu, £50. Buyer collects. G2VO, FDK Multi 2000, lx ,rx, fm;ssb, fitted T T prearnp, toneburst, Tel Keighley 603021. manual. £150. GM4DNM, QTHR. Tel 0592 720224. FT200, FP200, DC200, exc cond, with leads and manuals, £275 or K W Atlanta, ac psu, handbook, ne,.v pa valves, exc cond, with offers. Wanted: G3ZVC ic txf rx kit. G3SCU, QTHR. Tel Exeter 77714 Shure mic, £170. Lionel J36 bug key, £5. Ribbon desk mic, hido Z. after 6pm. £6. Collect or carr extra. Crisp, Rante Barton, Rame, Penryn, Corn- Heathkit Mohican, plus manual, £20 ono. G8L WD, 87 Alderson wall TRIO 90Y. Tel Stithians 516. Road North, Sheffield S2 4UF. Tel 584586. K W2000E, mains 'Jett, KW110 Q-multiplier, £325. G4CFF, QTHR. Heathkit 58303 hf rx, fitted with optional cm and a.m, filters plus Tel Thetford (0842) 2957 after 6pm, SB600 matching spkr, £250 ono. G8JBK, QTHR. Tel Colchester FR101 DD digital rx with all optional extras, perfect co nd, £410 ono. 230318. BSA/flake lour-stroke petrol generator, 500W at 240V de, £45. Trio JR310 rx, SP5DS spkr, exc cond, £66. AR88 rx, good cond, 5FP7 crt. £6. Creed 75RU teleprinter, synchronous motor. Murray £35. DX4OU lx, good cond, £15 ono. Homebrew 2m converter, 51, code, £20. Wanted: Icon) PL-VI vfo. M. Watson. Tel 01-903 4363. 7.1MHz if., £6. Buyers to collect. Gibson, 1 Tamar Gardens, Walney Pee Vanguard, modified ant, five lx ch, leads, control box, mic, Island, Barrow-in-Furness, Cumbria. instruction book, spares, £18. G8AEH 4m converter, to 29MHz, £7. FT101B, 2 years old, vgc, £320 ono. Microwave Modules 432MHz Both for £22. Buyer collects or transport agreed. GOYS, QTHR. Tel converter, MMC432'28, hardly used, £20. Modular Electronics rl Rickmansworth 76864. padboard with design data, £2. Deliver locally, or buyer collects. SSM Europa 2, transverter, in exc cond, comp with internal G4CIK, QTHR, Tel 0223 66466 ext 356 (afternoons). antenna do relay, preamp and fitted new knobs, 12V transformer Two AR88Ds in fair cond, one wkg, £35, one with fault on voltage for heaters, £65 ono. G3URE, QTHR. Tel 089-426 5311 (work), 3044 circuit, £25. Heathkit RA1, wkg order, £20. C. Fuller, 47 Cooper Road, (home). Croydon, CRO 4DL, Tel 01-709 0280 9.30am-3.30pm. CR100E128, manual, valves, £20. Buyer collects. Liner 2, mains peu, Hallicrafters 2m tx/rx SR42A comp with vfo, £50 ono. G313)(1, £120. Carr paid or exchange for FTV260 transverter or similar QTHR. Tel Great Easton 235. equipment. 2m to 76cm varactor tripler, £15. 70cm solid-state converter, i.f. Two linear QY4-250s plus transformers, £20. Buyer collects 28-30MHz, £15. G8IRJ, QTHR. Tel Steyning 814089. (Yeovil). G3WPB, QTHR. IC22A, mint cond, fitted prearnp, 145-000, 144-600, 145-300, S13, S20, Fine QTH, 5 miles Carlisle (A69), 4 beds, dining room, kitchen, S21, S22, S23, R3, R5, R6, R7, must sell due to purchase of TS700G, large lounge, hall, garagelshack, gardens, access to Lakes and £135 ono. Buyer to inspect and collect. G8DZH, QTHR. Tel 01-508 Scotland, offers around £13,550. G8IHV, QTHR, or Tiffen, 1 The 3434 after 6.30pm. Crescent, Carlisle.

556 RADIO COMMUNICATION July 1977 Liner 2 fitted with 2m rx preamp and 10m preamp (for use with Digital 11 with toneburst, brand new, in original packing with mic QM70 70cm transverter), QM70 28/432 transverter, 10W output, and accessories, covers all channels, repeater shifts etc, exactly as plugs, cables, manuals as supplied, buyer collects, £170 ono. SMC specification, used 10 hours as base station, cost £275. G4FAZ, QTHR. Tele 030-57 71053 evenings. accept £225 ono. DID. G5FH, QTHR. Tel Highcliffe 04252 5974. Icom IC202, 1-hour use only, &cads charger etc, maker's box, £150. Yaesu FTDX401, 560W p.e.p., immac cond, very little used, with T. Watts. Tel 01-485 2231. working hours. mic, plugs, manual and box as supplied, £250. Sphinx ssb Ix, 70W K W500 linear for te, BC221 and psu, £15. KW202 and KW204 for p.e.p., 160-80-20, £30. Rye base tx/rx. 4m low band, £25. UM3 mod tx/rx. Sell or exchange all with cash adjustments. Wanted: atu transformer, £4. 1 kVA transformer, 1,000-0-1,000, £4. R220 4m, £5. 160-10 or 160-20 (1kW). G4FY W, 13 Elmstead Road, Erith, Kent. G3XLT, QTHR. Tel Rochdale 57383 evenings. IC22A, 11 jch, mosfet preamp, all frequencies, just aligned, first- Som merkamp FT250, £190. G3W WH„.. QTHR. Tel Bayston Hill class cond, xtal toneburst, mobile mount and all accessories £145 3383. ono. G300S, QTHR. Tel Bristol 44922. FRG7 in mint cond, few months old, in maker's carton with ac and Storno Viscount, comp multichannel 2m, toneburst, Burns preamp, dc leads, all plugs, manual, surplus to requirements. £140 carr xtals for SO, S20, S22, R3, R4, R5, xtals interchangeable without paid. Stewart, White House, Harris, Western Isles, Scotland. Tel retuning, £60, or £65 with 573 Antec whip. G8KL W, 57 Austhorpe 085 983 223. Road, Cross Gates, Leeds LS15 8EQ. Drake R4C, mint. £300. G4EVS, QTHR. Tel 028 73 2426 after 6pm. Speech amplifier, four inputs, vu meter, soon output, with robust ST7I5A marine solid-state exciter, 1-6-26MHz, 30ch xtals, emission psu, £15. External psu for BC221, £3. Tape recorder with Wearlte Al/A21,43, suitable multi-frequency signal source. £18. Valves: deck, professional preamp, £40. RF ammeters, 0-5A, new, £3, 6146 £2.50. 58254M and holder, £2. RCA 1625s (12V 807). £1. Wanted: many other meters. Leach relays, 220V ac, tpdt, £1. Many others. Manual Alpha 7711 linear. G3JMJ, QTHR. Tel 073 271 3467. Micalex polystyrene. Filament transformers, 6.3V, 6A, 2,000V, £2. Hear what you can work with your pa—fit a mosfet preamp, more 750 heavy coaxial cable. Offers. Postage extra. Moving house. than 15dB gain, 3dB noise figure. pcb size 11 by i¡in, £3.50. Cmos SAE for list. GD3TIU, QTHR. Tel Marown (0624) 85442. toneburst, adjustable, built-In stabilizer, pcb 2 by 13in, £2.50. Barlow Wadley XCR30 mk 2, fm tuner, TR801, manual, exc cond, G4EBI, 99 St James' Road, London SE16 4RA. Tel 01-231 0879 £100. G8ASJ, QTHR. Tel Worcester 820882. evenings. Storno boot-mounted tx/rx (CQMD), stalled for 144.48 and 145.0, Complete station: Versatower P60, two years old, £160. Moseley £20. Rye PTC703/704 base station, needs attention, £7. B. Lambert, Mustang 3-el beam, one year old, £55. Ham-M rotator, as new, £70. 58 Broadmead Road, Woodford Green, Essex. Tel 504 6157. Latest FTDX401 tx/rx with a.m, facility. cw filter fitted, £325. SB610 IC2IXT, good cond, £125. KW2000 dc psu, £25. G3UKE, 65 Brook Monitorscope, £55. G4BLP. Tel 0242 42601 after 6pm. Road, Stansted, Essex. Tel 0279 814889. Eddystone 840A with ext spkr, £20 ono. 8YI2m, 22yds 7511 coaxial, Xtals for Storno Viscount: R5, R6, 144.48. Xtals for TR2200: R6, 15yds UR57/750 coaxial, £8. AR40 rotator, 15m control cable, £35. R7, £3 per channel. RTTY tu. plus printer. G4ALG, QTHR. Tel 2011 by 2in by 3,116in ah, £4. 8ft by 2in by 3/16in all. £1. 5ft by 1;In by Reading 345046. in ah, 50p. Two 2 by 2in scaffold swivel clips, £1. Two one-piece Heathkit amateur band rx, 80-10m, vgc, £50 ono. Four-drawer insulators, 50p. Buyers collect after 5pm Mon-Fri; after 1230 pm all-metal desk, 45in wide, 34in deep, 31In high, buyer collects. £15. Saturday. D. Wooller, 13 Cavalry Crescent, Eastbourne, East EMI Q/0101 oscilloscope and manual (small), needs attention, £5. Sussex. Xtals 99kHz B7G. 19-2kHz HC6/U, wire ends, £1 each. Shaw, 16 Hickock USA vom, 20k0/V. comp leads, case, mint, £25. US Navy Deansfield, Four Spires, Cricklade, Wiltshire. straight key, leads, plug, new, £5. Manuals: RA17, RA63, RA117, Mosley Mustang triband beam, high power, 2kW version, brand 880/2, 75S3. 51S1. 13A scope, etc. SAE list. AVO sig gen, it, 100MHz. new and totally unused, still In original packing case, new price exc cond, £25 plus carr. G3GUU QTHR. £98, will accept £130 ono. Genuine reason for sale. G4ERD. Tel Drake T4XC, R4C, 160-10m, W WV, AC4, 4NB, MS4, Magnum Six, 0509 212583 (Midlands) or 01 561 7903 (London) after 5pm. Shure 444, £850. G4DJC, QTHR. Tel 0245 69034. Redifon GR289 2m tx/rx, 10W output, 12V wkg, fitted R7 and tone, 40ft 2-section telescopic Versatower (Western Electronics) S22, 12ch available, remote control unit and handbook, £60. G3YNP, complete with ground post for swivel mounting, head unit, 40ft QTHR. Tel 01-399 2097. tubular pole with pulley and two braked winches, CDR TR44 rotator KVG XF9B filter, new, never used, with xtals and holders, best complete with meter. 2-el Gem quad antenna complete with all offer over £25. G3RUG. Tel 061 439 7183. accessories. Unused. Offers to: Mrs V. Nairn, G4BML, Cherryfield GRT 2m lcom 240, three months old. Liner 2 preamp, nine months House, Cane End, Reading, Berks. old. Both with mobile mounts 5A8-whip mobile antenna. 5-el X-Vagi. Electronic TO, keier with vibroplex key. Offers for all or separate. Wanted: heavy-duty key. Tel Polmont 711414 or 62770. IC22A, SO, S20, S21, S22, 523, GB3LO, all accessories as supplied, A REMINDER £130. G3G0G, QTHR. The flat rate for Me mbers' Ads was increased Property of late G3CFT. Heathkit DX11:0u te, exc cond, £40. Marconi TF340 op/m, £15. TF144G sig gen, £10. TF329G Q-meter, to 75p for 40 words or less fro m 2 July 1977 £20. TF886A, £10. BC221M, ac charts, recalibrated, mint cond, £25. Solartron VF252 ac millivoltmeter, £20. Ferris N and FSM 32A, £10. Unipivot mlcroam meter, 0-60i1A, mint, £20. AVO CT146 transistor W ANTED tester, mint, £90. AVO CT160 valve tester, mint, £65. All prices ono. K W VFO-4B, top price paid for clean unit, KW son dummy load. G4EJO, QTHR. G4LY, QTHR. Tel East Bridgford 349 evenings. Bolco m Liner 2, built-in mosfet preamp, Pye mic insert, comp with RTTY tape reperforator, type 7TR or similar, for making matching Belcom stabilized power supply, £135 ono or swop for fm punched tapes. Carr arranged. G4FAJ, QTHR. Tel 05433 2169. handheld or mobile gear. Tel 051 722 4669 or 051 227 1919 day. Reliable modulation meter. HF beam for 10, 15 and 20m. Will Trio R300, perf cond. new Dec 1976, £155. G4FQZ. Tel Derby collect up to 100 miles. Spot cash. G3NNY, QTHR. Tel. 0582 412513. 831724 after 6pm, W W2 radio set, type T-5 (also called 6P5). Urgently require follow- Yaesu FTIOIE, mint, little used, still under guarantee, £400. Prefer ing original ancillaries: mains power pack; converter 500V; converter buyer collects, will pay half Securicor. GM3GJB, QTHR. Tel 250V: external modulator/mic. Also require W W2 German ht gen Falkirk 23608. coy rx in exc wkg cond. G3UCT. Tel Fleet (02514) 6998. FRDX400, vgc, £140. Liner 2, £90. TE149 RCA wavemeter, £8. Copy of circuit diagram of Coder T28 rx. G3HQ W, QTHR. Redifon GR289, £15. 2m Parabeam, 4-el. £10. G3XNX, QTHR. Tel Pre-war copies of Guide lo Amateur Radio. Pre-war RSGB Handbook 08045 4504. G2BUJ, 32 Pound Lane, Pinehurst, Swindon. Wilts SN2 1PS. FT101 E, £390. FTV250, £100. 18AVT/WB, £35. Emoto 102LBX, £65. 16m m Ampro model UA projector, all sound head parts, dis- IC22A, £100. G-whip 80/10, £10. Magnetic mount with 5)3 whip, carded projector for parts considered, any information or manual £12. 160MHz digital frequency counter, £55. Elbug, £10. Osker swr on this model appreciated. Cheap 16mm camera, splicer. revvinder, meter, £12. All new In 1976. G3KNJ. Tel Watford 44069 after 6pm. spools, films, or any 16mm equipment. Restarting in hobby. G4BP W, 8-el sm beam, £5. Sentinel MF 2m converter, £14. Xtals: HC6U QTHR. Tel 0283 813395. 37.3125 (2), 9-028(2), 8.0555(2), 44.7666(2), 8.021, 8.07, 8.092, 2411, Manual, mods, control box plug for Storno CQM39;'23. Buy or HC25U 44-766. £1.50 each. G4DOV, QTHR. Tel Walsall 27738 after borrow and copy and return. El8CZ, QTHR. 5.30pm week. Circuit, handbook for army BP413 (ZA22773) rx. Coils for B2 lx. Atlanta, recently serviced by KW, no mic, £210. Zeiss Super Q-max gdo or winding details. Besford, 49 Blake Rd, Great Yarmouth Contaflex camera, with 0.2, 0.5, 35, 50, 85m lens, carrying case. 24V de motor with reduction gear. G3G AD, QTHR. tripod, £105. Weston light meter, £8. G4BLB, QTHR. Tel Deal 3538. Main tuning dial for AR88LF. G8KMS, QTHR. Tel 08045 6708.

RADIO COMMUNICATION July 1977 557 Circuit diagram or manual for Cossor CC303 Com mando tex. Vertical antenna in good cond, 18AVT, 14AVQ, G-whip or why? Will buy or copy and return for reasonable price. C. Sherman, 89 K W E-Zee match. Foster, 14 Audley Close, Lytham St Annes, Lanes Noyers Park Drive, Bristol BS4 1RH. Tel BS 668945 after 6Pm. FY8 4RT. Transformer for Cossor scope model 2100, also circuit or manual Service manual andior circuit diagram for Eddystone 77OR vhf rx. to buy or borrow to copy. Elliott. Tel Dunstable 69783 evenings or Buy or borrow. Reasonable price paid. GI3ZTG, QTHR. weekends. K W2000/AfB with psu, Joystick Joymatch A/ J, 2m beam, rotator. Low-band Pye W15A M, dash mount, any cond. Pyecall mobile pair Goodmans Magnum spkrs. Kai Chandler, 2 Argentan Close, decoder MD1, encoder PC90/960 and PG1 AM, high or low band. Abingdon OX14 SQ W. any cond. Reeds for P61 and tone filters for MD1. J. Griffiths, The Blind yl swl needs gen coy rx and stereo record player for small Grange, Gladstone Street, Abertillery, Gwent. Tel 049 532 3111 any room. Regret cannot collect. Contact G3XKM, QTHR. Tel Stour- time. bridge 5546. Acco m modation in Bristol area. Monday to Thursday each week. Potentio meter for Indicator in black round moulded cover about agreement to use own modern hf cw equipment would be appre- 21in diameter, connections marked 1,2,3, +6, —7. 12,077.5kHz sial ciated. G3IE W, QTHR, Tel Wedmore 712007. for KW2000 HC61.1. 12.125MHz sial for 2m mobile. G3MBL, QTHR. UHF M5 Starphone tx output board, working or faulty if complete Tel 01 445 4321. with covers, screens etc. G8CBE, QTHR. 5FP7 tube for slow scan tv. G3PMC, QTHR. Tel Aldershot 23497 Aspiring cw addict urgently requires Vibroflex bug key in good 9.30am to 5.30pm. Fleet 3916 after 6Pm. cond. Please give price. All letters answered. R. D. Elliott, 484 Yaesu FV401 or FV101 mk2 vfo. YO-100 scope, 1 Lovelace Road, Barking Road, Plaistow, London E13. Tel 01 476 8274. Oxford. Pair Pye Pocketphones, type PFI, for conversion or converted to T wo QV08-100 pa valves, or four 6HF5s. Willing to exchange for 70cm, with or without batteries and:or cases, but must be In wkg two unused RCA 813s with cash difference. G3VCA, QTHR. Tel order and with circuit. All replies answered. G4A NW. 16 Chestnut 01 848 8185. Drive, Broadstairs, Kent. S WL requires Trio J R599 rx, good cond, custom special preferred, 4m transverter, also antenna. G3XXQ, QTHR. Tel Newcastle 746723. but basic version better than nothing. Will collect good distance. Circuit and information on miniature oscilloscope type C152. Preferably tel Amersham (02403) 5670, or write to P. Q. Armitage, Borrow or purchase. GW4EVJ, QTHR. Tel Clydach 843948. 2 Longfield Drive, Amersham, Bucks. Manual for Pye W3OFM Westminster (boot mount) including noise Drake R4A or R4, top price paid. G130TV, QTHR. Tel Dublin blanker and tone lock modules if possible. To buy or copy. G8KBZ, (0001) 512436. QTHR. Tel 01-743 8000, ext 4409 .10 (work), 01-579 3958 (home 6-7Pm). I.F. chassis or set of i.f. transformers, including bto and xtal. for K W E-Zee match atu mk2. Longbottom, Sapeli Lawns Road, 13C348, scrap or non-working rx would be acceptable. Manual or Baynards, Rudgwick West, Sussex. Modification details to enable fm reception on valve "twoer" circuit for Airmee 712 valve voltmeter and Airmec 858 oscillator. (Heathkit HW30). Your postage costs refunded. G3WDS, QTHR. G3LYU, QTHR. Tel Leicester 876459. Pre-war RAB WS components, valves and books needed by collec- Remote vfo for Swan 500C. Electroniques amateur band front-end tor enthusiast. Civilian equipment only after 1929. Complete collec- (valve version). Furness. Tel Aberdeen 323808 or leave your number tions purchased. Christopher Sawyer, 210 Gordon Avenue, Cam- at Aberdeen 53553. berley, Surrey. Tel Camberley (0276) 29460. Redifon GR410 ssb tx/rx (military type SRC14 version) badly requires Power attenuator, 20dB lOW or higher rating, preferably N or BNC complete realignment. Grateful to hear from anyone with experience type connectors, must be 5011. HP power meter, type 431 or 432, not of this set, who has necessary test equipment and prepared to offer wkg or head blown or missing ok. G8BXH, QTHR. Tel 01 959 6799 help. G3UCT, 27 Glen Rd, Fleet. Hants. Tel Fleet 6998. after 7pm. Early books by John Scott-Taggart. Also original Scott-Taggart K W2000 or KW2000A with mains psu, spkr unit and manual, must rx ST100, Ediswan ES2 and ES4 valves. Radio gear from W W1 to be perfect cond and wkg fb. KW107. Cash waiting for right rig at 1929. G3SYX, Fir Glen. Beesby Road, Maltby-le-Marsh, Lincs LN13 right price. Urgent! G3UCY, QTHR. OJJ.

