W RELESS NEW EDU-KIT MAJOR Completely Solderless Electronic Construction Kit Build these projects without soldering iron or solder * 4 Transistor Earpiece Radio. * 5 Transistor Push Pull * Batteryless Crystal Radio. Amplifier. ` * Signal Tracer. * One Transistor Radio. 7 Transistor Loudspeaker * * 2 Transistor Regenerative * Signal Injector. Radio MW /LW. Radio. * 6 Transistor Short Wave * 3 Transistor Regenerative *e+ * Transistor Tester NPN -PNP. Radio. Radio. * 4 Transistor Push Pull * Electronic Metronome. * Audible Continuity Tester. Amplifier. * Electronic Noise Generator * Sensitive Pre- Amplifier. Total Building Costs Components P P 44p Include: 24 Resistors 21 Capacitors 10 Transistors 31" Loudspeaker Earpiece Mica Baseboard 3 I2 -way connectors 2 Volume controls L7.2 (Overseas 2 Slider Switches I P & P £1 85) Tuning Condenser 3 Knobs Ready Wound MW/LW /SW Coils Ferrite Rod 64 yards of I Yard of sleeving etc. Parts (- 8^0 VAT iV7p) wire Price List and Plans 50p. (Free with parts). NEW NEW ROAMER TEN Everyday ROAMER WITH VHF INCLUD- Series ING AIRCRAFT 10 Transistors. Latest 4" NINE Build this 2 watt Ferrite Magnet exciting New Loudspeakers. WITH V.H.F. sertes of designs 9 Tunable Wavebands. INCLUDING E.V.5. 6 Transistors and 2 diodes. MW /LW. Powered MW1, MW2, LW, SW1. AIRCRAFT by 41 volt Battery. Ferrite rod aerial, tuning condenser, 8W2, SW8, Trawler volume control, and now with 3" loudspeaker. Attractive Band. VHF and Local case with red speaker grille. Sire 9" x 51" x 21" approx. Stations also Aircraft Band. Parte Price List and Plans 20p. Free with parts. Nine Transistors, 9 Tuneable wavebands as Roamer Ten. Built in Ferrite Rod Aerial for MW /LW. Chrome Built to ferrite rod aerial for MW /LW. Retractable Total P P A lna. Sop plated 7 section Telescopic Aerial, can be angled chrome- plated telescopic aerial for VHF and SW. Push Building h (+ 8% VAT 23p) and rotated for peak short wave and VHF listening. Push Pull using 600 mW transistors. 9 £ 2 a 95 Poll output using 600mW Transistors. Car Aerial and output Transistors and amie (Overeeea P A P E1ß5) 3 diodes, tuning condenser with V.H.F. section, separate Tape Record Sockets. 10 Transistors plus 3 Diodes. coil for aurora! t, moving coil loudspeaker, volume ON /OFF Ganged Tuning Condenser with VHF section. Separate E.V.B. Case and looks as above. 6 Transistors and 3 coil for Aircraft Band. Volume and wavechange controls. Attractive all white case with diodes. Powered by 9 volt battery. Ferrite rod aerial, on /off. Wave Change and red grille and carrying strap. Size 91" x 7" x 21" tone Controls. Attractive Case in black with silver block- 3' loudspeaker, etc., MW/LW coverage. Push Pull out- ing. approx. Parts Price List and Plane 40p (Free with parts). put. Parte Price List and Plane 30p. Free with parts. Sire 9" x 7" x 4 ". Easy to follow instructions and diagrams. Parte price list and plans 50p (FREE with Total P P & Ina. 44p Total P P & Ins. parts). Building (+ 8% VAT 29 p) £6.95 (Overseas £3a60 Total building costs PPA Building l' & P £1.85) Costs (Overseas P & P £1.26) (Overseas P & P £1.85) £8.50 Ina. 62p Costs 1+ 8^;, SAT Gyp) E.V.7. Case and looks as above. 