May
MAY
1977
40p
GERMANIUM
Vcbo Vice lc
Type
max ma x
max
R .F.
TRANSIST
hFE
hie
APPLICT
O''
MH
N
20
20
12
15
20
20
15
15
LOW
15
1E
3`;
1
31
ME!
/ plus:2 -WAY
NIERCOM
Sc
03
2
PROTECTED
BATTERY
CHARGER
9
Completely Solderless Electronic
Construction Kit. Build these projects without
soldering iron or solder
Batteryless Crystal
7 Transistor Loud4 Transistor Earpiece
Radio
speaker Radio
Radio
One Transistor Radio
MW /LW
Signal Tracer
2 Transistor RegeneraSignal Injector
5 Transistor Short
tive Radio
Transistor Tester
Wave Radio
3 Transistor RegeneraNPN-PNP
tive Radio
4 Transistor Push Pull
Electronic Metronome
Audible Continuity
Amplifier
Tester
Electronic Noise
5 Transistor Push Pull
Sensitive Pre -Amplifier
Generator
Amplifier
10 Transistors
21 Capacitors
Components include: 24 Resistors
3 12 -way connectors
Earpiece
Mica Baseboard
5" x 3" Loudspeaker
3 Knobs
Tuning Condenser
2 Volume controls
2 Slider Switches
6} yards of wire
Ferrite Rod
Ready Wound MW/LW/SW Coils
Yard of sleeving, etc. Complete kit of parts including construction plans.
NEW EDU -KIT MAJOR
.,
e
.
Total Building Costs
*
*
*
*
£9.00
P k P + Ins. 85p.
*
*
receive the Aircraft Band by
placing it by the side of a
radio tuned to Medium Wave
or the Long Wave Band and
operating as shown in the
Instructions supplied free with
all parts. Uses a retractable
chrome
plated
telescopic
aerial Gain Control, V.H.F.
Tuning Capacitor, Transistor,
etc.
All Parte including Case and
NOW WITH 3"
3
Total Build Ing Costs
L3.60
£1399
Including Post and Packing
Case Enclosure Kit (if required) £1.80 inc. P & P.
P &P +Ins.SSp.
ELECTRONIC CONSTRUCTION KITS
Contained
Multi -Band
V.H.F. Receiver Kit.
TranEC K2 Self
sistors and
Diodes. Push /Pull
8
3
output. 3" Loudspeaker, Gain Control. Superb
9. section swivel ratchet and retractable chrome
plated telescopic aerial, V.H.F. Tuning Capacitor,
Resistors, Capacitors, Transistors, etc. Will receive
T.V. Sound, Public Service Band, Aircraft, V.H.F.
Local Stations, etc. Operates from a 9 Volt PP7
Battery (not supplied with kit).
Complete kit of parts Including construction plans.
&
NEW
Everyday
Series
Build this
exciting new
series of designs.
E.V.S.
5
Transistors and
2
diodes.
MW /LW. Powered by 45 volt Battery. Ferrite
rod aerial, tuning condenser, volume control, and now
with 3" loudspeaker. Attractive case with red speaker
grille. Size 9" x 5} x 2I" approx. All parte including
Case and Plane.
P & P + Ina. 60p.
Total Building costa
£430
E.V. 6. Case and looks as above. 6 Transistors and 3
diodes. Powered by 9 volt battery. Ferrite rod aerial,
3" loudspeaker, etc., MW /LW coverage. Push Pull
output.
Al parte including Case and Plans.
Total Building costs
P and Ins. 70p.
£495
P
&
P + Ins. 65p.
E.V. 7. Case and looks as above, 7 Transistors and
diodes. Six wavebands, MW/LW, Trawler Band,
SW1, SW2, SW3, powered by 9 volt battery. Push
Pull output. Telescopic aerial for short waves. 3"
Loudspeaker.
All parts including Case and Plans.
3
Transistors, 6 tuneable wavebands, MW.
3 Short Wave Bands.
Receiver Kit. With 5" x 3" Loudspeaker.
Push /Pull output stage, Gain Control, and Rotary
Switch. 7 Transistors and 4 Diodes. 6 section
chrome-plated telescopic aerial. 8" Sensitive Ready
Wound Ferrite Rod Aerial. Tuning Capacitor. Resistors,
Capacitors, etc. Operates from a 9 Volt PP7 Battery
(not supplied with kit). Complete kit of parte including
construction plans.
P&P and Ins. 70p.
EC K4
*
1
WITH Multiband V.H.F. section covering
Mobiles, Aircraft, T.V. Sound, Public Service
Band,.Local V.H.F. Stations, etc. and Multi band A.M. section with Airepaced Slow
Motion Drive Tuning Capacitor for easier
and accurate tuning, covering M. W.1, M. W.2,
L. W.,Three Short Wave Bands, S. W.1, S.W.2,
S.W.3, at Trawler Band. Built in Ferrite Rod
Aerial for Medium Wave, Long Wave and
Trawler Band, etc., Chrome Plated 7 section Telescopic
Aerial, angled and rotatable for peak Short Wave and
V.H.F. reception. Push Pull output using 600mw
Transistors. Gain, Wave -Change and Tone Controls.
Plue two Slider Switches. Negative Feedback circuit
and SPECIAL POWER BOOSTER SOCKET AND
RESISTOR, to virtually double gain if required.
Powered by P.P.9 9 volt battery.
Complete kit of parta including carrying strap.
Building Instructions and Operating Manuals.
Piano.
P & P and Inn. 43p.
P
1
*
*
*
MULTIBAND V.H.F. AND A.M. RECEIVER
13 TRANSISTORS AND FIVE DIODES
QUALITY 5" x 3" LOUDSPEAKER
POCKET
FIVE
£7-95
*
*
*
*
MODEL R.K.3.
Build this Converter Kit and
LOUDSPEAKER
Tuneable wavebands.
M.W., L.W., and Trawler
Band, 7 stages, 5 transistors and
2 diodes. supersensitive ferrite rod
aerial, attractive black and gold case.
Size 51" x 11" e 31" approx.
All Parts including Case and Plana.
*
*
*
NEW ROAMER TEN
VHF AIR
CONVERTER KIT
£395
*
*
**
*
*
*
7
LW, Trawler Band,
Total Building costs
Tel: 0234 32367
EDU -KIT JUNIOR
Completely Solderless Electronic Construction Kit. Build these
projects without Soldering Iron or Solder,
Electronic Metronome.
Crystal Radio Medirlm
4
Transistor Push /Pull
No
Wave Coverage
Amplifier.
Battery necessary.
One Transistor Radio.
including LoudAll
parta
2 Transistor Regenerative
speaker, Earpiece, MW Ferrite
Radio
Rod Aerial, Capacitors, Re3
Transistor Earpiece sistors,
Transistors, etc.
Wave
Radio Medium
Complete kit of parts includCoverage.
ing construction plane.
4 Transistor Medium Wave
Loudspeaker Radio.
P & P + Ins. 60p.
Electronic Noise Generator
-
*
*
*
*
*
*
P
&
P
+ Ina.
70p.
To RADIO EXCHANGE LTD
6IA HIGH STREET, BEDFORD MK40 ISA
£7.25
*
£695
£655
*
*
- -I
Reg. No. 788372
Callers side entrance "Lavelle" Shop.
Open 10 -1, 2.30 -4.30. Mon -Fri. 9.12 Sat.
ALL PRICES INCLUDE VAT
I enclose
E
for
Name
Address
PwS:.J
PRACTICAL
VOL. 53
NO.1
ISSUE 843
WIRELESS
MAY 1977
BRITAIN'S PREMIER MAGAZINE FOR THE DO- IT- YOURSELF RADIO AND ELECTRONICS CONSTRUCTOR
EDITOR
Lionel
E.
NEWS & COMMENT
Howes, G3AYA
20
ASSISTANT EDITOR
Eric Dowdeswell, G4AR
ART EDITOR
Peter Metalli
TECHNICAL EDITOR
20
25
30
38
Terry Carter
41
PRODUCTION & NEWS
EDITOR
Bill Tull
54
TECHNICAL ARTIST
60
Alan Martin
56
65
TECHNICAL SUB -EDITOR
Frank Ogden
SECRETARIAL
Linda Walji
ADVERTISING MANAGER
Roy Smith
-634 4612
01
CLASSIFIED ADVERTISING
01 -261 5762
Colin
R.
Brown
CONSTRUCTIONAL
22
39
42
PLEASE NOTE: We do not operate
Technical Query Service except on
constructional
matters
concerning
articles published in PW. We do not
supply service sheets or information
on commercial radios, TV's or electronic equipment.
All queries must be accompanied by
a stamped, self- addressed envelope
otherwise a reply cannot be guaranteed.
Send letters concerning advertising
matters to the Advertising Manager,
Roy Smith.
Send letters concerning editorial
matters to the Editor, Lionel Howes.
a
Published by IPC Magazines Ltd.,
Fleetway House, Farringdon Street,
Tel. 01 -634 4444
London EC4A 4AD.
BINDERS
Binders £2.10 and indexes 45p (inc.
VAT) can be supplied by the Post
Sales Department, IPC Magazines Ltd.,
Lavington House, 25 Lavington Street,
London, SEI OPF.
LEADER ARTICLE -You Lucky People
NEWS ... NEWS ... NEWS...
READERS PCB SERVICE
HOTLINES -Recent Developments- Ginsberg
KINDLY NOTE -Tug -'o' -war (April '77)
NEXT MONTH IN PRACTICAL WIRELESS
PRODUCTION LINES -Bill Tull
LETTERS -Comments from PW Readers
TELEVISION -What's in the MAY issue
ON THE AIR -Amateur Bands -Eric Dowdeswell G4AR
Broadcast Bands SW -Derek Bell
Broadcast Bands MW- Charles Molloy
VHF-Ron Ham
50
-WAY INTERCOM -Steven Davies
S- DeCNOLOGY- Project No 5 'The Ohm Gnome'
David Gibson
THE PW SEEKIT metal locator part 1 -W. Opel
PROTECTED BATTERY CHARGER -G. O. H. Sjogren
-
2
OTHER FEATURES
47
MONOLITHIC VOLTAGE REGULATORS part -Fixed
Regulators -Brian Dance M.Sc.
IMPROVED ETCHING OF PCB'S -J. A. Kennedy
IC OF THE MONTH -No 62- SGS -ATES TBA 820 Low
Voltage Audio Amplifier
CIRCUITS FOR AUDIO AMPLIFIERS part 3-
57
COMPACT 2m BEAM AERIALS -F. Judd G2BCX
26
33
34
1
F. G. Rayer G3OGR
FREE
THIS MONTH!
SIDED INFO-CARDSemiconductor Characteristics.
ALSO:
4 page INDEX listing all articles, letters, Production
Lines, 'Kindly Note', etc., for Volume 52, May 1976 to
April 1977.
THE
SECOND
DOUBLE
COPYRIGHT AND QUERIES
p IPC Magazines Limited 1977. Copyright In all drawings, photographs and articles published In "Practical Wireless" is fully protected and
reproduction or imitation in whole or in part is expressly forbidden. All reasonable precautions are taken by "Practical Wireless" to ensure
that the advice and data given to readers are reliable. We cannot, however, guarantee It and we cannot accept legal responsibility for It.
Prices are those current as we go to press.
We regret that we cannot answer technical queries by telephone nor can we provide Information or advice on manufacturers' products other
than that given In the magazine. We will endeavour to assist readers who have queries relating to articles published but we cannot offer
advice on modifications to our published designs. All correspondents expecting a reply should enclose a stamped addressed envelope.
Practical Wireless, May 1977
1
!ijr!ri1
rn! ]
Capacitive discharge
electronic ignition kit
RSGB INTERNATIONAL RADIO
COMMUNICATION EXHIBITION
AND CONVENTION
Alexandra Palace, London N22
6 -8
May
1977
LARGE TRADE EXHIBITION
Equipment and components from leading manufacturers by
well -known suppliers.
LECTURES
On Microwave, VHF/UHF, HF and SWL topics
(See April Radio Communication for details)
*
*
*
*
*
*
DINNER /DANCE -Saturday 7 May
MEMBERS' MART -Sunday 8 May
FOR THE FAMILY -All the free facilities and attractions
Smoother running
Instant all- weather starting
Continual peak performance
Longer coil /battery /plug life
Improved acceleration/top speeds
Up to 20% better fuel consumption
of Alexandra Park
I
Sparkrite Mk. 2 is a high performance, high quality capacitive discharge,
electronic ignition system in kit form. Tried, tested, proven, reliable
and complete. It can be assembled in two or three hours and fitted in
t5130 mins.
Because of the superb design of the Sparkrite circuit it completely
eliminates problems of the contact breaker. There is no misfire due to
contact breaker bounce which is eliminated electronically by a pulse
suppression circuit which prevents the unit tiring if the points bounce
open at high R.P.M. Contact breaker burn is eliminated by reducing the
current to about 1/50th of the norm. It will perform equally well with
new, old, or even badly pitted points and is not dependent upon the
dwell time of the contact breakers for recharging the system. Sparkrite
incorporates a short circuit protected inverter which eliminates the
problems of SCR lock on and, therefore, eliminates the possibility of
blowing the transistors or the SCR. (Most capacitive discharge ignitions
are not completely foolproof in this respect). All kits fit vehicles with
coil /distributor ignition up to 8 cylinders.
OPENING HOURS
lam -7pm Friday; I lam -6pm Saturday;
I lam -5pm Sunday
ADMISSION
Exhibition and lectures (at the door): Adults 40p;
children under
Dinner /Dance (tickets
CALLERS WELCOME.
For Crypton tuning and fitting service
'phone (09221 33008.
in advance): f5.50
DORAM KITS CONTAIN
EVERYTHING DOWN TO
THE LAST NUT!
Ready drilled pressed steel case coated in matt black epoxy resin, ready
drilled base and heat -sink, top quality 5 year guaranteed transformer
and components, cables, coil connectors, printed circuit board, nuts,
bolts, silicon grease, full instructions to make the kit negative or
positive earth, and 10 page installation instructions.
Electronic/conventional ignition switch.
Gives instant changeover from ''Sparkrite" ignition to conventional
ignition for performance comparisons, static timing etc., and will
also switch the ignition off completely as a security device, includes:
switch connectors, mounting bracket and instructions. Cables excluded.
Also available RPM limiting control for dashboard mounting
(fitted in case on ready built unit).
20p
Bookings for trade exhibition and members mart space, and
applications for dinner /dance tickets, should be sent to J.
Hitchins, RSGB, 35 Doughty Street, London WCIN 2AE.
THE KIT COMPRISES EVERYTHING NEEDED
OPTIONAL EXTRAS
14,
_
I
EAIDO
MW /LW PUSH - BUTTON
-
PRICES INCLUDE VAT, POST AND PACKING.
IMPROVE PERFORMANCE 6 ECONOMY NOW
Note-Vehicles with current impulse tachometers (Smiths code on dial
RV1) will require a tachometer pulse slave unit. E335 inc. V.A.T. p 48.
E.D.A. 52 BATH STREET, WALSALL, WS1 30E.
QuickinsN//otioa
MAfe
write sedirrcetJea
required
Electronics Design Associates, Dept., PW.
5
82 Bath Street, Walsall, WS1 3DE. Phone: (0922) 33662
Name
Address
Mk. 2 DI
I
V Asa.
Kit
O
enclose cheque /PO's
fore
I
E11.80
**
A professional standard Car Radio you can build yourself. 5 push-button
selectors or manual tuning. Full 4W RMS output with tone control,
illuminated tuning scale and automatic polarity selection, suitable for any
12V car. Supplied complete with full assembly Instructions, fitting kit &
speaker. Order code 991 -962
Car Radio less speaker £16.95+ H
VAT (Order code 991 -978)
Mk. 2 Ready Built Negativs Earth O E14.97'
Mk.
2
Rsady Built PositiveEarth O E14.97
Cheque No.
Ignition Changoovar switches O E4.30
t\kaR.P.M.
Limit systems
in above
units
0
E2.42
Send SAE if brochure
only required.
Overseas orders -add 15%, for p 6 p. All Items offered for sale subject to the
Terms of Business as appears In Doram Edition 3 catalogue, price 50p. The
Doram Kit brochure Is also available, price 25p. Combined price only 70p which
also entitles you to 2 x 2Sp vouchers each one usable on an order placed to the
value of £5.00 or more (ex VAT).
DORAM ELECTRONICS LTD. P.O. BOX TR8 WELLINGTON
ROAD INDUSTRIAL ESTATE LEEDS LS12 2UF
An Electrocomponents Group Company
2
Practical Wireless, May 1977
3
WATT DISCO SYSTEM
4fZ00
r
PRICES INCLUDE VA
ALL RSC
TDI DISCO CONSOLE
* DISCOMAJOR /200
Incorporating twin SUL type
turntables and Undone or Aeo.
POWER DISCO CONSOLE
with integral Power Amplifier.
lull sire GARRARD
* TWIN
with cueing device.
*
*
Sl
Consisting of
Rec. M c.
(1) TWIN T/TABLE CONSOLE
with PRE -AMP, and
POWER OUTPUT STAGES
(2) & (3) PAIR 100 WATT L'SPEAKERS
CARTRIDGES with Diamond Styli
3 SEPARATE VOLUME CONTROLS
for each turntable and Mic.
FULL HEADPHONE
MONITORING FACILITIES
CONSOLE COMPLETE WITH LID
I
£9.95
Also available: 100
40 WATT SYSTEM 199.95. 200 WATT SYSTEM 1209.95
WRIT
DISCOM AJORI 100 TWIN TURNTABLE POWER CONSOLE
DISCOMAJOR /200
£129.95
Power ratings R.M.S. Cont. 2 YRS GUARANTEE
Gauss 14000 Imp 8-15 ohms. CARR FREE.
POP 33T 12" 33w 113.95 Dual cone. Full range
POP 50/2 12" 50w [15.99 Dep for Pair 1800 and
8 monthly pymts 13.54 (Total [36.32
"POP 60 15" 60w 125.95 Dep 17.00 & 8 monthly
pymts £2.87 (Total 129.96
'POP 100 I8" IOOw £4495 Dep 110.00 & 8
monthly pymts ES 17 (Total £51.36)
26915
Rating 50 watts. 3 inputs, 2 vol. controls-Base, Treble Presence. Carr. 21.50
Suitable for Lead or Rhythm Guitar, mir., Radio, Tape etc. Inc. High Flux 12"
60w Speaker. Dep. 110-96 A 8 monthly payments 1671 (Total £80.08).
TITAN GROUP /DISCO SPEAKERS
100W POWER (SLAVE) AMPLIFIER
Suitable for use with DISCO Consoles. Also for increasing output of lower powered Amp. Dep. £9.00 and 8 mthly £49.95
pyts of £6 05 (Total £57.40) Carr. £1.50
100W MODEL 169.95 Carr. £150
100
+
GUARANTEED 5 YEARS Carr. El. under 216
Let ROC Price
T12/45 12" 45w
116.80 11196
Stockists of
T12 /60A 12" 60w 121.00 11886
Lighting by
T12 /100 12" 100w 236.00 18495
PULSAR
T15 /60 15" 60w
226.00 818-99
Group Equipment Tl5 /70 15" 70w
228.00 519-96
by CARLSHORO
Full range of
speakers by
PANE
TITAN TA /50A 50W AMPLIFIER
i
3 sep. controlled inputs plu Master control
A Presence Controls. Vynide covered cab
with comer protectives. List price 260. Terme: Dep. £0
& 8 monthly paymts £6.06.
149.95
(Total 25740). Carr. Al.
Matching Cabinet Spkre. I x i2" 12996 2 x 12" 14996
Bolid state,
.
TITAN TA /IOOA 100W AMPLIFIER
TWIN CHANNEL-4 INPUTS £69.95
A De -luxe professional unit with
Carr. £1.50
many facilities. R.M.S. Rating. Matching
2 x 12" 120w Cabinet speaker £49.50. with
above only. Carr. £1.50
Credit Purchases
settled in 3 months
Carr tree
FULLY GUARANTEED. Impng.
RSC TRANSFORMERS, L.F. CHOKES and Interleaved when unwary.
MIDGET CLAMPED TYPE 200.250v 60 Ha
11.76
230v. (Or 250-0 -250v) 60mA 6-3v. 2a.
ETD. UPRIGHT MOUNTING OR DROP -THEO
260- 0 -200v. 100nÚ 51v. la. 0 -6 -68v. 3a. 14.55
300- 0.300v. 130mA S-3v. 4a. C.T. 6-3v.
16.20
la. for Mallard 510 Amplifier
860- 0.350v. 100mA 6.5v. 4a. 0-6 -6.3v. Sa. 6456
160- 0 -350v. 150mA O-8v. 4a. 0.6 -6.3v. 3a. 6620
426- 0 -425v. 200mA 6 -11v. 4a. C.T. 5v. ga. 1085
200mA O-8v. 4a. 6.3v. 4a. 6v. ga. 110-00
460.0460v. 260mA 5.3v. 4.. C.T. 5v. Sa. 51040
250- 0 -250v. 70mA 6-3e. 2a. 0- 6 -S-3v. 2a. 12.00
250.0.230v. 100mA 6-Sv. 3.6a.
19.90
260.0-250v. 100mA 0.3v. 2a. 6.3v. la.
MI PO
350- 0 -350v. 80mA 5.Sv. 2a. 0- 641.5v. 2a. 1020
300- 0 -300v. 100mA 6 -Sv. da. 0- 6 -51v. 3a. 6436
FILAMENT OR TRANSISTOR POWER PAON
13v. la. 1110, 63v. 1.5a 61011, 6-3v. 2a. 11.10.
6.3v. Sa11-70, 0-3e. 6a. 1200, 13v. U. or 24v. 1.5a.
12-60 0.9.10v. lia. 88.88, 0- 1226 -42v. Ia. 6019
CHARGES TRANS 09- 150.1 ;a. 1308; 21a. 1226;
3a. 5236; 5a. 12.84. ea. 1319; 8a. 53.48.
AUTO (STEP UP/STEP DOWN)
TRANSFORMERS 0- 110/120v 200 230.250v. 80w. 12.90; 150w. 16.20;
250w 1837; 500w 1884.
OUTPUT TRANSFORMERS
Pentode 5000 or 7000 to 311 5112;
Push Pull 8w EL84 to 3 or 15 (I
81.68; 12w 6V6 to 3 or 16 n 1961;
12w OVO to 3, 8 or 150 1272;
EL84 to 3 or 15 n 12w 12.61; Ultra
Linear for Dullard 510 etc. 8436;
18w. sect. wound 6L6, KT66 etc.
to 3 to 150 23.71; 20w. sect.
wound EL34, 6L6, KT66 etc. to 3
or 15 0 1637.
L.P. CHOKES 150mA, 7 -10H,
250Q 1128; 100mA, 10R, 2000
21-10; 600)4, 10H, 4000 419.
HANLEY
WOLVERHAMPTON,
YORK, LIVERPOOL
41
New Branches at
OPEN ALL DAY SATURDAYS (S Day Weak)
B RADFORD 10 North Parade (Closed Wed.). Tel. 25349
BOLTON 23 Desnsgets. (Closed Wed.). Tel. 33612
BIRMINGHAM 30/31 Great Western Arcade.
Tel. 021 -230 1279 (Closed Wed.).
CARLISLE 8 English Street. (Closed Thum.). Tel. 38744
COVENTRY 17 Shelton Sq., The Preelnct.Tel. 25083
DERBY 97 SI. Peter's Street. (Closed Wed.). Tel. 41361
DARLINGTON 19 Northgete (Cl. Wed.). T.1. 05043
DEWSBURY 9/11 Kingewey (Closed Tues.). Tel. 468058
DONCASTER 3 Oueensgeta, Waterdate Centre.
(Closed Thur.). Tel. 83069
E DINBURGH 101 Lothian Rd. (Cl. Wed.). Tel.429 9501
Practical Wireless, May I97
199.95
FANE HIGH POWER SPEAKERS
1149 95
(NORMAL OR BRIGHT)
Care. E6 00
(Total 114406)
High quality 15- high dux Base Unit and J104 Hom
Tweeter in folded horn type enclosure to provide amazing
level of sound output. List price 1144 Terme Dep. 614-96
and 18 fortnightly payments 56-68 (Total 611639) Carr. 13.
200 watt version of above. Terms: Dep. 229-95
and 18 fortnightly paymte £7.87 (Total £171 -61)
AMP.
£I25.00
Terms DEPOSIT 110
16 fortnightly
WATT SYSTEM E 1 69.95 and
payment. 4686
Carr. E2ß0
Twin Full size BOR turntables. Sonotone or Aw8
Cartridges with Diamond Styli!. Facilities as TD1 Console but with
built -in 100 watt Power Amplifier complete with lid. Term.:
Deposit 21995 and 18 fortnightly pynmte. 1703 (T,.t:,l 2148 49)
INTEREST REFUNDED
TD2S STEREO VERSION
OF ABOVE
9195
TITAN 100W BASS BINS
FOR
for Free catalogue
OTHERS UP TO 300 WATTS AT UNBEATABLE PRICES
Bass, Treble
0ÿj1
09.9
16 fortnightly pymts.
1611 (Tota11126.47) Carr. a3
with Dynamic Suck MICROPHONE.
including 12" UNITS
RSC PHANTOM 50 COMBO
/1
9
and
oota
11 monthly payments 0 and
(Total 682720) Carr. £7.50.
Cardioid
extra
with system only
UD 150
Cartridges with diamond ASH.
Separate Vol. controls for auk
turntable. Also MONITORING
FACILITIES,
plu ?Milo ao1
Bus Controls. Separate Input
for 'mike' with vol. control.
Black Vynlde covered
Cabinet with lid.
p
Or DEP. 116.49 and
5
turntables
£41.00
T15 /100 15" 100w
T18/100 18" 100w
247-00
129.95
13896
CABINETS FOR ABOVE SPKRS Henry duty.
Beautifully finished in black Vynide with Vynair fronts
fitted protective comer pieces. Various sizes and cut -outs.
TE1 1 x 12" 81096. TE2 2 x 12" 116.96.
Low Deposit Terms on orders over 120
i
TITAN TA /IOOC COMBO
R.M.S. Amp. incorporating
fabulous Fane Crescendo
12" 100 watt spkr for really
superlative results with Lead
a
High Frequency
50W
Imptiní5Rohme
HORNS
Guitar
Imp 8 0 Range 3-1:
kHz. Very Sensitive
Complete with 2mtd
non -elect. capacito
£119.95
Or Dep 61796 a 18
19.89 (Total 113837)
f'tntly pyts
Carr. £5
£7.95
Pair for series wiring HI -POWER TWEETER
plus single X -over' unit 117 95
Response 3KHz -20KHz with 2
mid. Non elect. filter available 65p.
FANE J 104 50-70w
Rating 50 Watt
Imp. 80. 3-15 KHz. Sup,,
16.95
sensitive 10" x 4" appro..
Complete with 2 m.Ld.
TITAN
Non Elect Capacitor. Use
with twin l2 "150 or single
H.F. UNIT
15" or 18" 8 n speakers. 115.50 A super
sensitive 80 m,Yreww xs
4-IS
TITAN H.F. UNITS
kHz. Use with pair 15 0 12" or single
8
0
15" Drive unit.
L27.95
Carr 75p
FAL SOUND -TO -LITE UNIT £21.60
COMPLETE SYSTEM
£50.95
£3795
ECHO CHAMBERS from £5395
COLUMN SPEAKERS from £2995
Incl.
Inc. pair of Highly Sensitive Horns.
Range 3.15 KHz. Rating 70/100 watts.
Uee with 2 x 1.2" 8 n speakers in
aeries, or single 15" or 18" 15 n. Dep.
£6.95 a 8 monthly payments £3.12.
(Total £31.91).
Corr. 75p.
Opotbanks and bulbs
GROUP/DISCO SPKRS
from
CABIN
CABINETS
127.95 in
Barclaycard a Access
PHONE ORDERS quoting
CARD NO. accepted
2
JINGLE MACHINES from
N
1.11-9S
MAIL ORDERS A EXPORT ENQUIRIES TO:AUDIO HOUSE. HENOONNER LAIE, LENDS. 13.
Tel: 0331 577631.
MAIL ORDERS MUST NOT BE SENT TO SHOPS
TEEMS 0. W.O. er O.O.D. No C.O.D. under U. POSTAGE 40p FEB
All 'terns subiect to availability.
Prices correct at 16.3.77 E. A O.E. ORDER OE Al QUOTED Phone or Write for FREE CATALOGUE.
MIDDLESBROUGH 103 Linthorpe Rd. Tel. 210585
GLASGOW 326 Argyle St. (CI'd Tues.). Tel. !W 4165 (Closed Wad.)
NEWCASTLE UPON T
(CI 59 Wad rial. 21469
NOTTINGHAM 19119A Market Strut
Whltefrlargate (Cloud Thurs.). Tel. 20505
(Closed Thurs.). Tel. 48088
LEICESTER 32 High Street (Closed Thurs.).T.I. 66420 PRESTON
41 Friergete Walk. St. Georges Shoppg Prep. Tel. 51979
LEEDS 6-7 County (Mecca) Arcade, Wingate
Exchange
Strati (Castle Mkt. Blde.)
SHEFFIELD
13
(Closed Wed.). Tel. 45525!
STOCKPORT
LIVERPOOL
707tí
(Cloud Thum.). Tel.
C tre Tel: 08 0380 (Ci. Wad ). OL h UnnderbankMarket
Sq. (Closed Wed.). Tel. 70579
LONDON 238 Edgware Road. WI. (Closed Thurs.). SUNDERLAND 6
Tel. 72315!9 WOLVERHAMPTON 6. Wulfrun Way
MANCHESTER SOA Oldham Street (Closed Wad.). YORK S Church St. (Closed Wed.)
Tel. 34355
s
T.I. 236 2778
HANLEY, Stoke -on-Trent, 44 Piccadilly
HULL
j
7
pni
ig
3
I'
Stop wasting time soldering
The NEW MW BREADBOARD accepts
Transistors, LED's,Oiodes, Resistors, Capacitors
and all OIL packages with 6 to 40 pins
MINI CONSOLES
for small desk control
Ideal
panels and consoles.
Moulded in orange, blue,
BOXES (square corners)
Easily drilled or punched,
orange, blue, black and grey
ABS. Incorporate slots for
holding 1.5mm thick pcb's.
SC
black and grey ABS.
Incorporates slots for holding
1.5mm thick pcb's
Aluminium panel sits recessed into front of console
and held by screws running into integral brass bushes.
Add 25p per
E1
integral brass bushes.
77p (10+)
80p (1 -9)
£1.07 (1-9) £1.04 (10+)
E1.49 (1-9) £1.46 (10+)
Add 25p per £1 order value for Post & Packing
SC 85 x 56 x 35mm
SC 111 x 71 x 48mm
SC 161 x 96 x 59mm
£1.50 (10+)
(1 -9)
£2.20 (1 -9) £2.17 (10+)
order value for Post & Packing
MC 161 x 96 x 58mm
MC 215 x 130 x 75mm
£1.53
Includes slot -in Component Support Bracket and has over
400 individual sockets, plus Vcc and Ground Bus Strips
Price £9.72 (includes VAT & P.P.)
LIGHT EMITTING DIODES
-
100 for E9
Economy Quality 50 for E5
Mixed bags, all sizes, various colours
-
=`
125"
a<7
-
16"
Íens
Full Specification (In packs of 5 LED's)
Red (specify size) 75p per pack
Green, Yellow, Orange (specify size) £1.20 per pack
(bunting clips and data with Full Spec. LED's only)
Red, Amber, Clear, Opal
In
AG
19p each
28p each
Red, Amber, Clear, Opal
Green
20p each
SEVEN SEGMENT DISPLAYS
TYPE A NEON INDICATORS
Supplied with resistor for 240 Volts operation
Held in 8mm hole by plastic bezel
150mm wire leads
AA
240 VOLTS MINI HAND DRILLS
Ideal for drilling pcb's, chassis
etc as well as model making.
Supplied with 3 collets that
accept tools and drills with
1mm, 2mm and 1/8" dia
shanks.
£9.72 (includes VAT & P.P.)
Accessory tools... 5 Burrs, 1mm, 2mm, 1 /8th Drills,
3/32" Collet Price E1.75 (Includes VAT & P.P.)
TYPE MP NEON INDICATOR
Supplied with resistor for 240 Volts operation
150mm leads, held in 6.4mm hole by nut
2"
Íens
lore
into
Aluminium panel sits recessed
into front of the box and
held' by screws running
Economy Quality
Left Decimal
Common Anode 0.3"
Red, Yellow and Green @ 45p each
-
a
Common Anode
AH
RC BOXES (round corners)
Easily drilled or punched,
orange, blue, black and grey
ABS. Incorporate slots for
holding 1.5mm thick pcb's.
Close fitting flanged lids
held by screws running into
integral brass bushes.
-
Full Specification
Left Decimal
- 0.3"
-
Red
@
98p each
Green and Yellow @ £1.35 each
(Data supplied with Full Spec.
displays only)
12 VOLTS MINI HAND DRILL
Ideal for drilling pcb, chassis
etc as well as model making.
RC
RC
RC
RC
RC
Quantity quotations on request
P.P. Note Unless included in price add 25p Post & Packing
for orders totalling under £10. All prices include VAT and
are valid in UK only for 2 months from journal issue date
Supplied with 2 collets that
accept tools and drills with
3/32" and .050" dia. shanks.
£7.56 (Includes VAT & P.P.)
r
Michael Williams Electronics
47 Vicarage Av. Cheadle Hulme, Cheshire SKB JJP
I
100 x 50 x 25mm
112
120
150
190
62 x 31mm
x 65 x 40mm
x 80 x 50mm
x 110 x 60mm
x
51p (1-9)
59p (1.91
68p (1.91
49p
52p
62p
74p
E1.30
(10+)
(10H)
(10+1
(10+)
(10+1
E1.33 (1.9)
Polystyrene version
in grey only with no slots, no integral brass bushes
32p (10 +)
35p (1-9)
RCIP) 112 x 61 x 31mm
Add 25p per Et order value for Post & Packing
77P (1 -9)
,nldom.
(TSWINiBANKs
ÁSNEß1ÑÌT
LIGHT
fr
DORAM KITS CONTAIN
EVERYTHING DOWN TO
THE LAST NUT!
14(mches URI T
4`
(441,11
W fired rend u for
Comdete will,
a
100watt coloured
in
three
Q8 95
chat Stash
Sound to Light
MASTER UNIT WAPER
CHANNEL
4424
BC
Fitting
S.9te1O5
Fitbn
j,
TYPE A SPOT
ELECTRONIC
CAR
IGNITION
(less lamp)
£30'95
,..
.A,,,g,
..-
TYPE B
3
51re01 GtU694v
YAMS rN!`V r 3tlrXET
BANK UNIT
£9.95 + S VAT
(Order code 997 -005) Subject to availability
Avoid difficulty in starting your car on cold mornings with the Doram
C.D. Ignition Unit. The complete kit incorporates features such as
single switch reversion to the standard ignition system for servicing
etc. and also an immobilisation facility. Improved performance and
fuel consumption,along with reduced points erosion and longer plug
life makes this unit a must for any 12V neg. earth car.
100 WATT SPOT LAMPS
RED. YELLOW,OREEN
BLUE.
30 auch
CLEAR
£,
B.C. or
ALBEN
r.....
3
lamps
(less lamps)
.
..
ittia1
BC£15601 Fsin£11_00
}7FIK71"1"1
"l"i11a
ENGINEERING CO LTD,
DEPT P W THE CRESCENT WORSTHORNE,
BURNLEY LANCS. Tel Burnley 20940
4
orders-add 15% for P +P. All items offered for sale subject
to the Terms of Business set out in Doram Edition 3 catalogue, price
60p. The Doram Kit brochure is also available, price 25p. Combined
price only 70p which also entitles you to 2x25p vouchers. each one
usable on any order placed to the value of £5.00 or more (ex. VAT).
DORAM ELECTRONICS LTD..
P.O. BOX TR8, WELLINGTON RD. IND. EST.- LEEDS LS12 2UF.
O'seas
An Electrocomponents Group Company
Practical Wireless, May 1977
J
135.00
p
6
o
.
mplete
cow,n
circuit
x 20 WATT STEREO AMPLIFIER
-..
£2990
diagram
PYE STEREO GRAM CHASSIS
p 3 p
Complete ready to install -Wave bands L.M,
VHF STEREO, VHF MONO. Controls tor
:
ax
tuning, volume, balance, bass and treble.
Power output 7 watts R.M.S. per channel
14 watts peak into 8 ohms. 2v 8 "approx
chassis speakers and BSR C141 auto
.Bert
rSOttR)
indairl
35 -WATT DISCO AMP
.
C
20
.
mNno
r"
r,,.
cartidge, de luxe plinth
£8000
RT -VC for cost-conscious
hi -fi enthusiasts, these
34
cartridge, diamond stylus, and
de luxe plinth
p0pC650
and cover.
Requires some attenLion. Complete with built
in pre -amp, A.C. 240V °
4x4 STEREO AMP
f 2.00
KIT £14.50 P
f1
P
For the experienced constructor
who wants to design his own stereo, kit includes all
necessary components including constructors manual.
Plus Pair of easy to build 4 watt speakers in kit form,
with teak simulate finish cabinets 12" x 9" x 5" approx
MOTOR TOP 10 AWARD
Complete with speaker, baffle and
fixing strip.The Tourist IV for the
experienced constructor only. The
Tourist IV has five push buttons, four
medium band and one for long wave
band. The tuning scale is illuminated
and attractive small aluminium control
knobs are used for manual tuning and
volume control.
Single play record player
(Chassis form) less cartridge E1 5.95
Cartridges to suit above
p 6 P E2 00
.. £4.95
f1.95
automatic record player deck
(Chassis form) with cueing device
and stereo ceramic head
f9.95
BSR
Practical Wireless, May 1977
l:. 4
pk
BSR MP60 TYPE
P6PE200
fi500
r1 50
CAR RADIO KIT
BSR
STEREO
Brilliantly styled for easy disco performance!
Sloping fascia, so that you can use the
controls without fuss or bother. Brushed
aluminium fascia and rotary controls. Five
smooth-acting,vertically mounted slide controls
- master volume, tape level, mic level, deck
level, PLUS INTER -DECK FADER for perfect
graduated change from record deck No. 1 to
No. 2, or vice versa. Pre -fade level control
(PFL) lets YOU hear next disc
70 WATT
before fading it in VU meter
monitors output level 70 watts
- P 8 p £3 ce
rms, 140 watts peak output.
All the big features as on the
100 WATT
70 -watt disco amplifier, but
£
with a massive 100 watts rms.
200 watts peak output power.
"f
£695
its
TOURIST IV PUSH BUTTON
TURNTABLES
CERAMIC
70 & 100 WATT DISCO AMPS
£4900
CARTRIDGE
PLAYER MECHANIS
f,
ACOS MAGNETIC STEREO
£2.10
8-TRACK
speaker, why not build your own from
this kit. It's the unit which we supply
3i with the above enclosures. Size 13"x8"
(approx.)woofer (EMll,tweeter,
61 and matching crossover. Power
'O)
handing capacity 15 watts rms.
30 watts peak.
Here's the big -value portable disco console
from RT -VC! It features a pair of BSR MP 60
type auto -return, single -play professional
series record decks. Plus all the controls and
features you need to give fabulous disco
OO
performances. Simply
£
connects into your existing
- P 5 p £6.50
slave or external amplifier.
pSpi350
BSR T145
Ii
PORTABLE DISCO CONSOLE
with built -in pre -amplifiers
Pale
p 8 p
7.00 STEREO
15 -WATT KIT IN
CHASSIS FORM r3 40 P & P PAIR
When you are looking fora good
*,nA,gOkA..,....xmo,,aw>naanonthi
epprox.
PER
£2900
How about this for incredible bookshelf
value from RT -VC! A pa`r of high efficiency
units for only £7.50 - just what you need
for low -power ampifiers. These infinite
baffle enclosures come to you ready
mitred and professionally finished. Each
cabinet measures 12'x0"x5" (approx.)
deep, and is in wood simulate
Complete with two B"
£ 750
I per par
(approx.) speakers for max.
power handling of 7 watts
p
p £' 70
A
55
£240°
Specially designed by RT -VC for the
experienced constructor, this kit
comes complete in every detail.