MEMBERS' AD ORDER FORM FOR SALE E WANTED El (a pTpircoltpit e

• See Me mbers' Ads page for conditions of acceptance.

• Not more than 40 words, including name, address, etc

e Do not forget 75p remittance plus wrapper.

• Please write in block capi- tals, or type.

Licensed members are asked to use their callsign and QTHR, meaning that their address in the current call book Is correct. BRS and A members will, of course, have to provide their name and address.

I enclose cheque/PO for 75p to cover the cost of this advertisement.

Signed

Date

558 RADIO COM MUNICATION July 1977 Yo112,« AND AMSAT PHASE RI

An exciting new era In amateur radio Is about to begin... Your valued contribution can be as small as one of the the era of AMSAT Phase 3 Oscar satellites. 5,000-L solar cells needed. A handsome certificate will Many of you are familiar with the benefits of the AMSAT acknowledge the numbered cells you sponsor for £6 each. Oscar satellites, notably Oscars 6 and 7. These satellites, Larger components of the satellites may also be sponsored with a combined total of over eight years In orbit, have with contribution acknowledgements ranging to a plaque provided communications between amateurs throughout the carrying your name aboard the satellite. Write to AMSAT UK world. They have also provided a capability for an educational for the opportunities available. programme in space sciences and many interesting Your membership of AMSAT is important to the satellite experiments. programme, and will give AMSAT the support it requires and deserves. At £6 per year or £60 for life, you will be making AMSAT, with members and national groups worldwide, and headquarters in Washington, DC, has been responsible for a most significant contribution to the satellite programme and the future of amateur radio. You will also receive the our current satellite programme. Many people feel that quarterly AMSAT newsletter. perhaps the greatest value of the amateur satellite programme is the dramatic demonstration of amateur resourcefulness Cut out the AMSAT Phase 3 coupon below and send it with and technical capability lo radio spectrum policy makers your support today. around the world.

The value of this aspect of amateur radio as we prepare for AMSAT UK the 1979 World Administrative Radio Conference (WARC) is BOX 63 enormous. el> HARRO W, MIDDX HA3 6HS The AMSAT Phase 3 satellite programme promises a continuing demonstration that amateur radio is at the forefront Yes, I want to support AMSAT Phase 3 Oscar satellites. Enclosed is: of modern technology. Phase 3 satellites will routinely £.... in sponsorship of.... solar cells (,Ti £6 each). provide reliable communications over paths of up to 11,000 E £6 annual membership. E £60 Ilfe membership. miles (17,600km) for 17 hours each day You can think of E Send information on sponsoring larger satellite components. them as a resource equivalent to a new band. Name The cost of these Phase 3 satellites is a projected £150,000. Cal/sign AMSAT Member? Commercial satellites of similar performance would cost Address nearly £6m. Your help is needed to put these Phase 3 Oscar satellites in orbit.

RADIO COMMUNICATION July 1977 559 NORTH WEST AMATEUR RADIO CONVENTION

TO BE HELD AT LANCASTER UNIVERSITY ON SEPTEMBER 17-18th, 1977

LECTURES: The fee for the full weekend includes accommodation, (some double rooms available) all meals, and refreshments (including 25 years as a regional representative Basil O'Brien G2AMV an excellent dinner on the Saturday evening, with a guest speaker) Integrated circuits Dr. I. Saunders as well as entry to all the lectures, films, and exhibition. The Elementary OSC AR P. J. A. Gowen G3IOR convention will start at 2.00 pm Saturday, with registration from Advanced OSCAR P. J. A. Gowen G3IOR 11.30 am, and finish at 18.00 Sunday. Interference forum Home office/R.S.G.B. Also other lectures to be arranged Full weekend, accommodation and lectures .. £15.00 Further attractions include: Saturday only, including dinner and lectures .. £7.00 FILMS CONSTRUCTORS COMPETITION BRING AND BUY STALL TRADE EXHIBITION STANDS Sunday only, with meals and lectures .. £5.00 RSGB BOOKSTALL CLUB STANDS Lectures only, no meals .. .. £3.00 TALK IN STATION RAFFLE To book places send your name and address, with payment COACH TRIP Sunday tour in the Lake District for XYL's, charge- (cheques should be crossed, and made payable to "The Univer- able separately .. £1.30 sity of Lancaster Amateur Radio Society N WARC") to the DINNER BAR EXTENSION following address:

N W ARC, c'o J. R. MOR RIS, DEPAR T MENT OF PHYSICS, LANCASTE R UNIVE RSITY, LANCASTE R LA1 4Y13.

RSGB PUBLICATIONS ORDER FORM

TICK BOX IF YES Please use this for m when ordering RSGB MEMBER Post your order to

CALL-SIGN or NAME In— ORS/BRS/A RSGB PUBLICATIONS (SALES'), ADDRESS

Full details of conditions of sale 35 DOUGHTY STREET, can be found on the RS G B price LONDON WC1N 2AE list. Please check the latest

price list w hen ord ering as Telephone

incorrect pricing causes delay. 01- 837 86 8 8

QUANTITY PRICE TOTAL FOR OFFICE ITEM CODE ITEM DESCRIPTION USE ONLY REQUIRED EACH DIY ORDERED

I enclose cheque, giro cheque, postal orders to the value of

560 RADIO COM MUNICATION Ju ly 1977 THE COMPLETE RANGE

Keep It to yourself, won't you, but did YOU know that we have the widest range of converters and varactor triplets, which have gained world wide acclaim over several VHF and UHF equipment available to meet the most stringent requirements of the years, but to arouse new interest by launching on to the market certain new products discerning amateur radio enthusiast, who is continuously endeavouring to keep Iris such as our 50MHz and 500MHz frequency countera, -:- 10 500MHz prescaler and our shack up to date without upsetting his bank manager. latest range et all-mode linear transverlers for 144MHz and 432MHz. This month we aro briefly reviewing this wide range, but please do not hesitate to It's no secret, though, that we have recently expanded our entire production capacity contact on either by post or telephone for any technical details, or to request detailed enabling us not to lust manufacture our standard range ol first class VHF/UHF data sheets for any of the products mentioned below.

144MHz. 432MHz.

M MT4.32;28 : 432MHz ati.mode linear transverter. M MT144;28 r 144MHz all•mode linear transverter. Features: 10 watts RMS output power. Features: 10 watts RMS output power. 30d8 receive gain. 3003 receive gain. 3.0d8 noise figure. 2.5dB noise figure. Aerial Changeover achieved by a pin diode switch. Aerial changeover achieved by n pin diode switch. I.F. 28-30MHz. I.F. : 20.-30M Hz . Price £109.131nc. VAT Price £83.881nc. VAT M M T432,144 432MHz DOUBLE CONVERSION all-mode linear transverler. M MD14.4/28 Single conversion 144MHz receive converter with protected dual Features: ID watts RMS output power for 10 watts 144MHz input. gate MOSFETs. 10dB receive gain. Typical gain: 30dB. Noise figure: 2.5d8. 3.0d8 noise figure. I.F.'s : 12-14, 14-16, 18-20.24-26,28-30MHz. Aerial Changeover achieved by a pin diode switch. Price £29.25 inc. VAT I.F. 144-146MHz. M MC144.28L0 As above unit but has an extra butter amplifier Ott16MHz for use Price £149.63 Inc. VAT in transverters. M MC432428 432MHz receive converter featuring 2 RF anlp and a Provides 5inW at 1I6MHz. MOSFET mixer. Price £22.50 Inc. VAT Typical gain: 30dB. Noise figure: 3.948. M MC144,2 Double conversion 144MHz recelen converter which achieves I.F.'s : 14-16, 1B-20, 28-30, 144-146MHz. good image rejection nt low intermediate frequencies. Price L24.15 inc. VAT I.F.'s 2-4, 4-6MHz. Price £20.25 Inc. VAT M MAI44 Low noise preamplifier with two independent outputs. DIGITAL PRODUCTS. Typical gain: 1848. Noise figure: 2.5dB. ALSO AVAILABLE For 70 and 136MHz. M MD050 Six digit 50MHz frequency counter. Price £14.63 Inc. VAT Frequency ranger045-50MHz. Input sensitivity: Better than SOmV RMS. Price £86.96 inc. VAT

M M 0050;500 Six digit 500MHz frequency counter. 1,2% MHz. Two ranges:0.45-50MHz. : 00-500MHZ. M M C1296 28 : 1,296MHz receive converter utilizing a hybrid ring mixer, with a Combined version of MMD050and MMD500P. matched pair of schottky diodes driving a MOSFET I.F. amplifier Price £85.32 Inc. VAT Typical gain: 25dB. I.F.'s : 144-146MHz. M M D 500P Divide by 10 presenter 10 give 500MHz capabil ity when used with Price : £29.13 Inc. VAT MM0050. Fully TTL compatible. M M V1296 : 1.296MHz ',wader triple,. Output ',wells 2.5 volts p.p. Vkrill accept up to 30 watts ol 432MHz drive and achieves 60% Input sensitivity: Better than 200roV. efficiency. Frequency range: 50-500MHz. Price E.33.75 Inc. VAT Price L27.00 inc. VAT

70MHz.

M MC70f28 : Receive converter for 70MHz. M MC70281.0 r SIrndar to MMC144/28LO. Similar to MMC14428. Features buttered local oscillator facility al 42MHz far transverter I.F 's 4.-4•7, 14-14.7, 18-18•7. 28-287MHz. tISO. Price £20.25 inc. VAT Price : £22.50 Inc. VAT

Just a phone call will put you in touch with our experienced sales and technical staff, who will be pleased to assist you with any queries you may have. Incidentally, ALL of our products are FULLY GUARANTEED FOR 12 MONTHS. MICROWAVE MODULES LIMITED BROOKFIELD DRIVE, AINTREE, LIVERPOOL, 19 7AN TEL: 051-523 4011 TELEX: 628608 MICRO G.

RADIO COMMUNICATION July 1977 561 LEE ELECTRONICS LTD 01-723 5521 CL O SE D T H U RS D A Y S G8J VL

400 EDG W A RE RO A D, PAD DIN G T O N, W.2 LO N D O N'S LA R GES T S T OC KIS TS OF YAES U e A N TEN N A SPE CIALIS T S e S T A N D A R D • ICO M BA N TEX 5 JAY BE A M REV C O o Q M70 e ET C.

S PECIAL EXCLU SIVE OFFE R Perspex Dust Covert designed and manufactured by us to keep your View equip - mentie mint condition. Suitable for Models FT101.10IB. FL101. FR101, FT201. FT101E, FL2100, FT277, FT288A, FRG7, etc. Price £4.00 each Inc. VAT. Carriage 45p. FT301. FT221, FT220, FT620, £.00 each Inc. VAT. Carriage 45p.

YAESU MUSEN PRICES IM ME DIA TE DELIVE R Y. All prices - VA T FT301 T'Rn 1-8.30. 100W 12v. £485.00 FT2Auto T!Rx 2m. FM Auto YV3550 220 MHz counter AC! Y0846 Hand mic. £7.50 FT30ID Digital Readout '301 £585.00 Scar £15.00 CO £139.70 FRIO1S Rn 1.8-30. 121240v. £.220.ce FT301S IOW PEP '301 £340.00 Sig SOR T/Rn. 2m FM 80 25 TC355 35 MHz counter AC/ FRIOID De luxe "S" BC, FM ese.re DC £105.00 FRIOISD Digital readout "S" £387.00 FV301 External VFO £62.00 kHz 12v. £220.00 TC601 Dig, Display 101 and FR101130 Digital reociout"0" £480.00 FP301 PSU!Speeker £79.00 FTV250 Trensverier 2m. 12/ 230v. £130.00 401 £110.00 SP101(5 Entamai speaker £I5.50 FP3010.FP301 .r. Clock, Ident £125.00 FL101 In 1.8-30 MHz 230v. £325.D0 Y0844 Desk microphone £18.00 YC301 Monitor scope £123.50 FT200B T Re 3.5-30 £249.00 FL210013 Linear 1.2 KW PIP £248.00 Y0100 Monitor 2 lone asc. E118.00 FP200B AC PSU/Speaker £54.00 YV500E 500 MHz 002 PP M. £285.00 FT1OIEE TiFlx 1.17.30 AC/DC £408.00 TP150 Dummy lead/wall- FRG7 Rx •5-30 Cord. AC .DC £145.00 7C500S 500 MHz counter I. FTIOIE "EE" with RF Clip,. £429.00 FT22IR T,Rx 2m. "All Mode." £339.00 P.P.M. £225.00 meter £44.00 FT101EX "EE" loss DC PSU FT223 TIts 2m. FM 23 chnl. 7C500J 500 MHz counter 10 FF50DX Low pass filler £15.25 etc. £369.00 12v. £139.50 PPM £155.00 QRT24 World time clock £13.00 FV10115 External VEO £62.00

SPE CIAL S T O P PRE S S OFFER! SO Habla Espanol FOR YAESU CATALOGUES Send Ferranti VDU's complete with keyboard. Size of cabinet 15 high 15" wide 24-deep. Ideal 265 ,n ylamps for customers who are building their own visual displays. PRICE £42.50 - VAT (less than the price of keyboard and cabinet). Securicor delivery £7 up to 100 miles; £9 up to 200 miles. SUMMER HOLIDAYS LIMITED NU MBER AVAILABLE Closed from 27th July, re-open * EXPORTS * ACCESS * BARCLAYCARD * SEC URICOR * FREE PARKING AT REAR OF SHOP 28th August

A M BIT international- the radio component source * Listed here is a selection of popular components for the radio ** HA N-SPARES constructor/enthusiast. Our latest catalogue includes more in- * * formation on our AM/FM tuner modules-with all those hard-to-get * .x. G3WCS GlC00 bits, like coils, filters, trimmers etc.

H S ..Y.*• 262 KE N SIN G T O N, TOKO coils: Ambit now holds over 200,000 in stock if.:- * * * LIVE R P O OL L72RL. Tel. 051-264 9924 AM IFTs for 455/470kHz 1st, 2nd and 3rd £0.30 * * FM IFTs for 10-7MHz Also detectors £0.33 * * DUALITY COMPONENTS AND ACCESSORIES Ratio discriminator coils for 455kHz or 10-7MHz £1-35 * * BY RETURN-ALWAYS Tunable chokes of 2, 3-5, 7, 11-8, 23, 36mH £0.33 * $18 molded VHF coils: 0.09, 0-12 and 0.18mH ex-stock £0.33 Veroboard et lesti than hallprice, packs of six pieces in different sizes and Special molded spiral formers with two slugs and can £0.25 matrix, our chome. Excellent value. £1.00. Various RF and oscillator coils-see catalogue for details.