7 Transistors and 3 (+ 8% VAT 68p) diodes. Six wavebands. MW /LW, Trawler Band, SWl. SW2, SW3, powered by 9 volt battery. Push Pull output. Telescopic aerial for short waves. 3" Loudspeaker. POCKET Parts Price List and Easy Build Plane 35p. Free with parte. Overseas P S 1' £1.05. " EDU- FIVE Total Ovrreeas F1 L, 185 KIT" NOW WITH 3" LOUD - Building £4x08 Al' 1 SPEAKER 3 Tunable wavebands. M.W. Build Radios, L.W. and Trawler Band, Amplifiers, etc.. 7 stages, 6 transistors and from easy stage 2 diodes, supersensitive Total Building Costs ROAMER EIGHT diagrams. ferrite rod aerial, attractive black ) 1 t and gold case. Size 6 }" x 1 }" x L Ins. MkI 34" approx. Plane and Parts Oia//'ía50 26p NOW WITH VARIABLE Price List 20p (Free with parts). ( +8 / VAT 20p) (Overseas P & P £1.225) TONE CONTROL 7 Tunable Wavebands: MW1. MW2, LW, SW1, SW2, SW3 and Trawler Band. Built in TRANSONA Ferrite Rod Aerial for MW and LW. Chrome plated Tele- Five unite scopic aerial can be angled and rotated for peak short including master unit wave listening. Push pull output using 600mW translators. to construct. FIVELOUDSPEAKER Car aerial and Tape record sockets. Selectivity switch. 8 transistors plus 3 diodes. Latest 4'2 watt ferrite magnet Components include: Wavebands, transistors and loudspeaker. Air spaced ganged tuning condenser. Volume/ speaker as Pocket Five. on /off, tuning, wave change and tone controls. Attractive Tuning Condenser: 2 Volume Controls: 2 Slider Switches: Larger Case with Red casein rich chestnut shade with gold blocking. Size 9 x 7 x Fine Tone 3" Moving Coil Speaker: Terminal Strip: Ferrite Speaker Grille and Tuning 41n. approx. Easy to follow instructions and diagrams. Rod Aerial: Battery Clips: 4 Tag Boards: 10 Transistors: Total Building ColtsCos Prat. Plane and Parte Parts price list and plans 50p (FREE with Darts). 4 Diodes: Resistors: Capacitors: Three 4" Knobs. Units P A once constructed are detachable from Master Unit, l' Ins. Price List 20p (Free with l' P Ins. 47p £2.75 26e parta). Total building costs a 8 & enabling them to be stored for future use. Ideal for Overseas P A P £1.85) 6 9 v (+ 8% VAT Schools, Educational Authorities and all those interested 1.8 ^, VAT 21p) (Overseas P & P E1ß5) £ 56p) in radio construction. Parts price list and plans 40p (FREE with parts). A l building A IA 3£p 8 TRANSISTORS TRANS EIGHT and 8 DIODES cToaas £5.50 (OvePr sPea s P P .8 6 Tunable Wavebands: MW, LW, SW1, SW2, SW3 and Trawler Band. 5% VAT 44p) Sensitive ferrite rod aerial for M.W. and L.W. Telescopic aerial for Short Waves. Sin. Speaker. 8 improved type transistors plus 3 diodes. Attractive case in black with red grille, dial and black knobs with polished metal inserts. Total building costs size 9 x 61 x 21in. approx. Push pull output. Battery economiser switch for P P A Ins. 33p extended battery life. Ample power to £448 * Callers aide entrance "Lavelle" shop. drive a larger speaker. Parts price list 1+ 8% VAT 36p) * Open 10 -1, 2.30 -4.30, Mon. -Fri. 9 -12 Sat. and plans 35p (FREE with parts). (Overseas P A P E1ß5) MI To RADIO EXCHANGE CO., 61a HIGH STREET, BEDFORD, MK40 ISA Tel. : 0234 