Same fadities as Viscount IV amplifier.
Chassis is ready punched; drilled and formed Cabinet is finished in teak
veneer. Black fascia and easy- to-handle aluminium knobs.
Output 30 +30 watts rms, 60 +60 peak.
'COMPACT' FOR TOP VALUE
=
MP 60 type. complete with magnetic
PER PAIR
30 x 30 WATT
AMPLIFIER KIT
25
.
teak veneer, 12 watts rms, 24 watts
peak, 18'/:" x 131/2" x 7'4" approx.
£4
(approx.) woofers, two
tweeters and a pair of matching crossovers. Easily constructed, using a few basic
tools. Supplied complete with an easy-tofollow circuit diagram, and crossover
components. Input 15 watts £
50
rms. 30 watts peak, each unit.
Cabinet size 20" x 1 T' x 942"
PER PAIR
- p 8 p s5 5C
(approx)
00
TURNTABLE Popular BSR
Duo III, 20 watts
rms, 40 watts peak,
27" x 13" x 111/2'
kits incorporate two teaksimulate enclosures
two EMI 13 "x 8"
'5
SPEAKERS Two models- Duo Ilb,
£
Specially designed by
,
Carnage surcharge to Scotland System 10 .2 00 System 2
EASY -TO -BUILD
WITH ENCLOSURE
disc inputs, both for ceramic cartridges, tape
input and microphone. input. Level mixing
controls fitted with integral push -pull switches
Independent bass and treble £
50
p a p n So
controls and master volume.
PA,:>,,n>x.ans,.
watt Viscount IV amplifier: a pair of
our large Duo Type III matching
speakers which handle 20wattsrms
each, and a BSR MP 60 type deck
with magnetic rtndge, £9200
de luxe plinth and cover.
.,60
and cover.
WY SPEAKER KITS
ax
SYSTEM 2 Comprising our 20+ 20
For only £80, you get
the 20+20 watt Viscount IV amplifier,
a pair of our 12-watt-rms Duo Type
Ilb matched speakers; a BSR MP 60
type deck complete with magnetic
A build- rt- yourself stereo power
amplifier with latest integrated circuitry
RMS per channel output, full short- circuit
use
ouR
and overheat protection nase
£495 PNIC(
4.
Here's the mono unit you need to start off
with. Gives you a good said 35 watts rms 70
watts peak output. Big features include two
27.
HWYOUCAN AVE
20 WATTS STEREO AMPLI a [ KIT
WITH PZ 20 POWER UNIT FANTASTIC
SYSTEM 18
SAYING
to
"'
.`...
Superb Viscount IV unit in teak- finished cabinet.Silver fascia with aluminum
rotary controls and pushbuttons, red mains indicator and stereo jack
socket. Function switch for mie, magnetic and crystal pick -ups, tape, tuner,
and auxiliary Rear panel features two mains outlets.DlNspeakerand input
sockets, plus fuse. 20 + 20 watts rms, 40 + 40 watts peak.
rson
record player deck.
12 10
;¡
gi
-'
GOODSNOTDESPATCHED OUTSIDE UN
Ar ens aubec ru a evade y Ft ce cv nee a
1¡4177 and subtect to change wehovt nonce
R
The modem style fascia has been designed to blend
with most car Imenos and the finished radio will
slot into a standard car radio aperture. Size
approx 7" x 2' x 4'.Power Supply
Nominal 12 volts positive or negative
earth tattered internally) Power
.
p
050
s
p
t
-
o
walour
Send Stâmped addrt sect enve
e,s?
for our fully descnpbve catalogue and any :
further mformatxxt p
-
B
21c HIGH STREET, ACTON, LONDON W3 6NG
323 EDGWARE ROAD, LONDON W2
Personal Shoppers EDGWARE RD. 9 30a.m. 5.30p.m. Ha lf day Thuns
£,
Ouptut 4 watts into 4 ohms.
unable
Woducts
products s0 please
ALL PRICES INC VAT AT 12
50
DO NOT SEND
CARD
Just wnte your ordel
giving your credit
card number
-
:a_
ACTON
- Mail Order only
no callers.
5
1
PW Seekit kit
Metal detechnology from
NI\ M\ NI
ambit
!
FROM
í
i Soldering Iron
220 -240 Volts
16 -18 Watts
BIT TYPE
19
5mm
20 3 Omm
*
Advertised
onTV
TBA651 -1.81
HA1197 -1.40
MC1496-1.25
NE560/1/2 -3.50*
NE565/6 -2.50*
NE555 -0.70*
TDA2020 -2.99
uA723 -0.80*
MC1312.1.50
MEM614 -0.38*
MEM616 -0.57*
MEM680 -0.75*
BF256L-0.34
ZTX107.14p
ZTX108 -14p
ZTX109 -14p
Telephone
6
:
d
0752 65011
0
N
NIL Nib.
TICS can provide the technical knosdedgc that is so essential
to your success, knowledge that will enable you to take advantage of the many opportunities open to the trained person. You
study in your own home, in your own time and at your own ,
pace and if you are studying for an examination ICS guarantee
coaching until you are successful.
'
City & Guilds Certificates:
Telecommunications Technicians
Radio, TV, Electronics Technicians
Technical Communications
Radio Servicing Theory
Radio Amateurs
Electrical Installation Work
MPT Radio Communications Certificate
Diploma Courses:
Colour TV Servicing
Electronic Engineering and Maintenance
Computer Engineering and Programming
Radio, TV, Audio Engineering and Servicing
Electrical Engineering, Installation
and Contractin
power trs. in list
MVAM2 -1.35
MVAM115 -0.95
MVAM125 -0.90
3x115 -2.70
3x125 -2.65
88104 -0.45
MODULES:::
EF5800-14.00
7030 -10.95
91196 -12.99
91197 -11.35
7252/3 -26.50
High Street, Brentwood, Essex. CM14 4RH
telephone 216029 - STD 0277.
37a
7
TECHNICAL TRAINING IN
ELECTRONICS TELEVISION
AND RADIO SERVICING
POST OR PHONE TODAY FOR FREE BOOKLET
'WITo
in
International Correspondence:
Schools
Dept. No. 777/, Intert.xt House, LONDON
SW8 4UJ or telephone 622 9911
of interest............ __.. _._ _..___.__...._...
OSubject
NM
Ambit international
*
PRICES: IRONS £3-70 each
BITS 41p each
k.
ZTX212 -17p
ZTX213 -16p
ZTX214 -17p
ICL8038CC4.50*
indicates 8 %.
CWO please, min. order £1.00 VAT extra,
Postage etc. 22p per order, except where stated, catalogue
40p (inclusive). SAE with enquiries pse, overseas orders are
welcome. Access accepted on phone orders if required.
* Slim, easy to hold
Four tip sizes
& R. BREWSTER LIMITED
86-88 UNION STREET, PLYMOUTH, PL1 3HG
A selection from the list of our ICs, transistors,
MOSFETs, JFETs, VARICAP diodes:
LM3900 -0.78*
uA741 V -0.40*
TBA810AS -1.09
TCA940 -1.80
0
S.
coils, ceramic and mech. filters
for AM /FM, tunerheads, trimmers, tuning pots etc.
Send an SAE for our current price leaflet (Revised Feb 77),
with the full range of TOKO coils, semiconductors etc.
Ambit is now stocking over Y* million coils for immediate
sale, thus making us the largest supply source in Europe.
BLR 3107N Multiplex filter (two channel).......... £1.95ea.
CFSE10.7 ceramic filters for WBFM ..................£0.50ea.
BBR3132A 6 pole linear phase filter for 10.7.......£2.25ea.
Coils for AM /FM /IFTs etc from .. .. .. .. .. .. .. .. £0.30ea.
Chokes - a new extended range: luH to 120mH, 16/33p
New for constructors: 10mm coil former assemblies, in the
TOKO 10E and 10K format for 50kHz to 150MHz £0.12ea.
TOKO 13k style precision 13mm former with slugs £0.15ea.
-1.81
0
Trade enquiries welcome. (Inc.VATand P& P)
Cheques & Postal Orders to Manufacturers a Distributors
-
N
*
*
As
*
Complies with
Consumer Protection
Regulations B.S. Nt3456 2/14
All parts easily replaced
New bit securing method
Built in suspension hook
45mm
22 6Omm
components thereon, including hi -stabs and the
special selections where necessary. Signal meter (200uA), and
miniature loudspeaker, search coil wire and coax lead.£16.95.
Plastic parts for the casing, tube and fittings, not cut or
drilled, thus suitable for other metal locator designs. £12.45.
And of course, there is the Bionic Ferret - a VCO metal
locator kit with two extra features: All plastic is cut and
machined to accept the standard controls we supply, and we
£34.95.
also supply U7 battery holder fittings.
Prices exclude 8% vat. PP for plastic /complete kits £2.25.
LM381
FEA7*
ES
*Lightweight
1
PCB and all
LM380N -1.00
with
Insulation tested at 1500 Vac
21
CA3089E -1.94
HA1137W -2.20
TBA120 -1.00
MC1350 -0.97
uA753TC -1.80
MC1310 -2.20
CA3090A-3. 75
HA1196 -4.20
uA720PC-1.20
9
New Miniature
A
16/
Wireless components
nQ
A
MIL
INTRODUCING
Or
From the firm that brought you varicap tuned AM
radio for MW /LW, the 6 circuit varicap band two
tunerhead, and first with the HA1196 MPX module now the first kit for a VCO metal .locator, with a
special presentation of the PW Seekit locator at a
special introductory `constructor' price:
N\
11.
Name
_..._
Address...
.....
.._..
_..
st
'
0
s>
Tel
i4mmmmimlmmummumnimui
Practical Wireless, May 1977
Stirlïnn Sound
Q.V. MODULES FOR COST CONSCIOUS CONSTRUCTORS
SS.
SAVE £1.95 ON THIS 100 WATT
R.M.S. POWER AMPLIFIER
WITH POWER SUPPLY UNIT
SS.I 100
SS.370
Delivers 100 watts R.M.S. into 4 ohms using a 70 volt /2A supply.
Input sensitivity 500mV for full output. Response-10Hz to 50KHz
±1dB. S/N ratio better than 75dB. Distortion at half power typically
0'1%. With heat sink mounting bracket. 5" x 3f" x 11" (SS.1100H
with full size heatsink).
£2I.00*
FOR THE
100
Full size
heatsink £1
tL
A new heavy duty power supply unit to deliver 70 volts /2 amps.
Complete with mains transformer and low-volt outlet Plp -£1 00)
YOU PAY ONLY
1
I00W AMPLIFIER
1
250*
SS.370
TWO TOGETHER
70V POWER
SUPPLY UNIT
There is real power and reliability in this assembly. By buying them together you
save nearly £200 on these already competitively priced units. IDEAL. FOR DISCO,
P.A. and such Ilke applications. Send only E2100(+ L1-00 p /p) for SS.1100H with
full size heatsink and Power Unit SS370.
MORE STIRLING SOUND Q.V. MODULES TO SAVE YOU MONEY
POWER SUPPLY UNITS
WITH 13 -15v
TAKE -OFF
POINTS
Except
SS.312
3
TO
40
POWER
AMPLIFIERS
WATTS R.M.S.
SS.103 3 watt r.m.s. mono. Uses one I.C.
protected against short circuit
£1.75
SS.103 -3 Stereo version of above using
two I.C.s
£3.25
SS.105 5 watts r.m.s. into 4 ohms,
using 12V
£2.25
SS.110 10 watts r.m.s. using 24V and
4 ohm load
£2.75
SS.120 20 watts r.m.s. into 4 ohms,
using 34V
£3 25
SS.140 Delivers 40 watts R.M.S. into
4 ohms using 45 volts supply unit such
as SS.345. Ideal for small disco, P.A.
£3.95*
etc.
If ordering Stirling Sound power supply
units with Modules SS.103 to SS.120,
V.A.T. becomes 124 %.
TONE CONTROLS /PRE -AMPS
SS.100 Active tone control, stereo.
±15dB on bass and on treble
£1.60
SS.101 Pre -amp for ceramic cartridges,
etc. Stereo. Passive tone control details
supplied.
£160
SS.102 Stereo pre -amp for low output
magnetic P.Us. R.I.A.A. corrected. £2 65
UNIT ONE
A real money saver this. Compatible
with all relevant Stirling Sound modules
as well as other makes.
Combined pre -amp with active tone control circuits. ±15dB at 10Khz treble
and 30Hz bass. Stereo. Vol. /balance/
treble /bass. 200mV out for 50mV In.
Operates from 10 to 16V supply. £780
8
UNIT TWO
As above but with input for msg. input, 1 -5mV.
R.I.A.A. corrected.
£10.85
F.M. TUNING MODULES
SS.201 Front end tuner, slow geared
drive, two gang. A.F.C. facility. Tunes
88 -108 MHz.
£5 00
SS.202 I.F. amplifier. Metering and
£2.65
A.F.C. facilities.
SS.203 Phase lock loop Stereo Decoder
for use with the FM mono tuners. A LED
£3.85
may be fitted.
SS.203-1 Coil -type stereo decoder
Neg. earth with I.C. £250. Pos. earth
£2 00.
WE MAKE DELIVERY QUICKER by saving time
in turning round your orders. Now when ordering,
you send direct to our factory where QV (Quality
and Value) Modules are made. Our shop and showroom continue as usual for those calling personally.
WATCH
HOW
RANGE GROWS!
THE
STIRLING
A GOOD START FOR MOTORISTS
with a STIRLING SOUND "SUPER SPARK" Mk. 5
Electronic Ignition Unit. Over 1,300 Super Spark
Units have been sold by us. Adjustable for + orearth; simple rev. limiting control; on -off immobilising switch; switch for Instant revert to car's own
ignition; neon; indicator; In strong enclosed metal
box 61 x It x 4f ins. Inc. transfrmr. (P/P add 50p
either model + 8% V.A.T.).
KIT £8.95* READY
BUILT
Shop & Showroom:
Practical Wireless, May 1977
NOW
EI095*
220/4
SOUND
MODELS
TO CHOOSE FROM
Complete with mains transformers and
low volt take -off points not SS.300).
All at 8% V.A.T. rate.
Add p/p
£3.75"
SS.312
12V/1A
50p
18V/1A
£415"
50p
SS.318
SS.324
24V/1A
£4 30"
50p
SS.334
34V /2A
£5.20"
50p
45V/2A
£6.25"
50p
SS.345
SS.350
50V /2A
£6.75*
50p
70V /2A
£1250`
£1
SS.370
SS.300 Power stabilising unit 10-50V
adjustable for adding to unstabilised
supplies. Built in protection against
(p /p 35p) £3,26"
shorting
SS.310 /50 Stabilised power supply with
variable output from 10V to 50V /2A.
Built -in protection against shorting
(p/p
50p)
£1195"
WHEN ORDERING
add 350 for 0/p unle::s stated otherwise.
add 121% to total value of order unless price Is hown when
the rate Is 8%. Make cheques, etc. payable to BI-Pre -Pak Ltd. Every effort
made
is
to ensure correctness of information at time of going to press.
V.A.T.
Prices subject to alteration without notice.
Stirling Sound
A member L.! ire, B, -Pre -P,rn group 01
ern
es.
37 VANGUARD WAY. SHOEBURYNESS, ESSEX.
Telephone: Shoeburyness (0702.28) 5543.
WEST RD. , WESTCLIFF -ON -SEA, ESSEX SSO 9DF. Phone: Southend (0702) 48344
Dept. PW.5,
7
Test Meters
Incredible Value in Precision
WRITE OR PHONE FOR LIST
AVAILABLE FROM SELECTED STOCKISTS.
MICROTEST 80-I.C.E
20,000
Ohms /Volt 40 RANGES
SUPER TESTER
20,000 Ohms /Volt, (d.c.) 4,000 Ohms/Volt (a.c.) 2% accuracy. V d.c. 100mV to
d.c. 50µA to 5A (6 Ranges). V a.c.1 5V to 1 kV (5 Ranges) I a.c.
1 kV (6 Ranges).
680R- I.C.E.
I
250µA to 2.5A (5 Ranges). Resistance, Low Ohms, Ohms x1, Ohms x10,
Ohmsx 100. Output Level Measurements 1.5V to 1000V (5 Ranges)
+ 6dB to + 62dB (5 Ranges). Capacitance 25µF to 25,000 µF (4
Ranges). 1000 times overload protection (on Resistance ranges).
Meter movement diode protection. Size (without case) 90x
70x18mm. Automatic zero, non -parallax mirror scale. Unbreakable carrying case and probes supplied. Full After
Sales Service available. Price £16.15 inc. VAT
i
The I.C.E. Measurement System includes
a comprehensive range of accessories: shunts, transformers, specialised probes, transistor- tester etc.
I.C.E. High -Voltage d.c. Probe, Model 18.
Input Impedance: 500M Ohm, nominal (Other
values available to order). The Model 18 d.c.
20,000 Ohms /Volt 80 RANGES
20,000 Ohms /Volt 1% d.c. 4,000 Ohms/Volt a.c. 2°%,
V d.c. 100mV to 9kV (13 ranges). V a.c. 2V to 2kV
a.c.
(11 Ranges). I d.c. 50µA to 10A (12 Ranges).
2504A to 5A (10 Ranges). Resistance Ohms x 1, x
100, x 1600, x 10,000 and Low Ohms. Reactance
Detector 0-10M Ohms. Freq. Measurement 0 -5000 H
I
Ranges). Output Level 10 -2000V (9 Ranges).
Decibels -24 -+70dB (10 Ranges). Capacitanc0- 500,000 pF (2 Ranges using mains supply) 0.20,'''
(2
using Internal 3 Volt battery). 1'''
times overload protection on Resistance ranges
and meter movement diode protection. 10 Measurement Functions and 80 Ranges. Size 128 x 95 x
32mm. Non -parallax mirror scale. Unbreakabl
carrying case supplied which contains probes,
mains lead. crocodile clips and shorting link.
laF (4 Ranges
Price £27.27 inc. VAT
Probe consists of a highly insulated moulded
plastic body, fitted with a hand guard -ring,
containing a stable, precision 500M
hm resistor, which may be used to
extend the d.ac voltage measuring
capability of analogue multi- meters
or electronic voltmeters, to a maximum
value of 25kV. The probe is fitted with
a prod -tip for connection to the voltage
source to be measured and a connecting
lead terminating in a 2mm plug for insertion into the measuring instrument's d.c.
voltage input socket. (4mm plug available to
order). f6.42 inc. VAT
/
Sole Importers
and Distributors
Electronic Brokers Ltd
49 -53 Pancras Rd., London NW
BATTERY ELIMINATOR8P&P
240v Inputs, 7.5 or 9v
Connoisseur
25p
.. £3.25
output at 300mA
d.c. Input (specify output 8, 7 5
.. £50
or 9 d.c.) at 300mA ..
12v
D-D
CARTRIDGES A STYLI
P&P 25p
Cart.
6 RPL
Styli
Acos GP9112SC or 3CS
£1.N £1ß9
(ster. comp)
£2.0S £12e
ster. tryst
GP94/1 or 96/1
star. ceram.
GP101 cryst. comp.
GP104 star. ceram
-
£2N £18
E1 M
£21111
BSR X5M or X5H
£1.20
£105 £1.20
tryst. comp.
SXBM or SX8H
E225 £1211
E275 £1.20
cryst. ster.
SCSM star. ceram.
Sonotone 9TAHC or
9TAHC /G (Diem.)
£2.00
£10
-
£200 £128
£211
3509
Audio Technics ATS5
GoldringG850
G800
G800H
G800E
£3511 £1.75
£5S
£1.75
£52S £175
£9.80 £3.58
Shure Cartridges 6 Styli
M44G /M44C
M55E
M75ED Type 2
M75EJ Type 2
£110
£120 £7.15
£7.711
117.15 E12-S5
SPEAKERS
EMI 13" x 8 ", 3,
8
P&P 70p
E3.40
ohm Plain
8" x 5" C.Mag. 5 watt,
..
3.8 or 15 ohm ..
..
8" x 5" Dualcone
8 ohm, 10 watt
ELAC 61" 8 ohm Dualcone
8" 8 ohm Dualcone ..
10" Dualcone
Richard Alien 30w 12" 8 or
..
ohm
.
.. £235
.. £3.70
.. E3.35
.. £345
.
15
£1220
.
P&P 45o
MICROPHONES
UD 13050K/600 ohm
uni -dlr. ball metal
£110
£7'80
Condenser Mic. 600 ohm ECM77
.. £1050
omni -dlr
with
Mic.
Cassette Stick
.. £1 05
R/Control
Cass. Stick Mic. with
R. Control (Philips type) .. £1.03
CASSETTES
Low Noise
Philips
..
P&P
C60
£037
£000
C90
£0.48
£080
£081 LI.38
Memorex
Cassette Head Cleaner
DeCleaner
Bib
Head
..
..
magnetiser
.
C120
£0.75
£1.27
£1.00
£8.55
£I99
P&P £135
RECORD DECKS
£2070
GARRARD SP25 Mk IV
GARRARD SP25 Mk IV /G800
.. £3320
with Plinth & Cover
BSR MP60 (P128R)
.
£17 35
Plinth & Cover for Garrard,
11430 LI-7S
Send
M,O. prices only. VAT Inc. Subject to Availability & manufs. increase.
30p for Catalogue. Barclay/Access.
Callers
Leeds
St. Tel. 0632 2108.
4
New
Llvar0ó0I15 Whlteehapei.aTlell.051-236
EWMAR
NELECTRONICS
8
25
AmstradTeleton AkaiSansuiWharfedale
Garrard
01
-837 7781
Radio Component Suppliers
SÍNLWJRcT
Pioneer Rotel
2Q6. Tel:
J. BIRKETT
1'Ìqt1?1g.1
Stockists of:
I
Mail Order DeptPW /5
Belmont St, Menton,
Eccles, Manchester.
Tel 061.789 5268
The Strait, Lincoln LN2 1JF
Telephone:
20767
10,000uf 16v.w. ELECTROLYTICS size 3f" x y}" @ 15p ea. 4 for 50p.
SOLDER -1N FEED THRO' 300pf, 1000pf. at 20p doz.
100 ASSORTED NULLARD C280 CAPACITORS for 57p.
CRYSTALS 5 MHz IOX Type 0150p, 600 KHz IOXAI Type @ 50p.
TUNING CAPACITORS 150 + I50pf Direct Drive @ 50p each.
20 VARI -CAP DIODES Untested for 40p.
VHF SUB- MINIATURE 10 + tOpf AIRSPACED PRESET CAPACI1
TORS
@ 22p each.
SILICON PHOTO TRANSISTORS
DARLINGTO NS @ 22p.
@
15p,
SILICON PHOTO
BRANDED T090 PLASTIC BC 108 or BC 212 types at 10 for 60p.
VHF DUAL GATE MOS FET's like 40673 033p, 4 for £1.10.
200 ASSORTED }, } WATT RESISTORS for 75p.
BOOKS "Practical Test Equipment" @ 75p, Simple Short Wave Receivers",
@ 60p, Practical Electronic Projects @ 75p. The Three Books for £1.60.
To 10 Watt @ 57p.
60 WIRE WOUND RESISTORS Assorted Values
SUB- MINIATURE LOUDSPEAKERS 8 Ohm If" Dia at 75p.
6 FET's like IN 3819 for 75p.
200 + 200 + 100uf 300v.w. ELECTROLYTICS size 21" s II" @ 25p, 10 for
I
11.80.
50 BC 107 -8 -9 TRANSISTORS Untested for 57p.
TBA 1205 I.C's Untested with data @ 6 for 60p.
MINIATURE SILICON DIODES Assorted for 57p.
GHz DUAL NPN TRANSISTORS Untested with data
MULTI -TURN TRIMPOTS Assorted for 60p.
100
2.5
10
at 4 for 57p.
COMPRESSION TRIMMERS lOpf, 30pf, 50pf, I50pf, 750pf, I000pf All at
6p ea.
To SLOW MOTION DRIVES @ 55p.
SILICON SOLAR CELLS 0.5 Volt 5 mA at 35p each.
SILICON NPN POWER TRANSISTORS BD 187 at 4 for £I.
TEXAS 500 Volt 2 Amp NPN PLASTIC TOO TRANSISTORS @
6
1
50p,
3
for LL.lO.
50 AC 128 TRANSISTORS Branded But Untested at 57p.
I000uf 40v.w. ELECTROLYTICS size 14" x }" at 3 for 35p.
PLASTIC TRIACS 50 PIV 6 Amp @ 15p, 400 PIV 6 Amp @ 60p.
PLASTIC S.C.R's 50 PIV @ 15p, 400 PIV @ 40p.
FT 234 CRYSTALS. 8040, 8100 KHz @ 75p ea. 7620, 7720, 7966.7, 8166.7,
8233.3, 8300, 8366.7, 8483.3, 8583.3, 8650, 8716.7 KHz. All at 40p ea.
TRANSMITTING CAPACITORS 80pf, @ £1.85, 500pí @ E3.50.
TANTALUM BEAD CAPACITORS .Iuf 35v.w., 15uf 35v.w.,
47uí
35v.w., tuf 35v.w., 2.2uf 35v.w., 4.7uf IOv.w., 4.7uf 35v.w., 5uf 25v.w.,
6-Ouf 25v.w., 6.8uf 35v.w., Ouf 25v.w., I5uf 20v.w., 20uf 6v.w., 22uí 16v.w.,
33uf 25v.w., 47uí 6v.w. All at 9p each.
Please add 20p post and packing on U.K. orders under £2. Overseas orders at
cost.
I
Practical Wireless, May 1977
barcia
CASIO
fx-201 P
L.C.D.
KLC3A
address, subroutine
etc. The programme
function allows you
to handle any type
of talc. under any
*£49.95
condition
world's first fractional
-102. The
calculator. 10 digits or 8
plus 2 Exp. sin, cos, ten, Deg. rad. (exp.
10±"). Trig. Inverse common & Natural
logs. Reciprocals. Sexagesimal, Pr
entry. Statistical talcs. Incl. 2 kinds of
Standard deviation and other appli-
fx
*£19.95
cations.
Exp.
nverse 2ttrig. All
log functions. Sqr roots, Reciprocals.
Trig,
conversions.
Sexagesimal/Decimal
Fractions. 2 kinds of Standard Deviation
and other applications.
£1695
8 digits 2 exponents. 21
Scientific functions.
£15.95
fx -100.
A 110.
Liquid crystal Sci. 1000 hr.
Bat. life
£19.95
As AL8 but with 10 digits!
£15.95
TEXAS
SR56
K LC
Hours, Minutes, Seconds,
Beautifully finished with
S /steel back á FREE
stylised leatherette strap
stop Watch
mine & secs. May be set
to alternate hr & mina to
mth á date every 2 secs.
resets to time. 4 yr cal.
t
secs.
programme steps. 20
Independent memories. 9
224
10 digit, 2 Exp Rechargeable. Ail log. and trigs,
Hyperbolic x to the root of y. Rad & Deg.
Factorial. Mem. 3 Inds. mems. Linear
regression. Mean, variance, standard
deviation. Generation + 7 basic converts., and their inverse Engineering
Notation.
(R)£4495
functions plus Algebraic
operating system. 15 seats
parenthesis. Constant, roots, powers,
reciprocals. Sci notation. Log, trig, deg
rad, mem, step function
£15'95. RK2 Nic Charger Kit £7'95
slide
NOV US
4640
(Il!us.)
10 digit,
2
3
Fully addressable
-level roll stack.
memories. Logs, Trigs, Stat and Metric
conversions etc.
(R)£42.95
digit, 2 Exp, Algebraic logic
4650.8
J 2 -level
parenthesis. Full mem.
Addressable. Trig, sin, cos, fan and
inverse trig functions. Deg rad. Reciprocal, Sq root. Powers and Pi entry.
Mem Ex and Register Ex (R)£2Ì.50
4
4525
Exp.
step prog.
E :change.
Full lug dOtrio..
Mem. 4 roll stack, skip, delete. Additional props within the 100 step
step
4515. 100
ve rsio n
Metric.
6010.
prog
(R)£34.50
(R)£23.80
£1595*
Practical Wireless, May 1977
PR100 New Prog.
N60 (Navigator)
£19.95*
Scientific
S /steel
ROCKWELL
44
Date, Day of Week, Auto
5-digit and 2 Exp.
Green Display. Store.
Similar to the 63R
£19 50*
less factorial.
24K. Stainless Steel Slimline. Green
4 -Yr
calendar, A.M. /P.M.
Set /Indicate. One of the
most sophisticated
watches at this price.
Accurate to within a few
a year. Finished In
Satin Stainless Steel with
FREE matching Steel
bracelet.
£33.90 ONLY Gold Plate £36
display. In beautiful leatherette wallet
to hold pen, note pad and credit cards
(all Included). Full memory. Click
buttons. Rechargeable.
(R)£21 95
Including recharger.
secs
HP25R Prog. £18530
HP55 Prog. + Sci. + Time
HP91 (Sci. Printer)
Prog.
HP97
£32158
RD
90
£2376
DECIMO DIGITAL
CLOCK RADIO
£3690printer E82179
Fully
MIRDIGITAL
READOUT
DE LUXE
MODEL
DELUXE
THIS
Football
Tennis,
HAS
Squash, Solo. 2 bat sizes,
2 Ball speeds. 3 distinct
pings -one for point score, one for bat
strike ball, one for ball strike boundary
and automatic scoring.
90
Tennis, Football, Squash. Score marker.
Ball sound affects -2 pings. Player
Identification. Red light point winner
indicator.
£48.
£39
family!
These games are easy to play and a joy for all theVAT
FREE B.S
6025.
I
titian.
programmable Stasis-
Rechargeable. Financier 100step programmable
(R)£34'95
I.£12,95'
level stack.
6030.
Statistician.
4520.
Sci. 8 Dig. +
roll stat. etc.
Plus
£1 P&P
ORDER FORM
A
(R)£34'95
procal Memory, etc.
OUR PRICE £33.95
PRICES INCLUDE
YR GUAR.
Rec. arueable.
3
4510.8logdigits.
tunctlons.
This Is the most unique clock /radio in
the country today having a soft, 1}" high
orange -glow digital readout which Is
completely silent and non -pulsating.
In a beautifully styled enclosure with
up-to -date VHF/MW radio. You can
awake to soft music or alarm. Automatic 80 minute 'sleep' button in case
you drop off while the radio Is ont
(R) FREE Charger
adaptor.
100 -step
95
64RD12(- óii)
NEW ZYTRONIC TELE-GAME
1
£12
£24.50"
£24.90
ALL ITEMS CARRY
£4295
Yr calendar. Case in
Mins, Secs, Date, Mth á
HEWLETT PACKARD
6035.
Exp. 54 functions.
Green display and
Bat 4140 but
KED6D
TI30,48
figures funct.
TI40.Sci-47
rule
£24.50
Print unit for Fr52 á 56
PC1 OOA.
£175.50
As
2
Month A Day of the Week
In Letters! Shows Hrs,
£26.90
S /Steel
+
trig funct.
or 8 -digit + 2 Exp.
Additional to the
44RD. Polar rec.,
co- ordinates. Log
Trig, rad or grad.
£36.95
Plate or with stylised
Chrome Bezel, each
with matching
bracelet.
GOLD PLATE
10 -digit
Exp. Full log and
Xx, Reciprocal, nr,
root of y. Polar rectangular co -ord-
a
with
scratch proof mineral
glass. FREE
matching S/steel
adjustable bracelet.
£29 95 Gold Plate £3390
This is a superb jewellery piece.
miniaturised electronic wizardry! Gold
SR51 II
inates. 2 -store mem. Mean and Standard
deviation.
(R)£21.95
solid
An elegant 6- function
watch, Shows Hrs,
Mins, Seca, Mth,
Date, Dayl She'll love
this piece of
ONLY £25 each
4148,
£18.95
4
THE IDEAL PRESENTI
level parenthesis. Card programmable.
Supplied with 20 blank magnetic cards
and prog. manual.
(R)£194.40
Any of the following pre- programme
2. Electrical
Statistics.
1.
manuals:
Engineering. 3. Mathematics. 4. Finance.
£11.75
calendar. Beautifully
finished with S/steel back
á FREE Matching Stainless
Steel Bracelet
letters. Single button.
Auto -hold 6 Fade -out.
LADIES DIGITAL
£54 ' 95(R)
mema.
Hrs, Mins, Secs, Mth &
Date. Day of week In
Auto -time reset. 4 yr
calendar. 'Nite- lite'.
FREE matching S/Steel
tronic engineering,
financial
statistical,
and navigation.
(R)£29.95
fantastic 6- Functions1800
KED6CAwindow
display shows
',
Continuous hrs, mins á
pulsating secs. Press
command button for mth
& date. Press again for
secs readout. Setting for
alternating hrs & mina to
all log trig
and Stat functions.
Can be programmed
for maths, elec-
1
logs á trigs. etc. Polar rec co /ord.
Gold Plate £20 95
K LC9
101nde memories,
10-digit,
2 Exp. 90 function
pre -programmed. Metric
conversions. Extra
functions to the 4148R:
Perms and combinations. Gamma. Poisson and Binomial
distributions, factorial, complex numbers, hyperbolic
functions, linear
regression and integration of Y = t(x).
4 -Yr
i
Thinnest on the market.
£39.50 Gold Plate £42 -S0
FREE matching bracelets
with each.
CBM
5190R
functions. /0 +2
7949D50
Means á standard dens. All
8- Functs. Shows Hrs, Mins,
Secs, Mth & Data and Day.
WATCH FACILITIES
2
£11,95
KED5B
I.
'Nile Lite'. PLUS STOP
mth & date every
!
or Matching Slated Bracelet. Watch & bracelet In gold
ONLY
plate £1395
Constantly shows hrs, mins
á Pulsating secs. Press
command button for mth
á date, press again for
bracelet
;óób Step
programmable
10 digit, 2 Exp.
S R52.
Ideal present! This stylish
3- function L.E.D. shows
Chrome with Stainless
Steel back £1180 Square
face with back light.
£22S0. Both with FREE
Adjustable S /Steel
bracelet.
and manual jump
as well as indirect
f x -21.
L.E.D
KED1A
1-/".
Constant display. Hrs,
Mins & pulsating secs.
conditional jump
102.
ELECTRONICS
New range of Quality
Electronic Watches
ZYCON
The
1(2; sTéó
programmable
10 digit or 8 digit, 2 Exp.
127 Steps. 10 Inde.
mema, cos, sin, tan.
All log functions
Degree Rad. Un-
fx -19.
TECHNOLOGICAL
PRECISION PRODUCTS
All trig
nr.
Reci-
£1595*
2
Exp.
4
Figure
£22.95
PHONE CALLS AND PERSONAL CALLERS WELCOME MONS to
THURS BETWEEN 2 & 5 p.m. 01 -450 4755. SUNDAYS 10a.m.to 1 p.m.
FINCHLEY ROAD,
To: BARCLAY ELECTRONICS Dept. SPW, 1115
TEMPLE FORTUNE, LONDON N.W.11 (Near the M1)
Please send me
with /without optional mains adaptor.
value
£
I
enclose chenue/money order total
Please add 55p to all Items to cover p. A p.
NAME
ADDRESS
SINCLAIRall trig,
log
CAMBRIDGE SCIENTIFIC
£8.95
á deg. rads etc.
OXFORD SCIENTIFIC larger version of
Green display
£12,95*
PARENTHESIS.
COMPANY. GOVT. DEPT. AND
ORDERS. NANCLATI
ACCEPTED SYY PHONE
s ACCESS
ban:
88888
4180)
9
YOU BUY AN AMPLIFIER MODULE- CHECK:
BEFORE
DOES IT HAVE
1.,
* NT
3A DR VERS (100 W SUNIT)
LIE
CAPACITOR
THEN COMPARE WITH THE TAMBA RANGE -EXCELLENT VALUE -25,
£7
50
£475
(WITH
1
1
or
or
2
2
£T50
TAM250 /500
TAM1000
60
High & low impedance Inputs
High sensitivity
Built in supply smoothing
48.110
(Carr. 50p on supplies)
20- 20,000 hz
Low distortion (0:1%)
Low profile (1" High 31"
Suits loads 4 -16 ohms
20- 20,000 hz ±1dB
Silicon circuitry throughout
Glass fibre P.C.B.
High sensitivity (100mV 10k)
mm SLIDER VOLUME)
Anodised 6 printed facia
Suitable for multiple input systems
POWER SUPPLIES
For
For
W RMS
ALL PURPOSE
MIXER /PREAMP
£550
TAM1000 100W 4 OHMS 65V
TAM50) 50W 4 OHMS 45V
TAM250 25W 8 OHMS 45V
50 & 100
+1dB
80dB Noise level
Accepts a wide variety of inputs
Wide range bass & treble controls
x 3 ")
75% efficient
Use up to 10 preamps with
Accepts most mixer / preamps
Four simple connections
1
power
COMPLETE & TESTED assembly
with Treble & Bass controls plus
£6 50
slider Volume Control.
High Grade Components used throughout: Texas, Mullard, R.C.A., Plessey, etc.
Hours, 9.30 a.m. -5 p.m.
Monday- Saturday.
Callers welcome.
Tel: (01) 684 0098
You may order as follows: C.W.O. (crossed cheques, P.O.s, M.O.s, etc.) C.O D. (60p
extra). We accept Access and Barclaycard -send or telephone your number -do not
send your card. Add VAT at 8% to orders for 50 -100W units and at 12i% for 25W
units
TAMBA ELECTRONICS
BENSHAM MANOR ROAD PASSAGE, BENSHAM MANOR ROAD, THORNTON
I-
SOUTHERN VALVE COMPANY
Upper Floor, 5 Potters Road,
New Barnet, Herts. Tel: 81 -440 5841
"QUALITY" Branded Valves -90
day guarantee.
ALL NEW 6 BXD VALVES (Icl.tax) -many makes.
PY801
62p
UBF89
41p
47p
50p
539
400
45p
680
95p
50p
UCC85
4es
UCH42
75p
420
420
589
72v
42p
75p
459
480
72p
802
60p
70p
689
60p
759
800
36p
420
18p
362
35p
34p
409
PCC85
44p
PC088
PCC89
PCC189
ECH42
489
750
EC1181
42p
ECH83
ECH84
ECL80
201,82
ECL83
ECL86
EF80
EF85
EF86
821,
PCF801
PCF802
55D
PCF805 2145
PCF806
759
PCF808 £140
PCH200
859
PCL82
409
PCL83
509
AZ31
DY86/7
DY802
EB91
ECC81
50182
50083
ECC85
ECC88
"99
EF79 3
EF184
EÚ18
EL34
EL41
EL84
EL509
529
620
479
689
48p
30p
379
tí29
589
38p
3 89
389
999
809
38p
12.50
25184
Sop
EY51
EY86 /7
47p
38p
PC86
PC88
PC97
Pe900
PC84
48p
PCL84
PCL85 1
621(
FCL8o5
PCL86
509
PCL200 £140
PD500 £2.50
PFL200
73p
709
PL36
P1.81
P1.82
PLOP
PL84
PL5001
SOP
21.10
P1.802
36p
669
03p
83p
079
49p
352
60p
642
380
469
409
FL81A
PL504
PL508
PL509
PL519
EY500A21 45
8240/1
53p
EZ80
EZ81
OY501
OZ30
FCF80
PCF82
PCF88
PCF200
f
909
E1.10
r1CH81
UCL82
UCL83
UF41
UF89
UL41
UL84
UY85
U25
U26
U191
/30L2
6BW7
8F23
6
a
WORLD -WIDE RECEPTION
WOE
30 FL1
30FL21
30L1
8200
1280
£200
30L15
30L17
30P12
62p
PY33
419
PY81 /3
41p
PY88
PY500
£110
PY500A £1.10
41p
PY800
30P19
709
400
70p
759
£1.45
609
070
350
859
700
869
70p
30PL1
11 40
30PL13
7011
30PL14
85p
85p
30PL15
30P4MR 90p
.II
IIIÌ
IIII
I
iiljÌ
PRICES
III,
Newest, neatest
system ever
devised for storing small
parts and components:
resistors, capacitors, diodes, transistors,
etc. Rigid plastic units interlock together
in vertical and horizontal combinations.