Reed Relays lor recent kuyer designs and other hmer speed switching. Operate TOKO FILTERS: Low cost and high performance on 9 volt and above. Heavy duty contacts. 30p. MFH41TIMFH7IT 4 or 7kHz Bandwidth, 455kHz mechanical Micro-switches roller lever, miniature. Single pole o over. 5 ter £1.00. filters with matching transformers £1-95 TEIA12ASN76660N FM dlecrimlnator IC. Unmarked but fully tested. 40p. CFT series ceramic filters for 455kHz 6 and 8kHz BW £0-55 Neon Panel Indicators wired with series resistor for 240V. 20p or 5 for £1.10. Mosfets all lull spec and brand new. 40673!40822,65p. 3N204 very low noise figure. 2kHz 6 element mechanical filter for 455kHz SSB Tx/Rx-' MFL £9-95 £1.25. BXS20 equiv. 4 for £-50p. 2N3819. 2 for 55p. FOIL trimmers-Mullard and Dau types BC107 Plastic case, full spec and brand new. Packs pilotos 50p. Miniature Level Meters 200µA FSD. Ideal as RF indicators etc etc. 50p. 1-8pF. 3-30pF, 7-45pF In 7-5mm diameter: 18, 23 & 26p resp. Solder at hall price packs of mullicore, reduced from 40p to 20P. 7-60pF 10mm diameter type £0-28 Electiet Capacitor Microphones built In FOI preamp. High quality. L1.65. VARICAP DIODES -VHF and MF/HF wide range tuning diodes PTT Microphones SOK or 300-600 ahE with transformer removed. Reduced from £5.50. Limited number left at £3.75. BA102-30p; BA121-30p; BB104-45p; MVAM2-£1-35 P.C. Pens Dale tree wilh spare nib. Accurate pump action. 85p. NEW MVAM125: 20 to 400pF with 25V bias available in singles or Digital 6 Function LED Watches complete with batteries. Few only. £12.25. sets for multi stage tracking 90p each, 3 for £2-65. Mullard Trim mers miniature. Grey. 5pF. 7p. Yellow. 100F, 139. Green, 22PF.10P. ICs for Radio: The best and most recent popular types: Coil formers with cores. -IC OM, 513. I' die.. 7P. /. dia.. 10P. I.C. Packs some unmarked, some out ol spec. Ideal for experimenters. 50p. HA1197 AM system, though suitable for SSB and NBFM Small Multimeters AC/DC yells to 1000V. 0-100mA. 0.150 KR. DIM. IFs. 80dB AGC, meter stable to use £1.40 Colino Plugs and Sockets, very high quality. PL259, No reducer required for £1.95 UR43 76, 87p. BNC 50 ohm plug, 51p. BNC chassis Mt 44p. $0235 chassis slit. HA1137 FM IF system sim to 3089 with better mute £1.81 44p. "N" type plug, 88p. TBA651 Linear RF/IF gain block with AGC 2200GX Inserts good quality audio, suit any rig 200-600 ohm. £1.50. TBA120 FM detector block with gain £0.75

This is only a smell selection from our large stock. Our catalogue is available Meese remember lo Include VAT (usually 12.5% esteof where marked •) and our N I rate free at charge, please write or phone for copy. ggp PAP charge. Catalogue Illo Inc. Neese acComOany enquiries will, an SAE. Price Ilst Callers welcome-gam to 5.30pm-half day Wednesday. Closed from 2nd July Inners available FOC WO an SAE. to 9th July Inclusive. All Orders despatched immediately on return. POSLIQC on all Items Z5p. Prices Include VAT. 37 High Street, Brentwood, Essex, CM14 4RH Telephone (02111 216029 altor 3pm if possible-Inn.

562 RADIO COM MUNICATION July 1977 N.B. 2 ALEXANDER DRIVE, HES WALL, ELE C T R O NIC NEW WIRRAL, MERSEYSIDE, L61 6XT SE R VICE S ADDRESS Toi: 051-342 4443 14.30-7.00pm) P.M. Cables: CRYSTAL, BIRKENHEAD. Telex: 627371 VAT -PRICES EXCLUDE VAT, WHICH SHOULD BE ADDED AT THE HIGHER RATE (12)%) FOR ITEMS MARKED (H) AN D AT THE LO WER RATE (8%) FOR ITEMS MARKED (L)-OVERSEAS ORDERS (Inc. Eire and Channel Isles) NO VAT CHARGEABLE. 2M TX & RX CRYSTAL AVAILABILITY & PRICE CHART CRYSTALS FOR THE NE W BRITISH 70C M CHANNELS We are stocking the following channels REA (434.601432D0), 562 (434651433'05), 504 CRYSTAL (43410143310), RB6 (434751433-15), SUS (43320), 51310 (43485143325), RB14 (434.051 FREQUENCY 43336), SU18 (43345) and SU2O (43350)-TX and RX for use with: PYE UHF Weetmin- (1192.DH•Xj-zlipd91 n zin.o.o a a c c c cc RANGE D D ster (WI5U), UHF Cambridge (U10B), Pochellone (PEI) and STORNO CO UCCIM 662 USE (TX or RX) D ..-6 ' ,E. e all at L2.36 plus VAT(H). For the U450L Base Station we have the TX crystals for all the end HOLDER u x x x above channels plus thoRX crystals tor SU8 and RB1I also at £2.36 plus VAT Oil. The X X X RX crystals for RB2, RBI. RB6, RBIO, SUIE and 5U20 tar use iv the U450L Base Station, together with the TX end RX crystals for 'ha remaining SU channels (SU12.433•30- RTTY, SU16-433•40 and SU22-433:55) for all the above equipments ore available at OUTPUT i' • FREQUENCY £2.90 plus VAT (H) delivery as per class (b) Pro ItemS• e 44MHz-RX-HC25IU .7* g I igmHz-Tx.Hc251u igmHz-Tx.Hc251u I 4es CRYS TALS FOR 70.26MHs-HC6IU 44 030 .. b b TX 8-7825MHz and RX 29-7800MHz . .. at £2.36 each . VAT (H) 441/433.2 .. a b 14MH2-TX-HC61U 14MH2-TX-HC61U RX 6-7466MHz . . at £3.90 each VAT (H) -

44 ,180 .• o b b - 10.245MHr "ALTERNATIVE" I.F. CRYSTALS - U.313 + VAT (H). For use in 44.800 -• b b crow crl 36MHz.TX_HC6 & 25w 25w & 36MHz.TX_HC6 crl crow . - PYE and other equipments with 10 7MHz and 455kHz I.F.s lo gel rid ol the "hirdy" lust 44 850 .. b5.251U 148MHz-7X-1.1GO crawler, vv.:role b above, 145 OMHz. In HC6/1J. HCIE111U and HC25'U. 45000.SO .. a a cr crl umHz-Rx.Hcgiu umHz-Rx.Hcgiu crl cr 45-050/02T .. a b CRYSTAL SOCKETS -H MI!. HC13IU and HC25jU (Low taux) 16e each 4 VAT 45 0751113T .. a

ci e (H) 10p P. ex P. per order (P. Ix P. free it ordered with crystals). 45:100/R4T .. a b CON VERTER(TRANSVERTER CRYSTALS -HC18(1.1 45 .125/R8T - a b a a abb.:1'0,7n Cr Cr abb.:1'0,7n a a All nt £3.00 - VAT (Hl. 33•6666Mkiz (144)281, 42MHz (70/28), 58MHz (1441281. 70MHz 45.150?R6T .. a b (144(4). 71MHz (144 ,2). 95MHz (342/52), 96MHz (1,296;432 144), 101MHz (432;28). 45.175/R7T .. a b menc c c c c c c c c n c e cc am be 10I•50MHz (434123), 105:6666MHz (1,296,28) and II6MHz (144,22). 45-2001501 .. a a ma cccccc cracrn cril2MHZ-TX-HC2SIU cril2MHZ-TX-HC2SIU cracrn cccccc ma - 45.300/S12 .. b b 'Yong co roe roeue roe co 'Yong CRYSTALS SPECIALLY MANUFACTURED FOR AMATEUR USE

45.350/S14 .. a C e TO CUST O MERS REQUIREMENTS

45'400;516 cr .. cr cr cr cr cr 01171,, b b Now supplled to our new Improved amateur eoecIfication (temp. tot. .7.30oPm- 0-60'C. 45.500/520 .. a adl.tol. ±3000m) as follows: In NC R' 1:5-2MHz £3.95 VAT(H) and HC51U 2-105MHz 45525/521 .. a

o CI' CI' IT cr two:roc cr IT CI' CI' o and FICt8iU and 1-1C2511J 4-105MHz E.3.00 + VAT (H). Delivery usually 4-6 weeks. .

45:550/S22 .. a o Please glee circuit conditions (1.o. load In pf etc.) when ordering. Fundamentals . 45'5751S23 .. a (1:5.21MHz) will be supplied to 30pf circuit conditions, and overtones (21-105MHz) to 45b00/S24 .. a series resonant conditions unless otherwise apeclfled. For data/Is of closer tolerance

45-650/R2R .. crnnebn b crystals please send S.A.E. 45:675/R3R .. b 45 .700/ RIR .. b TEST EQUIP MENT FREQUENCY STANDARD CRYSTALS - 45.725/05R .. b 100kHz In HC131U, £2.95 + VAT (L). cr cr cr cr cr cr . 1MHz and 5MHz In HC6/1J and 10MHz and 10.7MHz In HC61U and 11C25'U. £2.80 45 -7501118R .. b VAT (L).

45:7751117R .. b aaa'aaaammmm 45-800/R8R .. a BURNS ELECTRONICS cr mmmmmmm a a » cr cr cre,:rcre-cre aaaaa 14MHz-RX-HC25IU 10MHz-RX•HC6/U cr 14MHz-RX-HC25IU cr aaaaa cr >Do cr a cre,:rcre-cre cr cr cr cr ee » a c a cry cr omproaoomanaaraa,rercrecrexeracro cr ere, cr mmmmmmm aaa-crecracramo»crer CC cr CT CT

weer tr tram cr.. treee. I 44MHz-RX-HC.51U 45-95 44MHz-RX-HC.51U .. I treee. cr.. tram mmmmmmmmmmmmmmm tr weer ammo.» ea cracracrecrcrecrcrcra crecrucreacrecra a crecrucreacrecra cracracrecrcrecrcrcra b We are the Northern Appointed Agents for BURNS KITS etc. and can supply most l l of their products horn stock. PRICES: (a) £2.36. (b) and (c) L2..90 + VAT (H). AVAILABILITY: (a) and (c) stock lloras, normally available by return (we have M ODULAR CO M MUNICATIONS SYSTEMS over 4,000 llores in stock). (b) Four weeks normally bu) It le quite possible we could For the RTTY enthusiast we ten recommend and aupplr the "MCS" range of prod- be able to supply horn stock. N.B. Frequencies as noted above but In alternative ucts. This Includes terminal units. AFS keyers, magnet drivers for TTL interface, holders and/or non-stock loads are available as per code (17). lelegreph distortion meesuring adaptor, RT TY audio processor. power unite. etc. etc. ORDERING. All we require to know Is (1) Output frequency. (2) Crystal IrequencY For the CW man we have the "MCS" CW filter which gives three stages of acti.o range, (3) The holder, and (4) Either the load capacitance (pIs) or equipment. Ills not filtering. Please send S.A.E. for full details of the "MCS" range. essential to give the exact frequency, though it would be of assistance to ouate It II known. ANZAC MD-108 DOUBLE BALANCED MIXER 5-500MHz supplied with full details tor only £5.95 plus VAT (L). JAPANESE AND AMERICAN EQUIPMEN TS With the ever increasing popularity of Japanese equipments we have further expanded oar range of stock crystals. We can now supply for YAESU (FT2F, M ET, FT2 Auto. CR YS TALS FOR PR OFESSIO N AL USE FT224), most of the ICOM range and the TRIO.KEN WOOD range. We can also supply (ron, stock crystals for the HEATH KIT H W202 and HW17A. CRYSTALS TO COM MERCIAL SPECIFICATIONS We cnn supply crystals to most commercial and MIL specifications. with an express Y A ES U FT221 CRYSTALS NO W IN STOCK. ALL AT £2.90 -4 VAT (H). All popular service tor that urgent order. Please send S.A.E. for detalls or telephone between channols-For repealer use advise Mal frequency required as earlier models have 4.30-7pm and ask lar Mr. Norchtle. diflerent shift stets to later FT221R. We can also supply Itie crystal to glee NORMAL "tuno to RX" working (as FT221R) For 70 cm we can supply the 1-8 MHz shift ata) for direct use with a MICRO WAVE MODULES MMT432/144 which we can supply tor TER MS: CASH WITH ORDER -M AIL ORDER ONLY -S.A.E. WIT H ALL £133.00 + VAT (H). SPECIAL OFFER) if ordered with transverter 70cm shift crystal ENQUIRIES -PRICES INCLU DE P. & P. (BRITISH ISLES) EXCEPT WHERE FREED STATED - OVERSEAS CHARGED AT COST.

M ASOCHIST! "SEE WHAT THE YANKS HAVE DONE TO / Still chasing DX the HARD WAY? Here's how to GET MORE... SOUND one "S" point LOUDER with a Speech Compressor, THE FT. 101 &OUR CLIPPER!!" switched compression HiFi Dx .. only £8.60 Make SURE your ANTENNA is OKAY, fast, with an Antenna Noise Bridge, 1-150MHz 20-200 ohms .. only £8.20 A level control for the FT.101E Mk.1 ? G3LLL's Clipper FREE DX Iront WHISTLES and CW interference with a Tunable fitted internally? Find out about the above plus tree Audio Notch Filter, Powers speaker .. .. only £7.90 CHECKOUT your LINEAR with a Two Tone 0Scillator only details of the International FT Club Newsletter, No £7.40 FT,101 owner can aflord to miss it-gives operating, Get SPOT-ON the DX with a Crystal Calibrator, 1MHz. ",00kHz. 25kHz with equal level harmonics to VHF .. only £13.80 service and modification gen. Send large SAE to Each kit includes ALL parts, printed circuit, case, battery, screws etc, postage, instructions, money back assurance. Take G3LLL, Holdings Ltd., 39 41 Mincing Lane, the EASY way, SEND TODAY. Blackburn BB2 2AF. • Tel: 59595 6 CAMBRIDGE KITS 45 (RU) Old School Lane. Milton. Cambridge. Tel. 0223 860150

RADIO COMMUNICATION July 1977 563 ADVANCED TECHNOLOGY FOR THE DISCERNING AMATEUR UNIVERSAL RF SPEECH CLIPPER Still unmatched otter two highly successlul years. tho "Datong r.l. Clipper" Is used THE UP-CON VERTER -MODEL UC 1 the world over by serious CIXers and professionals. * Comparable to a linear the Datong r.f. clipper introduces negligible distortion SYNTHESISER CONTR OLLED GENER AL while raising your average radiated power. COVERAGE RECEIVING ADAPTOR FOR RE- * Gives true r.f. clipping. Simply connects in serles with microphone. * Works with virtually any make of transmitter. CEIVERS TUNING 28-29MHz AND/OR 144-145MHz. GIVES COMPLETE COVERAGE FROM 90kHz TO * Equally effective for SOB, FM and AM. Price £38.88 plus VAT (12)5/). Also available with Jay 4 pin input connector and complete with matching output lead. Inclusive 30M Hz. price £41.90 plus VAT (12)%). Please state pin connections required. Until now if you owned amateur bands.only transceivIng or receiving equip- Fully alioned and tested P.C. Modulo, RFC,M. Price: £19.50 plus VAT (12; 5;1. ment and wanted general coverage reception, you had two alternatives: (1) Spend substantially more than tire cost of good amateur bands-only FREQUENCY AGILE AUDIO FILTER MODEL FLI equipment on a general coverage receiver of equivalent performance and Fast becoming a classic. Model Fit delights and amazes all who hear it in action. accept the expensive duplicatron of hardware: (2) Put up with Inferior This unique product improves any receiver and is Installed simply by connecting in performance on general coverage and purchase o "low-cost" general series with the receiver's loudspeaker. It offers the following advanced features: coverage receiver. * A notch filler which tunes Itself for fully automatic removal of unwanted whistles The Datong Up-Converter now provides u very attractive third option. By in phone reception. With Model FL1 In circuit you can Ignore tune-up whistles. connecting this unit in the aerial leed to your existing equipment you get the * Fully variable bandwidth tailoring for enhancing phone reception In the presence following advantages: (1) There is no wasteful duplication: 121 Expensive features Of Your existing equipment are fully utilised; (3) Perlormence on of Interference and sideband ISPIreter. other frequencies Is as good as you nre used to on thearnateur bands; (4) You * Band pass filtering with fully variable centre frequency and bandwidth (1,000)-tz to gel a two-metro converter "thrown In"; (5) The extra cost is even less than 25Hz) plus etc., for the kind of CW reception which you would not have believed for a "low cost" general coverage receiver. possible. Quito simply, you get more performance for less money. Supplied with connectors and fully Instructions. Ready-made connecting leads also available. Price: £47.50 plus VAT (12)%). If you own one of the increasingly popular all -modo two-metre transceivers you now have the basis of a high performance semi-synthesised general All Datong products ale designed and built to professional standards using high quality coverage receiver. What better way for a G8 to sample what the HF bands components and glass-epoxy printed circuit boards. have to offer (Including Morse practice)/ FOR DETAILED INDEPENDENT TEST REPORTS OF MODEL ELI, PLEASE SEE It you later exchange your two-metre transceiver for a HF bands transceiver RADCO M JUNE 1976 AND SHORT WAVE MAD. JULY f976. your Up-Converter will still supply general coverage reception, and in addi- Data Sheets on any product available on request. tion will provide a continuation of two-rnetre reception facilities. PRICE INCL. DELIVERY, 1NSUR., f-97.50 + 12)% VAT. DATONG ELECTRONICS LTD. TO TAL £109.68. SPENCE MILLS, MILL LANE, EIRA MLEY, LEEOS, 1513 3HE See photograph In previous advertisements. Tel Pirdser (05321 552461

G2BS W D. P. HOBBS LTD. G4DSG G3HEO REG. WARD & CO. LTD. G8CA The Component Specialists K.W. YAESU 103 VS WR Meter and FT101E Transceiver £429.00 combined Power-Meter .. £18.00 FT200B Transceiver and 107 Combined E-Z March, TRIO QR668 Communications Re- M MC 432 ?Urns converter any IF FP2OOPSU £289. CO VS WR end RF Power ceivers £145.00 £22.00 Yaesu 301D all solid slate Indicator, Dummy Load taw . £599.00 Bolcom Liner 2 Mk2 2 metre Trans- M MC 1296 23cms converter any IF and Antenna Switch for FR101 S Receiver .. £299.00 ceiver £164.00 £25.00 3 outlets £85 .00 K W Dum my Load. 500 (en- FR101 D Receiver .. £390.00 UnIden 2030 12 channel 2 metre tran,- M M A 144 2 metro Preamp £13.00 cased with S0239) .. £16 £365.00 colver fitted five channels £131.00 .00 M M T 432/28 Transvorter £97.00 Trap Dipole Co-axial FT224 VHF/FM 2m Mobile Q M7O. 28/144 Scorpion Transverter Feeder £36.00 Transceiver £148.00 M M T 432/144 Transverter £123.00 £96.89 Trap Dipole with %tun .. £29 .00 Y0100 Monitorscopo £118.00 3-way Antenna Switches M M T 144128 Transverter £79.00 £359.00 New Cobra 2m170cm. FM Trans - (for co-ax) £7.50 verter with MIL. Audio £76.45 Now G/C Receiver FRG.7 £144.00 M M V 1296-70-23cms. Varactor triplet SHURE MICR OPHONES Technical AssocieteS Audio £30.00 2 metro Solid State Linear Amp. Model 444 £19.20 Model 201 £9 .50 Compressora £.42.00 £46.23 NR 56 VF1. 2 metro monitor receiver Ail above pri ces plus VAT at f2¡%. £48.00 281144 Solid State Transverter £53.34 FDK Multi-II 2 metre transceiver 2FM70 2rn to 70cms. FM transverter USED EQUIP MEN T £413.89 21 channel £177.52 FR101S FB cond., £250.00 K W2O1 Ru and handbook, complete with external Heat/skit "0" multiplier, £130.00. NOMBREX Model 27 Sig. Generator up to 50K Push-to-Talk Mks £3.75 144-28 Converter £16.00 220MHz (battery operated). £16.00. £17.34 ALL ABOVE PLUS 123 % VAT 432-28 Converter Valves for Yeesu. etc., 6BZ6. GUS, 13K06, 12AX7A, 12BY7A, 12AU7, 8JS5C, 6145, 61-1F5, (IL08, SEA& OGRO, 614613, 6K06, RCA Valves for KW equipment, etc. 1296-28 Converter £21.34 Microwave Modules Counters 50MHz Sentinel 2m Prearnes and 2m converfore/Europa transvertors, J Beams and Stolle Microwave Modules 2 metre con- £62.00 rotators. 140' 14g ant, wire, insulators. 52 & 75 ohm co-ax, and UHF plugs, sachets verters 2-4, 4-6, 28-30M112. IF £18.00 and reducers, G-Whip mobile antenna, Wightraps. Mast couplers. Hy-Galn 50M Hz Counter with built-In Pre- verticals, SWR 10 (Twinmeler), SWR/P WR Meter., M MC 144128 LO 2 metre converter scaler £79.00 A MTRON KITS £20.00 500M Hz Pre-Scaler £.25.00 TRADE INS WITH PLEASURE. OUR STOCK OF GOOD SECOND-HAND M MC 704 metre convertor any IF EQUIPMENT CHANGES DAILY-LET US KNO W YOUR REQUIREMENTS. £113.00 ABOVE PLUS 13% VAT. Due to currency fluctuations prIce of Imported equipment are liable to alteration. ADD 12)% VAT to all prices except used equipment. HP TER MS AVAILABLE CARRIAGE EXTRA ON ALL ITEMS PART EXCHANGE WELCO ME ACCESS OR BARCLAY CARD ACCESS/BARCLAYCARD Ii King Street, Luton, Beds. 20907 AXMINSTER, DEVON EX13 5DP Telephone 33163

564 RADIO COMMUNICATION July 1977 AIMATEU RADIO 0Ç)v ‘e , sy% .• e EXCHAMG Proprietors: Brenda Aptaker, Bernard Godfrey (G4A0G)

The Aladdin's Cave for the enthusiast, with a secondhand selection that is second to none. Come and browse ... Corne and buy. ... Corne and have a cup of Brenda's coffee either way ... But corne this month as we shall be closed In August!