52367. Reg. No. 788372. CASE AND LOOKS AS TRANS -EIGHT ROAMER SIX 6 Tunable Wavebands: MW, LW, SWl, SW2. Trawler band plus an extra Medium waveband for easier tuning of Luxembourg, I enclose £ for etc. Sensitive ferrite rod aerial and telescopic aerial for Short Waves. Sin. Speaker 8 stages -.6 transistors and 2 diodes. Attractive black case with Ared grille, dial and black knobs with polished metal inserts. Total P P 4lne. 31p Name Site 9 x 53 x 21in. approx. Plans and building (Overseas parts price list 36p (FREE with parts). costs P A P £1861 (+ 8% VAT 32p) Address (Dept. PW12.) IMI PRACTICAL VOL 50 NO. B ISSUE 814 WIRELESS DECEMBER 1974 RRRAIN'S PREMIER MAGAZINE FOR THE DO- IT- YOURSELF RADIO AND ELECTRONICS CONSTRUCTOR EDITOR NEWS & Lionel E. Howes, G3AYA COMMENT ASSISTANT EDITOR 702 CHIPS UNLIMITED! -Leader article Eric Dowdeswell, G4AR 703 NEWS ... NEWS ... NEWS... ART EDITOR Peter Metalli 709 TELEVISION- Coming in the December issue PRODUCTION & NEWS 710 HOTLINES on recent developments by Ginsberg EDITOR Colin R. Riches 725 NEXT MONTH IN PRACTICAL WIRELESS PROJECTS SUB-EDITOR 742 PRODUCTION LINES Products reviewed by Colin Riches Geoffrey C. Arnold 748 ON THE AIR TECHNICAL ARTIST 748 Amateur Bands -Eric Dowdeswell, G4AR Alan Martin 749 Broadcast Bands- Medium Wave -Char /es Molloy SECRETARIAL Susan King -Short Wave -Derek Bell 01 -634 4292 ADVERTS. MANAGER 01 -634 4293 Roy Smith CONSTRUCTIONAL CLASSIFIED ADVERTS. 706 INEXPENSIVE CAPACITY BRIDGE -Eric Dowdeswell, G4AR 01 -634 4301 Colin R. Brown 713 MAKE YOUR OWN PCBs -John Jackson 717 ADD -ON BEAT FREQUENCY OSCILLATOR -F. G. Rayer, G3OGR 721 ANOTHER BATTERY SAVER -Arthur Dow Published by IPC Magazines Ltd., 726 P.W. 'KEMPTON' -CAR STEREO CASSETTE PLAYER -PART 1 Fleetway House. Farringdon Street, -Keith Cummins & Tony Francis London EC4A 4AD. Tel. 01-634 4444 732 TAKE 20 No. 66 IC PHOTO TRIGGER -David Andrews 733 P.W. "SANDOWN" FM STEREO TUNER -PART 3-J. R. W. Ames SUBSCRIPTIONS B.Sc. and M. J. Carey, B.Sc. Publisher's Subscription Rate for one 738 EXPERIMENTAL WORKSHOP Phase Shift Circuits -M. J. Hughes, year to the UK Is £325 and to the rest of the world £4.35 including postage. M.A., C.Eng. MIERE. Enquiries to Subscription Department, 744 2W I.C. AUDIO AMPLIFIER -R. A. Pen fold IPC Magazines Ltd., Carlton House, 68 Gt. Queen Street, London, WC2 5DD. Phone 01- 242 4477. International Giro facilities Account No. 5122007. Please state reason for payment "mes- FEATURES sage to payee". OTHER Binders (£1 -34) and Indexes 30p (inc. VAT) can be supplied by the Binders 704 SPECIAL PRODUCT REPORT -R T -V C 'TOURIST' II Car Radio Kit Dept at the same address. 709 TECHNICROSS SOLUTION No.7 BACK NUMBERS 736 IC OF THE MONTH -SGS TBA790 Audio Power Amplifier. We regret that we are unable to supply 747 GOING BACK -Equipment of yesteryear-Colin Riches back numbers of Practical Wireless. Readers are recommended to enquire at a public library to see copies. Re- quests for specific back numbers of FREE PRACTICAL WIRELESS SCREWDRIVER (page 702) Practical Wireless and Television only PLUS BUYERS' GUIDE to Radio and Electronic Components -PART 3 can be published in our CO Column.