Transparent plastic drawers have label slots.
ID and 20 have space dividers. Build up any
size cabinet for wall, bench or table top.
AS SUPPLIED TO POST OFFICE,
INDUSTRY & GOVERNMENT DEPTS.
egolo KT66)
20L1
709
20P4
30C1
30015
30C17
30C18
30E5
'
/d
f,--`
r
hl
N T-E-R-L-O-C-K-I-N-G
PLASTIC STORAGE DRAWERS
KITS
6E28
8V6
809
0L8 (near 999
We offer return of post service. Post free over
EIS 00. Postage: 1st valve 12p. extra valves 6p,
Max. 75p. Minimum order 65p. Most types available, send sae for lists. Discount Prices. All
prices subject to alteration without notice due
to market fluctuations etc. Telephone enquiries
welcomed, sae with enquiries PLEASE! C.W.O.
ONLY. No C.O.D. Export enquiries welcomed.
VAT Invoices on request. Mail order only,
10
H.A.C.
SHORT-WAVE
HEATH, SURREY
Panora for Omer 35 years for Short -Wave EgWpmrnt of quality. "H.A.C." were the Original
suppliers of Short -Wave Receiver Kits for the
a ateur constructor. Special offer A6.8 valves
-
709 each.
1977
"DX" RECEIVER
Complete kit-Price 07 -20 (incl. p. k
Customer writes: "1 think the performance is
a,toniehing for such an inexpensive and foolproof
kit. I would wholeheartedly recommend this kit
to anyone, however inexperienced. as an antidote
to TV-itie, end es an entry into a fascinating
hobby".
This kit is ready to assemble and contains all
genuine short -wave components, drilled chassis,
valve, accessories and full instructions. Full range
of other 8.W. kits. including the famous model
"K plus" (illustrated above). All orders despatched
within 7 days. Send now for free descriptive
catalogue of kite end en,ponent.e.
Send stamped envelope for details.
"H.A.C."
SHORT-WAVE
SINGLE UNITS (ID)
2 }ins).
(Sins
'x
41ins
>.
2 }ins).
L4.90 DOZEN.
TREBLE (3D) L4.90 for 8.
DOUBLE TREBLE 2 drawers, in one
outer case (6D2), L7.25 for 8.
EXTRA LARGE SIZE (6DI) L6.25 for 8.
PLUS QUANTITY DISCOUNTS!
Orders over £20, less 5 %.
Orders over E60, less 71%.
PACKING /POSTAGE/CARRIAGE: Add 75p
to all orders under £I0. Orders £10 and
over, please add 10% carriage.
QUOTATIONS FOR LARGER QUANTITIES
Please add 8% V.A.T. to total remittance
All prices correct at time of going to press
FLAIRLINE SUPPLIES
(Dept. PW5)
PRODUCTS
P.O. Box No. 16, 10 Windmill Lane
Lewes Road, East Grinstead, Sussex
RHI9 3SN
(Sins x 2 1ins
L2-90 DOZEN.
DOUBLE UNITS (2D)
114
Cricklewood Broadway, London NW2
Tel.
01
-450 4844
Practical Wireless, May 1977
R.C.S. 100
watt
RETURN OF POST MAIL -ORDER SERVICE
BAKER MAJOR 12" £14.95 BAKER DISCO SPEAKERS
MIXER /AMPLIFIER
ALL VALVE CHASSIS
retttli", 4
Four inputs. Four way mixing, master volume. treble and
basa controls. Suite all speakers. This professional quality
amplifier chassis hi suitable for all groupa, disco. P.A., where
high quality power is required. 6 speaker outputs. A/C mains
operated. Sloe output. Produced by demand for quality
valve amplifier.
Suitable rrying cab netr114. Price X85 Darr. SS 60
ANOTHER R.C.S. BARGAIN
!
ELAC 9 + Sin. HI -FI SPEAKER TYPE 59RM
This famous unit now available, 10 watts, 8 ohm.
Price
£3'25
IO" ELAC
Large ceramic magnet.
60- 16,000 cps. Bass resonance
55 cp.. 18 ohm Impedance.
watt..
Pout4Op
£4.45
TEAK VENEER HI -FI SPEAKER CABINETS
MODEL "A ". 20 x 13 x 121o.
Por 12 In. dia.
101n. speaker.
Illustrated
orE:13.50 Poet
96p
MODEL "B ".
For 13 x Sin. or
B
in. meeker
E7 SO Poa
76p
4, 8 or 16 ohms.
GROUP "50/12"
1210 80 watt professional
ERASER & HEAD DEMAGNETISER.
suitable for cassette., and all eues o!
tape reels. A.C. mains 200 /240V.
Leaflet B.A.E.
¡oo
40p
EACH (FOUR FOR X150)
-Dinounta for quantity.
or 16 ohms.
L
£
`'24F
A
.95
7
ocoo.,
-_tltl
/
an
6X8 .00
Component. List.
Practical Wireless, May 1977
E52
Can. 81
3.50
QUALITY LOUDSPEAKER
ENCLOSURE
10p.
E.
Price
4 ohm. 4 watt. ceramic magnet
General purpose replacement unit.
il 80.
£ 14.00
E I.95
MAINS TRANSFORMERS
áö
6 VOLT
8 AMP. 8140
4 AMP. 81.00
18 VOLT
800 NA. 81.00
760 MA. 81. SO
80 VOLT 6AMP. AND 34 VOLT RAMP O.T. 18.45
AMP.
1
AMP.
88.00
8 AMP. 8880
20 VOLT 1
81.76
80 VOLT 10 AMP. 8260
80 -0-80 VOLT LAMP. 8895
40 VOLT 2 AMP. 8896. 0.20 -40.60 VOLT 1 AMP. 2350
E.M.I. TAPE MOTOR
Post 455
E.M.I. GRAM MOTOR
Cash
base. Fitted with a special
copper drive and concentric
tweeter cone resulting in full
with
reproduction
range
remarkable efficiency 10 the
upper register.
Esp.
Ban Resonance
16,600 gauss
FluoDemity
Useful response 20- 17,000cps
8 or 16 ohm. modele.
£2I.95
fit,
"AUDITORIUM"
watts
12ín. 35
reproducer for
Shupe
Bass Resonance
15,000 gams
Flux Density
Useful repon.. 25- 18,000cps
8 or 18 ohms models.
£20.95
LI -25
Post
SOP
Post
u80
"AUDITORIUM"
I5in.
45
A high wattage
watts
loudspeaker
of exceptional quality with
to
above
level response
8,000 cps. Ideal for Public
Address, Discotheque., Electronic instruments and the
home Hi-Ft.
38cpa
Base Resonance
15,000 gauss
Flux Density
Ueetul response 20- 14,000cp.
8 or 18 ohm. models.
£2495
4
240V a.c. 2,400 rpm
2 -pole. Bise 21 x 211n.
Collaro gram motor 120v. 75p.
watts
Discotheques.
inch PHILIPS LOUDSPEAKER
pole, 240 v. Size 31 x 2110.
1200 rpm. Spindle bin. diameter. 75v version 81.
12ín 25
high power, Electric Guitar..
Public address, multi- speaker
organs.
systems, electric
Ideal for HI -Fi and
Complu s kit of parts with R.C.B. printed circuit. Three
channels. 600 to 1,000 watts each.
As featured in Practical Wireless.
8
Full range.
A high quality loudspeaker,
its remarkable low cone
clear
ensure.
resonance
reproduction of the deepest
A full range
Teak veneered Un thick wood cabinet.
Sin 18410 x 181in x Sian. Weight
Elk. This cabinet features
wide
mesh Silver Grill covering a separate
compartment for mounting Tweeters
or Mid -Range Horn. The fully sealed
bus compartment is cut out for
Olin. Woofer 8696. Rosewood Version 8896. Carr.
Baffle could be cut for larger speaker.
Cabinet extra
High quality.
{`SUPERB HI-FI
baker-`..-1
Latest 50 watt Model E49
RADIO COMPONENT
Minimum post 30p.
I x 15 "+ I x 12" 100 WATT CABINET
Size 36" x 24" x 15° £75.00. Carr. E5
Ideal for Disco, Ogran or PA work.
£20.95
P.W. SOUND TO LIGHT DISPLAY
OFFERING 1001 USES for every type of beating and
drying applications in the home, garage, greenhouse.
factory (available in manatacturing quantities). Approx.
sise 101 x 82 x bin. Operating voltage 200/260V. a.c.
250 watts approx. Printed circuit element enclosed in
asheeto. fitted with connecting wire.. Completely flexible
providing sate Black beat. British -made for use in photocopiers and print drying equipment.
Ideal for home handymen and experimenter.. Suitable
for Heating Pads, Food Warmers, Convector Heaters, etc.
Must be clamped between two sheets of metal or asbe.o,,
etc., to make efficient clothes dryers, towel rafia -ideal for
airing cupboard.. Ideal for anti-frost device for the garage
-preventing frozen radiators or acting as oil .amp heater.
Use in greenhouse for used raising and plant protection.
Invaluable aid for bird houses, Incubator., etc., etc. Can
be uad in aerie. for lower beat. Or in parallel for higher
beat applications.
70
Carr. 64
Professional amplifier using advanced circuit design. Ideal
for disco, groups, P.A. or musical instrumenta. 4 input.
4 way mixing. Master treble, bass and volume controls. 3
speaker output socket. to suit various combination. of
specken. 4 to 16 ohm. Slave output. A/C mains. Guaranteed.
Detallo S.A.E. 150w SLAVE 880
/h
HEATING ELEMENTS
ALL POST PAID
£ 1395
1
THE "INSTANT" BULK TAPE
119
R.M.S.
X69
Post 81
B.S.R. SINGLE PLAYER DECK
3 .peed. Plays all sise records. Stereo Cartridge.
Pet 760 E
Cueing. Ideal Disco Deck
£3.95
Carr.
WATT
4 speaker outputs. vol., treble bue controle
CAN BE USED AS 100WATT SLAVE
WATT AMPLIFIER. 4 Transistor
Push -Pull Ready built with volume, treble and
bot control.. 18 volt battery operated. Mains Supply 8895.
8
R.M.S.
£50
100
£ I I-95
MADE BY JENNINGS MUSICAL INSTRUMENTS
musical highlights and sound
effects to recordings. Will mix
Microphone, record., tape and
tuner with separate controls into
single output. 0 volt
X5.75
battery operated.
STEREO VERSION OF ABOVE 8760.
SO
WATT
.
100 WATT DISCO AMPLIFIER CHASSIS
BARGAIN 4 CHANNEL'IRANESTOR MONO MIXER. Add
CABINETS
12"
for Disco or PA all fitted with carrying liana's' and su'res't.
Black finish. Other cabinets in stook.
SAM For leaflet
Carr 13
model. 8 ohms or 16 ohms.
Post 81 60
With aluminium presence dome.
MIXER/AMPLIFIER
X3.25
MADE
Post 61
TRANSISTOR
GOODMANS CONE TWEETER
ONLY
GROUP "35"
1210 40 watt
QUALITY
Olin. diem. 18,000 C.Y.B. 25 WATTS 81-1
8 in. woofer 16 watt. 88.76. Sin. mid range 86
THIN
4, 8 or 16 ohms.
x
- BRITISH
R.M.S.
£55
Robustly constructed to stand up to
GROUP "25"
1ß1n 80 watt
HIGH QUALITY
2
WATT
post 81.60
CABINET
LOUDSPEAKER
WADDING 18in. wide. 20p ft.
WAFER
BAKER SPEAKERS
"BIG SOUND"
BAKER 150 WATT
r,M)
£4.25
£18.95
Please state 4 or 8 or 16 ohms. Poet 21 60
8
SPEAKERS
Site 14ín. x Blu. x 81e.
Response 60 to 14,000 cps
8 watts rms 4 or 8 or 18 ohm,.
BARGAIN
kit, 30- 17,000 c/s
with tweeter, armorer, baffle
and Ineiructtone.
Module
GROUP "50/15"
1610 76 watt
R.C.B. BOOKSHELF
£16 pair
1210.
long periods of electronic power.
As used by leading groups.
Unto! response 30-13,000 cps.
Bass resonance 66 ups.
Post 40p
HI -FI SPEAKER
10
Post 81
double
cone, woofer and tweeter cone
together with a BAKER
ceramic magnet assembly
having
flux density of
14,000 gauss and a total Buz
o! 145,000 Maxwells. Bass
resonance 40 c/s rated 26
watts. NOTE: 4 or 8 or
18 ohms must be stated.
80- 14,600 c /s.
Po
11 80
Loudspeaker Cabinet Wadding 18in wide. 20p per ft.
HI -Ff Enclosure Manual containing plana, dealins,
crossover data and cubic tablea, 63p
EHORSE(ROAD,pCROsDON
SPECItALISTSopen97dwHI9
price includes YAT
L Barclay carde welcome.
A
Rail
SIhurat.
Tel 01.114
1663
11
ECC189 -80 E3486 1.20
ECC807 2-80 EM87 140
ECF80
-50 EMM803
ECF82 60
860
BENTLEY ACOUSTIC
CORPORATION LTD.
ECF86
ECH2I
ECH36
ECH42
ECH81
ECH83
ECH84
101.90
EOL82
101.81
ECL84
1CL85
ECL86
7e GLOUCESTER ROAD. LITTLEHAMPTON, SUSSEX
Telephone 6743
All price. Inclusive of V.A.T. at Il ¡%
0A2
OB2
OZ4
1A3
1A6GT
1A70T
1B36T
SHOOT
1L4
1N6GT
106
104
1T4
1U4
1U6
2D21
.86 eAW8A 84 6.170
.40 6AX4
.75 eJUBA
-66
6B80
60 BBAB
66 6BC8
40 613E6
.66 gBH6
.80 6BJ6
26 6BK7A
76 8BQ7A
.60 6BR7
40 69R8
80 61387
-70 BBWB
86 8BW7
2016
.66 6BZ6
.76 804
3A4
-66 6C6
2112
308
3Q4
3Q6GT
384
3V4
4CB6
70 6CáG
.40 609
.80 BCBBA
-70
60060
.86 12BA6
90 128E6
36 120117
.60 12B17
36 8K70
-40
6180
6A16
6AK6
6AM8A
6AN8
6AQ5
6A 115
.36
.60
.70
.70
-46
.70
.70
.70
6915
6918
6923
6924
6926
6928
6F32
6060
-88 6GHOA
110
6015
6A870 1-00 6007
6AT6
.60 61166T
6AU6
-40 6J6GT
6A96
.60 616
86
3 60
.86 6L18
-00 6L19
8.00 1218
76
-80 12Q7GT 60
60
1.86 61.17GT -70 12807
66
1.70 6Q76
"60 12807
80170T 60 128117
66 eQ7(M) '86 12817
i10
-60
6070
40
O9A7
.46
6807
.70 128Q7
.00 68C70T
66 128E7
76 14117
60
60
BO
76
76 OSAS
108C1
1487
1 00
-66 19AQ6
46
840 88H7
'60 19G6
6 60
-60 68J7
68K70T
19111
.56
4.00
2.60
'60 20D1
70
90 6EQ7
.75 6V60
80 2092
86
96 MGT 60 20L1 120
6X4
.46 20P1
1 00
1.00
.90 6X5GT 46 2093
1-00
-80 2094
.75 7B6
.84
7B7
'80 2096
1.60
.56 707
00 26A60 .70
110
.85 10DE7
-60 10F1
2.00 251.80
-80 2516G
'80 25246
.60 2605
-70
.80 30A5
66 10F9
80 10918
2.00 1OLD11
.74 10913
.70 10914
47 30016
-80 DM70
-80
.70
1.00
-70
40
.80
1922
1940
EF4I
13942
1973
EF80
EF83
EPOS
EF86
EF89
EF91
76 1182CC
-40
300
160B2 1-00 E188CC
21680 -60
2-50
807
1-10 E1148
-60
1626
2-50 EA60
40
6702
1.20 BA76 1-30
6768
1-66 EABC80 -40
6057
1-00 EAC91 -66
6060
1.00 EAF42 .70
6067
6463
7025
-70 7193
110 9002
.60 9006
2-00 AL60
.76 ARPS
-77 ATP4
.66 30017
.66 9095
-77 AZ1
.70 AZ31
-76 AZ41
.80 30L37
.70 036
2-60 3094MR -98 BL63
40 12A6
-66 30912
-74 CL33
-80 12AC6
CY10
-80 30P19/
.76 12AD6 '80
3094 -90 0Y31
.90 12AE6
-80 30PL1 1-00 DI
-30 12AT6 -46 30PL13 1 00 DAF91
.50 12AU0 .60 3091.14 1-29 DAF98
.36 12AV6 .60 30PL161.00 0090
-75
-E6
30LI6
1992
EF97
F.L92
EL34
EL36
EL97
11.41
E1.81
EL83
EL84
-40
-46
-40
E1,86
POCOS
PCC189
PCF80
PCF82
'46 -P0984
.50 PCF86
1.20 penal
6l
0409
68
17801
P830
.50
.49 QQVOS/10
-40
46
Q895/10
U404
04020
VP28
VP41
VR106
VU111
131120
VU133
W107
W729
X41
X86
-46 2759
1.00
Q8160/16
1.80
160 0183
67
-71 E184
120 QV04/78-00
-40 E186/7 -37 9092011-00 0V06/20
-66 PCF801 49
50 EY88
860
-76
-50 EY91
60 109802 64 1119
-68 PCF806 .58 UABC80 46
46 EZ40
50 1041
UAF42 '70
58 PCH200
88
-74 1080
2.00 UB041 '60
-80 E1761
8-00 EY81
1281
-66
70 GY601
0232
1.00 0233
.78 6094
.76 0Z37
.64
-46
-70
PCL82
.40
.49
-60 PCL84
-46
PCL86
.64
-60
-40
96 PC1.83
1-80
-75
PO1.800
160 PENIS 1.00
-90 HABC80 -BO
PRN46 1-00
00081
-42
.50
.60
-90
-90
KT41 1.00
KT66 3.00
KT81 2.00
KT98 6-76
KTW61
1.60
KTW62
.60
1.60
3-00 KTW63
3-00
180
47 MHLDB
1-00
1.00
UF80
.67 2E3703
-70 203709
.80 AA119
-40 AA120
-60
13F86
-60
1701A9
11673091q0 PENDD4020 1-00 UF41
HVR2 1.00
HVR2A1 00 PFL200 .70 UF42
-66
.70 MU14
.84 961
99
116
-60
-60 PABC80 .46
91.39
PL36
PL81
FL81A
9L82
PL83
PL84
49 ÚF89
AAI29
WHAT READERS SAY
Interesting, absorbing,
power to your elbow.
a
joy to study. More
C.B.T., Wood Green
To say I am completely satisfied is inadequate as
B. W.J., Stoke-on -Trent
to the fabulous value.
The volumes are way ahead of any self-taught
instruction books available.
A.B., Brockenhurst
a great pleasure to meet up with such excelC'. W., Sawbridge
lent publications.
It is
12
Bl
ACY20
ACY21
ACY22
ACY28
!ü
13E210
30
68
30
.76
.66
-90
-50
46 AAZ1S
AF114
AF116
AF117
AF180
AF188
BA116
BA118
BA129
80109
28 BC113
.33 BC316
.18 BC118
-18 BC118
-18 BCY10
21 BCYl2
.48
BYZ13 .30
FEY11A 24
-58
-86
.gg
.36
.
86
.56
44
F8Y41A
0A9
0A47
0A70
0473
0479
0A81
0A90
0A91
0495
0044
.14
.12
00415
1
1
-14
44
40
48
-80
-26
-53
-58
-23
14
-13
-18
-18
.11
-11
11
14
OA85
-16
-21
BA130
BA168
BC107
BC108
-21
-80
AF121
AFI24
BYZI1
BY212
58
58
30
76 ADM
1-20
1-00
1-60
6.86
-93
16
1.00 40140
100 AD149
1-00 ADI81
8E126 13
131127 81
-11
11
-12
-13
-18
0046
0070
0071
0072
0074
0076
0076
14
.11
16
-26
.18
-18
OC77
-82
18
18
18
0078
00780
-70
0081
11.95
.67 PC86
68
2.20 EBL21 2-00 ELMO 140
PC88
-68
40 E086
-84 EL506 1-20 PC92
.56
60
.66
EM80
E088
PC95
-70
84
-50
-56 E5181
40 PC900 .40
.80 1092
-60 ^0084
-39
-50 OCCIS 8.00 01883
-46 PCC85
-47
ECC36
00 EM84
76
2-00 10040 .90
34 Special offer of E760 valves, soiled, but new and tested. Al each.
1-76 ECC81
1.00 10082 -84
.70 E0083
.84
B5 00086
-60 ECC86
.70 10088
-39
1 26
.61
60 00084
86
All good. are unused. tested, and guaranteed. Despatch charges: -12p on all orders below 615 In
value. Orders over E16 poet Tree. Orders despatched tame day es received. Any parcel Insured against
damage in transit for 6p per parcel extra. Terme of baeinea available on request. Many others In
stock too numerous to Wt. Please enclose S.A.E. for reply to any queries.
ELECTRICITY(5vols)
ELECTRONICS(6vols)
TELEVISION(3vols)
perience.
The Selray Book Co., 60 Hayes
Hill, Bromley, Kent, BR2 7HP.
BY114
8S
23
00810 .18
AC1o7
18 BCY33
-53
-18
64 AC118 .60 BCY34 2e 0082
87
0082D .18
-14 BCY38 -26
-60 AC126
45
0083
-20 BF168
-21
-83
.60
-50 AC127
BF169
0084
28
AC128
-23
.80
91.604/600
50
86 AC132 .88 119163 ß3 00123 36
-80 BF173
44 00139 -50
91.605 2ÓÓ
1-00 AC154
-50
PL508 1 10 012/14 1-16 AC166 -23 BF180 -86 00189
-47
00171 40
-30 BF181
PL5O9 200 U19
4-00 AC157
.30 BF186 -47 00172
41
PT4D 1-00 3126
-71 AC166
PY39/2 60 U26
60 AC186 .80 BFY60 -E6 00200 -56
00204 -60
FY80
-60 U93
2.76 AC168 .44 BFY61 ß8
.gg 00205
AC176
-04 BFY62
-50
PY81
40 U36
p-ÓÓ
AC177
-a2 BY100 -21 00206 1-05
PY82
-40 U17
PY83
-44 U46
180 MATCHED TRANSISTOR BEMPY88
-40 U91
:b0 1.915 (ACI19. AC764. AC157. AA120) Sip
PY600A1.80 U191
per pack. 1/OC8ID A 2/0081, 60p
FY800 -40 U251 100 1/0044 6 2/0040, -608. 1/00020. 6
.69
PY801 -40 U301
2/0082 .66p. Bet of 310083 -76p
ÚL41
UL84
UM80
ÚY41
UY42
UY85
U10
You'll find it easy to learn with this outstandingly
successful PICTORIAL METHOD. The essential facts
are explained in the simplest language, one at a time,
and each is illustrated by an accurate cartoon -type
drawing. These clear and concise illustrations make
study a real pleasure. The books are based on the latest
research into simplified learning techniques. This easy approach -to- learning method has proved beyond doubt
that acquiring knowledge can be an enjoyable ex-
The series
ceptlonal valus In
training mechanics and
technicians le electric/0f.
Radio and electroniea.
i6
NO ACYI9
-50 Transistors
-89 & Dlbda
1JBL21 2-00 114744 .16
.81
UC92
.60 21404
00084 -90 2N966 -61
U0086 46 211766 -68
UBF80
UBF89
N
BASI
will be of sx-
.90 ACY17
76 ACY18
UCF80 80 2N2147 90
1.76 HL28DD68 PEN46DD
UCH21200 202297 96
11L41D1)
100QQ
2.26
1.00 PEN48 60 001142 71 2N2869 l8
66 HL42DD
PEN458DD 001181 46 2N8066 .SS
-45
2-00 UCL62 .46 2N3121240
1.00
0998
19183 .42
EF184 -36
19804 1-75
EH90
46
1-00 EAF801 -75
2.00 E1134
.80
1 -60 EB91
-20
.60 E13041 96
.66 EBL781 46
-45 EBF80
-76 ACPEN 1.80 EBF83
-80 ACOPEN -60 EBF89
26260
70 28D7
-30
NO
2.50 DM71 1.76
49
1-26 0Y87/6 .86
50135
.96 DY80'1 i6
5005
-70 180CC 2-50
600000
E800F 6.00
E80F 2.20
60E115
85 188C0 1-80
601.66T100 E92CC -70
86A2
-76 1180F 1-16
.60 12K7GT 60 42
100 6L020
76 DF91
DF92
-90 DF96
36L60T -80 DK40
.ó6 D192
31W4
9523
80 DK86
36Z40T .70 DL96
90 6K8GT .66 12E1
40 6L1
&60 12J6GT 40
70 6L600 .70 12J70T 70
.60 121E5
.66 6L7
140 36ZSOT
.46 6CG8A
.80 6CL6
-76 6CL8A
6008
76 6CM7
6040Y 1-00 6CU6
5040 .60 603
6940
.80 6D E7
6Y36T .56 6DT6A
5Z3
1.00 8EW6
46 7R7
6Z40
48 6E5
1.00 7Y4
7Z4
6040T .66 eF
6/80L2 .79 6F60
-60 8D2
.B0 9D7
6A80 1.40 6913
6AC7
.90 1002
-66 6914
6A05
6A07
6AH6
eAJ6
60 86A3
56 3606
56 36D6
PCC88
To The SELRAY BOOK CO.,
60
..':,rOdt4lddd.dd104`dih44`:
-
.
YOUR
GUARANTEE
Should you be, in
any way dissatis-
fied with the
MANUALS your
money will be refunded by return
of post.
s4ítHt/i
'/441stIIS111111111'-.,.+
14í
: 'i h`hhh i'ii iÀ`'Ji
: :
HAYES HILL, HAYES,
BROMLEY, KENT. BR2 7HP
Please find enclosed P.O. /Cheque value £
BASIC ELECTRICITY 5 parts £8.00
BASIC ELECTRONICS 8 parts £9.50
BASIC TELEVISION 3 parts £5.00
Tick Set(s) required.
Prices include Postage
YOUR 100% GUARANTEE. if after 10 days examination you deelde to
return the Manuals your money will be refunded In full.
NAME
BLOCK LETTERS
FULL POSTAL
ADDRESS
-------------------- --6s.J
Practical Wireless, May 1977
GREENWELD
Southampton
443 Millbrook
THE GREENWELD DRAGON-GUARDIAN OF GOOD VALUE
Road
Tel:(0703) 772501
SO1 OHX
TAPE DECKS
71b
Hundreds of new components -pots,
switches, resistors, capacitors, PC
Boards with semiconductors, loads
of odds and ends. Amazing value at
only L2-90.
Only £298.
Data Tape Deck by D -Mac. Not much
Info.. just arrived. Reel -to -reel, takes
3" spool. 2 heeds, 12V motor. 3
position switch. 17 transistors, R's,
C's. 200V 6A SCR, min 6V relay, etc.
In good condition, but not new.
Size 225 x 165 x 120mm high. £S SO.
Large quantity always available; 31b
asstd. LI-75; 7lbs as IS; Silk LIS,
Pack with about 500 components inc.
at least 50 transistors LI -Si; Pack
with 12 High quality panels. Incl. IC's,
power transistors,
i
transistors,
hundreds of small signal
CALCULATORS- E2.75111
7400
mechanics only. Diecest ally frame
131 o91 o 61" overall depth. Free head
(no data) supplied with every order.
There has to be a catch -these
Rapldman 1208 machines are a mains
powered desk top calculator with
0-9 and des point, and 7 function
keys Inc X. but the liquid crystal
display Is missing. However, apart
from this they are complete with
PSU, 3 IC's + discrete components.
Overall size 11 o 7 x 3 ". Only L2.75.
Few complete working and booed,
as new L10.
KEYBOARDS
Front half of calculator, really. Case
130 x 75mm has display window.
2 slide switches, and 25 keys. Only E1.
WATT AMPLIFIER
1
Nmm with LM380 and
associated components to make 1W
amp operating from 9V. (Can be
Increased to 3W output by raising
supply voltage and fitting heat sink).
Complete with volume control.
Connexion sheet Included. Also on
the board Is a speed control circuit
comprising 10 transistors, 2 presets,
4 pole 3 way switch, etc., but no
data on this. Only E1.
PCB 100
x
POT PACKS
An overwhelming abundance of pots
of all shapes and sizes, Including
duals, switched, sliders, etc., prompts
us to make this offer: 20 asstd for
E2 20, NO for £S SS.
PO 4 DIGIT METERS
Ex- equip, 500R coil, operates on 18V
only 40p, 10 for £3, 100 for E20.
RELAY UNITS
Units vary slightly, but
guaranteed
minimum 20 relays, PO 3000 type,
various coil resistances and contact
arrangements. May be a few bent
contacts, but excellent velue at
only L4 M.
Parcel of PO 3000 type Relays-Lots
of diff. types. Total 12 for £255.
a
SWITCHES
(few only) 40p.
Bank of 5 push button switches, 4 are
8 pole c /o, interlocking, 5th is independant dpco. No knobs 75p. Sub min dpco slide 1Sp; push to make
15p; push to break 2Sp. 10A 250V
rocker ISp; DPCO rocker Np. Sub min toggles spco 62p; dpco 740;
dpco centre off Sip.
PO 1000 type lever switches, In
vertical bank of 4, each 4 pole c /o,
centre off. Ex- eciulp Sip. Also with
7p2w 20p, 1P 12w
4th switch biased Sip. Few horizon-
N.
Push button
switch (No knob) DPCO, non -locking
12p. As above, but locking on or oft
rated 250V 2A 19p. Microswitch
18 x 9 x 8mm, 5A 240V rating, has
55mm lever 19p.
tal
banks of
10,
L1
COMPUTER PANELS
All
8-3Opf ceramic.
1Sp each. Compression types,
100 -500pf Up; 500 -1230pí
3-400 15P;
56p.
NEON BANKS
Bank o140 sub-min neons
Bank of 20 std neons
1 track,
Recording heads,
type X/RPS /18
r
IC
panels L7.20.
PC ETCHING KIT
Contains 1Ib Ferric Chloride, 100
sq Ins copper clad board, DALO
Quick DO Etch resist pen, abrasive
cleaner, 2 miniature drill bits, etching
dish and instructions. £3 65.
FERRIC CHLORIDE
Anhydrous technical quality in lib
double sealed packs. 1Ib LI 00; 31bs
E2.1S; 10Ibs ES-09; 1001bs E39-N.
FIBREGLASS PCB
Large quantity of offeuts, all usable
pieces. 200 sq Ins, single sided,
double sided or mixed E1.40.
LI
E1-Np
HIGH POWER POTS
Barco preset rheostat, type SEF
28.6 ohms 3-3A, with metal cover
LI W. 11 ohm 3.4A without cover
LI N. Rotary types: 25W 6R, 25R,
114R LI-17 each 50W 50R, 16OR 1k5
LI 44 each; 100W, 7OR 11 66.
Moulded Carbon High Voltage Pots,
ideal for scope brill and focus controls, etc. Rated 3W. 21(6, 3k, 5k, 10k
50k, 100k, 260k, 500, 1M, 2M5, all
Op each.
Practical Wireless, May 1977
just catalogue).
VEROBOARD
Size
31 x 3
5
x3
}"
}"
17x3 "
0.15" 0.1" plain
N/A
Np
0.1"
Np
Sip
E1-N
S5p
E1-60
40p
E1-3S
PINS
Full or halt pins, 0.1 or 0.15 35p 100.
Spot face cutter for 0.1 or 0.15" ?Sp.
DIP BREADBOARD
Accommodates 20 x
IC' E200.
14
way or 16 z
16 way
OFFCUTS
Pack
Pack
Pack
Pack
A, All 0.1"
B, All 0.15"
C, Mixed
D, All 0.1" plain
Each pack contains 7 or 8 pieces with
a total area of 100 sq Ins. Each pack
is E1.30. Also available by weight,
1Ib E3.45, Nibs E25.
We are also VERO wholesalers
Trade price list on request from
-
Bone Fide Companies.
CR25 carbon film 1 /3rd watt resistors,
5%, 10 of each value 10 ohms to 1M
Total 810 resistors EA 00. Electrolytics, wire ended 25V working 10 each
of: 1, 2 2, 4.7, 10, 22, 47 and 100mid.
70 capacitors tor L3 20. 400mW
zeners 5% 10 each 3V to 30V, 298
in all. Only E14 -N.
watt Metal Film resistors, 5%
1
10 of each value 27R to 10M,
series. Total 680 resistors £11.98
Polystyrene capacitors, 150V 21%,
10 of each value from 10pF to 10,000pF.
Total 370 capacitors E12 SO.
E12
COMPONENT PACKS
LI -35
400 asstd. carbon resistors
LI N
100 Wirewounds 2 -15W
200 Miniature resistors, 0, 1 and 1W,
et -2S
mostly carbon film
LI IS
200 poly, mica, ceramic ups
LI N
100 Polyester, 01 -2 20F
200 miniature eleetrolytics, but many
LI N
unmarked so only
SURPLUS CAPACITORS
15,00006V 35mm dia o 55mm PC ISp
15P
1,260uF 18V 20 o SOmm, tags
Pip
1,250uF 40V 25 x 80mm, tags
16p
25 x 50mm, tags
159
10,0000F 10V 35 x 80mm, lags
Np
6,400uF 18V 35 o 80mm, tags
2Sp
4,000uF 25V 35 x 80mm, tags
Np
tags
10,000uF 16V 40 o 80mm,
129
500F 350V 25 x 50mm tags
Sp
1500uF 18V 18 o 34mm PC
18,0000F 25V 50 x 105mm, screws Np
for
any
quantity
NB: Add 300 postage
Miniature resistors, carbon film 5%
1yp each, Lt 00 per 100 of one value
1R to 10M. 1W metal film 21p each.
8000 40V
BULK OFFERS
wander plugs,
3mm
black only at
special price of £225 /100.
63m A 20mm quick-blow fuses, L2/100
24V 1W LES lamps E3 00/100
350mA 20mm A/S fuses £1/100
SPECIAL OFFER of
PLUG -IN MODULES
210 caps. 12 TO.
VEROCASES
Plastic top and bottom, ally panels
front and back.
Type 1410
1411
1412
1237
1238
1239
205 x 140 x 40mm
205 x140 x75mm
205 x 140 x 110mm
154 x 85 x 40mm
154 x 85 x 60mm
154z85080mm
E3-3S
£3.79
£4.00
L2.35
E2-110
Large quantity lust arrived, several
cliff types. Case size 77 x 50 x 50mm,
either octal or 11 pin base. Send SAE
for full list of types and circuits.
Type R: Contains fA 200V SCR,
4 x SA 300V diodes, 24V reed relay,
C, R, etc. Octal base. With circuit.
Only £1. N each, 10 for LS 00. Type M:
5 BC184, C426, min. R's and C's 6p.
Panel with 2 fA 400V triaca, 700C,
2N1711, 100V 1A bridge, 2 pots,
1 preset,
zeners, R's, C's, etc. Only
E1-N.
MULTIMETER MODEL
LT22
£3.60
PLASTIC BOXES
Professional quality, two tone grey
threaded inserts for
polystyrene
mounting PC
E2á5
Type 2519 120 x 65 x 40mm
siith
2520
2522
£2 -441
150 x 80 x 50mm
188 x110 x80mm
E3541
WHAT
A
m.
BARGAIN
RELAYS
Miniature Plug -in types: 1250 ohm
4c /o 411p; 700 ohm 4c /o Sip. PO 3000
contacts
75p81Ófor É4 00.
1" easily removable reeds In 3580
ohm coil SOp; Plug in relay, B7G Base
17mm dia x 42mm long 10k coil 1 c/o
contact /Sp. Omron MK3P plug in
relay. 230V AC coil, 3 sets 10Ac/o
contacts. LI 29. Bases 30p. 8V PC
type, SPCO contact 711p.
Ex -equip on PC board, min sealed
oil (ops on
type,
6
2
20
contacts Op.
equip 34 x 30 x 15mm, 250R coil,
ops on 6-12V 4 c/o contacts, Np.
Delay relay, 115V 20 sec coil, mains
contact 50p; 230V coil 30 sec delay LI.
Ex
CRYSTAL FILTER UNIT
Chassis 210 x 115 x 80mm containing
24 way switch, 24 HCSU otal holders,
24 beehive trimmers, + board with
4 BF115, R's C's, etc. L3 Se.
5MHz FREQUENCY
SOURCE
High stability, better than 2 o 10
per
short term, better than 1 x 10
month. 12 6V drive voltage, output
SMHz Into SOR £12. 4.433819MHz
colour sub -carrier crystals Np.
-,
00p
Np
OUR 44 page CATALOGUE FREE with orders
over £2. (Send 10p if
under, or 20p stamps for
DEVELOPMENT PACKS
50V ceramic plate capacitors, 5%. 10
of each value NO to 10000F, total
TRIMMERS
2 -7pí, 4 -15pí, 5 -25pí,
mere, capacitors, etc.
pack -20 74 series IC's on
resistors
Only E2-75.
with
Wafer switches, 8p3w 30p.
Wafer switch mechanism, 12 way.
Room for 2 wafers. 15p. Wafers to fit,
BOXES,
CASES &
BOARD
BARGAIN PARCEL
Reel to reel chassis, takes 7" spools.
Single motor operation. Made by
Telefunken. No heads or electronics,
BOOKS
All
by R. M. Marston, these
titles use
readily available components.
20 Solid State Protects for the Home
£2. 20 Solid State Protects for the
Car L Garage E2. 110 Semiconductor
Projects for the Home Constructor
L2-70. 110 Thyristor Projects for the
Home Constructor £2 70. 110 Integrated Circuit Projects for the Home
Constructor £2.70. 110 Op Amy
Projects for the Home Constructor
(uses 741) 12.70. 110 CosMos Digital
IC Projects for the Home Constructor
L2 IS. 110 Electronic Alarm Projects
for the Home Constructor E3.1S.
Sloping front version,
Type 2523 220 x 174 x 100/52mm ESN
Type 1798171 x 121 x 75/37-5mm EA S6
Gen Purpose plastic potting box
71 o 49 x 24. In black or white 40p
Hand Controller box, shaped for
ease of use in the hand, 94 x 81 x23mm
Probably one of the lowest priced
meters featuring a mirror scale,
overload protection and 20000 ohms
per volt sensitivity. A modern styled
meter with unusually clear scale
markings. Ranges: DC Volts 0-0.52-5 -10- 50-250-1000 AC Volts 0-10-00250 -1000 DC Current 0-S0uA -25mA0-50k- 500k -5M
Resistance
250mA
(Mid Scale 300- 3k -30k) db's 4 ranges
-20db to +42dB. Size 130 x 90 x
42mm. £12.70.
5V 12A REGULATED
S2p
S-DECS & T -DECS
L2.10
£3.75
S -DEC Breadboard
T -DEC Breadboard
SOLDERING IRONS
Antex 15W Model C
Antex 15W Model CCN
£3'75
SOLDER
L2811
£4 -114
£2 "40
with
spare
10 22g
LI-45: Size 12 18g £0-OS; 500gm
reels 180 £4.98; Smell packs of 18 or
22g 30p.
protection. Only E24-00.
E/44
DeeGee 25W Model 3812
Lltesoid 10W
EK40040W
Instant Heat Soldering Gun
built In lighting unit and 5
tips E4-66.