* SPECIAL THIS MONTH - FRG7 Not only ... the finest general-coverage synthesised communications AfeJul

receiver on the market, now .11 with Fine Tuning, at a basic S. 7 price of £162.00 inc. VAT. • • But also ... available from us with special - -me..t. • • 2m converter and accessories, all for only £179.00 inc. VAT. Pit

EASY TER MS Phone for full details of current stocks-new and secondhand-and opening hours,

UP TO 3 YEARS or see us on our Stand at these Rallies. COLCHESTER W OBURN ABBEY HARLO W LEICESTER

2 NORTHFIELD ROAD, LONDON W13 9SY. Tel: 01-579 5311

SM C THAN ET G3LRB IAN'S SHACK CB ELECTRONICS G3SN11 UNIT 3, 771 OR MS KIRK ROAD, PEMBERTON GM8DOX WIGAN WN5 8AT Phone Wigan (0942) 216567 NE W VM101 VIDEO MODULE THE BEST IN THE NORTH-WEST 70cms. Video easily achieved using this module and your Not just another new firm, but people with a wealth of existing 28/432MHz Tvtr; add a camera and 12V 50Ma. technical experience and know-how relating to and you have a high definition video transmission. amateur radio techniques, requirements and servicing, INTRODUCTORY PRICE. incl. VAT. & P&P. £29.00. who will always be pleased to advise and assist in all respects whether it be sales, service or information. NE W P512 3 Mains Power Supply for your mobile Rig 13.8V '‘u HO W TO FIND US 2.5Amps. Full over voltage and short circuit protection. From M6 Junction 26 follow signs for Wigan A577. At first traffic lights (T junction) turn right towards Wigan. At next £27.00 incl. traffic lights you are there but turn left, then 10 yards turn right by telephone kiosk and shop is slightly to your right. JAY-BEA M ANTENN AS Plenty of parking space. Distance from motorway j mile. FULL RANGE IN STOCK. (4m. 2m. & 70cms.) From Wigan follow A577 for Skelmersdale to traffic lights at Pemberton (Ye Olde White Swan Hotel on your left). YAESU & 1CO M Turn right then 10 yards and right again by telephone Come, see and hear the latest. kiosk. Distance from Wigan 21 miles. Closed Wednesday Microwave modules Electronic developments Antenna SEE US FOR YOUR SECON D HAN D EQUIP MEN T specialists Bantex Mobile Antennas Ken AEC REQUIREMENTS OF: FL400 Transmitter £165.00 Shure KLM Cushcraft. YAESU FL20013 Transmitter £130.00 UNIDEN FR400DX Receiver all options £185.00 ELECTRONIC DEVELOP- Trio R300 Receiver £130.00 SEC ON D HAND MENTS ECIO Mk11 Receiver £100.00 FR50B. £70.00incl. E.D. 2m. TVTR. 28144. £98.00incl. J. BEAM LTD. E.D. Magnum 2 Transverter £00.170 H W202. 2m. FM. £70.00. FT200. £198.00incl. Star 600. HY GAIN Microwave Modulos 28.'432 C D.E. SSB Transverter £70.00 Rx. £54.00incl. BELCOM Lowe Monitor Receiver with xtals £32.00 S.S M. Linear 2 Transceiver £110.00 S.A.E. for more details on above equipment please. WESTERN ELECTRONICS K.W. 202 Receiver £175.00 K.W. Monitor Scope £80.00 41 Westerlea Drive, Bridge of Allan FK9 4DQ. Ph. 833223 Part exchanges welcome M.P. and credit terms 8.A.E.allenquIrlee

RADIO COMMUNICATION July 1977 565 Now you can get all "ffloerp" die trettb -R raErCRS 2-metre frequencies at anb proinb 2nttnnat CR°,:s;(s Send for HANDBOOK containing full details of Antennas and other technical information. 33 pages 50p. Refundable upon the flick of a switch. purchase of Antennas. SO ME ANTENNAS Mustang 3 Elements, 10, 15 and 20 metres £108.00 TA-33 Jr. High Power Model incl. Balun 3 Elements, 10, 15 and 20 metres .. £98.50 TA33 Jr. 3 Elements, 10, 15 and 20 metres .. £85.00 TA32 Jr. 2 Elements, 10, 15 and 20 metres .. £58.50 TA31 Jr. Rotary dipole, 10, 15 and 20 metres .. £36.00 ELAN 3 Elements, 10 and 15 metres £69.50 TD-2 Trap Dipole 40 and 80 metres £32.50 TCD-2 Trap Dipole 40 and 80 metres com- pressed - • • • • • • £39.50 V-3 Jr. Trap Vertical 10, 15 and 20 metres £26.50 Atlas Trap Vertical 10, 15, 20 and 40 metres £48.00 S WL ANTEN N AS S W L-7 Dipole 11, 13, 16, 19, 25. 31 and 49 metres .. • . £25.00 RD-5 Dipole 10,15, 20, 40 and 80 metres . £25.00 Orbit Vertical 11, 13. 16, 19, 25, 31 and 49 metres .. £43.00 Prices correct at time of going to press. The new frequency MOSLEY 196 Norwich Road, ELECTRO NICS New Costessey, synthesized 2-metre LIMITED Norwich. NR5 OEX Ad mInIer•tiv• Add,... only ENGLAND transceiver from Heathkit. (All antennas available ex works carriage and VAT extra)

The new Heathkit 11W-2036 gives you true digital frequency synthesis. For real operating versatility. HIRE OR BUY All 2-metre frequencies in the band are available. VHF UHF Ti Rx's IC22A etc. From £6.50 month. And operation just couldn't be easier. You just select the MICRO W AVE MODULES TRANSVERTERS from £10.00 per month. frequency by flicking the front panel switches. And should 2m Mobile Tx Rx FM Quartz 16, 10 channels you inadvertently select an nut-of-band frequency, the SALE £169.00 transmitter simply won't key. ALL PRICES INCLUDE VAT The HW-2036 gives you a very clean, minimum 10 watts SAE FOR DETAILS output and sensitivity is an outstanding 0.51.S. BOOTH HOLDINGS BATH (Incorporating Ham Hire and Rent-a-Rig) For more information on the HW-2036 and all our other Slomber vIo T.A.F.A kits, post the coupon and we'll send you our latest 6 Golf Club Lane, Sanford, Bristol 712730 catalogue. Then you'll. have all the facts at your fingertips. G3X 0 D, G3N X U after 7pm Saltford 2402 GOD PH Windsor 51767 after 7prn Heath (Gloucester) Limited. Dept.RC-77, Bristol Road. Gloucester,G1.2 6F.E.1m:Gioucostur (0452) 29151. r"--- HEATHKIT s R.T. ei, I. offer the finest selection of Better built because you build it yourself. : first-class new and fully overhauled second-hand communications and [Tx Heath (Gloucester) Limited. Dept RC-77, I Gloucester, GL2 6EE. electronics equipment in the U.K. I Please send me a Heathkit catalogue. e Constantly changing stocks of a east range of equipment. e Cosh or Hire Purchase terms easily arranged. enclose lip stamp for postage. e Part exchanges welcomed. • We are 'spot cash' buyers for almost all electronic equipment.

Name Send S A E for our latest list of over SO receivers and rnsny other Irte,- Address siting Itorno. R.T. & I. ELECTRONICS LTD. Postcode L Ashville Old Hall, Ashville Road, London E.11 Tel: 01-.539 4986

566 RADIO COM MUNICATION July 1977 QM70 ELECTROITIÇi, f. VHF LET US k COM MUNICATIONS CONVERT YOU Q M 70 ELECTR ONICS now offer you the most comprehensive NO W PUBLISHED range of Amateur VHF and UHF Converters available today. the SPRING 1977 edition NE WLY INTRODUCED are our Dual Band Converters which are designed for the operator who wishes to listen to the which includes articles on 432:434 and 434'436 MHz bands. TRANSISTOR LINEAR AMP FOR ATV OUR RANGE OF CONVERTERS now include all those VESTIGIAL SIDEBAND FILTER FOR ATV below. GETTING STARTED ON 10GHZ For 4 Metres 70.28 £19.00. 250W P.A. FOR 2M £19.00. For 2 Metres 144;28 OVERTONE CRYSTAL OSCILLATORS For 70cm 43228 £27.00. Send £1.15 tor a copy of this edition or £4.30 for 1077 subscription 432-434 28 £31.50. 432 144 £27.00. VHF COM MUNICATIONS is the English longue» edition of lho German publication UKW-BER1CHTE. a quarterly amateur radio magazine especially catering for vhtfuhtl 432-434'28 £31.50. ski technology. It is published in spring, summer, autumn and winter. For 1.3GHz 1296128 £27.50. All special components required for the construction 01 the described equipment. Available with either Belling Lee or BNC sockets. Please such as printed circuit boards. coil formers. semiconductors and crystals, as well as state which are required at the time of ordering. All IF's 28-30 Complete kits. ere available for despetCh direct from Germany. Many of the printed MHz or 144-146M Hz as Indicated. circuit boards. in addition to a few selected kilt, are stocked In the UK. A price list el See our previous adverts for details of our other products. kits and materials are available-send sae for your copy. Agents: Peter Avili G3TPX. Darien 2517. Gordon Adams G3LEC). Knuteford 4040. Orders to VHF Com munications at address below. (BO» OTHR). Amateur Electronics. Amateur Radio Escheat». Craylord Electronics. D P Hobbs. Lee Electronics. Waters 6. Stanton. All PICOS Include VAT and UK Mainlend cardage. All units guaranteed for 12 months. Largo SAE for fully descriptive literature.

OMNI ELECTRONICS LIMITED Severnside South. Bewdley, Worcestershire DY12 2DX. announce Manufacturers and suppllets of VHF equipment to the Amateur and Professional user. atronics their new

SPECIAL OFFER. CA3089E. £1.70; 2N3886. 705; 2143553, £1.20; 40673. 50P; VHF DFM with extended range 2145180, 300;314201. 70p; 2m. 12V FM TX board. Phase modulator 5kHz deviation max. Size: 140mm 82mm n 23mm. HC25IU Crystal. Multiplication XIS. Sent for evaluation, P.S.P. 3,». 2V 1W E20,2144427. 80p ; CA3001, £1.50; 2145913. E1.50; now covering 10 Hz to 250 MHz 2N5945 (4W, 8dB). E.8.00; 2145946, £11.00; 2145641, E.4.00; ZTX327. 60p; 40964. £1.40; 40065. E1.50; 2143375. £2.00; 0C202. 10p; P73500. E1.20; BLY33, £1.801 2149500. E4.50; 2145591. £8.00; 2143632. E2.00; 2146080. E4.50; 2146081, E5.50; 2146032. E8.00; 2140033, £9.00; 2146084. £12.00; 2145642, £8,00; 2145643. 1E11.00; BYF50. 29p; 13C1133 10p: BCI83L, 10p; BLW39, E3.00; 2143478, 40p; 31,1292,10P: MPFI02, 40p; 40841. 50p; BC167A. 10p; BSY90, 311p; 2N3904. 10p; 2713905, 10p; Integrated Circuits: CA3007, £1.00; CA3014. 80p; CA3018, 70p; CA3023, 80p; uctssoe. SOP: MCI596G. £2.00: CA3000. £1.00; SL620/30C. E2.00; MC1741CG, 80p; 2N3819. 29p; 2N2270, 40p; BLY55. £3.00: Transmitter tuning capacitor 799F, E1.50; S0239 sockets, 50p; N socket to BNC socket adaptor, £2.50; N socket to N plug. E2.00; N plug to N socket. £2.00: HC25IU crystal sockets P.C.b.. 15p; lw 2m AMTX £25: Bolso cores 2Sp: Microminiature translate» (no pen) 25P. 2N236.11(erJ 8p Minimum order £1.00. Mall order only. P.S P.20p. HELLER ELECTRONICS

49 Blossom Way, . Hounslow. Middx.. TW5 8HB

Model DF M 5

CRYSTAL OFFERS The updated version of the Cabe:nice Frequency Meter with extended frequency range The following 2-Metre Tx types still to clear: covering 10Hz to2SOMHz. Size awes. fir o 7* * Full? digit 0•38" amber display. 6MHz HC25/U 30pF: R2-R7, S14, SO, S20-S24 and 145-8-£1.60 * LC. memory plying a "nomblinkIng" dltPlaY- * Automatic supp d zeros on 3 lending digits to reduce power consumption 12M Hz HC25/U 20pF: R2-R7. S24 and 145-8-£1.60 * TTL and ECL I.c.s used to giver good reliability. 36MHz 1-1106/U Pye: all previously advertised channels-£2.00 10M14e master oscillator for blots accuracy. * 12V(-.ne earth) tic. Input and 210.260V. mains psu filled. •FT241: 400, 455 and 500kHz with sockets-£2.00 Price only £148.50 incl. VAT (Add £1.50 for insured posit HC6,11.1: 455kHz-£.3.25, 10.7MHz-£1.60, Hi-stab cold-welded 10MHz (±5 ppm from -20 to -70 deg)-£5.50 Cheques and P.O.s should be croseed and made payable to "Catronics Ltd" or '32.768kHz watch crystals: standard bar type-£2.25 "VHF Communications" ns appropriate. cylindrical tuning fork type-£.2.50 CO M MU NIC ATION S HOU SE (Dept. 707) VAT extra at 12.5% except • which carry 8%. 20 W ALLING T O N SQ UA RE INTERFACE QUARTZ DEVICES LTD W ALLIN G T O N , SU R REY , SM 6 8RG 29 Market Si., Crowkerne. Somerset. Tel: (0460) 74613. Teloz 4.6783 Telephone: 01-669 6700

567 RADIO COM MUNICATION July 1977 6 to 1 FRICTION SLO W MOTION DRIVE at 55p. SUB-MINIATURE 5 P.F. AIRS PACED TRIM MERS nt 18p each. TUNING CAPACITORS Direct Drive 5 P.F. at 75p. 30 P.F. at 85p, 50 P.F. at J. BIRKETT 85p. 125 + 125 P.F. at 550. 100 200 P.F. at 550, lee 180 P.F. at 60p. 200 - 200 -i- 25 + 25 P.F. at 55p. 500 -- 500 P.F. al 600. RADIO COMPONENT SUPPLIERS TUNING CAPACITOR S WITH S.M. DRIVE 300 h 300 P.F. nt 55p, 300 - 400 P.F. alssp, 400 500 P.F. at 550, 500 + 500 + 25 + 05 P.F. at 55p. Member of the ARRA DIVIDE BY 2 300 M Hz COUNTERS with dnla el 80P. DIVIDE BY 4 150MHz COUNTERS with data et 800. WIDE BAN D R.F AMPLIFIERS 10 to 100MHz untested with data 5 for 570. ITT 300M Hz NPN TRANSISTORS TM11 at 24 for 60p.

VHF TUNER FRONTEND 88 to 108MHz, 107MHz out, with details for conver- 200 + 200 IDO U.F. 300 V.W. ELECTROLYTICS at 250, 10 for £1.80. sion to Aircraft band or 2 Metres at £3. MULLAR D VARI.CAP FM TUNER Front End LP 1186 at £4.40.