Multicore small reels, size
POWER SUPPLY
Brand new boxed fully stabilized
PSU,
complete with instruction
manual. Load regulation 0.15%x.
overload
Electronic
Thermal
C
TRANSFORMERS
have mains primaries, secondaries as follows: 6-0-6V 100mA Np;
All
9-0-9V 75mA E1 -N; 12 -0-12V 50mA
Sip; 12-0-12V 100mA LI .111; 6.3V 15A
1A
LIAO; 5-0-6V 15A E2 M;
E2 55; 12.0 -12V 1A L2.SS; 12V 5A
£3.65; 12V SA £435; 20V 55mA Np;
22V 100mA LI N; 29V 50mA Np;
Multltapped types, 0.12- 15- 20 -2430V
1A E3 N; 2A ES-N; 20-0-20V 2A
£1 40; 55-0.55V SA LI-30; 24V 500mA
LI 55.
Deptford Broadway, London, SES (51.052 2989) and
stock some of the adver3O Lower Addiseombe Road, Croydon (01-698 2050)
tised goods for personal callers only. Ring them for details.
COMPONENT PRICES
INDIVIDUAL
FOR
SEE PRACTICAL ELECTRONICS
orders despatched
All prices quoted include VAT and UK/BFPO postage. MostORDER
VALUE LI
on day of receipt. SAE with enquiries please. MINIMUM
over £3. Official
orders
Send 10p for Multimeter catalogue-free on request on
L5). Export/
Orders accepted from Schools, etc. (Minimum invoice charge for
bona-flds
Wholesale enquiries welcome. Wholesale list now available
Our retail shops at
21
traders. Surplus components always wanted.
13
BATTERIES 6 Volt sealed type rechargeable two
types both new unused. Type A 1-8 A /Hr size 21 x
2 x 2" £5.40. Type B 2.6 A /Hr size 51 x 11 x 2}"
£6.50. V.H.F. POWER TRANSISTOR type
2N3375 stud mt 28v 7.5w at 100Mc/s 3w at 400Mc /s
new £180. DIAL TELEPHONE KEYBOARD 0 to
9 digits new £180. PLUG & SK min type 12 way
single hole fix round type new £2 per pair. BLOWER
single ended for 240v 50c /s, 50 CFM. outlet size 2 x
1 1." very quiet brushless motor new by Woods £6.40.
TUNING COND 3 gang 78pf per section 1" shaft
£1.30. CRYSTALS 10X & 10XJ types in freq
range 2 to 10Mc /s 20 different for £2.20. RECEIVER
SUB ASS single chan crystal controlled Rx ass
for use in the 120/125Mc/s range uses 9 min valves as
RF stage, 3x IFs at 9.7Mc /s det & 0/P for phones
approx size 8 x 4 x 31- new £6.50. ISOLATING
TRANS 230v pria Sec 26v at 13.5 amps with c.t. in
carrying case size 10 x 7 x 7" fitted ammeter 0 to 20
new boxed £17.80. TRANSFORMERS. H.T. Pria
230v Sec 1125 -0 -1125 rated 900v at 800Ma DC choke
I/P filter size 7 x 7 x 5" £10.80. Auto Trans nom
220/240 to 110/120v at 150 watts term block conn £3.50.
H.T. Pria 230v Sec 700v 300Ma C. core £5.40. L.V.
Pria 200/250 sec 55v at 1.5 amps potted £3.50 all
trans new. C.R.T.s all are 4v heater, electrostatic
deflection, as follows CV2184 21" dia P7 blue/yell
trace £450. CV1593 6" blue /yell trace £6. CV1746
61" PI green trace for CRDF as center cross & north
marker can be removed £6. CV1534 11" P7 orange
trace £10.80 all tubes in new cases. R4187Rx sub
ass RF section 2 /18Mc/s as 2xRF, Mixer 2.15Mc /s
IF & 2nd mixer, tuning motor etc (there is no L.O.)
£4.75. I.F. & A.F. section as 100Kc IFs & filter, BFO,
2nd osc, Det, N.L. AVC 0/P etc both units with
valves & circ £5.50. AERIAL SYSTEM for use on
183.6Mc/s 8 element Yagi approx 11ft long, for use
on ground satelite comm channel, new in cases
£21.60. REMOTE CRYSTAL SELECTOR as
6x BC108, 6xtub trimmers, etc holders for 6xTx &6x Rx
crystals Pye spares new £1.80. ROTARY SWTS
larger inst type 8p 12w 8b & 2p 23w 2b both £1.60.
6p 12w 6b £1.40. 7p 23w 7b £2 all new. HELIPOTS
10 turn 1" shaft 5K or 10K both new £1.65. SIL
BRIDGE RECT 100 PIV 2 amps 3a on h/s new 54p.
MARCONI H.F. SPECTRUM ANALYSERS for
callers only £45.
Above prices include carr /postage & V.A.T. goods
ex equipment unless stated new. S.A.E. for list 17
or enquiry. Shop open Tues to Sat.
A. H. Supplies
122 Handswcrth Road
Sheffield. S9 4AE. Phone 444278 (0742)
14
CHINAGLIA DINO
-
ELECTRICAL AND ELECTRONIC TEST
EQUIPMENT MANUFACTURERS
PRESENT THE
DOLOMITI
20kSI /V a.c. and d.c.
A NEW HIGH SENSI-
TIVITY MULTIMETER
WITH ALL THE FEATURES YOU WILL
EVER NEED
Accuracy: D.C. ranges, ± 2 0 %, A.C. & 0 ranges ± 2 5 %.
38 ranges: d.c. V, 0150mV, 500mV,
5V, 5V, 15V, 50V, 150V, 500V,
5kV; d.c.l,
050 pA, 500aA, 5mA, 50mA, 0 5A, 5A; a.c.V, 5V, 15V, 50V, 150V,
500V. 5kV; a.c.l, 5mA, 50mA, 0.5A, 5A; dB -10 to +651 in 6 ranges;
0 0 05ki), 5141,50k0, 500kt), 5M0, 5OM0; pF 50kpF, 500kpF.
Automatic overload protection and high current range fusing.
Scale mirror and fine pointer for accuracy of reading. Single knob main range
switching and all panel controls. C.E.I. Class 1 movement with sprung jewel
bearings. Extended 92mm scale length for extra clarity. Compact ABS case 125
x 131 x 37mm. Weight 750g with batteries. Supplied complete with carrying
case, fused leads, handbook and full 12 -month guarantee. Optional 30kV d.c.
1
1
1
probe available.
Meter £45.90 incl. VAT (£1 P. & P.)
30kV Probe £ £12.85 Incl. VAT
For details of this and the many other exciting instruments in the Chinaglla range,
including multi-meters, component measuring, automotive and electronic
instruments please write or telephone.
a
19
MULBERRY WALK LONDON SW36DZ TEL: 01- 3521897
.
YES SIR 1st class post TONIGHT!
The service is available to anyone
that
I
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an account.
HIGH SPEC components FAST!
Agents for VERO - ANTEX BIB MULTICORE SOLDER
Open gam -5pm, 8 days-Phone orders
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capacitors, plugs, sockets, switches, cable, valves, meters, books, etc.
Post free envelope Included for your next order.
SUPER EXPRESS phone service -ask for details.
Shop at keen prices 6 days per week. Late night -Fri. 7 -10pm.
Discounts £5-5 %, £10 -7f %, £15 -'O%.
TRANSISTORS + 200 OTHER TYPES IN STOCK
AC125
26p BC109
12p BC262A 19p BFX29
26p TIP41A S7p
'
128
127
128
26p
Zip
109B
109C
151
35p
117
142
143
Up
153
178
187
188
Up
Up
Up
Up
ÁD149
48P
161
52p
182
MCH /PR
A F718
147B
148
1488
1498
52P
24
Up
AU113 1.72
BC107
11P
107A 12p
0411
90P
ME4001
90p
4101
11Ip
184L
187
212A
lip
1A
15p 200V 1A
1tP 400V 1A
219
20p
Up TAG
1208T106
1
BF158
lop'
11p
7p
91
Sp
10p
200
0C28
120
29
85
44
1.20
199
200
15 9a
ORP12
p
338
34p
TIP29A
30A
13p
15p
Np
Up
90
1Sp
12p
2$p
302
500
502
1N914
1N4001
4002
4005
ISp'
0A47
25p
25p
10p
12p
12p
25p
25p
40p
lip'
ME0401
184
185
194
196
197
12p
11p
BRIDGES
13D 100V
42p
54p
75p
20p
42A
TIS43
Op
3Sp
1.20
71
45p
Hp
tip
47p
56p
Ì
111p
15p
lip
Sp
Sp
Op
1Sp
39p
2N2219
2646
45p
29280 13p
2925G l5p'
3053
2Sp
3055
Hp
11p
3702
14o
3703
13p
94D
12p
3704
3705
3707
600
LED
TII
209 /0125
SL.807451.29
NE555N
SN78013ND
SN78013N
SN76023N
511p
C108D1
Red
0.2" T8Á800
Grn
,
9p
RESISTORS I }peach LINEAR I C's2Sp
741
331,
alp }WATT E12 (5 °/.)
LM380
309 1 ohm - 10m ohm
32p ZENERS(400mw) BZX83
3V, 3V3, 5V1, 5V8, 7V5,
9V1, 10V, 12V, 18V, 22V,
30V. All at 12peach.
1
13p
SO
150'
.75
75
35'
145'
1
1
1
Sop
SOP 78Á810S
29p
29p TBA820
1-20'
1.25BT109
Clips for above 2p.
ZN414
1
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VAT please add to total 121 %, rest 8%
to
&
14p
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179B
1848
THYRISTORS
Post
72
132
12p
700V 1A
400V
500V NA
52
124
139
155
108C
60V 1A
600V 1A
51
BD123
22p
22p
Up ZTX300
BY164
ISp'
11p
17p
2138
214
I200V 3A
400V 3A
160
15p
Isp
BCY71
12p
11p
3A
303
338
557
84
88
BFY50
10p
1tp'
BC1080
SOV
35p
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35p
301
177
2121.
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287
300
1578
15
108
lip
Up
149C
28p
30p
46p
117
124
239
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24p
147A
1
100V 3A
I
o ens
'
I
,
,
I,
IN
II
-SO,
a- --- 1- - -I- -- ___
ORCHARD ELECTRONICS
FLINT HOUSE, HIGH STPEET, WALLINGFORD, OXON, OX10 ODE
Telephone
0491 35529.
Practical Wireless, May 1977
Blob Board .1" or .15"
All approx. inch sizes
Circuit diagram to circuit board in minutes.
Layout circuit plan on .1 " graph paper.
Select Blob Board, lay components out
with leads on copper strip. Blob of solder
onto lead and your circuit is complete.
Blob Boards normally half price of competitive boards. Roller tinned to solder components directly. No drilling or mounting.
Modifications in seconds. Blob Board is reusable.
Blob Boards are circuit boards designed
exclusively for the home constructor and
prototype engineer and are normally half
the price of competitive boards. Blob
Boards are roller tinned for ease of soldering,
most require no cutting or breaking of con
tact rails. HALF PRICE AND RE- USABLE.
That is NEW!
-
ZB2V 2.5 x 3.75
ZB3V 3.75 x 5
ZB4V 10 x 6
£0.46
£1.51
a
discrete circuitry. See
Practical Wireless for new
series of S -DeC projects.
S -DeC + step by step
instructions to build
above projects and 3 more
+ which components to
use + free control panel
for mounting switches,
lamps etc. + free Blob
Board. S -DeC only £1.98 +
37p (VAT + post) send
only £2.35.
PB announce a precision British built drill for the home
constructor. Works better than most bigger drills and can be
used for fine detailed work. Drills through any circuit board,
need to break copper strip simply grind it off.
9000 RPM Drill + 20 Assorted tools £11.20 ( +VAT + post)
send £13.00
9000 RPM Drill only £5.22 + post + VAT send £6.00
Multi- purpose Drill stand £10.60 + post + VAT send £12.00
Practical Wireless, May 1977
3
off
£0.51
£1.05
£1.75
£4.05
Dip Blob Boards
1
of
£0.36
£0.40
£0.85
£1.70
3
ZB1IC4.5x3
ZB2IC 4.8 x 3.2
ZB4IC 4.75 x 7.5
ZB8IC 9.5 x 7.5
off
£0.90
£0.96
£2.13
£4.26
bent leads, no wasted IC
chip. Lines on DeC Show
contact rails, plug discrete
components in. Cross overs,
connections are made using
different coloured leads.
Circuit completed and
working unplug components
and use for next circuit.
No soldering, no damage to
components. Use your DeC
and small stock of components over and over again.
T -DeC send £4.30. U-DeC
"A" send £4.60. Adaptor
send £2.30.
For leaflets and further
DRILLSAW
GRIND-BURR
BRUSH.
POLISH
off
£0.20
£0.42
£0.69
£1.62
If you are using IC's to
build circuits use T -DeC for
1 chip circuits and U -DeC A
for 2 chip circuits. Draw
circuit on graph paper, plug
IC into Adaptor and plug
into DeC. No soldering, no
small
stock of components, insert
into S -DeC, no soldering,
make a radio receiver,
light operated switch, 3
stage amplifier. When
circuit is made unplug
components and use
them again to make a
morse practice oscillator,
LC oscillator, binary
counter and any other
1
off
£0.75
£0.57
£1.14
£3.78
Many other sizes and patterns available acd
30p post + 8% VAT to all orders.
1
Take an S -DeC, take
£023
3
ZB6D 2.4 x 7.3
ZB7D 4.9 x 7.3
ZB8D9x7.5
1
S -De
ZB 1 V 2.5 x 5
ZB5D3.6x2.4
off 2B1 V + 1 off ZB80 +
off ZB2IC normally £2.32 only £2.00 + free Blob Board.
Sample pack:
off
£0.30
Discrete Blob Board
FREE
BLOB BOARD!
1
information please
send stamped
addressed
envelope.
PB
Electronics Scotland Ltd.
57 High Street,
Saffron Walden Essex.
CB10 1AA
I
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NORMALLY 24 HOURS
SEVEN SEGMENT LED DISPLAYS
BRIGHT DL707 COY ANODE 8
DL704 COY CATE, 0,3" [1
DL747 0.8 "JUMBO CA 01.25*
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ZENON STROBE TUBES
WINOSOR,BERI(S.
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c
ELI]IP
E(11I5 lT
TOP DISCOUNTS.
04 a
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RED LEDS 209 STYLE 0.125"
OR 0,2" DIA. NO CLIP 10y.
TIL209 RED LED U CLIP 12p
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29p
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ORP12 54p *2N5777 /OCP71 34p
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LM380(60745) '[1
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L113900 4xOPA 53p
MC1303 2xPre f2
MC13I0 stereof2
MC1312P SQ 01,70
MC1330
75p
MC1339 Preampf2
MFC4000B }W 72p
[1
MPC6030
NE536 FETOPA 02*
NE540 or 550 f2*
NE555 TIMER 34p*
NE556 2x555 90p*
NE560/1/2/5/6/703
AY51224 CLOCK I4
CA3046
54p
ICL8038 Sigen 54 *
L9300N
El *
LM301A D11 8
33p*
LM309K 5V reg 52
LM309H TO5 can fl*
LM318 70VusOPA 53*
CITIOS
9E172741 as 741
SN76860 IF
74p
5N76611 IF
[1
TBA800 5W AP 84 p
TBA810 7W AF 94p
1N414 Radio [1.19
NEW 1466/69
04
TTL
4000
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4001
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16p
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4009
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4011
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4049
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7413
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1990
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74100 11.25*
74107
32p
74121
29p
74123
690
74141
74p
74145
85p
74147 02.50
74151
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74154
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69p*
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26p
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2N3904/5/6 15p
2N5457 PET 32p
BRIDGE1A50 20p*
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BARGAIN PAKS FULL SPEC Elea,
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PAK B:5 741C 8 PIN OP AMP
11*
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PAK E: 11 BC182 fl F 11 293704 fl
PAK G:
7 BFY51 fl* H 8 293819 El
PAK J: 6 293053 11 K 40xlN914 fl
PAK Y: 3 TO99 3055 fl *N 25 OA9101
PAK P: 20 PLASTIC BC109 TYPEnpnll
10
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INTEGRATED CIRCUITS
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90p*
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29p
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44p*
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21p*
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741 T099
33p
747 DUAL 741
69p*
748 DIL 8 pin 32p*
7805 5V1A.regt1.35*
7812 A 7815eae1,40*
76013 8W AF 01.50
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DIN:PLUGS all 15p,Sock 10p
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GAS DETECTOR TGS 308etc04
vero
VERO 0,1" PITCH COPPERCLAD
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THE O - EN DOOR TO QUALITY
Latest revised issue (4th Edition, Cat. 8). Includes new ranges of
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PRACTICAL
WIRELESS
(Nov. 75 article by A.
C.
T.V.
SOUND
IF Sub -Assembly (G8) £6-80. P & P 75p.
Mullard ELC1043 Varicap UHF Tuner £4.20. P á P 30p.
3 -way Station Control Unit E1-20. P & P 25p.
6 -way Station Control Unit (Special Offer) £1 00.
Resistors, Caps, Semiconds etc. £5.80. P á P 55p.
Printed Circuit Board £1 00. P & P 30p.
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16
IT'S EASY WHEN YOU KNOW!
TUNER
Ainslie)
01
-794 8751
Practical Wireless, May 1977
'There's only one way
to master electronics...
to see what is going
on and learn by doing:
1
Build an oscilloscope.
As the first stage of your training, you actually
build your own Cathode ray oscilloscope! This is
no toy, but a test instrument that you will need
not only for the course's practical experiments,
but also later if you decide to develop your
knowledge and enter the profession. It remains
your property and represents a very large saving
over buying a similar piece of essential equipment.
1
T
This new style course will enable anyone to
a real understanding of electronics by a
modern, practical and visual method. No
previous knowledge is required, no maths, and
an absolute minimum of theory.
You learn the practical way in easy steps
mastering all the essentials of your hobby or to
further your career in electronics or as a self employed electronics engineer.
All the training can be carried out in the
comfort of your own home and at your own
pace. A tutor is available to whom you can
write, at any time, for advice or help during
your work. A Certificate is given at the end of
every course.
have
All students enrolling in our
courses receive a free circuit
board originating from a
and understand
2 Read,draw
circuit diagrams.
In a short time you will be able to read and
draw circuit diagrams, understand the very
fundamentals of television, radio, computers and
countless other electronic devices and their
servicing procedures.
computer and containing
many different components
that can be used in experiments and provide an
excellent example of current
electronic practice.
a,
To find out more about how to learn electronics in
new, exciting and absorbing way, just clip the coupon
for a free colour brochure and full details of enrolment.
Write to:- British National Radio & Electronic School
P.O. Box 156, Jersey, Channel Islands.
NAME
3 Carry out over 40 experiments
ADDRESS
on basic circuits.
We show you how to conduct experiments on
wide variety of different circuits and turn the
information gained into a working knowledge of
testing, servicing and maintaining all types of
electronic equipment, radio, t.v. etc.
a
Practical Wireless, May 1977
I`
17
1111-PAll
High quality audio
STEREO FM TUNER
Fitted with Phase Lock -loop
** VARIInput
-CAP diode tuning
** Switched
AFC
Multi turn
-sets
* Stereo Indicator
FET
OUR PRICE ONLY
f 20.45
Stage
pre
LED
Typical Specification:
Sensitivity 3y volts
Stereo separation 30db
Supply required 20-30v
at 90 Ma max.
STEREO
The 450 Tuner provides instant programme selection at the touch
of a button ensuring accurate tuning of 4 pre -selected stations, any
of which may be altered as often as you choose, by simply changing
the settings of the pre -set controls.
Used with your existing audio equipment or with the BI -KITS
STEREO 30 or the MK60 Kit etc. Alternatively the P512 can be
used
no suitable supply is available, together with the Transformer T461.
The S450 is supplied fully built, tested and aligned.
The unit is easily installed using the simple
instructions supplied.
PA 100
PRE-AMPLIFIER
if
.yA top quality stereo
pre -amplifier and tone
control unit. The six
AL
push- button selector
switch provides a
choice of inputs
together with two
really effective filters
for high and low frequencies, plus tape output.
MK00 AUDIO
25
35mm.
£13.75
aluminium chassis, heats/nk
and frront panel bracket plus back
sockets etc. KIT PRICE £10.70 plus
pane and
62p postage.
Frequency response 20Hz.
Distortion better than 01 at 1kHz. Supply voltage 1550v. Thermal Feedback. Latest Design Improvements.
Load -3,4,5, or 16ohms. Signal to noise ratio 80db.
Overall size 63mm. 13mm.
{
TEREO3O
Especially designed to a strict specification. Only the
finest components have been used and the latest solid state circuitry incorporated in this powerful little amplifier
which should satisfy the most
critical A.F. enthusiast.
ONLY
COMPLETE
AUDIO CHASSIS
f4.35
Stabilised Power Supply Type SPM80
SPM80 is especially designed to power 2 of the AL60
Amplifiers, up to 15 watts (r.m.s.) per channel simultaneously. With the addition of the Mains Transformer
B MT80, the unit will provide outputs of up to 1.5A at 35V.
Size: 63mm, 105mm, 30mr,1. Incorporating short circuit
protection.
INPUT VOLTAGE
OUTPUT VOLTAGE
OUTPUT CURRENT
33 -40V.
A.C.
33V. D.C. Nominal
10mA-1.5 amps
OVERLEAD CURRENT 1.7 amps approx. £3.75
DIMENSIONS
105mm x 63mm x 30mm
TRANSFORMER BMT80 E2.60 + 62p. postage
18
:spp
x SPAM, 1 x BTM60,
1 x PA
Kit of parts to include on1 /off
1 front panel
and knobs. 1
switch, neon Indicator, too,
Instruction booklet. COMPLETE
stereo headphone sockets
PRICE E28.53 plus
p /us
TEAK 60 AUDIO KIT:
62p postage.
Watts
(RMS)
Max Heat Sink temp. 90C.
KIT:
Comprising: 2x AL60's
Frequency Response
+ Ids
211H0-20K Hz.
Sensitivity of Inputs:
1. Tape Input 100mV
Into
100K ohms
2. Radio Tuner 100mv
into
100K ohms
3. Magnetic P.U. 3mV
Into
SOK ohms
P.U. Input equalises to RIAA
curve within Ida from 20Hz
to
20KHz. Supply 20 -35V at 20mA.
Dimensions-280mm x 09mm x
7
1
7
WATTS R.M.S.
Stereo
comprises
and
onlythe addition eof a
will produce a high quality audio
unit suitable for use with
Inputs i.e. high quality ceramic
a wide range of
pick -up, stereo tuner, stereo
Simple to Install, capable of producing
tape deck etc.
really first class results,
Is supplied with full
this unit
Instructions, black front panel,
fuse and fuse holder and universal
knobs, mains switch,
mounting brackets enabling
stalled In a record plinth,
it to be Incabinets of your own Construction
available. Ideal for the beginner
or the advanced constructor or the cabinet
FI performance with
who requires HIa minimum of installation
In 30 wins.).
difficulty (can be Installed
TRANSFORMER
plus 62p p s p
TEAK CASE £5 .25
transforrmereoroveriwind
£2.45
plus 62p
p S p.
f16.25
Practical Wireless, May 1977
r
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;quipment mono and other modules for Stereo
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MPA
357 power Amp!
ONLY
30
Enjoy the quality of a magnetic cartridge with your existing
ceramic equipment using the new Bi -Pak M.P.A. 30 which is a
high quality pre -amplifier enabling magnetic cartridges to be used
where facilities exist for the use of ceramic cartridges only.
Used in conjunction are 4 low noise
high gain silicon transistors. It is provided with a standard DIN input socket
for ease of connection. Supplied with
full, easy -to-follow instructions.
6,)95
F
8% VAT
A High Fidelity Power Amplifier with a maximum Power Output of 35 watt R.M.S.,
which has a maximum operating voltage
of 60v. A MUST for all HI -FI users.
Maximum supply voltage
Power output for 2% THD
Harmonic dis ortion
Load impedarce
Input impedance
Frequency response +3dB
Sensitivity for 25 watts 0/P
Max. Heat sink temperature
Dimensions
Mounting
15 -60v
35 watts
3-8 -16 ohm
50K ohm
20Hz -40KHz
280mV R.M.S.
90'C
102mm x 64mm
POSTAGE &
PACKING
Packing add 25p unless other
Postage &
wise shown. Add extra for airmail. Min. E1 00
122%
0.1
AL 20 -30
15mm
2, 4BA fixing holes in heat sink
Fuse requirerrents
AND
R.M.S.
VAT
ADD
AUDIO AMPLIFIER
MODULES
x
1.5A
for those who need more
P- O -W -E -R
g
AL250
The AL20 and AL30 units are similar in their
appearance and in their general specification.
However, careful selection of the plastic
power devices has resulted Ina range of
output powers from 5 to 10 watts R.M.S.
The versatility of their design makes them
ideal for use in record players, tape
recordera, stereo amplifiers and cassette and
cartridge tape players in the home. Harmonic
3 watts f = 0.25% Load
Distortion Po
125RWB
-
Impedance 8 -18 ohm
2 watts 50Hz- 25KHz.
Frequency response ± 3dB Po
80 ohm.
Sensitivity for Rated 0 /P -Vs = 25, RL
1KHz 75m V. RMS. Size: 75mm x 63mm x 25mm,
-
f°
mew
O
40.
£2.95
R M$ w
-
£3.25
PAIS Stereo Pre-Amplifier
completely redesigned for use with
AL20.30 Amplifier Modules. Features include on /off volume. Balance,
Bass and Treble controls. Complete
with tape output.
Frequency Response 20Hz -20KHz
NEW
POWER AMP
Specially designed for use inDisco Units, P.A. Systems, high power
Hi -Fi, Sound reinforcement systems
SPECIFICATION:
Output Power: 125 watt RMS
Continuous
Operating voltage: 50 -80
Loads: 4-16 ohms
Frequency re:;ponse: 25Hz20kHz Measwed at 100 watts
Sensitivity for 100 watts output
at 1kHz: 450rr V
Input impedance: 33K ohms
Total harmonic distortion
50 watts into 4 ohms: 0.1
50 watts into 8 ohms: 006%
S/N ratio: better than 80dBs
Damping factor, 8 ohms: 65
Semiconductor complement:13
transistors 5 diodes
Overall size: Heatsink width
190mm, length 205mm, height
PA12
(-3dB)
£6.70
PA12,
AL20-30,
supply for
S450 etc. Input voltage 15 -20v A.C. Output
voltage 22 -30v D.C. Output Current 800 mA
Max. Size6pmnlx43mmx26mm.
Power
P512
L
Transformer T538 £2.30
`'e30
40mm
ONLY £15.95 +8% VAT
DEPT. P.W.5 P.O. BOX 6 WARE HERTS
COMPONENT SHOP:
Practical Wheless, May 1977
Bass and Treble range±12d8
Input Impedance 1 mop ohm
Input Sensitivity 300mV
Supply requirements 24V. 5mA
Size 152mm x 04mm x 33mm
18
BALDOCK STREET, WARE
v
19
You Iuckypeope!
dear reader, if you have just paid your 40p for this copy
of PW then you have really got your money's worth this
month! Apart from the free information card contained in
this issue you will also find a free copy of the index for Volume 52
of PW which finished with the April issue. 'Fine' you may say,
'So what'? Well, it is something new for PW because in the past
the index was produced some time after the end of the volume
had been reached and if you wanted to get a copy of it you had
to pay 45p! Plus all the bother of finding writing paper, envelope,
stamp and postal order or cheque!
One would need to go back into the past quite a bit to discover
how this practise arose in the first place, and more to the point,
why it has persisted. Anyway, that's all history now and, hopefully,
you'll get your free index on time in future.
Another relic of the past also needs to be dealt with and that is
to make our volume of twelve issues coincide with the calendar
year! I have no intention of wading through early volumes of
PW to discover just when this discrepancy occurred but in the
early days of PW in 1932 it was a weekly publication and the
subsequent change to a monthly appearance probably explains
the mystery.
I
have often wondered whether those conscientious readers
of PW who bind their copies do so by the volume or by the year.
Personally, mine go into binders by the year but the office copies
are very neatly bound by the volume! Ah, well, perhaps we will
get it all together 'ere long. I don't suppose these little matters
bother our average reader in the slightest, but it was something
to talk about!
Eric Dowdeswell Assistant Editor
YES,
BINDERS FOR PW
Keep your copies together
Keep them clean
with the
PW Easi- Binder
The Easi- Binder is attractively bound with
the title blocked in gold on the spine with
the current (or last) volume number and
year. For any previous volume numbers
please advise year and volume and o
separate set of gold transfer figures will be
supplied.
inclusive of VAT and post and packaging from: Post Sales Department, IPC
Magazines Ltd., Lavington House, 25 Layington Street, London, SEI OPF.
E2 IO
I
(
20
More outlets for trio
P to the present time, Trio
High Fidelity equipment
has only been obtainable
from selected dealers within the
UK. A move has now been
successfully made to enable all
Trio equipment to be available
from Comet Discount Warehouses. Of course the same equipment will still be available from
the selected dealers, but as from
1st February of this year, they
have been redesignated as 'Trio
Specialists'. B. H. Morris and Co
(Radio) Ltd., Precision Centre,
Heather Park Drive, Wembley,
Middx HAO 1SU.
Bib book
PLANNED, and written for
beginners
by
Clement
Brown, the BIB Book Of HiFi explains in laymens terms the
basics of Hi -Fi, stereo principles
and the source of high quality
programmes, and offers hints and
tips to those planning new
systems. Installation and adjustments are explained in a practical
form, and emphasis is placed on
good modern practice in equipment maintenance and record
and cassette care. A glossary of
Hi-Fi terms and an index conclude this latest offering from
BIB. Priced at £1.98, it can be
obtained from Hi -Fi dealers, bookshops, and audio components
specialists.
Bib Hi-Fi Accessories Ltd,
Kelsey House, Wood Lane End,
Hemel Hempstead, Herts.
The author of the Gas /Smoke
Sensor Alarm -April '77, acknowledges the help of WKF Electronics Ltd., Welbeck St., Whit well, Worksop, Notts., in the construction of the Alarm. WKF can
supply all components for this
project.
VACANCY ON PW
Applications are invited for
the post of TECHNICAL
EDITOR on P.W. which will
become vacant shortly.
Apply, with brief details of
career, to Eric Dowdeswell,
Assistant Editor.
Practical Wireless, May 1977
..
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NEWS...
HiFI '77
LREADY 74 exhibitors have
A
booked space for the fourth
annual HIGH FIDELITY
exhibition, which is to be held at
the Heathrow Hotel, London Airport, from the 19th April to the
24th April, 1977.
Special events taking place
during the exhibition will include
a series of lectures and demonstrations in the Hotel's York
Video Theatre, while facilities
are being claimed to be `second
to none'. These will include air conditioned and soundproofed exhibition rooms; free car parking;
free exhibition catalogue and
free transport between the
Heathrow Hotel and London Airport terminals and Hatton Cross
Underground Station.
Opening times for High Fidelity
'77 will be as follows:
Trade and Press only -19th to
21st April inclusive loam to
8pm.
Public-22nd to 24th April inclusive 11am to 9pm (with the
exception of the 24th which
closes 6pm.)
Admission for everyone is free.
from
information
Further
Emberworth Ltd., London House,
Stokenchurch,
Road,
Oxford
Bucks. Tel: 024026 2674/5.
Bits and pieces
ADIO clubs in the UK may
R
be interested to learn that
one of our readers has
acquired a large amount of prewar and war -time radio equipment and wishes to dispose of
most of it. Any clubs that would
be interested please contact M.
Robinson, 13 Tolmers Gardens,
Cuffley, Potters Bar, Herts.
.
N
'r>ii Ur.
;.2).;ti, .:
The displays will be
located on the ground floor and
will contain some of the most
sophisticated and up -to - date
equipment available in the World.
Amongst them will be alarm sysbackground
tems, amplifiers,
music systems, sport event timing
equipment and general PA and
audio equipment.
The exhibition is open each
day from loam to 6pm (5pm on
last day). Admission is free and
"anyone having a professional or
business interest is welcome to
attend ", say the organisers.
Further information from
APAE HQ, 47 Windsor Road,
Slough, Berks. Tel: Slough 39455.
21st.
'
Roll up, roll up
.. .
members are required
for the Chester and
District Amateur Radio
Society, whose newly formed
committee is formulating a new
NNEW
Aerial guides
now the
general public and electronic enthusiasts have
realised the importance of a good
aerial system, to utilise the full
potential of modern tuners and
radio receiving gear.
In the forefront of modern
aerial development is Antiference,
who have, recently published a
Wall Chart and FM Stereo guide.
The Wall Chart measures 2312in X
1612in and is printed in bright
yellow, red and black and gives
a complete up-to-date guide to all
UHF TV transmitters, together
with all the main Antiference TV
aerial products.
FOR many years
,2: v:(. n;:x.t,i:4:`2..
t{l
programme for the coming
months. Meetings are held at the
YMCA Chester on the 2nd, 3rd
and 4th Tuesdays of each month
at 8pm.
Any readers interested in joining the club should contact G. W.
Chaliner GW8DMR, 34 Chestnut
,Apenue, Summerhill, Wrexham,
Clwyd.
Rally call
THE North Midlands Mobile
Rally will take place on
Sunday 17th April at Dray-
ton Manor Park, near Tamworth,
Staffordshire. This event is
organised by the Midland and
Stoke-on-Trent Amateur Radio
Societies, and will include the
usual exhibitions.
Further information, stickers,
badges etc., from Barrie Willetts
G8DEM, Alf Walton G3ZKQ or
Max Gutteridge G8BHE at 68
Max Road, Quinton, Birmingham.
The FM Stereo Guide comprises a three colour pocket folder
illustrating the complete range of
"Mushkiller" VHF/FM aerials
with individual polar diagrams
and comparative gain graph. The
FM Station guide gives a complete "run down" on BBC and IBA
transmitters showing clearly the
polarisation, ERP in kW and frequency of transmissions. A map
of the UK is also incorporated to
show the relative positions of the
transmitters, together with detailed photographs of aerial accessories.
Further information from Anti ference Ltd., Aylesbury, Bucks.
Tel: 0296 82511.
PA Exhibition
IF PA Equipment is of interest
to you, the Association of
Public Address Engineers will
be holding their annual exhibition
at the New Wembley Conference
Centre, from April 19th to the
Practical Wireless, May 1977
21
I
M
m
G
_
3M
M
M
II
I
IIMI
w
MI
INTERCOM
Steven DAVIES
gain. Negative feedback is applied from the output
to the base of Trl.
The DC voltage at the emitters of Tr4 and 5 is
set by R3, although for optimum performance this
voltage should be half supply voltage, which could
be obtained by substituting a 10112 preset and 12kí1
resistor in series for R3. This is not strictly necessary
here, since HiFi is not really needed. The AC gain
is set by the ratio of R5 and R4, and if a volume
Fig. 2: First stage of the .
complete circuit show
ing the connections and
components required
for the addition of a
volume control. R3 and
R4 are shown reversed
in this drawing.
THE author required a two-way intercom for his
workshop, which would also permit listening
for the telephone, doorbell, burglars, etc, when
no-one else was at home. Suitable amplifier designs
which have been published all seem to have a high
input impedance. Since it was intended to use the
loudspeakers as microphones, this would have
control is required, the circuit of Fig. 2 can be used,
which simply varies the amount of AC feedback
applied.
Capacitor C3 has been chosen to roll off amplifier
response at low frequencies to reduce pickup of
mains frequency. C2 rolls of response at high frequencies to eliminate RF pickup, which can be a
problem when long lines are used. (Radio 2 on
1500m is the main offender.)
necessitated a transformer to match the loudspeakers
to the amplifier input. The circuit described here
eliminates this need.
The Circuit
The amplifier circuit is shown in Fig.
a conventional push-pull amplifier, with
1. Tr2 -5 form
the quiescent
current in the output transistors being set by D1
and D2. The input stage Trl however, is connected
in the common base configuration, which gives the
required low input impedance, with high voltage
1
W331
Operation
To communicate, S2 should be in the "ON" position, Fig. 3, while the direction of communication is
+9 -12V
1
R6
1.5k
R1
Tr4
15k
2N3053
3116
Tr
BC212
Tr2lar
BC182
C5
01
N4001
1000uF
Fig.
D2
C2
1N4001
470pF
Tri
R5
100k
BC182
Tr5
Cl
250NF
r
2N2905
R4
i : Main circuit diagram
of the master unit giving
details of the push -pull
amplifier and the low impedance input stage, Tri.
R8
22k
47
Input
R2
330
R
8k
13
680nF
O
Output
5.6k 2ÓNF
OV
22
Practical Wireless, May 1977
*
components list
Master unit
[w333J
Resistors
R1
R2
R3
R4
R5
All
1
5kí2
R6
5.6k0
R7
R8 2.2k0
6800
R9
VR1 10kí2
15kí2
3300,
18kí2
470
100kí2
IN 5%
Capac tors
Cl 250i4F
15V
470pF
680nF
20µF
15V
C2
C3
C4
C5
C6
C7
1000µF
100µF
2000µF
D2
D3
D4
D5
D6
1N4001
1N4001
1N4001
1N4001
1N4001
15V
15V
15V
Semic inductors
Tr1
Tr2
Tr3
Tr4
Tr5
01
BC182
BC182
BC212
2N3053
2N2905
N4001
I
Miscellaneous
Si, CPDT biased switch.
S2,
SPST switch. S3,
SPST switch. S4, DPST switch. LS1, 8-350 loudspeaker. LS2, 8-350 loudspeaker. T1, mains transforme. with 7 to 8V 200mA secondary. Clip -on heat
sinks or Tr4 and 5. Aluminium or wooden cases to
suit. '.'CB, 120 x 60mm (available from the PCB
reade s Service page 25). F1, 2A fuse. NE1, mains
neon. Wire, plugs.
determined by the talk /listen switch Si, one speaker
acting as .s microphone. To conserve power, S2 will
normally be "OFF" so that there is then no DC
path between supply OV and amplifier OV, due to the
at the slave unit. If a DC path is made,
capacitor
either by shorting out C6 with S3, or by operating Si,
the circui : will oscillate, the resulting tone being
heard in both speakers.
The cause of oscillation is not at first sight clear.
Consider 'Fig. 4, which is a block diagram of the
system when "calling ". Initially C5 will be discharged. When power is supplied to the circuit, C5
will start to charge up, via Tr4, LSI and LS2. The
Fig. 3: Schematic, demonstrating the wiring and switching arrangements required between the master and slave units.
resulting voltage across LS2 will increase the input
voltage, and therefore the voltage drop across LS2,
will fall to almost zero. This will cause a negativegoing signal at the amplifier input, switching Tr5
on and discharging CS via LS1. The cycle then starts
again, producing oscillations.
Power Supply
The circuit can be operated off a 9V battery, but
for prolonged or frequent use a mains supply is
recommended. Any supply of 9 -12V DC at 200mA
minimum will suffice. The prototype used a small
8V bell transformer Tl, with rectification and
smoothing as shown in Fig. 5. Note that if a mains
supply is used any exposed metalwork should be
earthed, and the live line fused at a maximum of
2A, either in the plug or in the unit itself.
Construction and Installation
No problems should be experienced with construction, as all components are housed on a single PCB
as shown in Fig. 6.
The cases were standard aluminium boxes, 101x
132 X 38mm for the slave, and 177 X 127 X 63 for the
General interior photograph of the
master unit. As this is the prototype,
construction was on Veroboard and not
a PCB as described in the text.
Practical Wireless, May 1977
23
Vcc
OV
1W3351
Fig. 5: Alternative power supply for the intercom. The transformer in
the prototype was an 8V bell transformer, although any transformer
rated at 9 -12V 200mA would suffice.
of the system in the 'calling' mode, showing
how the tone is produced.
Fig. 4: B lock diagram
master. Wooden boxes are a possible alternative,
since screening is not necessary. Using smaller
speakers than specified would permit a smaller box,
Switch SI should be biased, and may be difficult
to obtain, although such switches are often available
on the surplus market. Alternatively, it is possible
to "doctor" a bank of push buttons to provide Si
and S2, as in the prototype (note that one of the
banks does nothing, so three would suffice).
Once made, the units should be mounted on a
convenient wall, and joined with two-core cable
(screened cable could be used, but is unnecessary).
Take care to get the polarity right, otherwise C3
ó
6100
)
0
'
'
9L61
Gil S3NIZ`d`JvW Dd10
o
+9 to
12V
C5
OV
i
o
Fig. 6: Drawing of both the foil and component side
but unless space is critical there is little point in
this. The amplifier will drive speakers down to 851,
so there should be no problem in obtaining something suitable.
24
of the PCB designed for this project.
might suffer. It is advisable to route the cable away
from mains as far as possible, to prevent undue
pickup, since the hum level in the amplifier itself
is very low.
29
Practical Wireless, May 1977
PCB SERVICE FOR READERS
All boards, except SRBP, are glassfibre, drilled and roller- tinned
To:- READERS PCB SERVICES LTD,
PO BOX
11, WORKSOP, NOTTS
Please supply PCB /s as indicated by tick /s in box /es
Ref
Issue
Project
Sep 75
Dec 75
Dec 75
Electronic Clock (set of three)
Sound -To -Light Display
Disco System, Amplifier
(2 required)
Disco System, Light Modulator
Music Box
Dec 75
Jan 76
Mar 76
Apr 76
Apr 76
June 76
July 76
July 76
Aug 76
Sep 76
Oct 76
Oct 76
Oct 76
Oct 76
Nov
Nov
Nov
Nov
76
76
76
76
Dec 76
Jan 77
Jan 77
Jan 77
Feb 77
Mar 77
Apr
Apr
77
77
May 77
May 77
May 77
DN0795/6/7
DN0798
each
AM0421
AM0423
SRBP DN1 /JM
glassfibre DN1 /JM
AM0438
CMOS Crystal Calibrator
AM0443
Wobbulator
AM0441
Auto. Slide Synchroniser
A015 and 4x A004
Dig. Freq. Meter (set of 5)
A002
Transistor Tester
A003
Disco Preamplifier
A001
Cassette Player Power Supply
A009
Capacitance Meter
Digital Car Clock (set)
Interwipe
Video -Writer (set)
Hazard Flasher
Low Level Battery Indicator
Electronic Thermostat
Cirtest Probe
Burglar Alarm
Chromachase
Oscilloscope Calibrator
Icelert
Polyphon, motor and main boards
Polyphon, tune disc, blank, SRBP
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25
MONOLITHIC
current devices provide maximum outputs of 200mA
to 1.5A and will usually be used with a heat sink,
whilst devices delivering still higher currents are
always used with a substantial heat sink.
Low current regulators can be used in more
complex circuits with external power transistors to
provide quite high output currents. This approach is
often more economical than the use of high current
monolithic or hybrid devices which are normally far
more expensive than the low or medium current
devices.
POLTAGE
REGULATORS
Brian DANCE M.Sc
Part 1:FIXED REGULATORS
E LARGnumber of integrated circuit voltage
regulator devices are now available which
enable very stable, high performance power
supplies to be constructed very easily with the
simplest possible circuitry. Such regulators are
extremely valuable when one requires a very stable
output voltage as the load current or as the input
supply voltage varies. They are equally useful when
the hum level from a mains power supply unit must
be kept to a very low level. For example, a few
mV of hum on the tuning voltage feeding a varicap
front end will produce hum at the FM detector
output, but a small monolithic regulator in the
varicap supply can be used to prevent this.
This article has been written to guide readers on
the general principles of operation of regulator
devices and to provide information on the types
readily available for the home constructor and the
basic circuits in which they can be used.
A
PACKAGES
The low current regulators are normally supplied
in transistor or dual -in-line packages. Many medium
current devices are in plastic packages with a tab or
metal insert for mounting the device on a heat sink,
whilst high current devices are often encapsulated
in the diamond shaped TO-3 metal package used for
power transistors. The recent trend is for the use of
low current "on card" devices, the regulator being
on the same PCB as the devices to which it supplies
power and this greatly reduces unwanted coupling
due to the line impedance.
The general principles of operation of a voltage
regulator are shown in Fig. 1 which uses a 741
op-amp as a comparator. The zener diode Dl provides a
reference voltage Vrer and the 741 compares this with
the voltage tapped off by VR1. If the value of Wet is
the greater of the two, the 741 output will be high
and Trl will conduct so that the output voltage, Vo,
rises towards the input voltage, V1. As soon as Vo
rises to a value which brings the potential of the
slider of VR1 to Vrer the output of the 741 falls and
Trl presents a higher impedance. Thus the output
voltage is stabilised at a value higher than that of
Vret the value being determined by the setting of
VR1.
(i;171-1
2N697
VR1
to increase this voltage somewhat whilst keeping a very
simple circuit, whilst the latter gives an output
voltage which can be varied by means of a
potentiometer in the external circuit. Regulators can
also be classified according to whether they are
designed to provide a positive or a negative output
voltage. However, these types are to some extent
interchangeable.
Classification can be according to the maximum
rated output current. The maximum current from
the low current devices is about 100 to 200mA; such
devices are normally mounted in a transistor type
package and seldom require a heat sink. Medium
26
Vo
2.5k
Dt
R3
1.2k
*3571
Fig.
DEVICE CLASSIFICATION
Monolithic regulator devices can be divided into
two main classes, namely fixed and variable output
types. The former is basically designed to give a certain specified output voltage, although it is possible
R2
1.2k
1
:
A voltage regulator using a 741 operational
amplifier.
Regulator
Vi
Input
votage
Regulated output
voltage
vo
Fig. 2: Regulator currents and voltages. ig is the quiescent current
which flows even when the output current is zero.
The 741 input requires little current and therefore
does not affect the stability of the Vrer voltage. Most
voltage regulators operate on this principle, with all
the components fabricated on a single chip and
usually including protective circuits. The maximum
output current is determined partly by the ratings
of the series transistor Trl.
Practical Wireless, May 1977
POWER DISSIPATION
The power dissipated internally in a regulator may
be estimated using the circuit of Fig. 2. A quiescent
current I., flows through the device at all times to
enable it to operate correctly, usually of the order
of 10mA. If no output current is taken, the internal
power dissipation is V,I,, and is quite small owing to
the low value of I,. When an output current is taken
there is an additional internal dissipation of
(V,- V)I, since (VI- V) is the potential difference
through which I. falls as it flows through the device.
Thus the total dissipation is (V, -V.)10+ Vlh,.
INPUT VOLTAGE
What nput voltage should one apply to a
regulator" The maximum value is quoted on the data
sheet and damage may occur if it is exceeded even
for a millisecond! The minimum input voltage should
always be a few volts above the output voltage, since
this additional small voltage is required to enable the
device to operate correctly. The minimum value of
(Vi- Va) is known as the `drop out' voltage, since at
lower volt ages the regulator 'drops out' and ceases
to provide regulation.
two possible forms. In one type an increase of the
chip temperature will cause the output current to be
reduced so that the temperature cannot increase
further and cause damage to the device. Nevertheless, it is bad practice to operate a regulator for a
considerable time at such a high temperature that
this current limiting circuit operates; such high
temperatures tend to reduce device reliability.
Another form of protective circuit used in low to
medium current devices is that of foldback current
limiting. If a low resistance is connected across the
output or if the output is shorted, the current `folds
back' to a much smaller value than the maximum
output. Thus the internal power dissipation is kept
relatively small.
BASIC CIRCUIT
The basic circuit used with simple three terminal
voltage regulator devices is shown in Fig. 3. The
input voltage is developed across the reservoir
capacitor Cl and the regulator provides a constant
output voltage. In addition, the hum level at the
Input
Regulator
Output
C2
1OyF
Fig. 3: A simple basic circuit for a
three-terminal regulator device.
Lambda Elect .onics supply the
LAS7000 series of regulators.
That shown here has a rating
of 400W.
As the internal power dissipation is
V,Iq, it is %ery desirable to keep V, as low as possible
in order to minimise the dissipation. This is
especially important in the case of high current
regulators where I,,, and therefore the internal
dissipation, is large. In the case of variable regulator
circuits which provide a wide range of output voltages, V, trust exceed the maximum value of V,, so
the value of (V, V.) and the dissipation can be large
when the output voltage is set to a low value. If the
output current is moderately high, it is advisable to
consider tt e use of a switching regulator circuit which
can offer Higher power efficiency at the expense of
circuit cot plexity.
-
PROTECTION CIRCUITS
Most modern regulator devices incorporate circuits
to protect -:hem from damage if the output is shorted
or if the device becomes too hot, the former by a
circuit whi ïtt limits the maximum value of the output
current to a safe value. Thermal protection can take
Practical Wireless, May 1977
!W3591
output is far less than that across Cl.
If a slightly increased output voltage is required,
a resistor may be included between the 'earth'
terminal and the zero voltage line. For example, if
this resistor has a value of 270!1, and the quiescent
current is 10mA, the output voltage will be raised
by the voltage across this resistor, namely 2.7V.
Alternatively a zener diode may be use instead of a
resistor.
LOW CURRENT DEVICES
One of the best known series of fixed output low
current regulators is the TBA625A (5V), the TBA435
(8.5V), the TBA625B (12V) and the TBA625C (15V)
series produced by SGS -ATES Ltd. (available from
Chromasonic Electronics). They can be used in the
very simple circuit of Fig. 3 to provide output
currents of up to about 120mA. The devices
incorporate foldback current limiting; if the output
is shorted, the current falls to between 30 and 45mA.
In addition, the short circuit current falls with
increasing chip temperature to provide further
protection.
These regulators reduce the hum level across Cl
by a factor of about 400 times (52dB). The larger
the value of Cl the smaller the hum voltage across
it and the lower the output hum level. If Cl is about
250µF the output hum level will be of the order of
lmV. C2 may be required with some devices to
prevent instability and should be close to the device.
The dropout voltage is about 2.3V at the maximum
current, whilst the output impedance is of the order
of 0.111.
This series of regulator devices is available in the
27
type of transistor package shown in Fig. 4(a). The
devices may be used in the type of circuit shown
in Fig. 5 to provide a small range of output voltage
variation. In this circuit the output voltage is equal to
V(1 + R2 /R1) +IQR2 where V is the voltage of the
regulator itself. The circuit of Fig. 3 can also be used
to provide a negative supply if the positive line is
earthed instead of the negative line.
THERMAL LIMITING
Another type of 100mA regulator is made by Fairchild as the 1uA78L00 series, by Motorola as the
MC78LOOC series and by National Semiconductor
as the LM78LXX series, but the latter has been
replaced by the improved LM340L -XX devices. When
referring to a specific device in the series, the `00'
or `XX' is replaced by the voltage of that device. For
example, the iu178L05, the MC78LOSC and the
LM3400L-05 are 5V devices, whilst the LM34OL -24
is a 24V device.
Input
Output
Output
nput
Voltage regulators of almost any type can be used
as a current regulator, in the circuit of Fig. 6. The
output current is held constant at a value of V /Rl +IQ
where V is the output voltage of the device
concerned.
MEDIUM CURRENT DEVICES
The National Semiconductor LM342 -XX series has
similar internal circuitry to the LM340L -XX series,
but can supply in excess of 200mA.- The SGS -ATES
TDA1405 (5V), TDA1412 (12V) and TDA1415(15V)
are available from Doram Electronics Ltd, and have
a similar internal circuit to the TBA625 series, but
can deliver output currents of up to 500mA. They
are encapsulated in a 3 -lead plastic package with a
hole for bolting the metal insert to a heat sink. The
foldback limiting causes the current to fall to
between 80 and 180mA on short circuiting the output.
However, thermal damage can be caused if the device
is not mounted on a heat sink. The L129 (5V), L130
(12V) and L131 (15V) are similar to the TDA1405
devices, but have a wider operating temperature
range. All these devices can be used in the type of
circuit already discussed.
Earth
Earth
LM78L series
(b)
TBA625 series
(a)
IW3601
Fig. 4: Connections for (a) the TBA625 series and (b) the LM78LXX
series.
These devices are available in TO -5 metal cans, but
the connections, Fig. 4(b) are different from those of
the TBA625 series; they are also available in TO -92
plastic packages. Some types are stocked by
Chromasonic Electronics Ltd., whilst National Semiconductor devices are available from DTV Group
Ltd., 126 Hamilton Rd., London S.E.27.
These devices can be used in the same circuits as
those already discussed. The output current on short
circuit does not fold back, but is limited in value and
a thermal limiting circuit operates at high chip
temperatures. The performance is similar to that of
the TBA625 series, but the dropout voltage (1.7V)
is rather less.
Input
Output
TBA625
R1
Cl
1
R2
R1
TBA625A
TBA625B
TBA625C
Fig. 5: above, a
430
1k
1.2k
R2(max)
250
150
150
Vout
12-15
15-17
IW3611
circuit using the TBA625 devices to provide
Fig. 6: below,
a
a
variable
current regulator circuit.
IW3621
Regulator
V
R
Output
current
k
28
Another series of medium current devices has been
adopted by many manufacturers, thermal limiting
being employed rather than foldback limiting. The
internal circuitry is similar to that of the LM342-XX
series but the output current can be up to 500mA in
some types and up to lA in others. These standard
types are available with nominal outputs of 5V, 6V,
8V, 12V, 15V, 18V and 24V. For example, the lA
range includes the LM340T -XX in a TO-220 plastic
package, the LM340K -XX in a TO -3 package, the
Motorola MC7800 series, the Fairchild µA7800
devices and the Texas Instruments SN72900 series.
The 500mA devices include the National Semiconductor LM341P-XX plastic types with a tab for
bolting to a heat sink and the Fairchild /,A78MOOC.
Other devices available from Doram Electronics Ltd
include the LM309K 5V regulator in a TO -3 package
which can give over lA and the LM323K in the same
package for 5V at up to 3A.
5-9
regulated output.
Input
1W36311
Fig. 7: A circuit for increasing the output current from a LM340T -15
device by a (actor o( five.
HIGHER CURRENTS
All these devices can be used in the circuits
discussed, but the type of circuit shown in Fig. 7
can be used to obtain more output current. In the
particular circuit shown, a LM340T-15 device is used,
the maximum current being 5A instead of the lA
of the device itself.
If the voltage across Dl is equal to the base -emitter
voltage of Trl, the current flowing through Rl is
about four times that through R2. This current boosting circuit takes advantage of the internal current
Practical Wireless, May 1977
Fig. 9: A dual tracking regulator
using the RC4195 device to
-15V
provide
+15V and
outputs.
Fig. 8: below, a high output
voltage circuit using
the
LM340T -24 device to provide
regulated 48V.
a
IV/3651
DUAL TRACKING REGULATORS
+ 60V
Regulator
LM 340T -24
Vout
Rl
600
Trl
2N3055
D3=
48V
lamp
C2
Cl
0.1yF
0lyF
D2
1N5365
(36V)
19 D1
- (24V)
11,15359
[W3641
limiting properties of the regulator to provide short circuit protection of the booster section. The short
circuit is limited to R2 /R1 times the output limiting
current of the regulator device itself. If the heat sink
fitted to Trl has at least four times the capacity of
the sink fitted to the LM340T-15 device, the thermal
overload protection of the latter will be extended to
Trl. As the load current increases from 0 to 5A, there
is a change of about 1% in the output voltage.
HIGH OUTPUT VOLTAGE
The circuit of Fig. 8 shows how the LM340T -24
can be used to provide an output of 48V. Under short circuit conditions the voltage at the input side of
the regulator falls to 35V, D3 aids the start-up of the
circuit and protects the regulator from high inputto- output voltage differentials during short circuits.
Work with operational amplifiers normally requires
dual power supplies of about ± 15V and the supplies
should be regulated to prevent the output voltage of
the operational amplifiers from drifting. Further, it is
desirable for accurate work that the drift in the
voltage of one of the pair of lines should be matched
by a proportional drift in the voltage of the other
line; that is, the two voltages must track one another.
One of the simplest ways of constructing a dual
tracking power supply unit with ± 15V outputs
involves the use of the Raytheon RC4195 device in
the circuit of Fig. 9. This device is available from
Doram Electronics Ltd (order code 303-636) as an
8 -pin dual -in-line package which can deliver over
100mA from each output with short circuit currents
of about 220mA. The input voltages should be in the
range ±18V up to the maximum of ±30V. The
frequency compensating capacitors C3 and C4
increase stability, but can often be omitted.
The RC4195 device incorporates thermal shut
down and short circuit protection for both outputs.
It replaces two separate regulator devices. The
balance connection to pin 6 can be taken to a variable
voltage so that the two output voltages can be
accurately balanced. The íC4195 can also be used to
provide a single regulated output of + 50V at 100mA,
whilst in another circuit with external power
transistors it will provide a dual tracking supply of
±15V at 2-5A each.
Next month, in Part 2, we shall deal with Fixed
Regulators
and TO -220
This photograph, provided by National Semiconductor, shows voltage regulator devices in TO -5 (small circular), TO -3 (large circular)
plastic packages.
Practical Wireless, May 1977
29
ON RECENT DEVELOPMENTS
Radio .... what?
Next time you are in the company of
people who delight in using long
words, get your own back; say
radioimmunoassay! If they call your
bluff and ask what it means, the
following explanation might help.
The word radioimmunoassay (RIA
for short) comes from the medical
profession, well known for its love of
technical tongue twisters. RIA is a
technique used to measure very very
tiny amounts of things in the blood
such as hormones etc. The medical
minnions often do this by putting in
some minute but radio active tracer
elements and following their path
around the body. These tracers are
often measured while still in the body.
A rather bright medical instrument
manufacturer has now gone one
better. The antigens (these are the
minute traces you want to measure)
are bound to microscopic flecks of
iron. It is then, in crude lay terms,
simply a matter of going fishing with
a magnet! The fluid is passed by a
magnet and the iron particles are
separated leaving only the elements
in the sample which are required for
measurement. In practical terms this
means that the manual separation
part of RIA can be fully automated.
Micro speaker
Beepers for use as alarms have
been marketed for some time and are
available in this country from various
electronics stockists. However, although their idea is not new am very
taken with the very latest one just
launched in America.
I
The beeper measures only 0.64in
cube and weighs just 6 grams.
Despite its very small size, the device
has a free field output of 105dB at lin.
The secret of this great output
compared to size is in the cunning
construction of the inside of the
cube which houses the device. This
internal structure is fashioned like
a miniature folded horn which is
tuned to 2.1kHz. An advantage of a
tuned horn as opposed to a resonant
cavity is that the horn tunes very
broadly and so is not critical. Yet
another advantage is that the beeper,
because of its broader bandwidth,
can be used as a truly miniature
loudspeaker. It is offered in a variety
30
of impedances from 2D to 2kfl and
it even has little solder tabs for ease
of mounting onto a PCB. One can
imagine a very small radio set for,
say, the bedroom using a ZN414,
LM380 and one of these tiny speakers. Alas-they've only just been
released onto the market in America
and are not obtainable in this country
up the tape is played to an analyser
unit which in turn feeds out printed
data on the accuracy of the hole at
as yet.
money.
Expensive games
Hot news
With television games gaining
greater popularity one would think
that this was a real growth area for
electronics and without too many
problems. Sad to tell this is not the
case. I hear of a report which indicates that the grid or pattern projected onto the CRT of a television
(i.e. the goals for football or the walls
for squash etc) is "burning" a
permanent image onto the TV tube
and, as such, will eventually ruin it
for normal TV watching. The time
taken for this effect to become
noticeable is, so I'm told, about 2,000
hours of use. However, with different
games, different intensity settings
and, indeed, different tubes, this time
is by no means a standard to judge
the situation by.
Now, a group has been set up to
study this affect and to report its
findings to the authorities. I will
mention this again as and when more
news comes in. However, the thought
of ruining a colour television tube is a
little frightening when one thinks
of the cost. Perhaps, if you play TV
games, it might be prudent to keep
the brightness turned down just a
little?
If you wanted to take the temperature of something it's almost certain
that you'd use some kind of thermometer. see that the market has just
been invaded by another non -contact
thermometer and it struck me that
some readers may not have heard of
these intrigueing devices.
This latest one is a small hand -held
unit which is simply pointed at the
target. It will then, within one second,
show the true temperature of that
target in degrees C. The target can
be up to 20 feet away and this particular "thermometer" has a measurement range from 10 °C right up to
Straight tape
If you drill a hole how do you know
if it's straight? Probably this is
unimportant for your ordinary average
hole, but if your drilling real big deep
ones, like oil people do, then it becomes very important. A British
company has manufactured what is
called an inertial navigation unit
(more long words). In use, this unit is
lowered down the hole. On its
journey it keeps careful records; it
has a cassette recorder to monitor
and log the distance it has travelled
and deviation in terms of lateral
movements. When the unit is hoisted
different depths.
Before you decide to use one for
the precision drilling of this years
potato crop, the price for one such
installation is quoted as around
£91,000-and that's a 'hole' lot of
I
1,000 °C.
It occurs to me that if was only 20
feet from 1,000 °C
would become
medium rare in about 20 seconds!
I
I
More expensive?
When hire transport in London
changed from handsome cab to
motor taxi there must have been some
regretful sighs. I wonder if there will
be any sighs for taxi meters. A
problem is that a cab may be laid up
for a matter of days while its electromechanical meter is adjusted. Owners
of a few of the larger fleets of cabs
have got together and formed a
company to manufacturer an electronic taxi meter. Readout of the fare
cost is, of course, digital while
changing the meter is just a matter of
unplugging one and plugging in
another.
Watch out for the new best seller
folks, "Electronic Taxi Meters-Are
They Really Fare ?"
Practical Wireless, May 1977
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£2950
(Panel £250)
As with the mixers the Mk II L.C. unit may be
purchased in module form with all controls, requiring only a panel,
case knobs etc. There are 13 simple connections
Fully suppressed
-240w Audio
8A RCA trlacs
0.5 -20Hz Sequence
(only with complete discos)
SEND YOUR SPECIAL REQUIREMENTS FOR A CUSTOM DISCO QUOTATION
£850
Has your light unit got?
dimmers
W handling
Automatic
Automatic audio level
Sequence facility
Smart 2 tone panel
OURS HASI
III Advanced IC circuitry
ONLY
Top grade components
All your needs In
one superbly designed unit
-00
An extremely compact and
versatile amplifier with
full protection and a clean,
-
A four
1dB
Input, high
Standard 8 ohm output
power amplifier
Twin mixed Inputs accept
which will deliver up
e wide range of signals
to 150 watts output. An
30HZ -30KHZ ±2dB
absolute must where multiple
23dB bass /treble
mixing R. power are required
Four individually mixed inputs
Wide range bass /treble +master
attractive appearance.
Ideal for all groups,
disco's
&
clubs
£49.50
SAXON
Vynide covered case
Fully short proof
Superb value for money
150 HEAVY DUTY AMPLIFIER
£59.00
1
CUSTOM MIXER MODULES
(Complete or in printed circuit form only)
Make your own mixer, mono or stereo, up to 2 channels, with full monitoring facilities,
and provision for echosend /return etc.
inputs for low and high 2 mic, ceramic & magnetic
cartridge etc.
Up to 20 input modules per single mixing module
Feed most types of amplifier- accepts ail inputs
MIProfessional low noise circuitry 20 Hz -30kHz
Infinitely adaptable- Extremely economical
COMPLETE MODULES With facia panel,
Knobs sockets, Monitor buttons, Ready wired tested
Mono mixing stage
Mono input
£8.50
£8.50
Stereo Input £12.00
Stereo mixing stage £12.00
PRINTED CIRCUIT MODULES
With
0'5W headphone
circuit
Full range bass/
STROBES & PROJECTORS (We stock the full Pluto
range) Send for details
150 WATT LIQUID
SUPERSTROBE £19 75
WHEEL
2-3 Joules
PROJECTOR
for
long
lire
80W Tube
Compact 4"x4 "x4"
PRO -STROBE £32-50
controls fitted,
requires only
-
6-8 Joules
External trigger
Long Life tube timer
Remarkable value
Sold elsewhere at
circuit
VIMJ1
treble controls
Nolse-80dB
sockets, facia knobs
Mono mixing stage £5.50
Mono input
£5.50
Stereo mixing stage £9.00
Stereo input
£900
Power supply for up to 20 channels- PPM18-£0.56.
Accepts all accessories
Clw with wheel & motor
plate
Sturdy steel construction
ACCESSORIES
£3950. Our price
is only:
£33.00
Condenser mice ECM77600 ohm E12.50
ECM 81 Dual Impedance £13 65 Crown headphones E0-75
Heavy duty boomstand E12.S0
All prices sublect to VAT @ 8°% except SA308/PM301, mica. headphones (12}
All prices Include carriage & packing except where shown other wise
Ordering: By Telephone- Access, Barclay Card or COD Ring (01) 684 6385/0095
/)
-Send cheque or crossed P.O's or 60p for COO
or send in your Access /Barclay card NUMBER ONLY
MAIL ORDERS CALLERS TO: CROYDON
Whitehorse Road, Croydon Surrey CRO 2HS
By post
SYSTEM 7000 SOUND -LITE (3- CHANNEL)
IN COMPLETE OR MODULAR FORM
(Modular form Illustrated)
Complete unit similar to Mk II unit above
327 -333
24 Hour
Long established & proven design
3 Channels -100W per channel
IN RCA 8A Triacs- Individual channel fuses
1 -240 W input- master audio level plus Bass /Middle/Treble
COMPLETE UNIT -Fully
cased with rear terminations -Just
plug In got
MODULAR FORM
Needs only
£24.75
Practical Wireless, May 1977
11
Ansatone service (01) 8846375
WALLINGFORD
Flint House, High St., Wallingford, Oxon (By Public Library) (0491) 35529
knobs etc.
Facia
simple connections
£16.50
(Panel £2-S6)
Both premises open
9
a.m. -5 p.m. Monday-Saturday Lunch 1
-2p.m.
Exporters to 17 countries -enquiries welcomed
Ring Sue Abegg on (01) 084 8385 for U.K. trade enquiries
31
Prime
LYNX ELECTRONICS (LONDON) LTD
T.I.
BROAD STREET, CHESHAM, BUCKS.
02
P. and P. 30p
-for Items
VAT 8% camp(
THYRISTORS
Ply
1A
M
3A
4A
(TO
6A 5A
(TO (TO
10A
(TO
15A
(TO
16A
(TO
220)
220)
220)
220)
43)
220)
-
1
RETURN OF POST
S[RV
Package Isolated Tab
4A
6 SA
8 SA
10A
15A
(s) (b) (a) (b) (a) (b) (a) (b) (a) (b)
0.60 0.80 0.70 0.70 0.78 0.78 0.83 0.83 1.01 1.01
0.64 0'64 0.75 0.75 067 0.87 0.57 0.67 1 17 1.17
0 77 0.75 0.60 0.63 097 101 1.13 1.18 1.70 1.74
0.96 0.06 0.87 1 01 1.21 1.26 1.42 1.80 2.11 217
without Internal disc. (b) with internal disc.
7476
7480
7400
0.19 7482
7401
0 16 7486
0.16 7489
7402
7403
7401
7405
7408
7409
7410
7412
7413
7414
7417
7120
7425
7427
7430
7432
7437
7441
0.16 7496AN
O .15 7491AN
6-10 7492
018
0.18
0.10
6.25
0.25
0.72
5.43 74121
AN
7442
7445
7447AN
714e
7470
7472
7473
7474
7475
1 10 74122
SM 74123
9.48 74141
0.16 74145
9 37 74154
6.15 4184
0.75 74165
0.65 74174
1'M 74175
501 4180
4181
O 31
6.32 4191
0.20 4192
4193
132 4194
1.47 4196
1M
Translators
2
1.15
0.15
6.13
AC728K 8.25
AC126
AC127
A
AC141
AC141K
AC142
AC142K
AC176
AC178K
AC187
AC187K
AC188
022
0.34
0.1/
f21
11.16
0ßS
0.18
0.25
010
ACI86K 8-25
AD149
AD161
AD192
AF114
AF115
AF118
AF117
AF118
AF124
AF125
AF126
AF139
AF239
AL102
AL103
AU107
AU110
AU113
BC107
BC107B
BC108
5.45
0-35
935
0ß0
028
8-28
8 28
0M
8-25
11.25
1ß5
0-35
0-37
SN
8.53
3.30
1.75°
1N
B-N
11.1111
O-M
BCINB 8-N
BC109
BC1096
BC709C
BC1n
BC119
BC125
13C126
8C140
BC141
BC142
BC143
BC144
BC147
32
7493
7494
7495
7496
74100
74107
11.119
5
N
8.12
5.15
0.25
8-16
0-29
0-32
0.33
0-23
027
SM
0N
C148
C149
C152
C153
C1S7
C158
C159
C180
C1e1
P M Linear I.C.s
O
C172B
C182
C182L
C183
C183L
C184
C184L
C186
C187
C207B
C212
C212L
C213
C213L
C214
C214L
C237
C238
C300
C301
C302
C303
C307
C396
C309
C310
C317
C319
C320
O
9
2.112
8
0.0
O
381
1
3900
709
2
N
2-N
CA3045
CA3016
CA3130
MC1303L
MC1304P
MC1307P
MC1310P
MC1351P
MC1352P
MC1353P
MC1458P
MC1496L
Opto-
Displays
11.85° 704
707
8-70 727
728
0-M
055
8.99
g'N
1.41
1.41
1N
8.85
1so
8.75
0.75
4
Pin
BCY30
O-SS
M
0.N
0.68
0-56
0.55
e.58
O-N
s-7!
039
0-097 BCY33
BCY34
BCY38
1.32 BCY39
036 BCY40
SN
0.12
0-11
0.12
BD11 S
BD131
BD132
8.111° BD135
11-15° B0136
11-11° B0137
8-12 50138
9W
BD139
0-11
BD181
111-12°
BD182
P24
813144
11.12° BD157
0-12 1313183
0.14 BD1N
B14
8D232
0-15° 821233
8-197 BD237
1.1S BD238
5.34 BD110
0-32 BDX32
11.40 BDY10
0.411 BDY71
11.15° BDY20
0.1B BDY38
6.18° BDY80
5.31
812
8.13
8-18
BDY81
BDY82
BDY95
BF121
C321
6.18° BF123
C323
C327
C328
C337
C338
C407
11-86°
0.15
10
517
0.17
1 22
BF127
BF157
BF177
BF178
8E179
BF180
11S
1.80
9.12
0-1/
0.12
0-1S
0-30
0.40
0.30
ON
0-N
11.48°
0'M
2-25
8.97
1.28
0.30
0.30
5-35
0.26
BSY54
5.44
BSY55
8-74
F183
BSY65
0-30
F184
BSY76
11.26
/17I,
F185
0'20 BSY78
F194
0.10 BSY95A 012
F196
012 BU1o5
F197
0.12 BU105/02
F200
1
0.40
F218
0.30 BU108 3-N
F219
0.36 BU109 2.M
F220
0.28 BU126 1 W.
F224J 0.16 BU133 1.M'
F244
0.17 BU201 1
F257
0.36 BU205 1-911'
F258
0.35 8U206 2 M'
F2M
0.48 BU208 2-N
F336
8-35 MJ480
11.110
F181
F182
1.N
-N
-N
F337
F338
FW30
FWM
FW60
FX30
FX84
FX85
FX86
FX87
1-32
MJ481
0.45- MJ4g0
0.80
6.16
0.17
8.21
8-30
MJ45/
MJE340
MJF520
6-2S
OC45
0C46
OCR)
0C140
MJE521
0C43
023 OCU
0.48
FXM
6-SS
FX89
FY11
0.25
8.20
0-20
0.06
1.18
FY18
FY40
0'M 0C139
11.50
FY41
OC170
ON
O-N
11.611
2.38
1.50
bM
0-N
0.N
1.70
1-B
115
FY50
FY51
FY52
FY53
FY64
FY90
2-14
0.50
0.50
LY15A
5X19
5X20
11.50
SX21
8.21
1.25
0.30
8.38
SX76
SX77
5X78
SY52
SY53
0M
N
B XY38.1200
ON
BZX61 Serias
6.20
BZX83 Series
611
0.15 BZYS8 Serles
0.45
011
Pin
Pln
Pin
Diodes
13A146
BA148
016 OM
OA10
6W
0.U1OMM
11.13.
0A90
0.13 OA91
9t2
PN
0.12
0.N
0A200
0-221N914
0-221NI001
0.251N4002
915
929
IN4003
IN4001
01S IN4148
TIL209 Red Led ..11.12
OCP71 .L1.15
BC10718/9.
25 pcs 1.20, 100 pcs 3 -N
11.611
9.811
5-112
'
$6309K IATO3 5v..1.25
.ü
1.25 BCY31
0.15 BCY32
40
0.10
877 RPM TO-3 Power Tran0.62' sistors. Fully tested but
1.61 unmarked. Similar to 2N3055
22
'
B YX38 -900
BYX38.300
IN4005
0-12 I N4006
Sockets
Pin
0.10 BYX36-600
IN4007
8.75
0
N
41
BYX38.000
C
3.28 TAA861
6.45
Pos L1.86, 25 pcs E4'N,
1.23 TBA330
1
pcs £7.80, 100 pcs E13 -N
1.35 TBA5300 1-90"
1.3S TBA560
2-88 ITT Branded Transistors.
1.20 TBA570
9-N Medium Voltage, High Gain
1.64 TCA270S01.55 Type BSY65. Similar to
BC408
16
24
BA15S
BA156
BA157
MM5316 5 N BAIM
AAY- 5 -1224A BA159
3 25 BY206
AAY- 5 -4007D BY207
TAA300
1.38 except: BVCEO = 50+
0.04 TAA310A
5-45 HFE (gain) = 20 + at 3A,
1.86 TAA550
TAA511 B121 d5 VCE SAT < 1.3V at 3A
0.N
1.N
2
SPECIAL OFFER SECTION
118
I.100
BYXâ8400
9NN
747
0N
8-20
6.18
8.19
8.25
8-35
0.85
0.10
0-1t
OC71
0072
OC84
TO -3
Rectlgers 130 -4 Package.
10A MV 5 N Please specify
10A 100V 6.45 Polarity
10A 200V 1.80 Stud Cathode
or 10A 400V 5 -N Stud Anode
Ideal for Power Supplies,
Inverters, etc.
1.27
0-15
0.21
0-35
0.35
0.45
0-45
0.15
0.44
2112217
0.30
2N23M 0.14
2N23MA 0.14
2N2483
6-20
2N1303
2N1304
2N1305
2N1306
2N1307
2N1308
2N1309
2N1711
2N2102
5.28
6.10
0-30
5,35 2N1131
0.30 2N1132
8 30 2N1302
010
2544124
2N4290
2N4291
2N4292
2544347
2544348
2544870
2544871
2544918
2544919
2544920
2N2712
0-1S
2N2904A 0.25
2N2905
8-15
0.941 2N2905A 6.22
1-1S 2N2908
0.18
0.N
2N2925
0.45 2N29260
O-M 2N2926R
O-N 2N2926Y
0.14
8 N
1-10
11-N
0.32 2N29286 9-10'
0.32 2N3053
0-20 2N3055
0.30 2N3133
0 35 2N3134
0.22 2N3137
6-40 2N3440
1-38 2N3442
1.38 2N3570
0.23 2548702
2543709
2543710
8-11
0-12 2N3711
8.10 2N3715
0'22 2N3718
0-14 2543771
1.15 2543772
516
2N4123
2N2711
/-IS
B-N
2543904
254390e
O-M 2N4922
6.20 2544923
2N2646
TIP29A 1-44 2543703
TIP30A 0.52 2543704
TIP41A 0-N 2N3705
TIP32A 0.54 2543706
TIP41A O-N 2N3707
TIP42A 0.72 2543708
2N404
2N696
2N697
2N706
2N718
2N929
Hardware.
Mica,
Washers, Solder tag, Nuts,
Bolts, 50 sets for Np
2742484
2543773
0-25 2543819
LON.
JC12 POWER
0-1S
0.58
0311
11.36
1-70
8.56
1-20
0.1111
0111
0-197
0
15
0
10
KIT
1 Amp L3 N.
JC12 PREAMP KITS
Type 1 for magnetic pickups, mica and tuners,
Mono
Stereo L2.75.
for ceramic or
Rpickkup.
Ste o
Supplies 26V
SINCLAIR ICU
616
B YX36.1200
0.41
0.45 760
1 60
1'80
1.41 L.E.D.
'2
Red
6
13
UM 2 Green 0.28
180 '2
Clear 114
135
1.35 Clock Chips
135 MM5314 4'25
1.35
1.511* E lectronics
5R
0.113
723
7805
7812
7815
7818
8.45 L M340.18
.45 NESSI,
SN NE665
NES86
NE567
O
1.02
1.07
0.35
0.34
0.47
0.40
0-7a
0.68
1.62
0-22
75
Regulators
0 27 LM340.5
9 20 LM340.12
9 35 LM340 -15
.06 741
0'57 748
BCY42
C1N 11.12° BCY54
CINC 6.14° BCY70
C1708 0-12 BCY71
512' BCY72
C171
C168
N
N
0N
80
.56 301A
0.75 307
5.32 380
Diodes contd
r
L1.09
DELUXE KIT FOR JC12
Contains extra parts esm01 JC12 needed to
complete the amp including balance, olume,
bass and treble controls, Mono L219. Stereo
S Y/136400
U
00
TRIACS-Plastic TO420
TTL74N
Serias
circuit
Semiconductor Pack
£16.15
Resistor Pack
£2.13
Capacitor Pack
£4.36
(Polyester and Electrolytic only)
ALL THREE PACKS
£22.46
All prices Include P. and P. and VAT
--
,11'
with free data and
P.W. MARCH '77
Now Catalogue
N.B. -(a)
AMPLIFIER
601 IC audio amp
FM TOUCH TUNER
035 080 046 0.10 0N 0 N 0N 114
0.10 0 80 0N 046 0.07 0N 0N 110
1N 110 123 80
065 0 86 0 70
BT106 LtN, BT107 LI MI, STiN LI BP, 15T109 LI 110, BT110
L1 N, 2110626 L9 N.
100V
500V
400V
600V
(02405) 75151
-
(C
200
400
000
PRINTED CIRCUIT KIT L311
Make your own printed circuits. Contains etching
dish, 100 so Ins of pc board 1 lb ferric chloride,
etch resist pen, drill bit and Instructions.
6e "Ja
Matching 200 per pair. ACCESS
Overseas 900
which are 12 }%
No VAT Overseas,
106)
(T06) (STUD)
-
et
at 31st Jaw '77
u
I
IC20 10W+10W stereo Integrated
circuit amp
kit with printed circuit and data U.N.
Power supply kit for above L3.61.
VP20 Volume, tone control and presmp kit LON.
P7-20
JCIO AMPLIFIER
New Integrated circuit 20W amplifier kit complete
with chip, printed circuit and data L395,
FERRANTI ZN414
IC radio chip LI 44. Extra parts and peb for radio
£3 -115. Case LI. Send see for fres data.
I
BATTERY ELIMINATOR
RADIO MODELS
INS
with press -stud battery connectors. 0V
SOmA
L345. 5V £3 45. 9V +9V L545. 6V +5V £5.4.
41V +4 }V ESIS.
CASSETTE MAINS UNITS
7
1V with
S
pin din plug. 150mA L3-65
3-WAY MODELS
With switched output and 4 -way multi -jack
connector. Typa 1: 3/4i/6V at 100mA 22.35.
Type 2: 6/70/9V at 300mA £2.911.
FULLY STABILIZED MODEL £45
Switched output of 3/6/7 {/9V stabilized at 400mA.
CAR CONVERTORS L515
Input 12V DC. Output6 /71/9V DC
1
Amp stabilized.
BATTERY ELIMINATOR KITS
Send sae for free leaflet on range.
1NmA radio types with presa-stud battery
terminals. 4 {V E2 II. 5V £MS. 9V £2.10. 41V+
45V £2.80. BV+BV £2.51. 9V+9V 92.80.
1
mA casseNe type
7 }V
with
S
pin din plug
L2.111.
Transistor stabilized 4way type for low hum.
3/4 {/6/7}/9/12/15/18V. 100mA £31. lAmp LSN.
Heavy duty 13-way typos 4}íe/7/8{/11/13/14/17/
1
Amp model £4-41. 2 Amp
model £7.55.
Car convertor kas Input 12V DC. Output 6 /7} /9V
DC to transistor stabilized LI .N.