SPECIAL HIGH PO WER X BAND GUNN DIODES 300mw cw., 1 Walt Poised ITT SUPPRESSOR UNIT 220 Volt A.C. 1 U.F. at 10p each. at £8.95 each. LED'S 0•2 Red. Green at 15p. Oranoci at 180. STRIPLINE TRANSISTORS non up to 6GHz with data at £3. 40kHz TRANS DUCERS at £1.50 each. SPECIAL STRIPLINE 1 W ATT AT 2GHz TRANSISTORS situ limited data at £5 each. BD207 90 W ATT NPN PLASTIC TRANSISTOR al 55p. ITT CRYSTAL FILTERS 10.7MHz bw 7kHz et £3.50 each. MINIATURE BUTTERFLY VARIABLE CAP ACITORS 25 • 25 P.F. at 50p,

5MHz 10X CRYSTAL at 500 500814e IOXAJ CRYSTAL at 50p. 25 • 25 P.F. Wide spaced at 55p, 38 .• 38 PT. et &Op, 38 e 38 P.F. Wide spaced at 65p. SUB MINIATURE DIFFERENTIAL 10X10 P.F. TRIM MERS al 220 each. VHF PETS BF256at25p. 2N3819 nt 20p. 6for 75p. SILICON SOLAR CELLS 05 volt 5Ma at 35p. DUAL GATE MOO PETS LIKE 40673 at 330.4 or £1.10. 2/14414 RADIO I.C. et £1. 2-5GH. DUAL NPN TR ANSISTORS untested with data at 5 for 57p. 20 ASSORTED FT241A 9618 HAR MONIC CRYSTALS 71 to 98MHz for £1.10. TBA120S untested with data at 6 for 600. VHF TRANSISTORS 2N918 nt 25p. SFY 90 at 50P• SPECIAL J.F.D. PISTON TRIM MERS Oil to 28 P.F. at 33p each. 200 ASSORTED RESISTORS for 750. 10 ASSORTED MULTI-TURN TRIMPOTS tor 60p. PLEA SE ADD 20p POST AND PACKING ON U.K. ORDERS UNDER £2. DISC CERA MICS 1000 P.F. 50V.W., 1000 P.F. 500 V. W.. 1000 P.F. 1 K.W. all 200 doz. OVERSEAS OR DERS AT COST.

25 THE STRAIT, LINCOLN LN2 I JF. Telephone 20767

Tune into the world...

The 31st edition of World Radio TV Handbook ... the only complete directory of international broadcasting and TV stations ... endorsed by UNESCO, Eurovision, lntervision and the world's leading broadcasting organizations. Includes 'Listen to the World', a special editorial section; the latest world time charts and tables: with comprehensive coverage of short-wave, long-wave and medium-wave. /- The essential guide to anyone associated with , Please send me f / World Radio TV Handbook at £5 each. broadcasting or television ... national or t enclose a cheque for

international, professional or amateur DX-er. / NA ME Copies at £5 each can be obtained from /ADDREss Argus Books Limited, Station Road, Kings Langley, Herts.

568 RADIO COMMUNICATION July 1977 NOTE NEW Shop Hours 9-30am to 5.30pm Mon. to Sat. Easy •ccess to th• MIL M51, Mt2, MII3 STEPHENS-JAMES LTD PHONE NUMBER NO PARKING PROBLEMS 47 WARRINGTON ROAD, LEIGH, LANCS WN7 3EA TEL 0842 676790 SWL Tuning Unit Mk I 2•30MHz £17.59 YAESU MUSEN 2m 8 Element .. £9.11 SWL Tuning Unit Mk II 5506c5-30MHY - as.00 FT101E Transceiver .. 2m 10 Element £19.35 NY-KING Morse keys £2.75 FT200B Transceiver .. PBMI ern Parabeam £28.35 KATSUMI EKIS electronic keyer £60.75 FT4018 Transceiver .. 2m 5 over 5 .. £12-37 F1221 Transceiver .. 2m 8 over 8 .. £18.59 S.T.E. MILAN FRIOIS Receiver .. 2m Ground Plana .. £8.42 ARAC 102 2 band Receiver £100.00 Atal 222 144-146MHz AM-FM TX .. £126.00 FRIOIS Digital Receiver 2m Crossed Dipole .. FRIO1D Receiver .. P.O.A. SPM Portable Maui £9.50 ARIO 28-30MHz Receiver Module £37.50 FRI010 Digital Receiver 8 Element Crossed 2m £18.11 AT 144-146 Transmitter Module £50.00 FL2100 Linear Amplifier 5 Element Crossed 2m £14.51 A134 FM DIscrImInater £5.00 AA1 Audio Module TO-100 Monitorscope 2m 4 Element Quad .. £14.85 £4.25 Y0844 Desk Microphone 2m 6 Element Quad .. £19.80 AGIO Tone Generator .. £4.50 YD868 Hand Microphone D8/70cms £14.06 AT23 10 Channel Crystal Tx Modulo £45.00 FRG7 Receiver.. .. PBM/18/70cma £18.05 AT20 10 Channel Crystal Ra Module £45.00 MBM48170cms Multibeam £19.85 AL8 Linear Amplifier Module • • £27.00 DRAKE - • MBM88/70cms Multlbeam • • £28.32 AS15 stabilised 12V dc board £9.00 R4C Receiver .. £45010 AK20 2M FM Tranaceiver £170.00 TO( Transmitter £450.00 MICRO WAVE MODULES AK20 FM Transceiver kit .. £110.00 TR4C Transceiver £475.00 MMC144 2m Converter .. £20.25 Bug 20 Electronic keyer • • £106.00 AC4 AC Psu £90.00 MMC/144 LO £22.50 MS4 Speaker .. £21.00 TECHNICAL ASSOCIATES MMC70 £20.25 £23.62 SSR-1 Receiver £185.00 Audio Compressor MMC(70 LO £22.50 SPR-4 Receiver £510.00 Notch Filter £25.60 MMC432 £24.75 Low Pass Filter £18.00 Band Pass Filter £25.60 MMC1296 £28.12 Crystal Calibrator .. £21.37 DECCA COMMUNICATIONS MMA144 Pre-ame £14.62 Proselector £25.70 KW204 Transmitter .. .. £281.25 MMV1296 £33.75 KW107 Antenna Match .. .. £95.63 MMT432128 £109.12 SECONDHAND EQUIP MENT Yaesu FR1010 Digital Receiver £400.00 KWI09 Antenna Match .. •.: £1 £918..0012 MMD050 £59.75 KW Antenna Switch MMD 500P .. £28.12 Ynesu SP101 Speaker £12.00 KW Salue £ 6 MMD 050(5000 Frequency Counter £88.87 Barlow Wadley XCR30 Receiver .. £110.00 £8010 KW1000 Linear £247."505 MMT 432(144 £149.62 Barlow woolor XCR30 Receiver • • KW202 Receiver .. • • £236.50 MMT 144128 £10.87 Belcom AMR140 Receiver £10.00 KW Traps • • £9.00 Eddystone 838 Receiver £60.00 UNIDEN Grundlg 1000 Satelil Receiver .. £15.00 BELCOM 2030 2m Fm Transceiver £178.37 Icom IC20 Transceiver .. £120.00 Liner 2 Transceiver £184.50 loom IC22A Transceiver £145.00 Liner 430 Transceiver £290.00 G.WHIP MOBILE ANTENNAS Heathklt RAI Receiver £A5.00 NR-56 Tunable FM Receiver £54.00 10-15-20m Helical Whip .. £18.11 Heathklt IN 100 Frequency Counter.. £0.00 Basemount £2.47 HeathkItH W202 Transceiver .. £100.00 OMEGA Coils for LF Bands each £5.411 Heathkil Marauder Transmitter £150.00 7E-701 Antenna Noise Bridge 2-30MHz .. £21.00 FloslwhIp Basic with mount .. £15.00 Swan 1200X Linear Amplifier £195.00 1E-702 Antenna Nolan Bridge 2-220MHz £25.00 Coils for ell bande each .. £5.60 Telford TC7 and TC10 £110.00 ROTATORS 80-40m Traps .. £8.10 Trio TS700 Transceiver .. £300.00 A R30 £42.19 160m Traps .. .• .• £710 KW2000A Transceiver .. £195.00 AR40 £43.94 Heathkil HW101 Transceiver £195.00 CD44 £100.13 CALLETTI VHF Antenna range KW Vest]. Mk II Transmitter uo.00 Ham II .. £133.33 2m Ground plane 4 radials £13.39 Sony CRF150 Receiver £95.00 2m Gutter mounted mobile whip £12.00 Trio GR5GD Receiver £50.00 NY-GAIN r 2m Standard mount mobile whip £12.00 Eddystone OCIO Mk2 Receiver £120.00 12AVO 10-15.20m Vertical .. £3810 Eddystone 0035 Receiver £70.00 14AVT 10-40m Vertical .. £53.43 ACCESSORIES ALL OUR PRICES INCLUDE VAT 18AVTANS 10-80m Vertical £72.81 UR43 50ohrn Co-Az oer metre Ilip TH3M103 Trlbander Beam .. £140.17 Stamped addressed envelope please with all general UR67 50ohm Co-Ax per metre 45p enquirlee. Postage extra at cost. Deliveries Ire. In THODXX Trlbander Beam .. £1113.30 300ohm twin feeder .. 100 110fTle areae. BN/36 Balun £20.25 70ohrn twin feeder 10p Bumper Mount EA.15 75ohm low loss co-ex 14p ACCESS AND BARCLAYCARD FACILITIES Full alter sales service. All equipment air tested and ATLAS Single meter SWR Meters • • £10.20 sold from above eternities. We do not employ any 210X Transceiver PL259 Plugs 509 mos.% part-lime sales staff or sell to private individuals for 218X Transceiver £445.00 S0239 Sockets 45e Cable reducer. .. 16p resale. On the spot HP and credit facilities available. JAYBEAM ANTENNAS Line connectors .. 'Sp Part exchanges welcome. instant cash paid for good 4m4 Element .. £11.47 Junkera Heavy Duly Morse Keys • • £29.57 cloan equipment or we will sell your equip ment for 2m5 Element .. 03.94 Scour Paddle Unit u.r; you at a small commission.

G8AY N CRAYFORD ELECTRONICS GSI W X M U M M A JAYBEAM VHF/UHF AERIALS GENERATORS 144MHz 70MHz rigi element .. £1.20 4Y 4 element £40.20 BY 8 element £8.10 432Mhis AT KEENEST PRICES! 10Y 10 element £17.20 D8 8 over 8 siot • • £12.50 300-4000 WATTS AC, 6-24 VOLTS DC PBM10 10 ele.Parabearn £.20.50 P8M18 18 ele. Parabeam • • £15.00 PBM14 14 ele. Perabeam £25.20 MEIM4848 ale. Multlbeam £17.50 INCL. THE NEW E3500-115/230V AC & 12V DC 08 6 ele. quad .. £17.60 MEIM88 88 ele.Multlbeam • • £23.40 8XY 8 ele. crossed .. £15.10 12XY 12.1e. crossed .. • - £24.00 C O O KERY BO O K IOXY 10 ele. crossed .. £21.30 MICRO WAVE £..25 Incl. Postage All harnesses. clamps, masts, etc, available, mostly es-slock. Catalogues LEADING MAKES OF MICRO W AVE OVENS FROM £199 inc. VAT S.A.E. please. VAT EXTRA 121%. Carriage extra, £1.40 each. KEENEST PRICES INCLU DE UK DELIVERY ACCESS BARCLAYCARD Open Tues -Sat 10.30-1.30, 2.304.30 (Ansafono out of hours)

6 Lovelace Close, West Kingsdown, Sevenoaks, Kent THIS 6DJ FARNCOMBE ST, FARNCOMBE, Tel. 047485 2577 ASHLEY DUKES GODAI,MING (Tel 23279) SURREY

RADIO COMMUNICATION July 1977 569 Can YOUR Antenna C&C electronics 10 West Park London SE9 4R0 do all this ? Telephone 01.852 9397 CRYSTALS THE MADE TO OR DER CRYSTAL SPECIALISTS A sent/ selection from our huge file of testimonial fetters on (he JOYSTICK 1 OFF CR YST AL PRICES VARIABLE FREQUENCY ANTENNA (0-5-30 -00MHz). Price G4DJY's COPY LOG shows 68 North Americans worked in the ARRE Fundamentals I. 0.030 to 0.099MHz 100pprn £14.25 W.VE contest. 2. 0.100 to 0.369MHz 100ppm £9.75 3. 0.370 to 0.730MHz 100t7Prn £10.00 W6TYP worked W A6JPR over hundreds of miles ore 40m. using the 4. 0.731 to 1.499MHz 10OPP01 £2.75 JOYSTICK VEA and MICRO WATTS "equivalent to 1,000,000 MILES PER 5. 1.500 to 1.999MHz 30Peni £3.45 W ATT"-A W ORLD RECORD-we can supply conclusive evidence! 6. 2.000 to 3.999MHz UPP. £3.00 7. 4.000 to 20.999MHz 30POrn £2.85 "I have used Rhornbics. 4 ; waves in phase. centre fed dipoles, etc.. 8. 21 .000 to 24 .000MHz 30pore £5.25 but the success I have had with the V.F.A. has been AMAZING ... only 3rd Overtones 9. 23 .000 to 54.999MHz 3Oppm £2.85 20ft. high ... In front of my mobile home. I NEVER RECEIVE LESS THAN 5th Overtones 10. 55-000 to 104•999MHz 30parn £2.95 R7 AN D MOSTLY R9 ON C W DX W ORKING"-Bob Green. SUI KG It. 105.000 to 119-999MHz 30Peln £3.115 G3APH. W.B.E.. W.A.C. Phone and CW. 12. 120000 to 130 -000MHz lOpprn £8.50 5th, 7th and 9th Overtones 13. 130 -001 to 216 ODOMHz lOppm £10.25 W7OE. U.S.A. Government Electronics Engr. Iretd.). claims "VFA Oft Unless otherwise requested fundamentals will be supplied with 30pF load below ground, same as dipole, elevated 151t., one'S' point UP on dipole." capacity and overtones for series resonance operation. HOLDERS 0.030 to 0.200 MHz HCI3R1, 0 170 to 196•000MHz HC61U. 4.000 to IN USE BY AMATEUR TRANSMITTING AND S WL STATIONS W ORLD- 216 .000MHz HC18 or HC25/1.1. Prices on application for other holders. WIDE AND IN GOVERNMENT COMMUNICATION. DELIVERY Groups 1 to 4. 12 and 13-6 to 8 weeks. Groups 5 to 11-4 to 6 weeks. DISCOUNTS 5% mixed frequency discount for 5 or more crystals within any price group. For orders of same frequency and spec discounts start at 5 oR In 250w. pe p. OR for groups 1. 4. 12 and 13. In all other groups discounts start at 10 off. Special retes SYSTEM 'A' the SWL £36.00 lor bulk purchase schemes Inci free supply ot stale for UK repeaters. CRYSTALS FOR POPULAR VHF TRANSCEIVERS Crystals supplied In approx. 5 weeks to any stated frequency for the following 500w. pep. VHF Tx's: Healhkit. !corn. Ken, Standard, Trio and Yaesu. Price £2.50 per crystal. (improved 'Q' LOW FREQUENCY STANDARDS (8% VAT) 100kHz in HCf3,'Ll. Price £2.95. SYSTEM 'X on receive) £42.60 1000kHz in 110611J. Price £2.80. CRYSTAL SOCKETS HC6jU and HC25/1.1. Price lop. MINIMU M ORDER CHARGE £.2.00 PRICES ARE EX VAT - PLEASE AD D 12k% UNLESS OTHER WISE STATED PARTRIDGE SUPER PACKAGES All prices include postage to UK and Irish addresses. Crystals Supplied to any CO MPLETE RADIO STATIONS FOR ANY LOCATION specification (or Industrial. mobile radio or marIne rise, etc. State equipment/ specification when enquiring. Please send sae with all enquiries. All Packages Feature the World Record Joystick Aerial (System 'A'), with 8f1. feeder, all necessary cables, matching communication headphones. Deliv. Securicor our risk, ASSEMBLED IN SEC ONDS! BIG CASH SAVINGS! PACKAGE No. I. As above with R.300 RX. SAVE £17.28! £210.55 NEW! SAMSON ETM-3C PACKAGE No. 2. C-MOS KEYER Is offered with the FRG? RX. SAVE £12.21! £193.11 114A battery drain- Why switch off? PACKAGE No. 3. • Self-completing dots/dashes/spaces. • Can be used either as normal electronic keyer or as an iambic-mode New low priced package, featuring the all-solid squeeze keyer. • 8-50 wpm. • Constant 3:1 dash-dot state SMC 73 Rx., with all the Partridge extras. ratio. 6 C-MOS ICs and 4 transistors. Plug-in PCB. SAVE £17.281 £154.86 • • • Long battery life-typically 1 tIA drain when Idling- RECEIVERS ONLY, inclusive deliv etc. Built-in batteryholder for 4 .• 1 -5V batteries (but will work over 3-10V range). • PCB has both a reed relay (250V, R.300 £184.50 FRG7 £162.00 SMC 73 £128.81 0.5A, 25W max) and a switching transistor (300V, 30mA max) -either keying method can be used • Has the well-known Just telephone your card number- fully-adjustable Samson precision keying lever assembly. • Operate/Tune button. • Sidetone oscillator. • Grey phone 0843 62535 (or risS case 4" 2' .< 6. £53.88 62839 after office hours) ETM-4C: As ETM-3C but with 2 combinable memories. or write for details, send BUILT FOR DEPEN DABLE MARINE & CO M MERCIAL A N I L SERVICE 9p stamp JUN KER PRECISION HAND KEY. A superbly engineered straight key used for many years by professionals afloat and NOTE: All prices are hose current at time of closing for press. inclusive of ashore. With this key you can't help but send good morse. Free- 121-', VAT and carriage. standing-no screwing down. Front and back contacts-fully- G3CE D G3VFA adjustable gaps,lension. Key-click filter. Hinged grey cover. £28.64. BAUER KEYING PADDLE. Single-paddle unit on 1 i" Y 2' base for home-built El-bugs. Adjustable gaps/tensions. £9.97 88m H TOROIDS for C W, RTTY, SSTV filters, 90p. each IcipTRIDG- 90' AU DIO PHASE SHIFT NET WOR KS octal based. f gROPOSTigIPS ('F/VTF KLMY0 All prices postpaid UK and include 12}% VA T. Please Pz send stamp with enquiries. SPACE MARK LTD. Box 6, Partridge House, Prospect Rd., Broadstairs, CTIO ILD Thornfleld House, Delamer Road, Altrincham, Cheshire. (Callers by appointment) (Tel : 061-928 8458)