21/25/28/34/42V.
MILLENIA KITS
Transistor highly stabilized power units.
Switched to 30V in 0.1V steps. Send sae for free
leaflet. 1 Amp kit £12.45. 2 Amp kit E14.05. Case
£2-IS extra.
S
1
MAINS TRANSFORMERS
6-0-6V 100mA Np. 9-0-9V 75mA Np.18V 1A LI -N.
0/12/15/20/24/30V 1A £315. 12-0-12V 50mA Np.
0/12/15/20/24/30V
2A £455. 6.3V 1 }A 42.10.
6-0-6V 1 }A £2.15. 9-O-9V 1A L2-16. 12-0-12V 1A
E2- N. 15-0-15V IA E2- N. 30-0-30V 1A £3.39.
S -DECS AND T -DECS
S -DeC E1 N T -DeC E3'91.
u -DeCA £3.97. u -DeCB £6.57.
IC carriers with sockets: 16
dii
E1
-...&.?''',/
.
-r
91.10705 LI-79.
SINCLAIR CALCULATORS, WATCHES
AND POCKET TV
Sinclair pocket TV £155. Cambridge Scientific
E055. Cambridge Memory 13.55. Oxford Scientific
£13.38. Mains adaptors (state model) £3211.
Assembled grey watch with free stainless steel
bracelet L1645. White watch £13-IS.
SINCLAIR PROJECT M AUDIO MODULES
PZ5 L4-95. 240 £5.75. Project 8050 £26 95.
BI -PAK AUDIO MODULES
5450 tuner £21 -115. ALM £4.01. PAIN £1495.
MK60 audio kit £31 W. Teak 80 £12 95. Stereo 30
E111 95. SPM80 L3-95. BMT80 £3.52. Send sae for
free data.
SAXON ENTERTAINMENTS NODULES
SA1208 £1595. SA1201 011.41. SA608 £1145.
£15' 95. PM1202/8 L15.95. PMI
PM1202/4 £15. PM601/8 £12.
PM1201 /8
201
/4 £12.
010
0-1
1-N
0N
0111
e.1e
1.1S
1.25
1.60
1.N
2.11
s-28
SWANLEY ELECTRONICS
DEPT. PW, PO BOX 68,
32 GOLDSEL RD., SWANLEY, KENT.
Mail order only. We will not serve callers under
any circumstances. Post 300 on orders under
L4.50, otherwise free. Prices Include VAT.
Official orders welcome. Overseas customers
please deduct VAT. Send sae for free leaflets
on kits.
Practical Wireless, May 1977
improved
ekhjnu of PCB's
AA .KENNEDY
MANY chemicals and combinations of chemi-
cals are suitable for etching copper but by
far the most common, due to its cheapness
and ease of use, is ferric chloride, either by itself or
:::
If oxygen is present:
+ 02 + 4HC1-+ 4FeCI3 + 2H20
2CuCl + 02 + 2HCI -->- 2CuCb + 2H20
From the above it can be seen that it is advan4FeC12
mixed with various additives. In solution ferric
chloride reacts with the water to form a small
amount of the insoluble salt ferric hydroxide,
together with hydrochloric acid (HC1). This reaction
is easily prevented by adding up to 5% HC1. In
either case HC1 is present and available for reaction
with both ferrous chloride and cuprous chloride,
converting them back to ferric chloride and cupric
chloride respectively if free oxygen is present.
FeC13 + 31120 -k Fe(OH)3 + 3HC1 Hydrolysis.
FeCla + Cu -->- FeCs + CuCI At copper surface.
FeCl2 + CuC12 In body of solution.
FeCl3 + CuCl
CuCIh + Cu --)- 2CuCI At high copper levels.
tageous to have an oxygenated solution. The two
commonest methods of oxygenating a solution
(spraying it through air or bubbling air through it)
also provide mechanical agitation at the copper surface thus removing the ferrous and cuprous
chlorides as they are formed and supplying fresh
etchant to the surface.
Spray etching produces better results than bubble
etching but the problems involved in producing a
uniform spray pattern and obtaining pumps manufactured in materials that are inert to the etchant
tend to cancel any advantages to the amateur. In
comparison, bubble etching is very simple to imple-
Photograph A shows the plastic tube suitably bent and fixed to a heavier
plastic base. In B the tube has been fitted to the air pump. Photograph
C shows the complete set -up with the tube in the bottom of a plastic
bowl. Finally In D the solution is seen bubbling with the PCB floating
on the surface with the aid of a cork in each cor-ier.
-
Practical Wireless, May 1977
33
L
D
}
J
11 IL
0
I
C-7
u
asool
by BRIAN DANCE
Number
SGS -ATES TBA820 LV AUDIO AMPLIFIER
62
THE SGS -ATES TBA820 device is not designed
to give a very high output power but is very
suitable for use in portable equipment where
the battery voltage may be as low as 3V. The typical
quiescent current consumption is only 4mA at 9V,
so one can obtain a long battery life at low output
power.
The TBA820 is very suitable for use in small
portable radio receivers, small record players and
tape recorders, etc. It enables much simpler audio
power amplifiers to be constructed compared to those
where only discrete components are used.
Bootstrap connection
Hum rejection
Positive supply
Frequency compensation
No connection
Frequency compensation
Feedback
No connection
Output
No connection
Earth
No connection
Earth
Input
v+
C4
100nF
n
SÓyF 10v
14
Input ---a
See text
7,
C6
T
BA 820
12
1000yF
5
R2
R1
100kn
See
text
Nwo
+
C7
C2
TOnF
100yF
T06V
T
,
IGT21
IGT11
Fig.
1 :
The TBA820 pin connections.
The TBA820 is encapsulated in a quad -in-line
package with the connections shown in Fig. 1. In
this type of device alternate pins on each side of
the plastic body are bent so that they protrude to
different distances at their lower ends. This configuration provides more space between adjacent
pins for ease of soldering than in dual -in -line devices,
but quad -in-line sockets are more difficult to obtain.
CIRCUITS
A typical circuit for the TBA820 is shown in
Fig. 2. If the input signal has any DC superimposed
on it, a capacitor of value about 0.22µF must be
placed in series with the input connection. R1 may
be replaced with a 10041 volume control, if desired,
but a resistor of value not exceeding a few hundred
kÇl must be present from pin 7 to earth to achieve
correct biasing.
The capacitor C6 prevents a steady current flowing
from the output (pin 12) through the loudspeaker
speech coil. A somewhat smaller value can be used,
but this will result in a reduction in the bass response.
The power supply decoupling capacitor, C4, should
be soldered fairly close to pin 14 to prevent spurious
RF oscillation. C7 is an electrolytic capacitor in
parallel with C4 which provides decoupling at lower
frequencies.
34
Fig. 2: A simple TBA820 amplifier circuit.
The gain of the circuit is determined by the value
of R2. An internal feedback resistor of value 6k51
is connected from pin 12 to pin 5, so the smaller
the value of R2, the greater the gain. The gain is
approximately equal to 6000/R2; thus voltage gains
of 30, 60 and 120 may be obtained by using values
of R2 of 20052, 10051 and 50,í1 respectively. The
maximum value of R2 is about 39051 if a 9V supply
is employed or 27052 with a 12V supply, since
saturation of the input circuit may occur with higher
values.
The value of C5 determines the high frequency
response of the circuit, but the value required for
any specified frequency response is affected by the
value of R2. The value of C5 required for various
upper cut -off frequencies is plotted against R2 in
Fig. 3.
The optional capacitor C3 provides a reduction of
about 42dB of any hum on the power supply line.
It is not required if a well stabilised supply is
employed. However, if a battery is used as a source
of power, this capacitor should always be included,
since it will prevent `motor boating' when the
internal resistance of the battery rises with age.
The maximum output power which can be obtained
from TBA820 depends on the impedance of the
loudspeaker and on the power supply voltage. For
example, one can obtain 2W with an 852 speaker
Practical Wireless, May 1977
WILMSLOW AUDIO
Firm for speakers!
THE
Elan 10" 10RM239
8
ohms
Eagle Crossover 3000hz 3. 8 or 15 ohm
Eagle FR4
Eagle FR65
Eagle FR8
Eagle FR10
Eagle HT15
Eagle HT21
Eagle MHT10
Eagle FF28 multicell. horn
Fane Pop 15, 8 or 16 ohm
Fane Pop 33T, 8 0116 ohm
Fane Pop 50, 8 or 16 ohm
Fans Pop 55, 8 or 16 ohm
Fane Pop 60, 8 or 16 ohm
Fans Pop 70, 8 or 16 ohm
Fane Pop 100, 8 or 16 ohm
Fane Crescendo 12A, 8 0116 ohms
Fane Crescendo 12BL, 8 or 16 ohms
Fane Crescendo 15/100A, 8 or 16 ohms
Fens Crescendo 15/125, 8 or 16 ohms
Fane Crescendo 18, 8 or 18 ohms
Fane 910 Mk II horn
Fane 920 Mk II horn
Fane HPX1 crossover 200 watt
Fane 13 x 8, 15 watt dual cone
Fane 801T 8" d /c, roll surr.
Goodmans Axent 100
Goodmans Audlom 200 8 ohm
Goodmans Axiom 402 8 or 15 ohm
Goodmans Twlnaxiom 8, 8 or 15 ohm
or 15 ohm
10P 8 or 15 ohm
12P 8 or 15 ohm
12PG 8 or 15 ohm
12PD 8 or 15 ohm
Goodmans 12AX 8 or 15 ohm
Goodmans 15AX 8 or 15 ohm
Goodmans 1SP 8 or 15 ohm
Goodmans
Goodmans
Goodmans
Goodmana
Goodmans
SPEAKER KITS
SPEAKERS
SPEAKERS
Baker Group 25, 3, 8 or 15 ohms
Baker Group 35, 3, 8 or 15 ohms
Baker Group 50/12 8 or 15 ohms
Baker Group 50/15 8 or 15 ohms
Baker Deluxe 12" 8 or 15 ohms
Baker Major 3, 8 or 15 ohms
Baker Superb 8 or 15 ohms
Baker Regent 12" 8 or 15 ohms
Baker Auditorium 12" 8 or 15 ohms
Baker Auditorium 15" 8 or 15 ohms
Celestion G12M 8 or 15 ohms
Celestion G12H 8 or 15 ohms
Celestion G12/50 8 or 15 ohms
Celestion G12 /50TC 8 or 15 ohms
Celestion GISC 8 or 15 ohms
Celestion G18C 8 or 15 ohms
Celestion HF1300 8 or 15 ohms
Celestlon HF2000 8 ohms
Celestion MH1000 8 or 15 ohms
Celestion CO3K
Decca London ribbon horn
Decca London CO /1000 /8 Xover
Decca DK30 ribbon horn
Decca CO /1/8 Xover (0K30)
EMI 14 x 9 Bass 8 ohms 14A770
EMI 8 x 5, 10 watt, dicono, roll Burr.
EMI 61" d /cone, roll surr. 8 ohms
EMI 8 roll surr. bass
EMI 5' mid range
Elac 59RM109 (15) 59RM114 (8)
Elan 64" dicono, roll surr. 8 ohms
OP 8
£13 00
E14-50
£21 00
E25-75
£17 50
£15 00
422 50
£12 50
£21 00
£25 75
E12
E15
£18
E20
E26
E39
E7
95
95
00
00
95
95
50
£8-55
£13 50
£446
£31-50
E6 95
£20 50
£475
£12 50
E3 95
E3.95
£6 75
El
50
E3 50
£3 95
E395
E1
57
E6 75
E11,95
£14 95
E18 50
£4-50
E5-50
ES 25
E7 50
ES75
439,95
Goodmans 18P 8 or 15 ohm
Goodmans Hlfas 750P
Goodmans 5" midrange 8 ohm
Gauss 12"
Gauss 15"
Gauss 18"
Jordan Watts Module 4, 8 or 15 ohm
Kef T27
E16 95
£4.25
£132
£139
£140
£16
00
00
00
25
ES 50
E10-75
E10-95
Kef T15
Kef B110
Kef B200
Oaf 8139
Kef DNe
Kef DN12
Kef DN13 SP1015 or SP1017
Lowther PM6
Lowther PMB Mk 1
Lowther PM7
Peerless KO10DT 4 or 8 ohms
E11
£2 75
£7 25
EC 95
E32 00
E35 00
£4860
LB-25
E9-50
Peerless DT1OHFC 8 ohms
Peerless KO40MRF 8 ohms
Peerless MT225HFC 8 ohms
Richard Allan CA1212' bass
Richard Allen HPBB
Richard Allan LPBB
Richard Allan DT20
Richard Allan CN8280
Richard Allan CN820
Richard Allan Super disco 60W 12"
Richard Allen CG1515" bass
Richard Allen Super Disco 10. 50 watt
Richard Allen Super Disco 8' 50 watt
Radford M139
Radford MD6 dome mid range
Radford TD 3
Radford Crossover network
BD25 Mk II
Coles 4001 GLK
Tannoy 10" HPD
Tannoy 12" HPD
Tannoy 15" HPD
Castle 8 RS -DD
E1050
E3 75
£1980
E12 50
C8 50
EO-25
E16 95
E31S
E17 95
E28 50
E13-25
E12 95
E12 95
E17 95
each
palr
pair
palr
LIS 35
£23.25
£34 25
£49.50
HI -FI
ON DEMONSTRATION
in our showrooms
Akai, Armstrong, Bowers and Wilkins,
Castle, Celestion, Dual, Goodmans,
Kef, Leak, Pioneer, Radford, Richard
Allan, Rote!, Tandberg, Trio, Video tone, Wharfedale, etc. Ask for our
Hi -Fi Discount Price List.
THIS
MONTH'S SPECIALS! Carr.
£2 50. Sansui
331
£114 00.
Pioneer
7070
£19900. Trio KR 2600 £109 00. Sugden
A21 £13000. Minimax MK II £4695.
Sansui SC 2000/2002 £16000.
CB 25
E2695
ES 90
E79.25
E87-00
£10325
£9.95
£9 95
1E16
Wharfedale Denton 2XP Kit
Wharfedale Linton 3 x P Kit
Wharfedale Glendale 3XP Mit
E16 95
£1250
95
We stock the complete Radford range
of amplifiers, preamplifiers, power
amplifiers, tuners, etc., and also
Radford Audio Laboratory equipment,
low distortion oscillator, distortion
measuring set, audio noise meter, etc.
£19 95
£21 75
E33 95
E 4295
E4465
E54 95
E64 95
E7505
E15 75
£ 45 95
E2 50
CS SO
C806
E8-50
£14.95
E2208
E10-60
C11.50
E695
L16
-17
E/0
SO
7S
75
E44 00
E49 -09
E24 00
SPEAKER KITS
Baker Major Module 3, 8 or 15 ohms
Goodmans DIN 20 4 or 8 ohms
Goodmans Mezzo Twin Kit
Helme XLK 20
Helme XLK 30
Helme XLK 35
Helme XLK 40
KEF kit
KEF kit Ill
1
Peerless 1060
Peerless 1070
Peerless 1120
Peerless 2050
Peerless 2060
Richard Allan
Richard Allan
Richard Allan
Richard Allan
Richard Allan
Richard Allen
Richard Allan
Complete kits in stock for Radford
each
each
pair
pair
plr
pair
pair
pair
each
pair
each
each
pair
pair
each
each
each
each
Twin assembly
Triple
Triple
8
12
Super Triple
RAB Kit
RA82 Kit
RA82L Kit
Studio
90,
pair
pair
pair
Radford
Monitor 180, Radford Studio 270, Radford Studio
HiFi Answers Monitor (Rogers), HiFi News No
Compromise (Frisby), HiFi News State of the Art,
Wireless World Transmission Line (Bailey), Practical
HiFi and Audio Monitor (Giles), Practical HiFi and
Audio Triangle (Giles), Popular HiFi (Colloms), etc.
360,
Construction leaflets for Radford, Kef, Jordan Watts, Tannoy, Hi -Fi
On dem. Answers Monitor, State of Art, Free on Request.
P.A. Amplifiers, microphones etc. by Shure, Linear, Eagle,
Beyer, AKG etc.
FREE with orders over £10-"HiFi Loudspeaker Enclosures" Book
Practical Wireless, May 1977
95
E24 95
Fane Mode One Mkt
E18 09
L15,75
E51.95
£17 50
E2195
E26.75
£30 50
E59 50
E56. 00
E61,50
£54 95
£61 50
£4395
£5050
E1395
E20.75
£25.95
C2150
E37 80
£59.40
All Prices Include VAT
(Prices correct at 2.2.77)
Send stamp for Free 38 page booklet
'Choosing a Speaker'.
All units guaranteed New and Perfect.
Carriage and Insurance:
60p
Speakers up to 12"
£1'00
12"
15"
18"
£1 75
£2 50
Kits £1 00 each (£2 00 per pair)
Tweeters & Crossovers 33p each
E95 70
WILMSLOW
AUDIO
Dept. PW
Loudspeakers, Mail Order and Export:
Swan Works, Bank Square, Wilmslow.
Hi -Fi, Radio & TV Swift of Wilmslow
Swan Street, Wilmslow, Cheshire.
5
PA, Hi -Fi & Accessories: Wilmslow
Audio, 10 Swan Street, Wilmslow,
Cheshire.
:
Telephone:
Loudspeakers, Mail Order and Export
Wilmslow 29599
Hi -Fi, Radio, etc., Wilmslow 26213
orders
(Access
accepted by phone)
35
SI NTEL
HIGH QUALITY
Send for free catalogue
KITS
votaora
CMOS
NM*
CCK
GCK
DIGIT CAR CLOCK WITH INDEPEN-
In hrs. mina. secs.
Runs off car 12v supply
Nine push buttons for Start- Stop -Reset,
selecting display to show time or elapsed time
controls functional
irrespective of display mode
complete with case. Order as CCK £42.00
ACK6x0.5" red digit alarm clock
£2760
ACK +BBK +XTK 6 x 0 5" red digit alarm clock with XTK and battery
backup
£3433
AUT -CK 4 x 0.5" red digit car clock with 12v negative earth
£1765
GCK 4 x 0.5" green digit mantlepiece clock
£1440
XTK 50Hz crystal ti mebase kit
£06. 2$
Kit
All
USEFUL PRINTED CIRCUIT BOARDS
Description
610 -950
246-050
915 -950
Sets of PCBs to hold displays and all the ICs tor building a 6 digit, 4
digit or2 digit COUNTER MODULE WITH LATCH USING TTL. The
PCBs hold one each per digit of TIL321, 7447, 7475, and 7490 as well
as Rs and Cs. Each set consists of one vertical PCB which holds the
displays and Is fastened toe horizontal board, which holds the remaining components (of these components, only the TIL3218 are available
from us -order these separately).
6 digit Set. Size h.30mm w.173mm d.109mm. £5.50
4 digit Set. Size h.30mm w.128mm d.109mm.
£3.05
2 digit Set. Size h.30mm w.80mm d.109mm. £2.30
DISPLAY HOLDING PCBs NON -MULTIPLEXED
876-001
675-Ní
472-001
D500-6
D500-4
DS00-6
142 -269
R's,
1
x
CD4002
CD4006
CD4007
CD4008
CD4009
CD4010
CD4011
CD4o12
CD4013
CD4014
CD4015
CD4016
CD4017
CD4018
CD4019
C04020
0.17
1.20
0.10
1.00
0.50
0.58
0.20
0.23
0.5$
1.04
1.04
0.5$
1.04
1.03
0.58
1.28
1.04
manufacturen snip
OTHER COMPONENTS
CD4022
CD4023
CD4024
CD4025
CD4026
CD4027
CD1028
CD4029
CD4030
CD4031
CD4032
CD4033
CD4034
CD4035
CD4036
CD4037
CD4038
CD4039
CD4040
0-94
CD4041
0-86
0.23
CD4042
CD4043
CD4044
CD4045
Co4046
CD4048
CD4049
CD4050
0.66
0-80
0-23
1
-78
0-50
092
1-1 0
0.58
2.30
1-02
1-44
1-97
1.22
3-29
0.N
1-10
3-20
t-11
1-01
0-96
1-45
1.37
0.50
0.5$
0.5$
CD4051
094
CD4052
CD4053
CD4054
CD4055
CD4056
CD4059
CD4060
CD4063
0.94
094
1.20
1.36
1.36
403
1.15
113
CD4066
CD4067
CD4068
CD4069
CD4070
CD4071
CD4072
CD4073
CD4075
CD4076
CD4077
CD4078
CD4081
CD4082
CD4085
CD4086
CD4089
CD4093
CD4094
0-63
3.95
0-23
0-23
0.51
0.23
0-23
0.23
0-23
1.34
0.45
Oß3
0-23
0.23
0-74
0.74
1
-
751410J
751411D
751237J
751238D
751239K
4518, socket pins, etc. Size h. 67mm, w. 71mm, d.
£0.6g
4.10
2.50
3.00
CHIPS
512MHz
1.50
1.49
5.80
5LT01
CD4511
CD4514
1-72
2.84
3-24
1-40
1-25
CD4515
CD4518
CD4518
CD4527
CD4532
CD4555
CD4556
MC14528
1-06
3-85
1-13
1-90
124
1.41
1.64
1-39
0.90
090
1.22
MC14553 4-60
IM6508
0.05
FORMERS
3.10
3.50
580
3.50
3.60
0.50
4.00
10.50
100
1000
3000
SC%MP
CPU2484
ISP8A/500
Z80
MEMORIES
TRANS-
CLOCK
32.708kHz
TI L321
TIL322
3 -S0
LEDTRF
5LTRF
9131
1.95
1.95
FLAT CABLE
1.00
20w 1m
10m for
000
(New)
2102A -8
2112A -4
19.511
3-10
4.10
8.05
8508
14-50
A
SO
MPU KITS
INTRO KIT
ISP8K/200E
6081
SUNDRIES
CA3130
µA741
78LI2WC
0.94
0.40
0.77
See Catalogue
Motorola CMOS Databook Vol.5 Series B
TMS8080 Microprocessor Datasheet
TMS5501 (Multifunction I/O Controller tor8080) Datasheet
for other titles
3.50
0.75
0.75
Our o //ices are at Link Properly, 209 Cowley Road, O. ford but please do not ,,se this
as a postal address.
ORDERS: C.W.O. add VAT ® 8"r + 25p p. 6 p. CREDIT (Invoice) orders SEND
YOUR
add VAT
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Items-contact us first. All prices valid until 31st August, 1977.
Cos
No
1.911
FOR FULL RANGE send for FREE CATALOGUE
SOLDERCON
DISPLAYS
MPUs
IC PINS
3.36
FND500
1.30
NEW DATA FROM SINTEL
915 -950
60
0-92
1.94
CD4095
CD4096
CD4097
CD4098
CD4099
CD4502
CD4510
VEROCASES
CRYSTALS
246 -950
COUNTER KIT
A complete kit for building a 2 digit, single PCB, CMOS COUNTER
MODULE WITH LATCH. Includes PCB 912-950, 2 x TIL322 or FND500,
18mm.
0.18
AY51202
AY51224
MK50253
610 -930
digit counter format for FND500/TIL321/TIL322 £0.75
digit counter format for FND500/TIL321 /TIL322 £055
2 digit counter format for FND500/TIL321/TIL322 £029
DISPLAY PCBs WIRED FOR MULTIPLEXING
6 digit clock format for FND500 /TIL321/TIL322
L1.10
4 digit clock format for FND500 /TIL321/TIL322
£064
8 digit counter format for FND500 /TIL321/TIL322 Li -10
8
4
2 x 4511,
CD4001
CD4021
COUNTER PCB SETS
AND
0-17
CD4000
CRYSTAL CONTROLLED 6
DENT JOURNEY -TIMER Shows time or elapsed time
Order as
Components
From leading
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-Ido Verdi well by
el my a!/my components
{root HOME RAD/0
Forgive the terrible puns. If you don't quite twig 'em just have a word
with your opera -going friends and they will reveal all! Frankly, we've
used the characters above simply to catch your attention and to lead
you on to the more interesting point that Home Radio Components
Ltd. are the people to deal with when you need components for the
projects in this magazine, or for any other electronic gadget you may
be creating. Thousands of constructors have proved that they get
good advice, good components, good value, good service from Home
Radio. Many buy over the counter at Mitcham, many purchase by
Mail Order sending a cheque or P.O. each time they need something,
and a growing number of customers are proving the advantages of
joining the Home Radio Credit Account Scheme.' Whichever method
you opt for you'll need a Home Radio catalogue. Read all about it in
the paragraph below.
The famous Home Radio Components Catalogue comprises
200 pages, listing about 5,000 items, nearly 2,000 of them
illustrated. Everything is set out so clearly and concisely
that the catalogue is a pleasure to use. When you buy
one we also send you a free mini catalogue filled with
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Send off the coupon with your cheque or P.O. for £1 -40 now.
The catalogue and bargain list will come to you by return
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rPlease write your Name and Address in block capitals
NAME
I
'
_..
ADDRESS.
NOME
234 -240
ç'}
_._.
RADIO (Components) LTD, Dept PW
London Road. M,:Cna, Surrey CR4 3MD
(Rego No
London 912966)
L
HOME RADIO (Components) LTD. Dept. P.W.
36
,234-240 London
Road Mitcham,CR4 3HD Phone
01
-648 8422
Practical Wireless, May 1977
and a 12V supply. The absolute maximum power
supply voltage is 16V which will enable 2W to be
obtained from a 1611 speaker. However, it is wise
to regard 14V as the maximum to allow a reasonable
margin of safety. If a 411 speaker is employed, the
power supply voltage should not exceed 9V to
prevent overloading of the device. An output of
up to 1.6W can then be obtained. If the circuit is
operated from a 9V supply when using an 852
speaker, the maximum output is about 1.2W, Fig. 4.
If the supply voltage is only 3.5V, the maximum
output power is about 0.2W. Although this may
seem very small, the ear has a logarithmic response
and this power level is quite adequate for a portable
receiver; indeed, many small speakers cannot handle
more. The writer found that the circuit shown will
operate satisfactorily with power supply voltages
down to 3V but at still lower voltages the distortion
increases rapidly and the gain falls. At low supply
voltages a relatively low impedance loudspeaker of
452 may be chosen so as to provide a reasonable
output power.
Cross-over distortion is not present in the TBA820.
2000
1000
10k Hz
500
c
j
20k Hz
200
100
50
20
100
200 300
R2 (n)
Fig. 3: above. This graph may be used to select the optimum value
of C5.
Fig. 4: below. Maximum power output at various supply voltages and
speaker impedances, for a total harmonic distortion of 10 %.
50
20
PO
the power output increases, the distortion
remains almost constant at a low value of about 0.2
per cent until clipping of the waveform begins. The
distortion then rises very rapidly with increasing
output power.
The TBA820 can dissipate up to 1.25W. In practice
this means that no heat sink is required when the
device is used with power supplies of up to 16V
with a 1612 loudspeaker, up to 12V with an 811
loudspeaker or up to 9V with a 411 loudspeaker.
As
I6T41
(w)
d=10°/.
1
=
R1
1kHz
=12011
3
RL-
8n
RL-1611
s
RADIO RECEIVERS
in
4
8
4
O
16
12
The writer has used a TBA651 AM radio circuit
(see Practical Wireless July 1974) which fed a signal
into a TBA820 power amplifier. This circuit used an
11V supply but a different integrated circuit must
be employed in the radio section in receivers using
a low power supply voltage.
A simple low voltage radio is shown in Fig. 5;
only medium wave coverage is provided by the circuit
shown, but a long wave coil could be switched into
V5
+3 to
+6V
moo
C7
T10
50yF6V
50VF6V
-
4n
R1
100kn
NVO
Fig. 5: A simple integrated circuit radio
85 Turns
tuner which will provide a low power
output from a low voltage supply.
285W0
Enamelled on
Ferrite Rod
C4
111-4,
ZN 414
VC 1
50pF
Ct
10nF
100nF
+
VR1
50k
T102onF
101'81
i
Practical Wireless, May 1977
37
the circuit if desired. About 220 turns of 40 SWG
insulated wire is suitable for a long wave coil. The
two silicon diodes D1 and D2 keep the supply voltage
to the ZN414 fairly constant as the power supply
voltage falls with an ageing battery. Low voltage
capacitors are used in the circuit of Fig. 6, since
they are smaller and cheaper than higher voltage
types. However, the power supply voltage must not
exceed 6V when these capacitors are used.
v+
Plastic tank
Pump
1
Plastic tube
Holes lcm apart
offset alternately
12.5mm (lin) dia
Plastic clips
Holes 0.5mm(0.02in)dia
C7
R3
CA
X100nF
IMPROVED ETCHING OF PCB's -contd from page 33
1000FT
56n
0 0 0 0
C5
14
0 0 i'
0
O
mim
C8
1005F
See text
Input
0
Illustration of the plastic tube showing how the holes in the tube
are
drilled.
TBA 820
12
5
+
10
C6
70),F
R2
R1
100
kn
See
text
"
ment, as it increases the useful life of the etchant
and can reduce etching time to less than five minutes
thus minimising any tendency for the resist to
deteriorate. All that is required in addition to the
etching tank is a high capacity air pump as used
for aquariums and a length of 12" dia. PVC tubing.
The pump should be capable of maintaining a
pressure of 21b /sq.in.
13
n
c1
1OpF 6V
Offz
CHI
Fig. 6: A circuit in which one side
of the speaker
can be earthed.
IN USE
The TBA820 may be soldered in position on a
piece of matrix board with 0 lin hole spacing. However, a neater amplifier can be made by using a
printed circuit board. It should be noted that the
input earth connection should be separate from the
output earth connection, to minimise unwanted
coupling.
If the constructor wishes to employ a circuit in
Which the loudspeaker is earthed on one side, the
circuit shown in Fig. 6 may be used. This does
require an additional electrolytic capacitor C8 to
provide the bootstrap signal to pin 1. The component
values not marked should be selected in the same
way as the corresponding components of Fig. 2. If
a hum rejection or "anti- motorboating" capacitor is
employed in this circuit, it should be connected
between pin 2 and earth and not as in Fig. 2.
KINDLY NOTE!
TUG 'O WAR
-
APRIL 77
Main PCB, page 1032. Track from pins 13/14
IC5 should join adjacent track going to
+9V.PCBs from Readers PCB Service are
correct.
38
CONSTRUCTION
The tube is mounted close to the bottom of the
tank as shown in the diagram with 0.5mm holes
spaced about lcm apart on the underside of the tube
offset alternately by about 45 °. The end of the tube
in the tank is sealed with a rubber bung and the
other end attached to the pump, the pump being
mounted above the level of the etchant.
The etch rate is greatest near the surface of the
etchant therefore the best results are obtained by
floating the board copper side down on the surface
of the etchant. This is most easily achieved by
cutting the board slightly oversize and inserting the
corners into small corks. Double sided boards should
be etched vertically. If it is desired to increase the
etch rate still further an aquarium heater set to
about 30 °C can be used to heat the etchant.
A suitable etching solution would be:
Ferric Chloride (FeC13) 500 gm.
35% Hydrochloric Acid (HC1) 50m1.
Water (H20) 1 litre.
NOTES
Up to lml of photographic wetting agent may be
added but this may cause foaming which could prove
troublesome. When in use adequate ventilation must
be provided and the solution should not be left in
an open tank any longer than necessary as it will
promote oxidisation of any metal in the room.
The most suitable method of disposing of the
ferric chloride is to neutralise it with calcium
carbonate (limestone) and then bury it. (N.B. hard
water should not be used for making the solution.)
The success or failure of PCB production depends
to a great extent on the cleanliness of the copper
being maintained at all times. An economical
medium for mechanically cleaning the board is a
Scotchbrite' pan scouring pad followed by a wipe
with a tissue wetted with acetone in order to remove any grease present. Acetone is also suitable
for removing 'Dalo' type resists.
Practical Wireless, May 1977
Si)eCnologg
DAVID GIBSON
THIS MONTH
AP"
`The Ohm Gnome'
MANY of the previous circuits in this series
have found major applications in novelty.
The project described here has a more
serious role.
Basically it is a device for indicating the value of
"unknown" resistors. To this end it employs rather
novel principles-and no expensive meter. In use,
the resistor whose value is unknown (or in doubt) is
plugged into S -DeC holes 55 and 60. The potentiometer, VRl, is rotated until the bulb lights. The pot
is then rotated slowly in the opposite direction until
the lamp goes out, and the value of resistance is
then read or interpolated from the calibrated dial.
x
Practical Wireless, May 1977
Circuit ideas
The most immediate thought in designing such a
circuit would be to use a simple bridge of some sort,
you will need
R1
3300
Tr1
R2
R3
R4
R5
R6
VR1
47kf2
4.7kS2
Tr2
Tr3
12161
LP1
5.fikS2
4 7ki2
10k0 pot
BC109
BC109
AC128
6V 100mA bulb
12V battery
B1
One S -DeC
One Blob Board ZB -5D
Full circuit diagram of the
'Ohm Gnome' resistance
checker. If power is applied
continuously, it's a good
idea to keep some sort of
resistance in the Rx position to prevent 7r3 from
getting overheated.
39
1
AM 05231
B1
Link
Í1R2
e
r
/".
+ve
Tr3
Component
Li\k
R6
layout on the
S -DeC
giving
the exact numbered holes in
which the semiconductors and
R4
L
i
-
h
Tr2
R3
resistors are
plugged.
LP1
R5
VR1
.1
Link
Link
Bi
and indeed circuitry exists which advocates this.
However, despite the most careful tests this idea
was rejected. To turn the potentiometer until the
lamp was extinguished was almost impossible without using a magnifying glass to be really sure that
the bulb was out or at least at "minimum red glow ".
In the circuit diagram, transistor Tr3 drives
LP1 upon receipt of a suitable signal from Tr2 and
so the Tr3 part of the circuit is quite straight forward. Let's look at the role played by Trl and Tr2.
These transistors are connected as a Schmitt trigger circuit. This useful arrangement can be used for
our purpose because it triggers at a reasonably precise level /value of input signal.
Potential divider
In the circuit we are varying the input by rotating
the potentiometer. The latter, together with Rl and
the unknown value of resistor under measurement
forms a potential divider. The setting of VR1 at which
the circuit triggers will vary depending upon the
value of the unknown resistor. Thus by calibrating
the potentiometer dial using known values, the unknown ones can be read directly or interpolated.
The circuit will work well by simply "tuning" for
the bulb to switch on, but it seemed easier on test
to set the pot more precisely by "tuning" for bulboff. The only real difference in practical terms is that
the dial readings are slightly displaced between the
two sets of readings. Providing, when calibrating, the
constructor settles for one method or the other and
sticks to it (i.e. the bulb-on or -off giving indication)
then either method is entirely satisfactory. Using a
1Ok11 potentiometer for VR1 gave a measurement
range from 3311 to just over 33k11. The useful
measurement range was found to extend from 1k11
to 33k11 because the lower end of the range (below
lkfl) tended to be very cramped and difficult to read
with any degree of accuracy. Substituting a 1M11
potentiometer for VR1 gave a measurement range
from about 3311 to 2.2M11 but the dial was rather
cramped.
40
-ve
Just plug -in
Assembling the circuit on the S -DeC is extremely
simple and easy. Just plug in the components via
their own leads. Push the leads into the S -DeC hole
number(s) given in the circuit and check again,
against the full size S -DeC layout drawing. Using
the little jumper leads with plugs on each end is
helpful when links are required.
For those constructors who would like to make a
permanent unit of the Ohm Gnome the following
suggestions are offered. The simplest method of
construction, once the circuit has been "proved" on
the S -DeC, is to transfer the components directly
onto a piece of BloB Board. Because all the components are soldered and fitted on one side of the
board only, the BloB Board may be stuck (with any
good adhesive) directly to the inside of a suitable
case.
A push button should be inserted between the
negative terminal of the battery and the negative line
of the circuit (point X in the circuit). In operation,
press the push button and hold it down. Rotate the
pot until LP1 lights, then release the push button
(if tuning for lamp -off, hold push button until you've
"tuned" back to extinguish the light). In this way the
battery life will be considerably extended since the
circuit will only draw current when actually
measuring.
Dial construction
With a reasonable size case, a useful size of dial
can be employed, and it is suggested that the constructor consider making the dial with the aid of
a protractor. Mark the dial around the potentiometer
pointer accurately, in degrees. Then, using a piece
of graph paper mark degrees along the X axis, and
the known resistance values along the Y axis. Plug
in, say, a lk1Z resistor, 2.2kf1, 4.7k11 10k11
12k11 22k11 27k1Z 33k11. These will give you all the
points you need to draw a graph. You will find most
of these resistors from previous projects in this
series.
Practical Wireless, May 1977
IN NEXT MONTH'S
PRACTICAL
WIRELESS
FOOTBALL
platm~
SOUJASH
[PELOTA
ON- SCREEN SCORING & SOUND EFFECTS
CW FILTER UNIT
VERSATILE AF GENERATOR
Practical Wireless, May 1977
41
Oscillator
1
Low pass fitter
and AF. amplifier
Mixer
Search
oscillator
Fig. 1. The block diagram of the
Beat Frequency Oscillator detector in its simplest form.
TI
Search coil
1
Beat Frequency Oscillator detectors
operate on the principle that the outputs of
two separate oscillators are combined to pro.duce an audio tone although the oscillators may be
at non -audible frequencies.
The metal locator uses the search coil as the
tuned circuit of one oscillator so the presence of
metal objects modify the resonant circuit causing
a change in the beat note. Fig. 1 shows the block
diagram of a typical detector.
Although this type of detector is easy to construct it does have drawbacks, namely:
1. Metering facilities are ineffective and insensitive.
2. The two oscillators may drift in different directions and make operation tedious.
Z. It is difficult to obtain high detection sensitivity
combined with stable (drift free) operation.
4. In general the battery life is proportional to the
output volume and, since the output is usually a
sine wave, high outputs are required.
TRUE
W OPEL
-
F.E.T. stabilised
1
COYER'
PROJECT
Detector dock
oscillator
PART
LM3900
TSlow
AFC
cc
Fast
VCO
Fig. 2. The block diagram of the
Seekit showing a single tuned
hva48)
42
circuit.
Practical Wireless, May 1977
PRACTICAL
WIRELESS
INDEX
to
Volume
52
May 1976 to April 1977
Pages
1
-96
97 -192
193 -280
281
-368
369 -456
457 -544
545 -632
633 -720
721
-808
809 -896
897 -984
985-1064
IPC Magazines Ltd.,
Fleetway House,
Farringdon Street,
London EC4A 4AD
Issue
May 1976
June 1976
..
July 1976
.. August 1976
September 1976
.. October 1976
November 1976
December 1976
.. January 1977
February 1977
.. March 1977
..
April 1977
INDEX
ill
I
I
III
I
III
I
I
I
I
I
I
I
I
I
II III1I111I
I
I
I
I
I
II
I
I
II I1I II
I
I
I
I
I
I
II
I
I
Volume 52
May 1976 to April 1977
IIIII IIII I11
CONSTRUCTIONAL-Audio
Audio Depth Alarm by J. Lewis
Electronic Polyphon by M. J. Hughes Part
Part 2
..
..
Gas /Smoke Sensor Alarm by R. A. Jenkins ..
Home Telephone Exchange by G. M. Rossetti
(Modification to March 1976 desgn)
..
A Jingle Machine by P. W. Bond
Jingle Machine Mains Unit by P. W. Bond ..
Preamplifier for Disco System (Dec. 1975) by C. Toms
Rhythm Generator by A. S. Webb Part
Part 2
Kindly Note
1
Versatile Transistor Tester by I. Hickman Part
Part
Kindly Note
332
764
855
1035
336
..
..
..
236
302
481
CONSTRUCTIONAL-General
401
489
229
48
122
252
1
1
2
..
..
478
Car Anti-Theft Devices by A. R. Twite
..
309
Cassette Power Supply for Cars by S. Davies
422
Kindly Note
..
..
676
Chromachase by W. Bean Part
Part 2
..
..
757
Kindly Note
870, 955, 1021
..
..
..
500
Digital Car Clock by M. Fischer..
.. 1024
Dual Regulated Power Supply by T. J. Johnson
..
751
Icelert (Black Ice Warning) by I. Hickman ..
..
..
..
658
Car Lights Minder by E. Vaughan
682
S- Decnology by D. Gibson No. Guardian Angel
No. 2 Christmas Pudding
..
..
778
Saver ..
852
No. 3 Police Car Wailer
957
No. 4 Passionometer ..
No. 5 Simple
.. 1017
Stroboscope
..
29
Take -20 No. 74 Snap Machine by D. Andrews
..
..
.. 1029
Tug '0' War Game by R. Dudley
..
.. 1011
..
UHF Modulator by E. Trundle ..
324, 424, 508,
Video Writer by M. Hughes Parts -8 ..
1
-
CONSTRUCTIONAL Receiving
1
Active Rotating Aerial by F. G. Rayer G3OGR
..
..
3 -Band RF Mini -Amplifier by F. G. Rayer
Battery Economy Conversions in Transistor Radios
..
..
..
..
by B. B. Rafter
..
Crystal Controlled HF Converter by F. G. Rayer
Easytune MW LW Receiver by F. G. Rayer ..
..
FM Stereo Touch Tuner by F. How Part 1
..
Part 2 ..
..
Simple VHF Converter by F. G. Rayer G3OGR
Vertical Aerials for 144MHz by F. C. Judd G2BCX ..
394
26
62
493
950
940
1004
654
218
1
592, 685, 773, 864, 928
..
870
Kindly Note
CONSTRUCTIONAL -Test Equipment
..
AF Signal Source by W. Mooney
..
Audible Continuity Tester by I. Hickman
Kindly Note
..
Capacitance Meter by /. Hickman
Digital Frequency Meter by
Note on 2N5485
Johnson Part 1
Part 2
Kindly Note
T. J.
DFM Pre -Scaler and Modified Display Boards
Digital IC Tester by W. English
Kindly Note
FET Voltmeter by N. D. N. Belham G8FCH
Octavia Variable AF Source by N. B. Naughton
Oscilloscope Calibrator by J. Thornton Lawrence
Kindly Note
Receiver Calibration Aid by F. G. Rayer
Simple Logic Indicator by P. Hemingway
Transistor Checker by P. D. Maddison
.
KINDLY NOTE
32
845
Points arising from articles in previous volume
Stereo Disco System Dec. 75 /Feb. 76
..
Tele- Tennis Scoring Unit Sept. 75
..
Wobbulator April 76
1021
410
653
144
..
247
304, 430
589
..
830
..
.
..
..
..
..
..
.
128
78
304
SUPPLEMENTS
1021
May 1976
..
Radio Servicing Chart ..
..
..
Oct. 1976
Car Electronics Project Sheet ..
Interwipe- (Kindly Note 674). Hazard Warning Flasher
..
..
Nov. 1976
Car Electronics Supplement
Low Level Battery Indicator-Electronic Thermostat
Cirtest Probe -Burglar Alarm
Mar 1977
Info -Card -Resistors and Capacitors
836
390
746
955
138
66
.
841
.
2
SHOW REPORTS
IC of the MONTH
No. 58 Motorola MN1312P Quadraphonic Decoder
No. 59 Nat. SemiCon LM1808 IF Amp -FM Det-Audio
No. 60 Ferranti ZN424 Gated Op -Amp
..
No. 61 Motorola MC1339P Stereo Pre -Amp
..
..
..
Leicester Show ..
Military and Civilian Radio at Horsham Museum
..
..
..
..
..
by W. Tull
..
..
Radcomex 76 by D. Gibson G3JDG
RSGB 22nd International VHF Convention ..
..
Sound and Vision 76 by Colin Riches
69
244
321
602
..
863
428
497
305
337
SPECIAL PRODUCT REPORT
Bi- Pre -Pak Capacity Discharge Ignition Kit ..
Sinclair Black Watch Kit
RT-VC Stereo Cassette Deck ..
..
RT-VC Stereo Amplifier Kit
Heathkit HW8 QRP Transceiver
PRODUCTION LINES
31
157
..
..
ADC Accutrac
Adcola Soldering Iron ..
..
Aiwa Music Centre
AMSA Cassettes ..
..
..
..
Antex Alarms
Advance Oscilloscope OS250A
Avo Multimeter Model 73
..
Barrie Electronics ..
..
..
Bench Grinders
421
.
782
925
MISCELLANY -Technical
Amateur Radio Satellites by R. F. Stevens G2BVN
Circuits for Audio Amplifiers by F. G. Rayer G3OGR
669
..
Part 1
..
Part 2
Discos and Associated Audio Equipment by
..
..
..
..
..
..
B. Duncan
Experimenter's Corner- Battery Discharge Indicator
..
..
Fault- Finding Guide by L. Lawry-Johns
922
1038
(continued from April 76)
General Servicing by L. Lawry -Johns Part
Bib Tape Head Kit..
Bib Cassette Care Kit
Bib Groov -Kleen Kit
..
Bi -Pak Modules
Burgess Soldering Iron ..
Cliffpalm Ltd. Power Supplies
Davis Electronic Digital Meter
570
341
..
Decimo Digital Clock
Drill Chuck
..
..
Eagle Alarms
..
Eagle R2020 Tuner /Amp ..
Electronic Services Cable Meter
..
Equipment Cases
..
Erg DIL Switches
..
Goldring G900 Cartridge
Goldring Lenco Audio Equipment
Gould Advance Digital Meter
Hadley Cassette Recorder
Heathkit GD1157 Car Alarm
Heathkit Electronics Courses
Heathkit Storage Units
Heathkit Catalogue
..
ITT Sounders
..
Jonelle Cassettes ..
Kelgray Soldering Iron ..
Kramer Realtone Clock Radio
Labgear VHF/UHF Amplifier
Lemo Trimming Potentiometers
..
..
Lemo Micropots ..
..
..
..
Lux Turntable
Nordmende Globemaster Portable
..
Olson Instrument Cases
..
Philips RS250 Digital Radio
Philips AC860 Car Radio /Cassette
Pronto LCD Clock Radio
Pye 1650 Portable Radio ..
Rank Leak Audio Equipment ..
Recklin Dust -Off Aerosol
Square M Tape /Slide Synchroniser
Sonus Cartridges ..
..
Texas TI- 2550 -11 Calculator
Texas TI -1270 Student Calculator
Texas PC -100 Calculator/Printer
..
Thunder Easydrivers
..
Wright Transformers
Warrior Products Cable Locator
151
3
41
Valve Radios
37, 166, 234, 314, 408
..
Going Back by Colin Riches
Hotlines by Ginsburg 46, 57, 165, 225, 313, 393, 517, 591,
661, 772, 861, 948
.. 1034
..
317
1
..
397
..
518
..
129
..
..
PW Surefire Project by D. Jones
Satellite Communications by B. Dance Part
Part 2
Kindly Note
Talking Transistors by P. Matthews ..
ON THE AIR
Dowdeswell G4AR 73, 169, 257, 346,
434, 521, 609, 693, 784, 873, 961, 1045
74, 170, 258, 349, 437,
SW Broadcast Bands by D. Bell
522, 610, 694, 786, 877, 965, 1046
MW Broadcast Band by C. Molloy 77, 173, 261, 350, 438,
525, 613, 697, 789, 874, 962, 1049
.. 482, 577, 672, 781
..
Vagaries of VHF by R. Ham
877, 966, 1049
..
VHF Bands by R. Ham ..
Amateur Bands by
E.
TECHNICROSS
Puzzle
Puzzle
Puzzle
Puzzle
Puzzle
Puzzle
No.
No.
No.
No.
No.
No.
13
14
15
16
17
18
and
and
and
and
and
and
Solution
Solution
Solution
Solution
Solution
Solution
30-137
230 -334
420 -481
606 -633
790 -854
938-1036
3
59
937
160
937
232
343
407
161
58
406
587
937
161
233
862
343
587
161
586
407
232
58
662
160
662
406
342
160
342
406
587
58
160
342
862
407
232
343
161
407
343
406
407
862
233
586
586
233
587
59
342
587
343
232
343
LIST OF AUTHORS
LEADERS
One Flew Over the Citizen's Band
Hear Hear? ..
Wireless or What ..
Merry -go -Round ..
Big Brother Watches
Witch Hunt ..
Ration Cards
Constructor He Say
Lend a Hand
In Passing
..
216
300
388
476
568
652
744
828
920
1002
Andrews D.
Belham N.D.N. G8FCH
Bell D.
Bond P.W.
Dance B. M.Sc
Davies S.
Dowdeswell E. G4AR
Duncan B.
Dudley R.
English W.
Fischer M.
Gibson D. G3JDG
Ham R. FRAS
Hemingway P.
Hickman I.
How F. BA Cantab
Hughes M. MA C.Eng
MIERE
MISCELLANEOUS
Books Received-New Books
CQ -CQ -CQ
34, 174, 246, 335, 423
..
.. 60, 245, 307
38, 231, 310, 431, 506, 581, 665, 849, 934
.
.
.
.
Letters
..
Mail Order Protection Scheme
News 24, 120, 217, 301, 389, 476, 569, 652, 744, 828, 920, 1003
PW Reader's PCB Service 65, 142, 254, 308, 405, 485, 576,
PW Subscription Service
Stray Signals by Point Contact
.
.
Judd F. G2BCX
Lawry-Johns L.
Lewis J.
Maddison P.D.
Matthews P.
Molloy C.
Mooney W.
Naughton N.B.
Rafter B.B.
Bean W.
Rayer F.G. G3OGR
Riches C.
Rossetti G.M.
Stevens R.F. G2BVN
Thornton -Lawrence J.
R.Tech.Eng GW3JGA
Toms C.
Trundle E.
Tull W.
Twite A.R.
Vaughan E.
Webb A.S. B.Sc
Jenkins R.A.
Johnson T.J.
Jones D.
660, 750, 835, 956, 1022
..
262
..
253
RVICE FOR READERS
Don't forget that when constructing many of the projects
published in Practical Wireless, a really neat and professional
job can be made by using a well designed printed circuit
board.
The service offered enables any reader to purchase a glassfibre, ready drilled and roller -tinned board, that has been
fully tested and approved by PW staff.
Each month PW carries a price list of all boards that are
currently available, together with reference numbers and
date of publication of the project.
READERS PCB SERVICES LTD, PO BOX
4
11,
WORKSOP, NOUS
CIRCUIT OPERATION
This new unit overcomes the first two of these
problems by using a single search oscillator whose
output is fed into a discriminator coil and the
frequency changes are converted to voltage variations in a similar manner to an FM tuner. Fig. 2
is the block diagram of this unit and Fig. 3 is the
full circuit diagram.
Since only one oscillator is employed it becomes
that much more effective to apply AFC to the
oscillator to cure drift and improve the long term
tuning stability. To accomplish this effectively, the
small voltage differential at the detector output is
amplified in a Norton Amplifier (an LM3900) and
fed to the oscillator, via a variable time constant
(R17 and C15), and applied to D2. Provision is
made to switch C15 in or out in order to give two
sensitivity settings.
'SEE
METAL LOCATOR
With C15 in circuit the high output at pin 10 of
IC1, resulting from the presence of a metalic object
entering the field of the search coil, takes an
appreciable time to effect the oscillator and the
detector is at maximum sensitivity to varying
frequency fluctuations.
With C15 switched out the output of ICIa is fed
direct to the oscillator and input variations produce
virtually instantaneous AFC correction. In this
mode the range is effectively halved.
The output of ICla is sufficient to drive a
sensitive meter. This meter provides an earlier
warning of the presence of metal objects since the
eye can detect smaller changes than the ear.
ICla also drives the audio amplifier circuit, based
on IClc and d, when the unit is switched to BFO.
The output is available either through a speaker
or plug -in earphones. This audio is in the form of a
square wave and produces a higher audibility than
a sine wave consuming the same power thus prolonging battery life.
The main tuning of the unit is performed by the
varicap diode D1 with resolution afforded by VR1,
a 22 turn preset potentiometer. Because the oscillator utilises a very high L/C ratio it is important
to use a heavy gauge wire for the search coil (the
prototype used 22 SWG) to maintain the "Q". This
also means that the large amount of capacity used
to tune the circuit results in relatively small
frequency variations, even with the abrupt type of
varactor used.
C17.L+
47 to 100yF
VR2
D6
0+91
010
1000 pF
R7
RD
22k
68k
R11
1M
+12V
16V
1Ok
R12
C11
C13
C12
270pF
1YF
T
í16V
12
Y4
LM3900
D7
0+91
R8
22k
010
11
68k
D4
114914
Rt.
D5
10
8914
0.4V-«
115
C14
001YF
10M
400YA
R14
VR3
00k
10k
+12V
R27
LM3900
Fig. 3. The full schematic circuit of the Seekit as
used with Alkaline Manganese batteries. A
stabiliser circuit for use with standard batteries
will be given In part 2.
Practical Wireless, May 1977
43
With the unit switched to "Pulse" it is possible
to adjust VR4 such that ICI.b is just below the
threshold of conduction. Under this condition the
output of ICIa is fed to one input of ICIb but,
because of the setting on the other input, the audio
amplifier is off. When a signal is present at the
search coil it results in a change at pin 10 of IC1
and ICb switches to the on state. Its output is fed
to the input of the audio stages and the treasure
is advertised, This mode has the advantage that the
detector can be used on the speaker output without
annoying others present.
In conjunction with the pulse operation is switching for Ferrous or Non -Ferrous detection. The
presence of ferrous (iron based) objects will lower
the frequency of the tuned circuit whilst nonferrous will increase it. In the Seekit type of
detection this will result in deviations in opposite
directions, see Fig. 4, and by switching from ferrous
to non -ferrous, whilst in the pulse mode, it is possible to decide if the object is what we are looking
for. Unfortunately, at the frequencies used, large
pieces of ferrous material can cause the detector
to react as if it had located something non -ferrous
due to HF eddycurrents set up within the material.
Although a sweep of the area will indicate whether
the find is large or small it could still be a large
non -ferrous item.
Detector output
* components list
Resistors
C4
33kû
68kû
C5
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
carbonate /Mylar
0021íF poly carbonate/Mylar
C6 470pF ceramic/
polystyrene
C7 470pF ceramic/
polystyrene
C8 270pF ceramic/
polystyrene
0'01 /eF ceramic/
C9
polystyrene
C10 1000pF polystyrene
C11 270pF ceramic
C12 270pF ceramic
MS2
1
22kû
MS2
1
680û
22142
22kû
68k12
68kû
Mû
R12 1Mû
R13 10kû
R11
1
R14
R15
R16
R17
R18
R19
R20
100kS2
R21
2.2M12
R22
R23
R24
R25
R26
R27
R28
R29
'IMO
10Mû
100kû
100kû
1kû
1Mû
1
MS2
470kS2
33162
C13
C14
C15
C16
C17
C18
C19
C20
1µF 16V
C21
02µF
0.01µF ceramic
2014F 16V
10µF 16V
47 to 100µF 16V
01µF ceramic
1000pF polystyrene
01 / +F ceramic
C22 47µF 16V
C23 331zF 16V
C24 10µF 16V
4.7Mû
3901111
1
002pF poly -
Use polycarbonate where
Mû
specified
100kû
33052
All }W 5%
VR1 100kû
multiturn
type AB47
VR2 10kû preset type
PT1OV
Reference
VR3 10kû preset type
level
PT10V
VR4 10k0 preset type
PT10V
Capacitors
Cl
Increasing frequency
Centre frequency of detector
íw4491
Fig. 4. The changes in output voltage resulting from frequency changes.
Use is made of the positive and negative changes to identify ferrous
or non -ferrous materials.
C2
C3
carbonate/Mylar
The capability of the unit is largely a function
of the search coil. Small coils are best for detecting
small objects fairly near the surface whilst large
diameter coils will sweep a large area and detect
Coil
diameter
Number
of turns
Inductance
Frequency
with 01µF
Capacitor
7" (175 mm)
25
24
23
22
22
243µH
224µH
235µH
215µH
242µH
220µH
245µH
222µH
102kHz
106kHz
104kHz
108kHz
102kHz
107kHz
101 kHz
107kHz
8" (200 mm)
9" (225 mm)
21
10" (250 mm)
21
20
Table
1.
The approximate resonant frequencies for coils
diameter and number of turns.
44
of varying
IC1
Tri
Tr2
Tr3
Tr4
D1
D2
D3
D4
D5
D6
D7
LM3900
BF256 (FET)
BC108 or similar
BC108 or similar
BC108 or similar
MVAM2, MVAM115
MVAM2, MVAM115
1N914, 1N4148
1 N914, 1 N4148
1 N914, 1N4148
0A91, 0A90
0A91, 0A90
Inductors
L1
L2
L3
THE SEARCH HEAD
0.01/4F ceramic
0.011/F ceramic
0-02/4F poly -
Semiconductors
search coil, see text
20 to 43 mH screened choke, Toko type 10RA /RB
Detector assembly, high Q, Toko type ST3/D2
Miscellaneous
Speaker, 35 to 80Q. Crystal earpiece with plug and
socket. 4 way change -over switch, push button, non interlocking. Meter, edge reading, 400µA or better.
Case, moulded or suitable box to hold components.
Detector head, moulded or home made. Plastic tubing
and joints if required. Coax plug and socket. Coax
cable, approx 1 metre (3ft).
objects at a greater depth. Thus the coil used will
depend to a large extent on the type of hunt.
Whatever size of coil is used it is essential to
exercise care in its construction, details of a satis-
factory method are given later. The varying
numbers of turns for various diameter coils are
given as Table 1. These coils have been calculated
to give an operating frequency of about 90kHz since
this is within the approved range of the Home Office
and has advantages over lower frequencies in the
band.
Practical Wireless, May 1977
A
Fig. 6. The component positions and orienafions. Note that provision is made for the
stabiliser required if standard batteries are to
Fig. 5. The wiring pattern of the electronics
board, shown full size to enable direct copying
for the 'Do- lt- Yourselfer'.
be used over long periods.
+12V
with stabiliser
53
S2
S1
S4
Ozal
+12V
without stabiliser
DA
VR1
-i
Meter
4
R29
-i
I-
/e
+T +
R
R
5
R
26
R
b
R
AiAAAAiAiA
21
IC1
T
R
C220
R
A
1
1R6
D2
D1
8
-{ R20 I-4
005
+
C18O
--{ R19 I--
T
p
C1
C
3
R12
R
R
9
10
e
T1 Tú
-i
q
8
T
C2
Note: On Fig. 3 the
R13
f- +'6
V0 0 pf
polarity of 07 is
incorrectly shown
reversed.
I-
L3
OD4
R
3
L1
-I
Zi1
7
C
VLlWWWW
LS via JK1
4+
C13
1
R
,
LS
+
R18
C21
D
T
TrA
OV
RA
Tr
C6
CyC9
-I
R6
jIAM0522I
Practical Wireless, May 1977
45
to the individual constructor but the following
points must be observed.
1. The wire should be 20 or 22 SWG.
2. The windings must be wound tight and held tight
after winding.
3. A Faraday electrostatic shield should be fitted
but remember that the shield must not be a
complete short circuit around the coil.
If searching for a particular object recently lost (e.g.
coins on the beach or a ring in the garden) a small
coil is required but if combing an old battle field
looking for swords etc., then the large coil is the
answer, see Fig. 7. The 8 inch (200mm) coil on the
prototypes was able to detect a 2 pence piece at
between 8 and 10 inches in free air and, with a well
shielded coil, in most other non -metalic materials.
,\1t
0111 ll
Fig. 7. An impression to show that
although the field may be more concentrated In a small search head the
penetration and area covered is much
reduced. For most applications a head
of about 8 inches (200mm) diameter
will provide a reasonable compromise.
The use of large diameter heads could
result in more digging than searching
due to the greater depth scanned.
i
1111111
I
11
1
{
li
1\
Smaller coil concentrates field and
assists pinpointing
i
j
'
11
1
Larger coil offers better depth of
penetration, though less ability to pinpoint smaller objects
CONSTRUCTION
Apart from the speaker, the phone socket, the
meter, the batteries and the search coil all the
components are mounted on a single printed circuit
board. Fig. 5 shows the wiring pattern of the board
whilst Fig. 6 shows the component location and
orientation on the board.
The prototypes were constructed as follows and
took care of the above conditions.
Firstly several strips of adhesive tape were fastened
to a saucepan of about 7 inches diameter such that
a portion of the sticky side faced outwards. Next,
25 turns of 20 SWG enamelled copper wire, with
a quality lacquer coating rather than a polyurethane finish, were wound tightly around the former
A photograph of the
prototype board, complete with
the stabiliser circuit components. Comparison with the
component overlay of Fig. 6
will show some changes in the
components used. These were
necessary to improve long -term
stability of the oscillator. The
second prototype, constructed
to Fig. 6, was working when
photographs were needed.
Fig. 8.
The meter and an output socket are mounted on
the case of the unit and, if the moulded case is
used, the mounting positions are cast in during
manufacture.
The batteries are fixed into standard holders and
the holders themselves are bolted to the case.
The electronic items do not present any problems
in their assembly since it is largely a matter of
wiring -up a printed circuit board. The coil, on the
other hand, does require very careful construction.
The details of a suitable former etc., can be left
46
and on the tape. When the winding was completed
the ends were held tightly whilst the tape was
folded over the turns. The winding was slid off
the former and the tapes bound tightly around the
turns, covering as much of the winding as possible.
Extra tape should be wound over the wire to cover
it completely. The tape should be wound as tight
as possible and if heat shrink tape is available it
could be used with advantage.
This article will be completed next month.
Practical Wireless, May 1977
Circuits for
AU 10 APLIFIER5
PART 3
COMPLEMENTARY SYMMETRICAL
OUTPUT
Fig. 17 is a more convenient circuit, using a single
battery. The speaker is coupled by C3. Each output
transistor has its own emitter resistor, to help to
stabilise working conditions. Overall stabilisation is
obtained by Rl from the output emitter circuit back
to Trl base. DC feedback of a similar type is found
in many driver /output circuits of this kind. It is
necessary to use the transistors shown (or near
equivalents) or the value of R5, in particular, may
need changing.
F.
G.RAYER G3OGR
Where a matching transformer is used, its ratio is
obtained from the formula:Optimum Load
Speaker Impedance
For example, a 3f1 speaker is operated from an output stage requiring a 25551 load, so 255/3 =9.2:1
approx. These are the operating conditions for the
amplifier in Fig.14.
The transformer must be able to handle the required power, from a few hundred milliwatts with
small amplifiers up to hundreds of watts with large
amplifiers. Windings must be of low DC resistance
for the rated power to be realised.
THERMISTOR COMPENSATION
With circuits of this kind, best results are obtained
with the correct speaker impedance. Somewhat
higher impedances may be used with a loss of
volume. Lower impedances should not be used, as
this may damage the output stage transistors.
It was seen that acceptable working conditions
are easily maintained over a range of temperatures
and voltages in the case of low power amplifiers
where emitter stabilisation was possible. In other
circumstances additional means of stabilisation are
needed, and Fig.12 included a thermistor in a Class
A stage.
Fig.18 is a 1W transformerless amplifier in which
the VA1040 thermistor stabilises the operating current of the output pair Tr3 and Tr4. The resistance
of the VA1040 falls as temperature rises, thus reducing the base /emitter bias voltage of the pair.
This effect is the opposite of that arising in the transistors themselves.
Quiescent (no signal) current is set by V111 to
between 12 and 15mA. The emitter of Trl samples
the DC voltage at the emitters of Tr3 /Tr4, and by
DC coupling through Tr2, maintains DC operating
conditions. Tr3 and Tr4 require heat sinks about
4X 4cm of 16SWG aluminium, or larger. DC operating conditions of all stages are related, so values
should be as shown.
QUIESCENT CURRENT
SPEAKER IMPEDANCE
The speaker impedance specified for a circuit
should be used, depending as it does on operating
conditions and power output expected. A lower impedance may cause peak currents to be exceeded or
result in too high a dissipation in output devices. A
higher impedance than specified usually causes reduced power output and possibly other troubles.
Changes to output load can upset feedback circuits
and the correct load is particularly necessary with
high fidelity equipment.
Practical Wireless, May 1977
The "silent" or quiescent current of an output
stage is very easily adjusted with circuits such as
Fig.19, as DC operating conditions are isolated from
other stages. Rl and R2 set the base bias point and
their relative values control the collector current of
Trl and Tr2. Reducing the value of Rl, or increasing
the value of R2, moves the base bias negative and
increases collector current (with PNP devices). Reducing R2 or increasing Rl has the opposite effect.
If the quiescent current is low, objectionable crossover distortion arises, especially with falling supply
voltage or reduced temperature. If current is high,
47
-9V
2.2k
80
510
125uF
5k
Tr3
i320pF
AC1
320pF
A 1W four- transistor amplifier In which a thermistor
VA1040 is used to stabilise
VR1
250
Tr1
VA1040
ItsAC127
the output pair.
ACi41
8pF
15k
Input
2.7
1.5k
C
gap. gr.AC128
AC142
400uF
ÁC 147
320,uF
2-2k
39
OV
700pF
I
W434
J
dissipation in the transistors rises, so close -tolerance
resistors are often necessary for Rl and R2. An alternative is to use a pre -set resistor, such as 10012 for
R2. The total collector current can then be set to
8 to 10mA, for the transistors shown:
INTEGRATED CIRCUITS
Numerous ICs suitable for audio applications are
available and they can be used in a wide range of
circuits. They may be obtained with gain, power handling and other ratings suitable for pre -amplifier,
output and other purposes. Some require relatively
few extra discrete components (resistors and capacitors) and they are available for a considerable range
of operating voltages. Some have integral overload
protection. These devices may be used alone or in
conjunction with transistors and can often offer
advantages compared with the use of individual transistors for all stages.
-9V
With many ICs there are optional speaker loads,
depending on the operating voltage and power dissipation. The TBA800 is also an example of this and
can be expected to deliver up to about 1.8W with a
1612 speaker but about 3W with an 812 speaker, when
using 14V. Apart from the obvious advantage of using
a pair of ICs for stereo, ICs may be combined in
arrangements similar to the push-pull output stage,
allowing more power than would be available from
a single IC of the same type.
THE MFC4000A
This is a simple, low-power audio IC having the
configuration shown in Fig.20, employing stabilised
driver and output stages. There are four external
connections only, as shown. Fig. 21 is an operating circuit for this IC the extra components consisting of an
input coupling capacitor Cl, by-pass capacitor C2,
speaker coupling capacitor C3, and feedback resistor
Rl.
The more important ratings for an audio IC
are similar to those which would apply to an amplifier constructed from discrete components. These
characteristics allow an IC to be chosen to suit the
IW438I
3
+ve
Driver
OV
4
IW435)
Amplifiers using ICs may be assembled on perforated board or PCBs prepared for the purpose.
Some ICs have tabs which must be soldered to areas
of the board, for heat sinking. This in turn, may depend on the operating voltage, or power required. For
example, the TBA800 audio IC requires no heat sink
provision, other than the tabs provided on it, for up
to 1W but for higher outputs the tabs are soldered
to copper areas of the PC board. Other ICs rely on
the use of certain pins, or alternative methods, of
carrying heat away from the interior of the device.
48
Output
2
Input
-ve
1
Practical Wireless, May 1977
purpose in view. For the MFC4000A typical ratings
connected from pin 8 to negative line. The 1000,4F
capacitor should have short leads to pin 14 and the
negative line. Top -cut tone controls may be connected
from pin 2 to 6.
are:
Operating voltage
9V
No signal current
3.5mA
Maximum output
350mW
Sensitivity (50mW output)
15mV
Harmonic distortion (50mW)
0.7%
If complete details of an IC are required, or an
internal circuit (such as that in Fig.20) these are
often available from the maker or supplier. Otherwise it is more general to show only the external
circuit (Fig.21) as this is all that is required to build
an amplifier. In Fig.21, the top of the device is shown,
with pins in their actual locations. With other circuits,
pins are numbered, and do not usually appear in
their actual locations. The latter are found by
reference to a diagram of the device.
Cl
100nF
00k
Input
400pF
100pF
Ov
I
W440
I
VOLTAGE /POWER
SL414A /SL415A
With an IC amplifier there is a range of possible
operating voltages. The lower limit is set by the device ceasing to give an adequate performance (or to
operate at all) while the upper limit depends on the
device itself, heat sink and speaker impedance. With
many circuits less than maximum operating voltage
is used, but the voltage should only be increased
when it has been checked that operating conditions
are still suitable.
These IC's provide 3W or 5W, with 18V or 24V
using an 812 speaker, the power dropping to approximately 2.2W and 3.8W with a 1612 speaker. The IC
includes a pre -amplifier (24dB) and main amplifier
(26dB) sections and automatic overload protection.
Fig.24 is a simple circuit for these ICs with input for
the main amplifier (4) taken from the volume control
VR1. Satisfactory working, with reduced output,
is possible down to 9V.
I
W4381
2W
1W
3W
Output
In Fig.22 the dissipation expected in the LM380
IC is shown for 12, 14 and 16V, with an 812 speaker.
When no heat sink is fitted, dissipation should be
kept under 1.25W. This sets 14V as a maximum safe
voltage with an output of a little over 2W. With
12V about 1.5W output would be expected. With 16V
a heat sink is necessary.
Fig.23 is a circuit for the LM380 and it also shows
the pins. When a heat sink is necessary, pins marked
HS are soldered to it and it may be a foil area of
the PCB. If high frequency oscillation arises, a 1000/4F
capacitor with a 2.712 resistor in series may be
Practical Wireless, May 1977
Fig.25 is also suitable for the SL414A or SL415A.
More components are required but the pre-amplifier
output (5) is taken to the main amplifier input (4)
and gain is increased. A high -frequency by -pass capacitor may be required from pin 9 to pin 1 near the
IC (as in Fig.24). In some cases a 2212 resistor and
47nF capacitor in series may also be required from
pin 10 to pin 1.
TO BE CONTINUED
49
ed
Oted
G.Q H.SJOGREN
BATTERY
CHARGER
battery charger offers several features
which are usually omitted on the general run
of charger circuits.
In particular, it protects itself and the battery
from damage in the event of the charging leads being
connected the wrong way round, it protects itself
against damage from the charging leads shorting
together, its charging rate and the end voltage of
the battery are easily adjusted during manufacture
or subsequently and the components are relatively
easy to obtain.
THIS
DESIGN IDEA
To provide the above features the author chose a
circuit using a constant current generator and a
variable on /off period of charging. The switching
for the on /off is a mixture of electronics and electromechanics since the charging current is switched
by a thyristor whilst the thyristor itself is switched
by a pair of contacts on a relay.
Board
D9 1N4001
Bridge
R6
rectifier
18k
2N3702
R9
33k
1
R14
1k
T
LED1
Mains
RL2
+
Battery
1
R11
680{íF
47k
Tr1
TH1
THY 5A/50
2200pF
R5100
2N3055
3x IN4001
I
1
LBoard
1
_____
J
R4
see text
L Tagstri__I
I
Connection to metal case
Fig.
50
1.
The complete circuit diagram
1W3561
of the charger. Although a single PCB is used the components mounted on It have been split to enable normal
progression through the circuit.
Practical Wireless, May 1977
Having determined the charging rate and the end
voltage the unit will regulate its on /off cycle quite
automatically, providing a rapid charge initially but
not tailing off quickly (as a normal charger) when
the battery voltage approaches its charged state.
CIRCUIT OPERATION
Fig. 1 shows the complete circuit for the charger.
The mains are stepped down by the transformer
Ti and the low voltage output is bridge rectified
by diodes D1 to D4 to provide the pulsating DC required for charging.
The additional circuitry of D5 and Cl provides a
smoothed DC supply for the base of Trl. This
potential, and the base current, of Trl is controlled
by R1, R2, D6, D7 and D8.
The charging current has to flow through Trl
and, with its base stabilised, the current is limited
by the emitter resistor R4. The charging current
must also flow through the thyristor Thl and it is
this device which switches the charging current on
and off.
* components list
Resistors
R1, R2
R3
R4
R5
R6
R7
R8
R9, R10
47e, 5W, Wire wound
22t1, 5W, Wire wound
see text
100525% 1W
18k12 5% 1W
1kS25%3W
10kí2 5% 1W
R11
47kí2 5% 1W
R12, R13, R14
VR1
1kÚ2
3
3ki25%INN
5162
5% 1W
lin. horiz. preset
Capacitors
C1
C2, C3
680 /rF or 1000µF, 35V
2,200 /4F, 16V
Semiconductors
D1 -D4
D5 -D9, D11
D10
LEDI
Silicon rectifier, 5A, 50V
individual units or single bridge
Silicon rectifier 1A (1N4001)
Zener diode 5.6V, 400mA
Any light emitting diode
Miscellaneous
T1, transformer, 16V and 18V tapped secondary at
4A. PCB, Readers PCB Service. RL1, relay, 12V coil,
2 WO contact sets. S1, switch, S.P.S.T. 5A rated.
Ammeter, 0-5A. Box (size will depend on meter and
transformer used). Double tag strip, 10 tags each
side. DIL socket, 8 pin. Terminals. Battery clips.
Grommets.
Note
1
of the components used can be obtained from
sources. Minimum requirements have been
and devices better than these can be used.
mail order companies will supply against the
specifications given.
Most
local
given
Most
Note
2
Suitable transformers are available from Everest
Instruments Ltd., 34 Shakespeare Street, Nottingham and Barrie Electronics, 3 The Minories, London
EC3N1BJ
Time (mins)
start
5
30
110
140
200
440
530
590
Battery Voltage
9
Current (amps)
3.4
11
3
12
12
12
12
13
14
14
3.0
1
29
28
28
28
27
2 8
Table 1. The charging rate and time to bring a fiat battery to fully
charged. The current and voltage figures have been rounded off Note
that a/though the charging rate does fall -off it is effectively level over
a significant portion of the charging time.
The heart of the thyristor charging circuit is the
operational amplifier ICl, which is acting as an under voltage switch. The negative input, pin 2 of ICI,
is fixed by tapping across VR1 which is, in turn,
regulated against supply variations by zener diode
D10. The sampling voltage on pin 3 of IC1 is a fixed
percentage of the battery voltage and is determined
by the potential divider R6, R7 and R8. Capacitors
C2 and C3 slow down the "hunting" action of ICl
when the battery is in the fully charged state.
With a discharged battery connected the sampling
voltage will be below the reference voltage and IC1
will cause Tr2 to conduct. The supply for the circuit
is obtained from the battery itself when first
switched on. When Tr2 conducts, the relay RL1 is
energised and a DC current is fed to the gate of the
thyristor. The anode of the thyristor is connected to
the negative side of the bridge rectifier and the
cathode is fed, via the battery, with the pulsating DC
from the positive of the bridge. Therefore the
thyristor can pass the charging current. Transistor
Trl already has base current and now has a collector voltage so it too can conduct. The battery is
therefore being charged.
When the battery reaches its fully charged voltage, usually set at about 14.3V, the positive input
at pin 3 of ICl exceeds that at pin 2 and ICI switches
off transistor Tr2. In turn, Tr2 de-energises the relay
which removes the gate supply to THl. With no gate
current, TH1 will switch off at the next half cycle
trough and will not switch on again.
The removal of the charging voltage permits the
battery to drop from its "voltage on charge" to its
"voltage off charge" and the cycle is repeated. Without the capacitors C2 and C3 the cycle is governed
by the relay energise and de- energise times and the
relay chatters.
PRACTICAL CONSIDERATIONS
Before obtaining any components it is necessary
to decide on the charging current required. For
most home garages about 3A is sufficient. Table 1
shows the time taken for a nominal 3A unit to bring
a very flat battery up to its fully charged condition.
Although the unit is a constant current design the
current does decrease as the battery voltage increases but not by a significant amount. The author
settled for 3A and the components list is based on
that current.
Having chosen the charging current the choice of
components can be made bearing the following
points in mind.
Practical Wireless, May 1977
51
The transformer should be double wound and have
a secondary of 16V to 18V, if higher currents are
required then voltages above 18 may be required.
Since the secondary is bridge rectified it doesn't
require a centre tap.
The rectifier bridge can be an encapsulated unit or
separate diodes. Silicon rectifiers are preferred because of space and reliability but it may be possible
to pick up a suitable selenium stack at a local shop.
Although in a bridge circuit each diode supplies only
half the rectified current it is better to use devices
with a generous safety margin, say a 5A device for a
3A or 4A charger.
Trl can be a 2N3055 for currents up to 15A but will
need a heat sink, (if a metal box is being used, bolt
it onto the side). By earthing the collector, as in
Fig. 1, there is no need to use insulating washers.
R4 may be dissipating several watts at the higher
charging currents and voltages. To assist in setting
and adjusting the current several resistors in parallel have been used. The values and numbers will
depend on what is available locally. Table 2 gives
the currents obtained against various values of
emitter resistance. Since the prototype used 212
units the table is based on numbers of these in
parallel.
Number of 1012
resistors in
parallel
(R4)
10
8
5
2
Charging
current at
16V setting
(amps)
2.8
2.5
1.7
not measured
Charing
current at
18V setting
(amps)
3.0
2.8
2.0
1.1
The relay resistance should be at least 100 ohms
and the transistor Tr2 should be capable of passing
at least 200mA collector current.
CONSTRUCTION
The small electronic components, which will be
common irrespective of the charging current selected, are mounted on a single P.C.B. The wiring
pattern for this board is shown as Fig. 2 whilst the
component positions and orientations are shown as
Fig. 3.
The only large component common to all charging currents is the relay. This is also mounted on
the P.C.B. but, to leave the choice of type as great
as possible, provision is made to make connections
between it and the board by flying leads. Some form
of mechanical fixing will be required but the type
and location will depend on the relay selected.
Although a metal box is not essential for containing the circuitry it has many advantages, both
mechanical and electrical.
The power transistor, Trl, will require a heat
sink approximately 312 inches square for a 3 or 4A
charger but could be bolted directly onto the side of
a metal box. Since the design earths the collector of
this transistor there is no need to use insulating
washers.
Whether the box is metal or not, heat sinks will be
required for the thyristor and the bridge rectifier.
These can be of 16 gauge aluminium approximately
312 inches square. To save space they can be folded
into channel sections but must be mounted vertically
to ensure an adequate air flow. The thyristor must
be fitted with insulating washers and if individual
stud mounting diodes are used they too must have
insulating washers.
Table 2. The charging rates against Tri emitter resistance and supply
voltage. Note that the charging current does not have a linear relationship with the supply voltage. Higher voltages were not tried on the
prototype and the requirements for higher currents cannot be specified.
Current setting can be achieved by adding or
removing resistors and, subject to the ratings of
the rectifiers, transformer and thyristor not being
exceeded, no components need to be changed.
Current levels could be changed by switching the
resistors in or out but the switch must be rated at
several amps. No details of switching are given nor
is a switch called for in the components list.
The thyristor passes the full charging current
and for a 3 to 4A charger should be rated at 5A
minimum. The applied voltage is low and the lowest
standard working voltage of 50V is ample. Similarly
there is a large gate current available and the device doesn't need to be a sensitive one.
The relay needs two pairs of contacts, both
normally open, one pair for the thyristor gate and
the other pair for the indicator. When an open relay
is used together with a large metal box for the unit
it will probably make a sufficiently loud noise to
enable the indicator to be dispensed with. In this
instance, of course, a single pole relay will suffice.
The relay noise and /or the indicator lamp coupled
with the reverse polarity protection built into the
unit makes it possible to connect the battery to the
charger in complete darkness. If the polarity is wrong
nothing happens. No noise, no light and, more importantly, no damage. On reversing the connections
at the battery or at the charger the system should
oper ate correctly.
52
A photograph of the inside of the prototype. This unit did not use a
PCB and several of the components now mounted on the board were
mounted on the tag strip.
The resistors making up R4 were mounted on tagboard. This made changes easy and would assist
switching if required. Although 211 units were used
the individual components can be of any low value.