570 RADIO COMMUNICATION July 1977 antenna specialists GAREX (G3 Z VI) BRITIS H MADE V.H.F. EQUIP MENT AT DISCOUNT PRICES!!! T WO M OBILE FOUR MOBILE Companion units for 2 or 4 metres. They feature Tx, Ru and PSU for 12V DC up to 20 discount on usual retail prices Input in a single unit 12 8 a 41'. Full coverage tunable AM/FM Ra with excellent V.F.O. stability even under mobile conditions. Professional grade sensitivity AND selectivity. Crystal controlled AMIFM Tx. with superb audio WHY PAY MORE??? quality. Based on popular R'T components lar ease ot servicing and ready Yusual Our You availability of spares. Comprehensive handbook and low-cost alter-sales service. Prices: Twornobile £135; Fourmobilo £121.50 (inc. VAT). Price Price Save We stock the popular NRS6VF-1 2m Ro.. with switched 144-146MHt V.F.O. ASP 201 1 wave 108-5 12Mhz £3.23 £2.58 £0.65 and 11 slat controlled channels, ideal for fixed, portable or mobile use. ASP 629 wave 130-174MHz 3dB gain £7.61 £6.61 £1.00 Built.in LS., 12V DC operation. £54 inc. VAT. (xtals £2.41 each, all usual ASP 677 wave 144-174MHz 3dB gain £13.51 £11.95 £1.56 channels in stock). ASPE 667 Colinear 420-440MHz 5dB Ann ac. brings you full details elan), 01 the above. Credit facilities available gain £16.91 £14.95 £1.96 and part-exchanges welcome. ASPE 462 wave 420-440MHz 3dB gain £7.23 £6.50 £0.73 NE W CO MPONENTS: Relay GPO type 3000, 162 coil, pull-in current aPPrOx 200mA. 1M + 119 K220 magnetic mount (with cable) contacts, ideal for psu cut-out. 75p fits 629. 667, 677 . £9.19 £7.69 £1.50 Integrated circuits (lull spec.) K203 trunk lid mount, fits 201. 667,677 723 voltage reg. TOS metal case. 2137V out at 150mA for 5140V in 759 (adapts to 629) £3.70 £3.20 £0.50 SN76660 FM quadrature detector 75p MOST ANTENNAS CAN BE INTERCHANGED WITH MOST MOUNTINGS. CD4001 AE quad. 2-input NOR gate for tone-burst gen. 25P NE555 Timer for lone-burst gen. or time-out Indicator 559 WE WILL BE PLEASED TO QUOTE FOR YOUR EXACT REQUIREMENTS. 7091 To5); 741 (DIU)) OP Amps 30p each THE ABOVE ARE ONLY THE MOST POPULAR MODELS FROM THE A.S. RANGE . WE SUPPLY THE FULL RANGE OF BASE STATION AND MOBILE Rectilinear pots multIturn, preset, p.c. mtg. ANTENNAS ALL AT DISCOUNT PRICES. 10, 20, 25. 100, 250, 500. 2.5k, 359 each, any 5 + : 25p BNC 50ohm tree sockets. 209 each; 12 for £1.45; 50 for £4.90 Terms: Cash with order, mall order only or callers by appointment. Add 121% Noon. Panel taannting. type JH8. 8nirn hole. 240V. red, amber or clear; VAT and 50e pKp to all above deals. 35p each, any 5 : 30p, 10 -1 279. Miniature, wire end 61P each, 10 51p, 100 • 4p. LE D's Panel mounting, type JFIS, 6.5eirn hole, red: 48p, green or amber: 72p Logic probo typo JH 320, £11.95. Roesler Kits. El2 series, 226-2 to IM, 57 values. 5% carbon film, 1W or IW "Stripes of Quality" (Please state). Starter oaCk. 5 each value (285) £2.40 Mixed pack, 5 each 1iNnr -4- 5W (570) £4.151 Commercial Communications Standard pack, 10 each (5701 £4.85 17 Lancing Road, Luton, LU2 8JN Tel: (0582) 21884 Giant Pock. 25 each (1425) £11.85 Replenish ment. available Distributor for Antenna Specialists (UK) Ltd., Thame, Oxon PL.259 UHF Plugs + reducer 611p each. 5 + 60p 50728 UHF Socket panel mtg. 55p each, 5 + : 45p Nicad Rechargeable cells U7 size, new. E1.05 each: 4 + : 95p:10 + :Up Slide switches, min. DPDT 18p each; 5 •e• ; 14p. 2 pole 3 position 22p each: 5 18p Toggle switches, min, full range SP thro' to 4P CIO: on list. GAREX FM detector conversion ready assembled with full fitting In- structions. Tailor made. easy-Illdesignfor AM Cambridge. replaces squelch BREDHURST ELECTRONICS board with minimum of other modifications, £5.40. Transistor Vanguard (AM257) version with modified squelch circuit, £5.94. Suitable lar most roe with 450-470kHz. IF. Sae details. FO R V HF IN THE N O R T H W ES T INTER SERIES AD APTOR KIT. Super value, up to 40 different com- FOR binations of BNC, UHF, N, TNC 8. C series connectors, male and female. MULTI II 2e1 FM fitted 7 channels £209.00 Complete in PVC wallet, £19.95. MULTI Ull 70cm FM fitted 9 channels £249.00 MULTI 2700 2m all mode £489.00 We aro stockists of REVC O aerials for VH F.-Amateur, gilder and P.M.R. VFO for MULTI It £89.00 band Woes available. AC PSU for MULTI II £63.50 Authorised distributor for J.H. Associates Ltd., professional quality TMS6B Scanning 2rrr RS tilted 10 Channels £85.00 switches. Indicators and special products. Quartz 16 2m FM fitted 10 channels £161.00 Lists available covering Revco & J. H. products.

ELECTRONIC DEVELOP MENTS EX-EQUIP. ITEMS (GU ARANTEED) 2m linoar 100W output £151.90 Toroidal inverter transformers (with circuits) Iranaverter 28144 £151.90 Input I2V DC, output 390V 200mA (doubled) £2.50 70cm linear 50W £151.90 gout I2V DC, output 1601260V 150mA (doubled) (Ranger) £2.10 VHF absorption wavemoter £19.00 HT choke suitable for 2-3kHz Inverters 60p Mains transformers, multilap primaties YAESU 515-450-0.450.515V 240mA. 50V. 50m A, 5V 2A, 6.3V 4A (12 lb) £6.50 FRG7 Gen coverage RS £162.00 1700.170V 90mA, 50V 5.11rnA, 6.3V. 3.3A. 5V 2A (5 .5 lb) £2.50 ANTENN A SPECIALISTS 0-146.232V 160mA, 26.5V IA 13 9V SA. 50V 50mA (10.5 £3.95 ASP 677 2m I wave £15.20 135.0.135V. 50mA. 6-3V, 3-3A £2.95 ASP 629 2m 1 wave £8.57 A u to 0-100-110-150-200-230-240.250, 200VA £3.25 ASPE 667 70cm 5dB collinear £19.02 11T chokes. 5H 80mA. 4H 240mA, 12514 350mA, 1.8H 125n1A £1.25 ASPE 462 70cm 3dB collinear £8.14 Butterfly trim mers large 2 r 17.501, 2 a 10pf 110p All mounting options POA 107 IFT (valve type) 21* e r square double tuned 25p: 2 tor 40p; 6 for 90p Mobile PSU 12V DC Input (floating for + or - E) transistor inverter 170, JUBILEE CASH BONANZA! 225 or 380V DC at 150mA. output, fully smoothed chassis section. sell- Free draw ticket with every new FOK set purchased contained, fully wired and tested, with circuit £5.15 £100 Cash Prize As above, but partly assembled (as cut out) complete with all com- See Waters Lt. Stanton Advert for full details ponents. circuit, finish•lt-yourself £4.34 PRICES ARE INCLUSIVE OF UK POST AN D PACKING AN D VAT HP - PART EXCHANGE - ACCESS - BARCLAYCARD tc NE W POSTAGE RATES INTRODUCED LAST MON TH. BUT NO CALLERS BY APPOINTMENT ALL PRICES INC VAT INCREASES IN OUR PRICES YET

Mail order only. Sole address for orders and enquiries WILL O W B R O O K, S C H O OL LA NE, BU N BU R Y, GAREX ELEC TRONICS NORVIC ROAD. MARS WORTH, TRINO, HERTS HP23 4LS T A R P O RLE Y, CHES HIRE. Tel Bunbury (0829) 26-0708 PHONE CHEDDINGTON (STD 0296) 668684 Northern Distributor for Waters and Stanton G30 Q T 6.30prn-gorn AND WEEKENDS ONLY S.a.e. with all enquiries please,

RADIO COM MUNICATION July 1977 571 DECCA/K W equipment continues to be valued in the (jK.and DECCA/E Overseas Amateur Radio Markets. equip ment eRma Stereer eug Woos,/

K W 108 PAONITORSCOPE K W 2)2

• Monitor your transmitted K W 202 Receiver G Ono pl tho n nest Amateur Band Receivers on tho market 'Waveform' 10-160 metres. • SSB fine aid 'Cr multiplier. • EKceilent sensitivity .,nd stability. • T.Yo ID -Ici metres. • Can be left permanently In K W 1)7 ANTENN A TUNING SYSTEM antenna feed. • Incorporates • Two-tone generator incor- E-Z Match, porated lo ensure optimum • Antenna s.vitch • SWR'RF Linearity for SSB. power meter dummy load. • A further safeguard tor your • High power PA tubes. version KW 10 / T also avail- K WIC-7 11r able. serving Radio A AMATEUR RADIO PRODUCTSrn World We • Easy terms on equipment available DECCA COMMUNICATIONS LIMITED over 12, 18 or 23 months Cramptons Road, Otford, Sevenoahs, Kent TN14 5F.A. Telephone: Sevenoaks (0732) 50911

T M P ELE C T R O NIC SUP PLIE S G. W. M. RADIO LTD. JR599. as new £170.00 FAG -i, as new £140.00 ALL PRICES Include VAT and Post'packing IcnA. 10 channels plus accessories £140.00 LINER 2 MOBILE MOUNT, etc. £130.00 RADIO TELEPHONES FR508 160-10m plus CAL £90.00 ARAC 102, all modes. 10 and 2rn £80.00 VITAVOX CN224 Table Microphone stands, new and boxed and professional quality OSKER BLOCK SWR 200 PO WER METER £22.00 £6. Mann° F1.8 base stations, telephone for details. 9R59 GC RECEIVER £55.00 AIRLITE model 62 head and boom mike sets, £5.50. NEW YAESU EQUIPMENT. AMIDON CORES. W2AU-BALUNS. S.A.E. FOR DETAILS. CA MBRIDGE Lo Band FM or AM complete cable, box, mike and speaker. £35. 3 Bryn Clod, Leeswood, Mold, Clwyd CH7 1RU ITT STAR A.M3 mid-bond solid state. 12V with dropper for 24V. 12¡kcia. Unit Tel. Ponty bodkin 1346 (035 297) weighs 61 lb (II) lb with speaker dropper mOuntIng). Single channel £32.40. ULTRA VALIANT MR19.8 AM. 12) keg Lo band. Solid state except driver and P.A. are quick heat valves, last few £15. VANGUARD units only single channel valve Lo band, no accessories, £11, POC KETFONES PF1 for 130 Mes. Clean and complete. untested because crystals removed by supplier. Less batteries. With circuit and tuning Instructions, £20 palr JAMES & MARTIN ELECTR ONICS LTD (one Tx ono Re). Normally we test Receivers for squelch noise. Staines Road. Feltham, Middx, ISOLATION TRANSFOR MERS, Double wound 0-250In, 0-115-250 out or vice versa. 250 watts. 5 n 41' x 3r, weight 12 lbs. shrouded type, £4.50. WATT METERS. PROT OTYPE AND PRO DUCTIO N METAL WORK Absorption AF Na. 1 (CT41) 200 rnIcrowatts to 6 watts e125 ohms to 20,000 ohms, £12. Specialists to the Electronics Industry. Panels, chassis and BC221 FREQUENCY METERS. Complete with charts, less power supply. Those sheet metal details. Milling, turning, drilling. Machining in all are recently recalibralod. £25. metals and plastics. G3VVB. RECEIVERS, PCR. 200-550 and 900 to 2000 Meters, 6 1. 22 Mcfs. Needs 250V DC 100m A arid 12V LT. sockets for 2i ohm spankers. Clean and tested, £20. Tel. 01-570 3127 Plant list on application. OS Ref TQ 113748 INTRUDER ALAR MS. Photo electric, Tx/Re end control unit. Put a light beam over, garage drive to open doors ? Max span 1011. £10. RECEIVERS 810. Two only £50 each. One only Marconi Atalanta, £150. OSCILLOSCOPES CT•136 double beam, 0cod workers. £75. METERS. 500V Oc, modern plastic type, £2.50 new and boxed. Compact HT transformers, standard mains, 500-C-500V at 150mA, £2.00. DIREC T REA DING CA P ACIT A N CE METER This Instrument is a completely portable, battery operated, direct reading Carriage charges are for England and Wales only. Capacitance Meter and requires no manual balancing. Simply clip test leads to cnpacItOr and road ail its value Item the linear scale meter. Sic ranges 2pF-11),(F. Terms: Cash with order Early closing Wednesday Accuracy ±5% or better. Lena battery life. Complete in attractive metal coso with test leads and battery. £19.50 Inc. VAT. G. W. M. RADIO LTD. 40-42 PORTLAN D RO AD, S TEP HE N INS T RU MEN TA TIO N W ORTHIN G, SUSSEX Telephone 34897 49 Hucknall Avenue, Ashgate, Chesterfield, Derbyshire S40 462

572 RADIO COMMUNICATION July 1977 RACAL RA17 AND RA117E CLASSIFIED ADVERTISEMENTS

COM MUNICATION RECEIVERS Private advertisments 15p per word, minimum £3.00. Air tested, Re-calibrated in first class condition. Supplied Trade advertisments 25p per word, minimum £5.00. in metal case with full manual and circuit £225.00 and Box number 75p extra to wordage or minimum. £300.00 including VAT. Carr £10.00 extra. All our sets are Semi-display 1/12 page (11. - s ri £18.04) bought direct from the Gov. 1116 page (V x r> £13.04). Please write clearly. No responsibility accepted for errors. CV89A RITTY AUDIO CONVERTERS Latest date for acceptance-4th of preceding month. All classified advertisements must be prepaid. Well known and sought after. Information and circuit in Copy and remittance to: teleprinter handbook R.S.G.B. £25.00 carr £3.00. ADVERTISMENT SECTION RADIO SOCIETY OF GREAT BRITAIN JOHNS RADIO 35 DOUGHTY STREET, LONDON WC1N SAE. 424 Bradford Rd, Batley, Yorks

Phone Batley 478159 or Leeds 496048 FOR SALE

SUPER ACCURATE WATCH. Continuous display hours/wins. A M ATEUR AERIAL PRO DU CTS Back light, 4-year calendar. "Time band" small leather strap £23 Inc. Large bracelets £33 Inc. Two seconds/week or WE adjust free. We shall have mobile whips al competitive prices ÷ Base G3LLL, Holdings Ltd, 39/41 Mincing Lane, Blackburn. BB2 2AF. aerials HB9CV 2m 6.70cm aerials ± aerial & mast clamps etc Tel 5959516. on display at UHF MOBILES all solid state, 5-7 watts. Dash mount, 2 H x 7V UPT O N MOBILE RALLY 10th JULY W x 9' L. From £5.00. G3Z0E. Wickham 832173. Sae Details. See you there? G.I. AMATEUR SUPPLIES G13ZIA for Trcyrs, Ro, To, Antennas, 55 VAUXHALL ST, WORCESTER WR3 8PA Mico, etc. Trade-in's welcome, Large stocks at 10 Church Street, Enniskillen. N. Ireland. Tel: (0365) 22955. SPE CIAL CO A X OFFER S FRO M G8M W W A DATE WITH SUSAN, GB3SN repeater handbook. Essential UR67....thick low loss 50 ohms 30p per Metre (pp 411 reading for all users of the repeater. Send 50p large SAE to U.K. Per M) F.M. Group (Southern), 12 Meadow Way, Aldershot, Hants. UR43 ....Standard 50 ohm 10p per Metre (pp 2fil per M) QUALITY QSL CARDS. s.a.e. for samples by return post UR95.... Miniature 50 ohm Nylon 4p per Metre (pp -1p (including Silver Jubilee styles—if requested). Quick delivery. per M) Compalith Printing Services, 115 Promenade, Cheltenham Glos. New stocks lust arrived ... SAE for complete lists. GL50 1NW. W. H. WESTLAKE, CLA WTON, HOLS WORTHY, DEVON STORN O VISC OUNTS. S20 with controls and microphone, £35.00 £4.00 carriage. Stoma 10W bases 520 with controls, £.35.00 collect. G8AKA, Reading 332582. RTTY PICTURE PERF. TAPES. Hundreds to choose from. Standard Murray paper tape. Send 9" x 4' sae for free catalogue. I N D E X T O A D V E R TI S E R S M. Watson, G3WMQ, 74 Rosirons Avenue, Wembley, Middx. BARGAIN. LOG BOOKS 65p EACH. Your callsign over-printed if you order four. Beauprint, Meltham Road, Honley, Huddersfield, A mo 6 General Supplies .. .. 574 Johns Radio ,. 573 A J H Electronics Corer le K W Amateur Radio Products .. 572 QSL CARDS. Sae for details. Budd, 49 Upper High Street, Amsat Phase Ill .. .. 559 Loo Electronics .. .. 562 Worthing. Sussex. .. 573 Amateur Aerial Products London Communications Ltd .. 574 QSL, JUBILEE and LISTENER'S CARDS. Competitive, quick corer II Lowe Electronics . 50223 Amateur Electronics .. service. Sae brings samples by return. G3VZF, 5 The Close, Radlett, Amateur Radio Ezchango 565 Marconi Communications Herts. Ambit International .. 562 Systems Ltd .. 575 Argus Books 568 Microwave Modules Ltd .. 561 NE W QSL CARDS. Original designs. Samples: SAE return post. B. Bomber .. 576 Modular Electronics .. .. 512 Carcus QSL, 45 Lutterworth Drive, Advvick-le-Street, Doncaster. J. Birkett • • 568 Mosley Electronics Lid 556 Tel: 722852. Booth Holdings Bath .• 566 William Munro (Invergordon) Ltd 510 Bredhurst Electronics • . 571 North West Amateur Radio Club 560 W ANTED Cambridge Kilg • . 563 Partridge Electronics Ltd .. 570 Catronics Ltd .. • . 567 PM Electronic Services .. 563 German W WII military radio equipment wanted for collection: C B Electronics .. •• 565 OM70 Electronics Ltd .. 567 wireless sets, receivers, transmitters, accessories. Write Box No.161. C & C Electronics .. • • 570 Radio Shack Ltd 513 Commercial Communications • . 571 RI S I Electronics 566 MISCELLANEOU S Compstock Electronics Ltd • • 574 SEM Electronics 514 Craylord Electronics 569 South Midlands PATENTS and TRA DE MARKS —Booklet on request. Kings Datong Electronics 564 Communications Ltd Patent Agency Ltd (B. T. King, Reg Pat Agent)-146A Queen Ashley Dukes — 569 Spacornark Ltd .. .. 570 Victoria Street. London EC4. Tel: 01-248 6161. Telex 8833805. Estab- Germ Electronics .. 571 Stephen instrumentation .. 572 lished 1886. G2DYM Aerials 574 Stephen-James Ltd.. .. 569 G WFA Radio Ltd 572 Telesonic Marine Ltd .. 574 ACCO M M ODATION AV AILABLE Ham-Spares 562 Thanot Electronics .. .. 504;5 Hartley Crystals 574 IMP Supplies .. 572 B&B. Plus use of house. Suit five-clay weeker. G4AK, QTHR. Heath (Gloucester) Ltd .. 566 Reg Ward I. Co Ltd .. 564 Blackmore 822910 Holler Electronics .. 567 Waters & Stanton Electronics .. 50819 D. P. Hobbs Ltd .. 564 Western Electronics (UK) Ltd .. 50417 Holdings .. 563 PROPERTY FOR SALE W. H. Westlake . .. 573 Ian's Shack .. 565 FINE QTH, 5 miles CARLISLE. (A69) 4 bed, dining room kitchen, Interlace Quartz Devices Ltd 567 Yaesu Musen Co Ltd .. 49329 large lounge, hall, garage/shack, gardens, excess to lakes and James d Martin Ltd.. .. 572 • . 511 Scotland. Contact G81HV. QTHR or Tiffen, 1, The Crescent, Carlisle for further details, Offers around £13,550.

573 RADIO COM MUNICATION July 1977 NE W R O B O T S S T V • "400" Solid state slow to fast and fast to slow Scan converter with Digital Random Access Memory, for full brightness, non fading, pictures of unbelievable definition on a normal TV set. C O M P ST O CIK Also picture transmission from a standard CCTV camera. £666 incl. VAT. S.A.E. for details and latest stock list please. Requires S ALES EN GINEER S for the S O U T H AER O & GE N E RAL SU PPLIES, Nanaimo House, 32 Huff ord OF ENGL AN D to handle existing custo mers and Avenue, Bra mcote, Nottingham NG9 3JH. Tel. 397588 develop new accounts.

FM CRYSTALS—prompt delivery from stock WE ARE one of the fastest growing distributors in the UK. 2rn To ranges:6, 12, 18MHz Rx ranges: 14,44,52MHz WE HA VE three new franchises. HC25 U Simplex 145.0, 145.2, 520, S2I, $22,523,524,525,1456 Repeater: RO, RI, R2, R3, R4, R5, 136, R7, R8 WE NEED more concentrated coverage to sustain con- Re crystals for repealer Input R3. R4. R5, R6. R7, R8 2in Tx ranges:4.8MHz. fix ranges: 10,44MHz. tinued expansion. H C6 U Channels : 145.0, S20.521, S22. S23. 524.1456, R3, R4. R5,116, R7 70cm HC18 U Tx range:12MHz Re range:84MHz HC25,U Tx range:24MHz Rx range:34MHz YOU ARE a bright and active person with talents as yet Channels SUB, 51J20, RBO. R82. R84. ROO, RE110. RB14 professionally unused. 106MHz in HC113,U for PF1 2nd Osc Inclusive price £2.90 each Giro 35 563 4007 Phone 04 868 7597 YOU HAVE experience in using electronic components In Mode-to-order crystals 4-105MHz 6 weeks delivery £3.60 each inclusive Practical or original equipment.

HARTLEY CRYSTALS YOU NEED the opportunity and challenge to satisfy your Green Lane, Milford, Godalming, Surrey GU8 5BG driving ambition. Rewards for this post are both financially and personally attractive. The position carries the usual benefits such as Company car, expense account, etc.

In the first instance, please send brief details to G2DYM PROJECTS & AERIALS In addition to our usual Cusiom.bulll and designing aerial service for SWL's Mr. Bernard Trim, Sales Manager, and To amateurs, we now offer new service: THE BRITISH RADIO TECHNICAL ADVISORY SERVICE Compstock Electronics Ltd. Full details 13p, 10-, zr sae and 3 X 9p. stamps. Briefly YOU send us details of 42 44 Bowler's Croft, Basildon, Essex. your technical problem; we will quote you the cost of our written advice on any technical problem in the field of radio communication, Tel: (0268) 27722 LAMBDA ANTENNA STUD FARM W HITEBALL. WELLINGTON. SOMERSET cs

N SITUATIONS VACANT C C1M P STCIC K RADIO-TELEPHONE BENCH The fastest growing professional component distributor in the ENGINEERS AND UK need an FIELD SERVICE ENGINEERS TOP SAL ARIES FOR TOP ABILITY INTERNAL PRODUCT SALES London's fastest expanding, independent, radio-telephone co mpany needs more engineers. ENGINEER If you have experience in mobile VHF ring NO W! 01-328 5344, Mike Rawlings or Bill Clarke The ideal candidate for this post will be familiar with electronic components, semi-conductors, resistors, capacitors, London co-axial cables and connectors, etc. The position entails Communications handling customer enquiries, telephone orders, etc. Pre- (Equipment) Ltd vious sales experience not essential, as training can be 30 One.ea., tond. tcrlden 1.0.1,6 01 326 5344 given.

Prospects are good for the right candidate as promotion to field sales engineer with company car and associated MARINE ELECTRONIC ENGINEER benefits could follow. Salary is negotiable. TECHNICAL MAN AGER

This last sysandmo company seeks o qunlified, experienced person capable of Telephone Alan Carpenter, Sales Office Manager, In the Installing and servicing SSB. VHF, Auto Pliote. Radar. Instruments. Electrics, first instance. etc., and to take charge of all engineering aspects with a possibility of a Board appointment as Technical Director. The successful applicant must live in, or very close to London. CO MPSTOCK ELECTRONICS LTD Salary negotiable. Send full curriculum vitae to: BO WLER'S CROFT, BASILDON, ESSEX TELES ONIC MARINE LIMITED Tel: Basildon (0268) 27722 243 Euston Road, London N W1 01-387 7467/8 cs

RADIO COM MUNICATION July 1977 574 Marine Communications Development Chelmsford

How will you fit into the professional scene? well:— If you are getting on with building that home-brew Linear, or that ATU, Top- Band Solid State rig, new MOSFET RX You will not have been Front End, or just forming ideas for around when Marconi's going on 282MHZ when it opens up, you could be the sort of person we're 2MT WRITTLE and 5SW looking for. CHELMSFORD were on We have room in our Marine Communications Development Lab. for the air, but you may engineers to work on new projects covering LF/MF/HF Transmitters, have the same Frequency Synthesized Drives, enthusiasm which led Receivers, Direction Finders and FSK equipment. Also, Satellite many amateurs to seek Communication, Digital and Analogue circuits, applying low power and high a career with Marconi power solid state techniques etc. in those days.

If you want to start a career in Communications Development, or Contact Mr T. Ford, build on experience you already Marconi Communication Systems possess, come and see us in Marine Limited, New Street, Chelmsford. Communications Development at New Telephone Chelmsford 0245 53221 Street Works, Chelmsford. Ext 114.

A GEC-Marconi m csL Electronics Company Marconi Communication Systems Limited

RADIO COMMUNICATION July 1977 575 TER MS OF BUSIN ESS: CASH WITH ORDER, MINIMU M ORDER OF £2.00. ALL PRICES NO W I NCLUDE POST & PACKING (UK ONLY) B. RAMER ELECTRONICS EXPORT ENQUIRIES WELCOME CALLERS WELCO ME by APPOINTMENT ONLY DEPT RC, 5 STATION RD, LITTLEPORT, CAMBS, CB6 ¡QE Please enclose stamp ed addressed envelope with ALL Enquiries TEL: ELY (0353) 860185 (TUESDAY-SATURDAY) PLE A S E A D D V A T A S S H O W N

ALL BELOW -ADD 8% VAT ALL BELOW -ADD 8% VAT ALL BELOW -ADD 8% VAT

18V DC RELAYS. 4 pole chenge-over (double con- PLASTIC PROJECT BOXES with screw on lids (In PYE SSB125T P.C. BOARDS (All brand new with tacts). Iwlil work from 14.24V DC). Brand New, boxed, Black ABS) with brass inserts. circuit diagrams) 12V DC. good quality, made by AEI 400 each. Type NB1 approx. 3' X 2)" e 1.r 40p each. SSB RF FRONT END PCB. 4 channel, 3-15MHz. RF SLIDER S WITCHES, 2 polo make and break, (or Typo NB2 approx. 31, a 2i* o 11'50p each, end Mixer stages, tint In. 1.4MHz out £2.00. can be used es 1 pole chenge-over by linking the Typo NI33 approx. or e 31' x 11'60p each. sse CHANNEL OSCILLATOR PCB. 4 channel with Wormers. for 4 Fundamental Mails (2 stage) £1.00 wo centre pins) 4 for 50P. QUARTZ-XTAL CONTROLLED CLOCKS, 9 to SSS AUDIO AMP PCB (3 stage) £1.50. SMART MIN. RECTANGULAR PUSH TO MAKE 12V DC at approx. 3mA required. Dial size aisle° , SSS 1.4MH. OSCILLATOR d, AGC AMP PCB. S WITCHES, black rectangular surround wth white 2', depth of unit approx. 2', Not In cases, unit only. (less etolO £1.50. rectangular button, overall urne 12 x 17mm. 3 for smart modern appearance, black face with white LIMITED SUPPLY ONLY... ORDER NO W! 50o. lettering, 12hr. with second hand, and red hour and minute bends (Coat over E4Oto produce) £10.00 each TELEPHONE HANDSETS wilh"PRESS-TO-TALK" A NE W RANGE OF QU ALITY BOXES & INSTRU- while stocks last, tested before despatch. buitons, on curly lead, brand new. £3.50 (few only). MENT CASES, 4MH: XTAL PACKS Aluminium Boxes with lids. OS MOR REED RELAY COILS (for reed relays re> to (10 assorted xtrils between 4MHz and 5MH1), our A1310 51 od e 1¡ 60p 0' día, not supplied) 12V. 500ohm coil, 2 for 50p. selection only. £1.00 Pack. ABI3O x 4 a 2 80P PERSPEX TUNER PANELS ((or FM Band 3 tuners) ALU-SOL ALU MINIU M SOLDER (made by Multi. AB14 7 e 5 x 21 £1.00 marked 88-108MHz and Channels 0-70, clear number Corot Solders Aluminium to itself or Copper, Brass, AB15 8 u 6 u 3 e1.30 rest blacked out, smart modern appearance, size Steel, Nickel or Tinplate, 16S WG, with multicoreflue AE118 10 7 x 3 C1.50 opprox. 8-)' X 1r, 2 for 35p. will, instructions, aPProx. 1 or Cell 40P peck. A017 10 e 4( • 351.30 Larga reel 1E2-75. AB256 04 0 351.00 MIXED CO MPONENT PACKS, containing resis• SOLDER SUCKERS (Plunger Type) Vynal Coated Aluminium Instrument Cases. tors, capacitors, switches, pots. etc. All new, and Standard Model £5.00. Light Blue Tops and White lower sections. Very hundreds of lloros. £2.00 per pack, while stocks lent. Skirted Model £5.50. smart finish. PROGRA M MERS (Magnetic devices) contain 9 Spare Nozzles 60p each. W B1 5 2¡ a 21 60P mIcroswitches (suitable for mains operation) with 9 MULTICORE SOLDER W B2 6 o 41 x (1 C1.10 rotetIng cams, all individually adjustable, Ideal for Size 5 Snyble 18S WG in alloy dispenser 32p. W B3 8 e 5 n 251.60 switching disco lights, displays, etc., or Industrial Size CISAV18 Suable 18S WG 55p. W B4 9 x 51. 2) Mee) machine programming. (Need slow motion motor to i&e. (1'1 lb) 60;40. 2OS WG on Plastic Reel, £3.00. W B5 II e e 3 £2.00 drive tarns, not supplied) 9 switch version, £1.50. W ELLER TCP2 and PU20 PSU. Temperature con- W B6 11 e 70 e 31 £2.25 trolled soldering iron, with reatchIng Po wer Supply W B7 12 e 61 e SI £2. 60 PLUGS & SOCKETS Unit. containing sponge and spring stand. £30 10 W B853 8 x x 35 £2.00 BNC PLUGS (or-equip) 5 for £1.50. SPARE TIPS (for TCP1/2). Throe types available, N-TYPE PLUGS 50ohm 60p each, 3 for [LSO. SMALL MAINS SUPPRESSORS (smell chokes, TYPE CC? (Standard). TYPE 107 (Long fine tip). Greonper (GE30015) Chassis Lead Terminations Ideal for radio, Hen Inputs, etc.) approx.4' a 11' TYPE P) (Very fine tip) £1.00 each. (These aro the units which bolt on to the chassie. 3 for 50p. W ELLER WOOD Mains operated temperature control the lead le secured by screw cap, and the lever of soldering iron, £13.80. the coax passes through tho chassis). 30p each. 4 RALLY SEASON HERE AGAIN I If you require Iteren SPARE TIPS (for W601)). Two types available. for M M. In our ads for collection at rallies or exhibitions, TYPE CC7 (W600) Standard. TYPE AA? (W800) PL259 Plugs (PTFE) Brand now, packed with reducers. please glee us a ring to rouerie, and we will bring Finer tip. £1.15 each. 65p each or 5 for £3.01). them alone for you. S0239 Sockets (PTFE) Brand new, (4 hole fixing type) SPIRALUX Tools for tire Electronics enthusiast... BARGAIN PACK OF LO W VOLTAGE ELECTR O- 50p each or 5 for £2.25. SAE for list. LYTIC CAPACITORS. Up to 50V working. VALVES HEAVY DUTY RELAYS. 24V DC operated (will work Seatronle manufacture. Approx. 100. £1.50 per peck on 18V) 3 heavy duty metro contacts (around 10A QQV03I20A (en equipment) £3.00. H- 121% VAT). rating) 4 change over contacts + 1 break contaet. QQV O3i10 (es equipment) 750 or 2 for £1.20. New, complete with mounting bracket (Ideal for TUNED COILS. 2 section coils, around 1MHz. WI Ira 23015 Ceramic (ex equipment) £2.00. switching HT on Linears). Many uses for this high black smart tuning knob, which moves an internal DET-22(es equipment) 2 for £1.00. quality unit. £1.50 each. core to vary the Inductance, ninny uses, easily re- 6BH6 (es equipment) 2 for 50p. wound. 3 for 50p. All the above valves are unteeted, except for healers. and no guarantee of percentage of emission is given. ALL BELOW -ADD 12+% VAT FULL RANGE OF BERNARDS MABANI ELEC- Sorry, no returns. VARIC AP TUNERS Muliard Typo ELC1043/05 Brand TRONICS BOOKS IN STOCK, S.A.E. FOR MULLARD 85A2 BSV STABILISER VALVES New, £4.40. LIST (brand new) 70p each or 2 for £1.20. TV plugs (metal type) 4 for 50P. TV sockets (metal tyPe) 4 tor 50P. NE W FOR THE VHF CONSTRUCTOR. A range of TRANSISTORS TV line connectors (back-to-back ski) 4 for 50P. tuned circuits on formers with slugs and screening PNP Audio Typo TOO Transistors, 12 tor 25p, 3 pin Oie plugs, 4 for 50P. cans. Frequencies quoted aro approximate, and 13FY51 Transistors. 4 for Sop. Din 3 pin Lino Sockets, 15p each. rango cari be greatly extended by using varying BOX 38/300 Stud Rectifiers, 300V at 2.5A, 4 for 60p. Din Sockets 5 pin, 2)0 deg. 4 for 50p. capacitors In parallel. BCY72 Transistors, 4 for 50P. Din Speaker Skts, 2 peel for 30p. Type S (5' square, dumpy type) BSX20. (VHF oscimult.). 3 for 50p. 50kohni lin, pole, r plastic spindle, 4011 each. Type SA 20 to 30MHz (when 33p1 fitted In parallel) BC108 (metal can) 4 for 50p. T WIN IF CANS, approx. .< + high, around Type 5B30 to 50MHz (with link winding) PBC 1)3 (plastic BC 108) 5 for 50p. 3.5 to 561Hr. 2 separate transformer. In one tan, Type SC 70 to 100MHz (with link winding) BFI52 (UHF ampfneser) 3 for 50P. internally screened, 5 for 50p. Type SD 135 to 175MHz (with link winding) 2N3319 Fol. 3 for 60P. TYPO M (Min. ('square types) BC148 NPN SIL(CON 4 for Sittp. ELECTROLYTIC CAPACITORS Typo MA 19 to 28MHz (when 33p1 titled In parallel) BC158 PNP SILICON 4 for 50p. Typo MB to 32MHe (when 33p1 fitted In parallel) Dubliner Electrolytics. 50irf, 450V. 2 for 50P. e BAY31 Signal Dlodes 10 for 35p. Type MC 25 to 35MHz (when 33pf fitted In parallel) Driblet:1r Electrolytic.. 100uf, 275‘/. 2 for 509. BA121 VerIcap Diodes. 4 for SOO. Type MD 38 to 50MHz (when 33p1 feted In parallel) Plessey Electrolytic's, 470r1F. 6.3V, 3 for 50P Type ME 45 to 60MHz (when 33p1 fitted in parallel) DIEC AST BOXES. We sell stock thine, but owing TCC Electrolytic'. 1000uF. 30V, 3 for 60p Type MF 100 to 200MHz (without slug) when 0 to 30p1 to frequent price rises from our suppliers, and costly Dubliner Electrolytic', 500Ornld et 35V. 50p each. variable fitted In parallel) postal charges, It has been found Impossible to Dubliner Electrolytic", 5000pF at 50V. 60p each. All the above coils available in packs of five only publish up-to-date prices on these Items. Pioneering ITT Electrolytics.6600mfd at 25V, high Credo, acrem (same type) at 50p por pack of 5. or >veto (with SAE). for latest mall-order prices. terminals, with mounting clips, 50p each. AEI C510B/R MICR O WA VE DIODES: up to X- Plessey Electrolytic", 10.00Ornfd al 63V- 75P •sch. RED LEDs (MI.. type) 5 for1OP. Band, max, nolse figure 8.5dB et 9-375GHz. 80p each. Plessey Cathedra), Capacitors, 0 04uF et 12 5kV DC. VIDICON SCAN COILS (Transistor type, but no 14 OIL REED RELAYS, 5 to 12V DC, 450 ohm coll. Screw termlnale £1.50 each. data) complete with vidicon baso £4.50 each. Brand Designed to work directly from TTL Logic, Single now. Polo Chengeover, Contact ratings. 23V, (A, 3W. A LARGE RANGE OF CAPACITORS AV AILABLE £1.75 each. AT BARGAIN PRICES, SAE FOR LIST.

576 RADIO COM MUNICATION July 1977 RADIO COM MUNICATION July 1 977

PUBLICATIONS OBTAINABLE FRO M RSGB RSGB me mbers can obtain al° per cent discount on the prices listed below (excluding Ham Radio Magazine and Ham Radio Horizons). To obtain the discount, deduct 10 per cent, calculated to the nearest penny, from the total value of the order (using the latest price list) and enclose a remittance for the balance. Also enclose an address label from a recent Radio Communication wrapper as proof of membership.

RSGB PUBLICATIONS OTHER PUBLICATIONS Technical books American Radio Relay League Amateur Radio Awards . . £2.15 Antenna Book (13th edn) . , , . . £4.08 Amateur Radio Techniques (5th edn) £3.55 Course in Radio Fundamentals . . . £2.93 Guide to Amateur Radio (16th edn) . £1.38 FM and Repeaters for the Radio Amateur . . £4.04 Morse Code for Radio Amateurs . 54p Hints and Kinks ...... £2.58 NBFM Manual . . . . £1.38 Radio Amateurs' Handbook 1977 (Paperback) . . £8.16 RSGB Amateur Radio Call Book 1977 . £2.35 Radio Amateurs' Handbook 1977 (Hardback) (Out of print) Radio Amateurs' Examination Manual . . £1.38 Ham Radio Operating Guide . . . • £4.44 Radio Amateurs' Examination Revision Notes . 86p Single Sideband for the Radio Amateur . • £3.85 Radio Com munication Handbook 5th edn. Vol 1 . £9.36 Specialized Com munication Techniques . • £4.04 Radio Com munication Handbook 5th edn, Vol 2 . £8.12 Understanding Amateur Radio . . £3.84 Radio Data Reference Book (Out of Print) VHF Manual . . . • £4.08 Service Valve and Semiconductor Equivalents 48p Electronic Data Book . . . £4.04 Teleprinter Handbook . . . £8.89 Test Equipment for the Radio Amateur £2.79 Radio Amateur Callbook Inc TVI Manual (Out of print) American Callbook (USA listings) 1977 . . £10.16 VHF/UHF Manual . . . £6.82 American Callbook (DX listings) 1977 . £9.66 World at their Fingertips (Paperback) £1.63 World Atlas (Amateur radio prefixes) . £1.72 World at their Fingertips (De-luxe) . £2.76 Radio publications Inc Log books Beam Antenna Handbook . . • £4.44 Standard Log . . £1.34 Better Short Wave Reception (3rd edn) • £3.42 Receiving Station Log . £1.46 Cubical Quad Antennas . . • £2.77 Mobile Mini-Log . £1.03 Simple, Low-cost Wire Antennas . • £3.46 De-luxe Log . £3.00 "73 Magazine" publication Maps, charts and lists SSTV Handbook . . . . £3.19 Countries List/HF Awards List 25p Great Circle DX map (In tube) £1.29 Miscellaneous Oscar map (in tube) . . 43p RTTY the Easy Way . . . £1.02 QTH Locator map (Western Europe) (in tube) £1.15 Radio Amateur Operators Handbook . £1.11 QTH Locator map (Western Europe) (on card) 57p Radio Valve & Semiconductor Data . . £3.00 RSGB Amateur Radio Prefixes (World) map 66p UHF repeater planning map . . . 40p UK Beacon List . 19p UK Repeater List . . . 19p MORSE INSTRUCTION AIDS IARU Region 1 Beacon List . 19p G3HSC Ryhthm Method of Morse Tuition- Members' sundries Complete Course (two 3-speed 1p records and one ep Callsign lapel badge (5 weeks' delivery) . £1.31 record plus books) . . . . . £5.60+ Lapel badge (RSGB or RAEN emblem, pin fitting) 51p Beginner's Course (one 3-speed 1p record and one ep Tie (Maroon or Blue) . . £1.96 record plus book) . . . . . £4.12+ Radio Communication Easi-binder . • £3.00 Beginner's 1p (0-15 wpm) plus book . . . £3.44+ Car window sticker (RSGB or RAEN) (self-adhesive) 31p Advanced 1p (9-42 wpm) plus book . . . £3.44+ Members' headed notepaper (50 sheets) quarto . 76p Three-speed simulated PO test lin ds ep record . £1.15+ Members' headed notepaper (50 sheets) octavo . 51p t Overseas orders: add £1.12. Radio Communication back issues . 84p RSGB contest log sheets (100) . 77p RSGB teeshirt (large, medium or small) . £2.25 MAGAZINE SUBSCRIPTIONS

Prices Include postage, packing, and VAT where applicable. For QST (including ARRL membership) (Per annum) . £10.50 air mail despatch, please ask for price before ordering. Goods are CQ (Per annum) . . . £6.89 obtainable, less p & p, at RSGB headquarters between 9.15am 73 (Per annum) ...... £6.60 and 5.15pm, Monday to Friday. Subscriptions for the magazines listed above should be sent to RSGB, 35 Doughty Street, London WC1N 2AE. POSTAL TERMS: Cash with order. Stamps and book tokens cannot be accepted. Cheques and postal orders should be crossed and made payable to "Radio Society of Great Britain". Ham Radio (Per annum) (includes air delivery) . £7.50 Giro A/C No 533 5256. Ham Radio Horizons . . . . . £6.50 Please write your name and address clearly on the order. Subscriptions and changes of address for Ham Radio Magazine and Ham Radio Horizons should be sent to: Ham Radio Magazine (UK), PO Box 63, Harrow, Middlesex HA3 6HS. OR DER FRO M: RSGB Publications (Sales), 35 Doughty Street, London WC1N 2AE IV RADIO COMMUNICATiON July 1977 A. J. H. ELECTR ONICS Proprietor: A. J. HIBBERD (G8AQN) Tel: RUGBY daytime 76473, evening 71066 Terms of Business Cash with order, Mall order only, or Callers by appointment. S.A.E. with enquiries Handling Charge 40p Minimum order £1.00. °Meryl orders accepted on a strict mordhly baths. Prices now include VAT FULL MONEY-BACK GUARA NTEE ON ALL ITEMS HOLIDAYS THIS YEAR: CLOSED 23rd JULY-8th AUGUST

ITT SFI UHF STARPHONE mind eortable working on SN74121 360. ITT 024DC 3.751,Hr ..è 3db imp 910 ohm 433 2MHz vrith battery and charger unites new £75.00. SN471411 80p. PYE PF1 CO MPACT working on R190 (UHF) built in SN74196 £1.40. ITT 0240E 923L - 3.5kHz ir 3db imp. 820 ohm lone burst. complete with batteries and new leather NE529K £1.45. £6.00. case. M AO. MC10116 62p. ITT 0440A 3.75kHz ii. 3dt: imp. 3.31, oho, KEN KP202 VHF hand held portable fitted sly sets el MC10131 £1.60. £.5.00. crystals SO. 520, S22. RS. RO, and R7, fitted with BNC rrA7805 5V regulator TO3 case £1.00. TOYOCOM T I4F02-M 3-75kHe .4: 3db imp. 910 ohm nerial socket and Helical aerial, supplied with leather PTE CA MBRIDGE 101 MHz IF AMPS. new £3.00. £4.00. case. nl.cad batteries and charger unit + tone burst. PVE CA MBRIDGE Tx phase modulator bonrds 68-83 41.MHz LS13. SSS. FILTER made by Cathodeen for new condition £.115.00. MHz new £3.00 with circuit. ICO M 1C202 2Mir SSS portable only used a few hours PYE 55812ST Radiotelephone £4.00. PTE F27 Tir PA TAN K UNITS"P" band can bonneted all above fillers are new a unused except for 445100: £130.00. STORN O CQL662 6 channel UHF mobile fitted crystals 102 MTis new 75n. 90913 which is EX-EQUIP. lor R136 no lone burst £100.00. PCB for breaking down contains 11 Plessey 5V reed ERNEST TURNER EDGE WISE METERS small ITT STARPH ONE A M7 mid band 108•140MHz 4 relays 2 pole make:break, 11 BC107 transistors. O ICs precision type 100 microamp F50. marked 0-100 dispaly channel model 121kHz channel spacing suit modifica- 74 series, It diodes resislOre ezènew equipment area 9:16' fr. make nice "S" meter new boned tion to air band, now condition less speaker £45.00. bargain MAO. PETRIFLEX FIVE 3Sm m SLR CA MERA recently MIXED BAG OF CAPACITORS polyester type 2501 JAPANESE TUNING METERS 1- sq. marked "mono: overhauled by importers the case is a bit rough but 400vw. PC mounting sold by weight but a bag contains stereo" special otter 45p each camera is in first class condition ma 50mm lens fitted :sperm 400, values -01-1mfd. 95% epee 1 lb bag £1.30 SEMICONDUCTORS at std. plus the following Soligor lenses-28mm wide HE WLET PACKARD HP5082-2800 hot carrier diodes angle 135mm telephoto, 300mm telephoto. all as new TRIM IP E0R 0s CAPACITORS: 70p each. £100.00. CERA MIC lOmm dry. 6mm high, 240. 3-10p1, A 10-40PI. HEVVLET PACKARD HP5082-3080 pin diodes 50p each 24hr DIGITAL CLOCK with 1 in display. alarm 10 nun all Sp each. Tnim din. 3-901, rS 7-35plep each. 4 lor snooze time. AM1PIIA indicator. size Only 51in 2in TUBULAR CERA MIC solder in type 1-6p1. 11p each 70p VAR1CUP D100E3E113105 in matched sets old, 90p pet o 31in deep. guaranteed by us 10,12 months, available tor ten. sel. BAIII 15p each. in the follOwIno case colours-black. red, white, brown CERA MIC MINIATURE COMPRESSION TYPE VHF PO WER TRANSISTOR SRF1117 (Motorola) end green. Please slate second choice, brand new 8 13nun P.C. mount 10-40p1 6p each. capstan type. 13e. 300 rn w input gave 23 watts output on unused £14.00 each. an Ideal clock for the shack. CERA MIC CO MPRESSION 10.25001 10p each. flor 145MHz FM. (21 watts nuts output) special otter 8517 PYE AMIOD)FMIOD dash Cambridge 6 channel crystal 70MHz Tr Feb. R.C.) pialen comp, with switch multi way crystal holders. Tx each any quantity. crystal trinuners but LESS the Rn crystal calls new and PLASTIC SEMI.AIRSAPCED 7mm din. 1-100, B M W VHF.UHF RF amp. 20p each unused £2.00 each. I-160 PC nicient Sp each. lOmm die. 2-25111. SP each ten BFI68 VHF RF amp. 15p each (replacement fOr WISAM STEREO CAR CASSETTE RADIO PLAYER AUDIO tor 50p. 2-32p1 d 5-6008p each. all 3 pin PC mount. Westminster front end.) A MPS contains two NEC irPC1001H2 audio Its Phis OXLEY AIR SPACED I' sq. bate 1-10p1. 1-15of. lOe BFT90 VHF RF amp 90p each. 30 capacitors. 30 resistors, 4 tranalflors, on PC board. ench ten lot £1.40.2.300 20p each. ST2110 RF amp FT950FAH: OK VHF Tx driver 15p each. 41* 11' approx. 31 watts RMS Per Channel 12VDC TETFER TRIM MERS Jackson C16 Cat. No 5640 2-10pi. 2N3055 RCA with ins. set. 509. supply. Those have been removed horn new units by Mi. sq, base, temp. cool. less than - IODOPml`CriOp each CA3089E 16 pin OIL. FM IF amp. "S" meter, AGC. AFC. manufacturer and are not faulty te any way. Price £1.60 ten for £.50. also timm die. PC mount Cal No 5750 outputs 011 for IF amp for 2 107r Ro. with dala sheet each or two for £2.00. you could not buy the capacitors price él info, as 5640. £2.00. tor this price) With circuit. ERIE TEFLON TRIM MERS "530 terms" -25.1 TBA641'Al2 AUDIO AMP IC. gives 2 walls Into 4 ohms CAR RADIO PCBs. Famous British manufacturers 600vw. j' dia. , 7/16" lona solder in type P.T.F.E. with 9 volt supply, with data sheet ELLS. rejects dueto P.C. track defects "sold for components" Insulation 10p each. 741 OP AMPS 8 pin OIL. 35p each. but can be used tor a number of projects Inc. top band JACKSON BUTTERFLY TRIM MERS 17 - t7pf NE555 TIMERS OK tor tone burst etc. 8 pin DIL. 4Sp. OF set. The IF and audio stages are complete, the 0.050 air gap Cat No. C713 screwdriver adjustment. INTEGRATOR UNITS for PYE FP1 Pecketfone teem , mixer stage is wired but was originally designed lOr • 50p each. law vuth j" spindle 65p each. eis fle w £1.00 . C11. Permeability tuner. new and unused. Only Et » Inc. PLASTIC SEMI.AIRSPACED TRIM MERS 10-600 se S WITCHES circuit. Circuit only-111p stamp S.A.E. used in PYE WESTMINSTER PA units 15p each. FM RADIO FRONT END TUNER UNITS 88-108M112 MINIATURE ROTARY SWITCHES I' die. 3 pole 11 VIDEO CA MERA SCAN & FOCUS COIL ASS. way make before break new 50p. 3 pole 3 way + (off with 10.7MHz I.F. output & fitted with A.M. gang. transistor type to suit std. vidicon tube, inc. centring position) & earthing ring) break before make„ 20p each. capacitor, FOI RF amp. npn miser, separate osc. AFC magnets & tube clamp no into new unused £8.00 each AGC inputs, geared tuning brand new with circuit SUB MINIATURE 2 pole 10 way (remove Me stop & il two tor £11.00. requires 9-I2V DC BARGAIN ONLY £2.30 each. makes 2p 12 way) 5.'32' 'Medic: 80p each. PLUGS'SOCKETS ITEMS FOR FREQUENCY COUNTER FEATURED SLIDE SWITCHES 2p CO old site three for 17p. 50 ohm BNC plugs 50p. 51) ohm BNC right angle adaptors IN MARCH 1276 R.C.: REVCO I wave mobile aerials for 145MH: £7.00 + 60p 60p. 50 ohm BNC single hole sockets Sep. 50 ohm BNC post. M AINS TRANSFOR MER 240.250V input-output 250V single hole sockets cable entry typo 50p each, PL259 . FERRITE RINGS feltr dry, no gen. 10p also s few 9" 50 ni:A, 63V IA. and 9V r, 1A. We had Ihts item plugs P.T.F.E. Ins. 50p. 50239 sockets P.T.F.E. Ins. Ma with 6 turns wire (removable) 3p each. specially made £4.00. SOp, DECA DE COUNTER PCB. Made to suit our miniature SPECIAL OFFER: 50 ohm "N" plugs for UR43 cra•az FERRITE BEA DS similar to FXI115 4 for 10p. ITT Niue tubes(ITT5853S) 61111,11, 4 for use with 1B way 35p. 75 ohm BNC plugs 30p. 75 ohm BNC single hole 101MHz IFTe, single tuned transistor lime j sq. 10p. 0 I" pitch edge connecter if required, ready drilled and sockets 30p. each. 455-470kHz IFTs, single tuned transistor type.1" sq. 110p. tinned to take SN7490. 7475 and 74141. 7So each set of 101 MHz CRYSTAL FILTERS: ELECTRONIQUES TUNING DIALS £5.00. five £3.40. -2' pitch edge connector to suit above PCB. STC 44510U:929 - 15kliz , 3db Imp. CIO ohm (for CRYSTAL HOLDERS HC6/1.1 usable P.C. or chassis 60p. PYE Peckelfone Pin £3.00. mount. HC251U. HC25.0 P.C. mount FT243, chassis MINIATURE NIXIE TUBES ITT-5835S to suit the TOYOCOM 10M-513-1 7•5kHz , 6db imp. 3k ohm mount all 11p each. above decade boards left and right decimal points. £3.50. COILS 5mm Me tOrmn sq. base far P.C. mounting com- 1" characters, envelope size only 711r 7116' new and SIC 4451100.901A ,..15lifiz 41. 3(11) Imp. 2k ohm unused with dula sheet Stlp each, five for £2.S0.1en for £2.50. plete with core as used in PTE radiotelephones Sp each. £4.50. STC 445/10U,1101N lOkHz 1.5db imp. 25k ohm I.C. SOCKETS 8 pin 10p. 14 pin 15p, 16 pin 16p each, HC6 U CATHODEON Crystal Ovens MC0-2M 45p. £A.011.. 10,000nifd 16V electrolytic 35p. STC 4451QU.109B 7.5kHz i. 3db as used in PYE (low nrOfIle) 10iiild 350V I0p. FM Westminsters E_X.EQUIP. REED RELAYS 14 pin OIL made by ASTRALUX type SN7400 17p. £2.50. 121A-3, 5 volt coil 500 ohms TTL compatible, with SN1413 35P. ITT 02413Hr923J - 7.51rHz ..4 (1c11: Imp. 820 ohm normally open contacts. new 45p each ten for £3.50. S117473 22P. 3 GANG TUNING CAPACITOR 385p1 per section Sh17475 60p. ITT 024CC &kHz 3db imp 910 ohm direct drive 75p each SN 7490 600. £4.00. SOLDER-IN INSULATORS approx )" die 100 for 50P ,

59 W AVERLEY ROA D, THE KE N T, RU GBY, W AR WIC KS HIRE

Printed in Great Britain for the RADIO SOCIETY OF GREAT BRITAIN. 3$ Doughty Street, London. WCIN 2AE by The Garden City Pre, Limited. Letchworth, Hertfordshire SG6 lis