Although the prototype didn't get more than just
warm, holes were drilled in the ends of the case to
enable an air flow when fixed to the wall. Several
Practical Wireless, May 1977
r
Battery -ve
terminal and TH1
1
1
ev-
Bridge rectifier +ve
4.1
e
b
R12
}--+
Tr2
r--{ R13
c
1---0
5
D11
C3
C2
Tri /base
4
Cl
+
8
f
f
RL2
Relay
R4 and
bridge rectifier -ve
1
1
LEO
1
anode
1
D10
--I
T+
---{
R5
Ho
R10
}--TH1
LED cathode
1AM05161
Fig. 2. The upper drawing gives the wiring pattern of the PCB designed for this charger, drawn full size. The individual tracks are capable
well over the 3A used. The lower drawing shows the location and orientation of the components
small holes are better than a few larger ones unless
a screen is used to prevent items falling in.
When the battery has reached its "fully- charged"
state the relay will de- energise. Because of the
differences in "on-charge" and "off- charge" voltages
the relay will pull in and drop out all the while the
charger is connected. The rate will depend on the
Practical Wireless, May 1977
of carrying
charging current set but will be 3f the order of 10
seconds. The meter will try to follow this change
from full charge to no charge and will seem to
fluctuate. To minimise possible damage to the movement a switch has been incorporated and the meter
can be short circuited. The relay noise and the indicator will show that the charger is still working.
0
53
I see new chips
Three new devices that have
recently come onto the market are
discussed below and are available
from Rastra Electronics, Distronic',
and SGS -ATES, respectively:
The first is a precision waveform
generator /voltage controlled oscillator, and designated the ICL8038CCPD. The IC is said to be capable
of producing sine, square, triangular,
sawtooth and pulse waveforms at
frequencies ranging from less than
/1000Hz to more than 1MHz. FM and
sweeping can be accomplished with
an external voltage, and it is claimed
to be highly stable over the temperature range of 0 °C to 70 °C.
Package is a standard 14 pin DIL.
Further information
from Rastra
Electronics, 275-281
King Street,
Hammersmith, London, W6. Tel:
-
Order in comfort
Regular readers of PW, will I'm sure,
have seen the Maplin advertisements
regularly carried on the back cover of
this magazine. Now, to make the job
of ordering components an easy,
accurate and enjoyable pastime,
Maplin have come up with a brand
new catalogue containing hundreds
of photographs and illustrations.
Measuring 285 x 205 x 10mm, this
latest offering contains 216 pages
packed with details of components,
circuit ideas, diagrams & PCB's, kits
for synthesiser, organs, amplifiers,
and sections containing tools, books
and cabinet hardware. In fact just
about everything the DIY electronics
enthusiast requires.
The catalogue comes complete
with up -to -date price list, order form,
postage paid envelope, and money
back guarantee if returned within 14
days of purchase. The price incidentally is 50p.
For those
interested, contact
Maplin Electronic Supplies, PO Box 3,
Rayleigh, Essex. Tel: 0702 715155 or
ca /I at Maplin's shop 284, London Road,
Westcliff-on -Sea, Essex. Tel: 0702
47379.
maPLIn
ELECTROflIC
SUPPLIES
01 -748 3143.
l
SUPERSONIC
SAME DAY
SERVICE!
QUALITY
L_S
COMPONENTS
FAST!
ct
54
Continuing with oscillators, Distronic have released details of their
crystal controlled oscillators, which
combine crystal techniques with
hybrid integrated circuit technology.
The units are claimed to have the
high stability temperature and aging
characteristics associated with ATcut quartz crystals, and are available
for driving multiple TTL or C -MOS
loads. For TTL types, the available
frequency range is from less than
0-25Hz up to 30MHz with an input
voltage of 5V DC.
The frequency range of the C -MOS
oscillators is from 300Hz up to
10MHz for TO -5 package types and
from 0.0002Hz up to 10MHz in 14 pin
DIL packages. Distronic Limited,
50-51
Burnt Mill, Elizabeth Way,
Harlow, Essex. Tel: Har/ow 32947.
Probe for faults
Electronic enthusiasts are well
aware of the ever increasing use that
is made of DTL, TTL/C -MOS devices
in almost every type of circuit that not
so very long ago would have necessitated the use of hundreds of transistors. Unlike transistors though,
logic IC's are generally more difficult
to test in circuit, especially C -MOS
devices which require extreme caution, if they are to survive the rigours
of testing.
A logic test probe is the answer,
and the latest to appear in the UK
market is sold by Rastra Electronics
Ltd, who have launched the LP -1 logic
probe. A few of the parameters of
this probe are a detectable pulse
width of 50nS, a maximum input
frequency of 10MHz and a power
requirement of from 5 to 36V. LED's
are used to indicate logic '1' (2.25V±
0.015V 70 %Vcc) or logic '0' (0.8V±
0.01V 30% Vcc) and pulse, which
blinks on for #S transients. Price is
£28.60 plus VAT.
1
The new SGS -ATES chip is a
terminal voltage regulator -the
L200. Output voltage is adjustable
between 3 and 30V and output
current adjustable from 0 to more
than
-8A. Thermal overload and
short circuit protection are also
incorporated, as is second breakdown and overload protection which
enables the L200 to withstand spikes
of up to 60V. Load regulation is said
while ripple
to be 0.1% of
rejection is better than 70dB. Other
applications for this device are
precision current limitation and
switching regulation in which neither
external transistors nor additional
protection circuitry is required.
5
1
Rastra Electronics Ltd., 275 -281 King
Street, Hammersmith, London W6
Tel: 01-7483143
Further information on this product
from SGS -ATES (UK) Ltd., Walton
Street, Aylesbury, Bucks. Tel: 0296
5977.
Practical Wireless, May 1977
Disco Separates
Rather than 'Cart around' a heavy
disco comprising of decks and
amplifiers combined in a single
cabinet, it is often advantageous to
have separate units. The new RTVC
70W and 100W RMS mono disco
amplifiers fit into this category, each
providing a full range of mixing
facilities and an input for a separate
slave mixer amplifier. Both units are
fully protected against speaker malfunction and against any short
circuit conditions. Maximum power
is developed into 4ohms.
Inputs 'Deck 1' and 'Deck 2' are for
ceramic cartridges with outputs in
the order of 200mV, while the 'Mic'
input is a dual sensitivity type,
accepting either 1mV or 10mV
outputs. Microphones may be of
either high or low impedance. Other
inputs provided are 'Tape in' (300mV
into 50k ohms), 'Tape out' (150mV at
100k ohm) and 'Slave in', 'Slave out',
both at 150mV at 5k ohm.
PFL- pre -fade listening is also incorporated on each input regardless
of the level, and is controlled by a
separate rotary control.
Along with other RTVC products,
these Disco Amplifiers are very
competitively priced, with the 70W
model selling for £4900 plus £3.00
p &p and the higher powered 100W
model carrying a price tag of £65.00
plus £4-00 p &p. -RTVC, (Dept. PW),
21
High Street, Acton, London,
6NG and
London W2.
W3
323
Edgware
Road,
4 -piece
meter
One of the most frustrating factors
instrument is that of
servicing and calibration. Alcon
Instruments claim that they have
solved this problem with the introduction of their new pocket-size
range of multimeters from Miselco.
These instruments have been designed for repair in a simple and easy
manner using factory matched rein owning any
tivity of 20k02/V and finally one intended for electronic work with a
sensitivity of '50kí2/V The latter
model has claimed accuracy figures
of 2.5% on DC and 3.5% on AC,
placement modules which, by virtue
of their design, obviate the need to
recalibrate each time.
The Miselco Tester range of four
Multimeters cover between them a
high current model capable of
measuring up to 30A; a model with a
high sensitivity figure of 1Mí2 /V; a
general purpose model with a sensi-
Everymans Sig. Gen.
Test equipment these days tends to
be so expensive, that only the largest
of service centres can afford to keep
up with new products. This of course
leaves the average enthusiast completely 'high and dry' when it comes
to the latest techniques in test
equipment.
To overcome this apparently insurmountable problem, Linstead have
launched a signal generator that is
one of the cheapest on the market
today, but without sacrificing quality
or facilities. Called the Linstead G5,
signals can be of either sine or
square wave, and range in frequency
from 10Hz up to 1MHz in steps of 1Hz
on the lower range. The output is
fed from a power amplifier which
allows output impedances from 600
ohms down to 5 ohms.
Claimed accuracy figures are 2%
+1Hz with sine wave distortion less
than .k% harmonic content. The outPractical Wireless, May 1977
while all the other models claim 2%
on DC and 2.5% on AC.
Each model comprises two case
parts, a movement and a PCB Any
one module may therefore be replaced by the user, using only a
screwdriver to complete the job.
Alcon Instruments Ltd, (Dept. PW)
19 Mulberry Walk, London SW3 6DZ.
put voltage of 5V RMS can be reduced
to less than 1mV by means of a
continuously variable control and the
switched atteouator. Size Is 130 x 130
priced at £58.70.
Linstead Electronic Instruments,
(Dept. PW), Roslyn Works, Roslyn Rd,
London N15 5JB. Tel: 01 -802 5144.
x 121 mm and is
55
ol/ect
butors: surely one of them could
come up with an effective design
along the lines indicated. And
then you could follow it up with
a design for a converter for the
70cm band, to work into the PW
FM receiver! F. Ness GD3ESV
4,
(Douglas, IoM).
attar
-
Designers
please note
I am one of the unfortunates
so roundly condemned by Paul
Heath of Wolverhampton on your
letters page in the February
issue. Unfortunately my QTH is
quite useless for VHF transmitting, so my activity is therefore
confined to low-power portable
working using FM. If it were not
for repeaters such as MP and
RF, I would have no contacts at
all. I rarely hear any signals on
the simplex channels.
Working through repeaters is
a great -. boon for mobiles also,
handicapped by low power and
whip aerials. And if we all incur
the wrath of the critics for not
listening on the input channels,
that is because of a shortage of
receiver designs. P.W. has published some splendid articles on
2-metre converters, and on hi -fi
equipment for the FM broadcast
bands. But never have I seen a
design for a straightforward FM
receiver for 2 -metre work.
May I suggest a possible specification? (a) single conversion receiver with tunable front -end,
using a variable capacitance
diode; (b) integrated circuit (e.g.
CA 3089E) for the complete IF
strip, possibly including the
cheap Toyocom crystal filter to
avoid the headache of alignment
problems; and (c) a small integrated circuit for the audio side,
such as the LM 380. This receiver
would work from the 12V vehicle
battery or from a small mains
power pack. I'm sure that there
would be a great interest in it on
the part of SWLs, many of whom
enjoy listening to the repeaters
but are handicapped through the
use of the inefficient method of
"slope detection".
PW has many gifted contri56
Hot tip
Re the stripping of Litz wire
(Letter H. Pruim) in the February
issue. I am now retired after a
lifetime in many branches of
work using all sorts of wires,
and for years I have used a
simple method of stripping Litz
that needs only a small meths
lamp with wick and shallow tin
lid.
Just put about a '4in of meths
in the lid and put it by the lamp.
First hold the end to be stripped
in meths flame till just red hot.
Then quickly dip the hot end into
the meths, presto -perfectly
clean strands just right for
soldering. Not much knack required, but a few trys will soon
prove the idea. George Comber
(Tadley).
High power
interference
Democracy, according to the
Radio Society of Great Britain
requires that minority groups be
given absolute priority over
other amateurs -or so it seems
on the 2m band. I will not
challenge Dr. Allaway's remarks
in your February issue about
minority groups having a right
to exist, but they must not be
allowed to take up unduly large
portions of any band, in a way
that absolutely prevents anyone
else using that band segment.
I am referring to the Oscar
command station which is located
at Surrey and requires about 100
kHz of the 2m band. The power
which is radiated (believed a few
kW E.R.P.) completely obliterates
any but the most local legal -limit
transmissions. The transmission
is in the "all-modes" part of the
band, which should be-shared by
all and not monopolised .by a
minority service which already
has its own "space" segment
elsewhere.
The RSGB required the greatest
persuasion even to publicise the
source of the nuisance. They will
now have nothing more to do
cannot even
with the matter
get them to tell me when to
avoid the frequency! The transmission begins without warning
about once every two hours or so.
It has caused interference as far
north as Liverpool.
"RSGB represents all UK radio
amateurs." It says so on my
membership card. The blatant
white -wash over the mistake in
licensing this wide -band transmission in an Amateur band
seems to suggest that the statement is in some way at fault.
How can I trust a society that
performs in this manner to safeguard my interests at WARC in
1979? It is the same society that
had a 6-month option on a very
costly investment, and although
promising "informed discussion"
on the wisdom of the purchase
and suggesting that they would
wait to hear any views that
informed members may have on
the subject, they abruptly bought
the machine in question with
most of the 6-month option
period still left to run.
Yet the RSGB is probably the
only body that can make representations to the delegation from
this country that will vote at
-I
WARC.
RSGB, you are in a position of
trust. You must be above
suspicion, in all your claims.
Please
realise
your
responsi-
bilities.-G. L. Manning, G8JBH
(Edgware).
More 'scope
Just a small but important observation I thought we ought to
share. Many useful projects have
been featured in PW associated
with oscilloscopes including the
"bolt on" goodies and details on
operation and fault- finding techniques. However, many of us, and
specifically myself, haven't got
the basic and necessary item, i.e.
an oscilloscope. The last featured
scope, correct me if I'm wrong,
was August 1973 "PW Student".
Could it be that 1977 is going
to give us a super new scope project? Well, that's it, except one
specification. Please! a minimum
4 inch tube. G. Starkey (Warwickshire).
The Editor will be pleased to
hear from potential contributors
on the above projects.
Practical Wireless, May 1977
COMPACT 2m
BEAR AERIALS
THE previous article "Vertical Aerials for
144MHz" (Practical Wireless July 1976) dealt
with omnidirectional types such as the ground
plane and vertical colinear which are convenient for
transmitting or receiving in any direction but have
relatively little gain over a dipole. For ellample, a
4- element colinear has but 4.3dB gain and is a
sizeable aerial, some 14ft or so long. Beams are the
only way of obtaining relatively high directivity and
gain and there are many to choose from with the
Yagi or parasitic array being the most popular.
However, fairly small but efficient beam aerials for
144MHz are not difficult to make and gain as high as
10dB over a dipole is possible without resorting to
large numbers of elements as are necessary for
Yagi or colinear arrays. The corner reflector aerial,
which employs only one driven element, may be an
exception and although a high gain, around 12dB or
more, is possible, the reflector itself is of somewhat
unwieldly dimensions.
TWO DRIVEN ELEMENTS
Small beams with a useful degree of directivity
and gain may be derived from "end-fire" or "broadside" arrays consisting of two driven radiators spaced
a specific distance apart with the current in each
phased according to the directivity required. In the
case of the "end -fire" array the pattern has zero
radiation broadside (at right angles) to the plane of
the array and maximum end -fire radiation when the
spacing between the elements is a half -wavelength
or less and the currents in the elements are equal in
amplitude but in opposite phase i.e. 180° phase
difference.
The configuration of this array is shown in Fig. 1
in which the spacing "d" may be from 18À to 5gÀ to
obtain the requisite horizontal plane end-fire radiation pattern when the array is vertical as in Fig. 2(a)
and looking down on the ends of the elements.
Radiation in the vertical plane i.e., with reference
to an angle to the ground, will be as shown in
Fig. 2(b).
To obtain "broadside" radiation, at right angles
to the array, the spacing between the elements is
usually a half -wavelength and the elements fed in
phase. The available directivity /gain is greatest
when the elements are spaced 12À or 58À but not
closer. The end -fire array is of greater interest
since considerable gain can be obtained with closer
spacing between the elements thus allowing for a
more compact aerial plus uni- directional or bidirectional radiation pattern as required. Such an
aerial may be operated horizontally (for horizontal
polarization) or vertically (for vertical polarization).
Greatest bi-directional gain is obtained when two
driven half-wave elements are spaced 0.125À apart
Practical Wireless, May 1977
,
I
JUDD
G2BCX
F.
and fed out of phase as in Fig. 3. The gain is about
4dB with reference to a half -wave dipole. However,
for 144MHz operation the high feed point impedance
presents a problem as it is not suitable for direct
connection to commonly used 5011 co -axial cable
although this can be overcome by the use of a matching stub.
Since beam aerials have to be rotated for maximum radiation in a desired direction there is little
point in using a bi- directional array. Better to use a
uni- directional system and obtain a little more gain.
This can be achieved with a two- element close
spaced array in which one element is fed 135° out
of phase with respect to the other. The radiation
pattern then becomes a cardioid as shown in Fig. 4
and remains virtually the same whether the aerial is
used vertically or horizontally.
An aerial based on this arrangement, to provide
even more gain, was designed by the writer some
26 years ago and is known as the "ZL Special"
although it was originally intended for HF bands
operation. It employs two driven elements fed 135°
anti -phase but the element lengths are such that one
operates as a driven element /director whilst the
other behaves as a driven element /reflector. The
radiation pattern is cardioid as in Fig. 4 and the
gain a little over 6dB with reference to a half-wave
dipole.
57
Gain
+4dB
0 B
Radiation from single vertical dipole
Max gain
Max gain
Max radiation
(a)
d
Feed point
Feed point
Max gain
(b)
Ground
Fig. 2: Radiation patterns and gain
of an end -fire array compared
with a dipole.
Max
1W4051
Fig. 1: Configuration
of
an end -fire aerial array.
Max
"ZL SPECIAL" FOR
2M
This beam is identical to the original model except
that an alternative feed method to suit 5052 co -axial
cable was necessary and the element lengths are
appropriate for 2m band operation. It is easy to
construct and the elements and phasing line may be
made from copper wire, copper tube or even 30052
ribbon feeder. Quite a large number of this 2m
version have been constructed and tested and being
a very compact aerial it has proved ideal for use
indoors since it is not generally affected by the
proximity of walls and even conductive structures,
providing these are not too close.
This beam has a broadband characteristic and
properly constructed and adjusted should exhibit
around a 1:1 SWR over the whole 2m band. Constructional details are shown in Fig. 5 and providing the phasing line length and the element spacing
and lengths are adhered to, the materials for these
may be as mentioned above. If 30011 ribbon feeder is
used the distance between conductors will of course
be that of the feeder itself.
The small air -spaced 20pF variable capacitor is
necessary to achieve a correct match to 5011 co-ax
cable and is adjusted for minimum SWR at 145 MHz.
Not more than about 10pF of this capacitance should
be necessary to achieve this. Do not use mica or
ceramic type trimmer capacitors. It is important to
curve the feed line away and down as shown in the
inset in Fig. 5 when the aerial is operated vertically
58
Feed
Fig. 3: One method
1W4071
of feeding an end -fire array (see text).
Gain
45+4 0dB
Close spaced /s)
1
phased 135°
Dipole
Close spaced /8T
phased 180°
1
Max gain
1
W4081
4: Gain and radiation pattern ofa close spaced end -fire array with
currents 135° anti-phase.
Fig.
Practical Wireless, May 1977
T.T.L.
7401
17p
17p
7402
7403
7404
18P
18P
25P
7408
7407
7408
7409
7410
ISp
7411
28p
27p 17430
7400
7423
7425
7426
7427
7428
45p
25p
25p
lip
7412
74
40p
80p
35P
40P
18p
25p
409
350
38p
409
45p
7413
7414
7416
7417
7420
7422
lip
I.C's By TEXAS, NATIONAL, I.T.T., FAIRCHILD Etc
30p
33p
33p
18p
780
76p
95p
110p
85p
850
7432
7437
7438
7440
7441
7442
7445
7446
7447
7448
7450
lip
20p
20p
7451
7453
7454
7460
7470
7472
7473
7474
7175
7476
7483
7485
7488
7489
209
20p
33p
30p
35p
37p
45p
369
7490
100P
130P
74105
74107
74109
74118
37p
265p
45p
74120
7491
Up
7492
7493
55p
45p
75p
74122
74123
74125
7496
OSP
135
809
74126
BOP
74132
74135
74136
7d137
74100
74104
359
BIp
1159
74121
1159
35p
55p
74138
74136
75P
70p
75P
74142
1359
135p
80p
320p
74154
74155
74156
74157
170p
90p
1009
1009
74144
76145
3209
7118
1209
90
74182
120p
74178
74179
2459
155p
1559
800
90p
74163
1209
74164
74165
74166
74167
1309
1709
1500
3709
74181
74181
74141
74130
150
74131
130p
00p
1009
74147
BSp
74151
1250
74153
74148
74150
280p
180p
1809
74175
100P
74191
74177
1309
1609
160p
74193
'
330p
330p
909
1850
150p
74182
74184
74185
370p
350p
200p
1600
74188
74189
74190
74170
74173
74174
74194
130p
130p
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1009
74196
74197
125p
125p
2509
2509
74198
74199
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by MULLARD, TEXAS, MOTOROLA, SIEMENS, I.T.T., R.C.A.
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AA144
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19p
25p
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2Sp
40p
200
35p
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AD149
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409
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AC126
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AF118
AF125
AF139
AF239
BZ X61
Zeners
1
8V8
90p
22p
22p
229
22p
Sop
25p
35p
4Sp
BZYSI
12V
3W 13V
15p
15
15
15
15
15
15
15
15V
18V
lop
10p
10p
10p
16p
16p
12p
15p
BC1686
1S0
BCI72C
18p
18p
Sp
Sp
35p
159
10p
10p
15p
BC168C
BC189C
BC171
BCI78A
BC182
BC182L
BC763
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BC184
101,
BC1B4l
12P
24P
100
BC186
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BC212
8C212L
12D
BC2I3L
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150
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100
11p
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10p
10p
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BC547
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tOD
129
ERIE
11V
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22V
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129
10p
129
10p
1/P
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130
11p
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35p
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159
60p
139
12p
12p
13p
120
20V
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27V
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33V
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BCY70
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13p
14p
13p
800
150
20p
15p
850
100p
05p
36P
390
45p
80132
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80182
409
/Op
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38p
409
800
809
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80137
130139
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1000
90p
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I59
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450
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250
25p
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10p
10p
10p
100
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28p
280
30p
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300
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CAPACITORS
CARBON
µF/V
RESISTORS 47/25
109 Type 7AD
1000
10p £4
10p
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10p £8
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100 Mixed
Zeners 850p Assorted
BZY88
Types
03V
15p Zeners 0509
47V
15p
51V
15p I.C's
850
56V
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1300
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68V
190p
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72V
450
15p LM556 14P DIL
160V
100p
LM710 14P DIL
SOp
LM273 TO5
60p
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LM723 14P DIL
75p
400M. W.
LM741 OP DIL
30p
Zeners
LM741 14P DIL
30p
10p LM747 14P DIL
OV7
80p
2V4
109 LM748 8P OIL
4Sp
4Sp
2V7
10p NE555 OP DIL
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100p
3V0
10p
TAA300
150p
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3V3
1909
3V6
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500
10p TAA570
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4V7
3809
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5V1
250p
200p
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100 TBA550Q
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230p
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250p
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250p
11V
109 TCA270S
2500
9V1
14p
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12p
12p
160
1/18
330/25
330/35
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,
1SÓ
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2 2125
470/35
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680/25
1000/16
1000/35
2200/10
2200/16
2200/63
2200/100
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3 3/25
47(10
47/16
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4.7/50
88/25
10/10
10/16
10/25
10/35
10/50
22/BV3
22/10
22/25
22135
2150
332/6V3
33118
33/25
33140
33(50
47110
47/16
47/25
47/35
47/50
100/10
470/10
470/25
3300/16
3300/25
3300/63
4700/25
p 4700/40
220116
220/25
220/50
35p
350
13FS94
Sip
Bep
BFW58
21p
30p
130p
BFX29
BFX81
BFX84
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BFX87
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BFY50
2Sp
BFY51
20p
20p
30p
25p
25p
ZOp
BFY52
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1259
35P
BR101
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BU105
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3Sp
35p
20p
25p
20p
800
150p
73p
220p
20p
150
iSp
22p
p
p
p
0068
01
P
022
033
p
147
p
p
1 p
p
1 p
1 p
20p
-22
.33
.47
1-00
2.2
4.7
6.8
1509
40p
TIP35A
0C171
0C200
sop
TIP36A
TIP41A
TIP41B
0A90
0A91
0A202
TIP30C
IK Lin
120p 1N11411
40p 100
12p
for 1509
80p
450 741 Op AMPS
509 100 for £20
555
100
TIMERS
5K Lin
10K Lin
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500K Lin
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Sp 100 for E300
Sp
Sp
Sp BYX94 DIODES
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Sp
12p MULLARD
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I
2
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Meg Log
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BY
LORLIN
1P 12W
20p 4500/64V C.432
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35P
75p 3P 4W
I09
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TIP29C
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0C35
0C42
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0072
0075
0081
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2Sp
0083
0084
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50p
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OOP
850
70p
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25p
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10p
5p
5p
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144002
2N897
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30p
30p
300
311p
30p
309
300
30p
30p
30p
3017
LA3
LA4
LA5
LA7
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100p
100p
1000
OSCILLOSCOPE 200p
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< 10KHz
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E22022/13
30p
300
30p
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30p
20p
30p 4000
20p
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20p
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4006
1200
4007
20p
4009
70p
200
4011
4012
200
4013
559
4015
90p
409 4016
SSp
110p
4017
40p
250p
IOp 4018
4020
140p
/Op 4022
180p
VA2600
VA3210
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VA3430
VA3708
VA8604
4054
13Sp
60p
1509
220p
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11Sp
700
50p
130p
4071
4072
4081
4082
4510
4511
4516
4518
4528
1
A 50V
IA
IA
to
IA
100V
200V
400V
00V
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306
25p
309
30p
359
40p
359
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4A
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6A
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6A
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100V
200V
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15p
149
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2N5061
2N5163
2N6027
2SD234
Sop
SKELETON
PRE-SET
POTENTIOMETERS
O.1W 50N -5M mini
up
vert L hone
-3M
5W
100N
25W
vert.
200N -4 7M
7p
horiz.
8p
LATE EXTRA
1000
TBA 800
TBA 641 Al2 250p
V A3410
4055
4056
4060
4066
4069
OSp
2N4062
2N4126
0.33, 0.47, 0.68,
1.0, 2.2, 3.3, 4.7,
6.8, 25V 1 .5, 10, 18V
4.7, 10, 22, 47,
10V 4.7, 15, 25, 33
Price 149 each
V A1111
20p
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200p
85p
155p
2013886
2143904
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35V, 01µF, 0.22,
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4023
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4028
4029
4030
4032
4043
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4047
4049
4050
12p
11 p
12p
119
12p
300p
1750
250
BEAD
V A1067
E298ED/A260
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lIp
TANTALUM
VA1063
E29522/01
E29722/04
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E29822/102
E298ED/258
SOP
2N3772
2N3819
p
Sop
1 p
20p
2 p
2Sp
100-500 KHz
22p
25p
30p
18p
20P
20p
50p
609
2103706
2N3711
2013715
P
MULLARD POT CORES
SOp
2N1711
2N3705
7p
2N456A
30p
389
2N1308
2103704
Sp
Sp
Sp
Op
N4003
N4004
N4005
N1006
N4007
N4148
S44
2N1305
2N1306
2N2219A
2N2483
2N2906
2N2907
2N3053
2N3054
2N3055
2N3439
2N3702
2N3703
tep
TIP42A
TIP42B
70p
600
65p
850
90p
100p
105p
115p
130p
115p
118p
145p
225p
TIP32A
TIP328
230p
280p
350p
70p
750
TIP41C
Sop
55p
580
850
TIP31
2000
100p
750
75p
35p
35p
35p
25p
30p
30p
30p
OC25
OC28
70p
150p
45p
47p
75p
55p
58p
65p
91039
Op
Sp
TIP35C
1850
1750
250p
550
CA3085
400p
CA3090AQ
Filter CFT455B OOp
f Op
SN 76013N
1400
SN76023
130p
SN 76227
1300
SN76228
SU7653op
TAA861B
TA
140p
1/5p
130p
5Sp
30p
309
30p
200
30p
1459
2009
140p
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125p
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40p
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15p
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CARBON
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2 Meg Lin
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p Mullard or
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£100 Each 50K
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0022
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120 BC147
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100
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759
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790
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RED '125
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1Sp
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25p
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14
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Practical Wireless, May 1977
59
ESSENTIAL
BOOKS for
RADIO
AMATEURS
Television
SINGLE CHIP SPG
Provide yourself with a broadcast quality sync pulse
generator using just a single, though rather special, i.c.
and a handful of other components. Full constructional
details of this very compact unit will be included.
RADIO COMMUNICATION HANDBOOK
Volume I
Fifth edition
First published in 1938, the Radio Communication Handbook has long been
a standard textbook on the theory and practice of amateur radio. Its
almost encyclopedic coverage of this fascinating subject draws on the
practical experience, gained over many years, of a multitude of radio
amateurs in this country and abroad. The text, which has been completely
revised and reset for this edition, is supplemented by hundreds of line
diagrams, together with many photographs, charts and tables, making
this probably the most valuable all -round reference book a radio amateur
can possess.
Volume
I
chapter titles
I.
6.
2.
3.
4.
8.
9.
Principles
Electronic tubes and valves
Semiconductors
l-IF receivers
VHF and uhf receivers
S.
464 +xvi pages
SERVICING FEATURES
Amongst the servicing features next month will be an
article by John Coombes on the GEC single- standard
monochrome chassis and advice on the French (EMO,
Eurovox and Eurosonic) colour receivers that were
imported into the UK during the colour boom period.
7.
10.
HF
transmitters
VHF and uhf transmitters
Keying and break -in
Modulation systems
RTTY
Price E9.20 post paid
THE COLOUR SUBCARRIER
PARADOX
VHF-UHF MANUAL
As we all know, suppressed subcarrier transmission is
used for the colour signal in the PAL and NTSC systems.
Yet a 4.43MHz signal is still present. Do you know why,
or what effect suppressing the subcarrier has on the
composition of the transmitted signal, and how this
affects modulation? These matters are basic to
understanding colour television but are seldom clearly
explained. E. J. Hoare remedies this situation and in
doing so brings home the full subtleties of the PAL
system.
(3rd edition)
by D. S. Evans, PhD, AIM, G3RPE,
and G. R. Jessop, CEng, MIERE, G6JP
Over 400 large- format (180 x 245mm) pages packed with ideas,
information and constructional details of tried and tested equipment, each specialist topic contributed by an acknowledged
expert in the field.
The most comprehensive and up -to -date review of vhf and
uhf techniques available today.
Chapters on receivers, transmitters, space communications,
filters, aerials, microwaves and much more. Simple amateur
television is covered and a data section provides valuable facts
and figures to help the constructor. Many of the designs make
use of integrated circuits, and the microwaves chapter gives
details of equipment for use up to 24GHz.
VCR MODIFICATIONS
Price f665 post paid
A collection of practical modifications to extend the
usefulness of the Philips VCRs.
RSGB AMATEUR RADIO CALL BOOK 1977
Incorporates all new callsigns and amendments notified between
August 1975 and August 1976.
Also includes valuable operating data such as band plans,
beacons, prefix list, ITU zone list, beam headings and QSL
Bureau sub-managers, and lists of clubs and groups.
Price E2.31 post paid
176 pages
RADIO AMATEUR'S EXAMINATION
REVISION NOTES
by G. L. Benbow, G3HB
PLUS ALL THE REGULAR FEATURES
ORDER YOUR COPY ON THE FORM BELOW
A pocket -size book containing facts and figures covering the
examination syllabus. Invaluable for reference and revision.
Price 6Ip post paid
62 pages
TO
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These are just a few of a complete range of technical
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Send a large stamped self- addressed envelope for the
Please reserve /deliver the
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continue every month until further notice.
complete list.
ting all
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NAME
interested in the hobby: write to the membership section and ask for full details.
ADDRESS
Radio Society of Great Britain
35
DOUGHTY STREET, LONDON, WCIN 2AE
L
60
Practical Wireless, May 1977
Q.
]L
Elements 12.5mm (1/2) copper tube
jW4091
4- 20mm(3/ 4")
spacing
zp,
4-
- 38mm(11/i.)+
215mm(81/
spacing
)
Forward gain 6to7dB
Rear radiation -20dB
215mm(8'/2')
Phasing line
inside tube
end
255mm (10 ")
-each
Wood
plug
Phasing line
910 mm (36 ")
:i
yL --, ,,--
_
d
E.
j
..
.-n.4
Plastic vaste
pipe 38mm
(11 2) dia
Feed point
as in Fig 5
Cx max 20pF
(see text)
13mm(V2')
r
4
4
890mm
(35 ")
Inset
470
mm
(18'/2')
Sleeve
(see text)
Director-.
Mast
Lead
I
(see text)
50 or 70ohm
Copper straps
soldered each end
Plastic waste pipe
38mm (11/2')
co -axial cable
Fig. 5: Details for the construction of a ZL Special aerial for 2 metres.
and the matching capacitor should be adjusted only
when the feeder has been secured. The short stub
mast used to support the aerial must be of insulating
material, wood or plastic tube and extended to a few
inches below the bottom ends of the elements when
it may be coupled to a metal mast. The gain remains the same when the aerial is used horizontally
but the cardioid pattern becomes a little narrower
to the sides. Note the unbalance-to- balanced co -axial
connection using a 14X sleeve which is bonded to the
main co-axial braid only where shown, at point X in
Fig. 5. The end near the feed point is not connected
to anything. For use outdoors the feed connections
and tuning capacitor must of course be protected
from weather as must the elements and for this a
small plastic electrical junction box could be used.
The elements and supporting frame (this must be
wood or plastic tube) can be given two or three coats
of polyurethane varnish.
This aerial is used by the writer on a cabin
cruiser (G2BCX /MM) at a height of only 9 feet
above the water and so far 10 European countries
as well as many UK DX stations have been worked.
The photo shows the aerial enclosed entirely in
plastic "plumbing" tube for complete protection
from weather and salt water. The aerial is also ideal
for portable work as it will fit comfortably in the
boot of a car.
Since the basic ZL is a driven array and the radiation pattern uni- directional it has been found possible to add parasitic director elements to obtain
an increase in forward gain. One director mounted
Practical Wireless, May 1977
[W4101
Fig. 6: Construction of a three element ZL Special beam.
/-
¡
r
215mm
(e'/2)
4
890mm
(35 ")
880mm 850mm
(341/2.)
(331/2')
Driven elements
as in Fig 5
I
W4111
Fig. 7: Details for the director lengths and spacing for a five element
ZL Special. Other constructional details as in Fig. 6.
61
I
300mm(12")
-
Wood dowel
Dowel or broomstick
25mm (1") dia
Elements and stub net work (see text)
1m
(391/¡)
Insulating sleeves
Stub matching details
see Fig,9
450 ohm co -axial
cable
1W4121
Fig. 8: Details for the construction
with about 4dB gain.
of
a
bi- directional end-fire array
Iw413J
use.
Element
Element
Jumbo size
electrical
connector
Insulating sleeve
through dowel
150mm
(6")
Adjustable bar
0 ohm co -axial cable
Fig.
9: Details of the feed system for the end-fire beam shown in Fig. 8.
0.12a in front of the main driven element (B in
Fig. 5), increases the forward gain by slightly over
2dB thus providing a total gain of 8dB which is quite
considerable for a beam measuring only about
62
50cm (20in.) from front to rear. The .addition of three
directors, still making the beam only about 1.2m
(40in.) high, yields a forward gain of a little over
10dB which is comparable with that of an 8- element
Yagi having a physical length of about 2.8m
(110in.), or twice the length.
The construction of a ZL with directors is much
the same as for the basic aerial shown in Fig. 5
except that the element support is extended for
mounting the directors. This must be insulating
material, such as wood or plastic tube, and one
suggested method of construction, particularly
suitable for outdoor use, is given in Fig. 6. The main
support which consists of the boom and stub mast
is made of plastic pipe. The stub mast is fitted into
the boom either by cutting a hole in the boom and
gluing the mast in with Araldite, or by using a
pipe "T" piece to make the join. The copper tube
elements are fitted tightly into holes through the
boom section and secured by screws through the side
of the pipe. The phasing line which may be two
copper wires (12 to 16 SWG) are inside the tube as
is the small capacitor. To ensure that the phasing
lines do not touch, they may be insulated with
sleeving.
This 3- element ZL Special has been tested over
a long period and operated both vertically and
horizontally with considerable Continental DX
worked. The half-power beamwidth (3dB) is about
90° and radiation directly from the rear is about
25dB down although the overall radiation pattern is
still cardioid but narrower than that from the 2element ZL Special.
The addition of two more directors, making a
total of three, and the aerial therefore a 5- element
version, will provide a gain of about 10dB. The aerial
is still not very large and may of course be operated
vertically or horizontally. Construction is the same
as for the 3-element version except for the three
extra directors cut to length and spaced as shown
in Fig. 7. Note that the amount of capacitance required across the 5011 feed to effect a good match
may be much less or even nil with the directors in
VERTICAL END -FIRE ARRAY
This is relatively easy to construct and will provide about 4dB gain over a dipole and is bi- directional. It needs only to be turned through 90° to
achieve all round coverage and being compact could
prove useful to flat dwellers unable to put up an
aerial outside. It consists of two half-wave radiators
fed 180° anti -phase to produce the radiation pattern
as in Fig. 2a. It may be assembled on a wooden
frame and the elements and stubs can be made from
copper wire as shown in Fig. 8. It could also be set
up to rotate on a floor stand, as the extension of
the diagram illustrates, making it suitable for indoor
use. Details of the matching stub and feed are
shown with more detail in Fig. 9. Adjustment for
minimum SWR is carried out by sliding the shorting
bar along the stub in conjunction with moving the
tapping point of the 5012 co-ax feeder. The approximate positions for these are given in Fig. 9 and
very little further adjustment should be needed to
obtain an SWR approaching 1:1 over the whole 2m
band. Used in the writer's workshop at about loft.
above the ground, this aerial could receive a substantial signal from the GB3PI repeater nearly 40
miles away.
Practical Wireless, May 1977
El
1111
electronics
Fortis Green Road, London, N10 3HN, England
56,
Telephone:
01
-883 3705
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Name
Address_
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Wedeln, without oNissóen to:
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1
& ELECTRONICS SCHOOL,
tr.O.Box 156, Jersey, Channel Islands.
NAME
ADDRESS
Practical Wireless, May 1977
I
Postcode
C
Showrooms at 233 Tottenham Court Road,
London and Bristol Road Gloucester.
I
(Block ups
tema;
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P
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Ext. Comp. 8 pin D L
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Audio Pwr. Driver TO99
NE555V
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NE558
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2587
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109
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759
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TIL209 Red
TIL211 Green
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MV5025
0.2"
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Green
Yellow
SEVEN SEGMENT DISPLAYS
3015F Mlnitron 0.3"
0L704 Com. Cathode 0.3"
DL707 Com. Anode 0 3"
DL747 Com. Anode 0.6"
VARIABLE VOL. REG.
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14 Pin DIL
459 DRI V ERS:75491 049, 754921649
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WHATEVER YOUR VIDEO
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CROFTON
RCA, TEXAS, MOTOROLA,
MULLARD, etc.
(East Grinstead), Ltd
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Tel: Forest Row 3782 (STD 034 -282) 3713
62
Tel.
Practical Wireless, May 1977
by Eric Dowdeswell G4AR
HAPPY man this month is Neil Braeman of
Southwater, near Horsham, and regular
contributor to this column. He has passed his
RAE and he is now G4FUP. Congratulations Neil, I
know the bit of effort required to get down to the
necessary studying will be found to have been worthwhile, for very many years to come. He has sold his
bike to get funds to buy a better receiver and
intends to make his own transmitter, a policy which
I heartily endorse!
When John Taylor of Cheadle Hulme found the
cost of a decent receiver a bit beyond his means he
dragged out an old R107 that hadn't worked since
1953! A simple signal generator and multimeter and
it was soon going again. John is thinking of building
a converter for the higher frequency bands which
is a very sound arrangement. In Stocksfield, Northumberland Simon Robinson is just starting to listen
to the SW bands and is thinking of getting a surplus
CR100 and `hotting it up'. Well, Simon, unless you
have the requisite test gear and a bit of experience
I should tread warily. Make one change at a time,
re-aligning if necessary, before doing anything else.
Personally speaking, I would get it going properly
on the LF ranges and use a convertor, as previously
mentioned.
A note from Jim Martin A7089, Secretary of the
newly -formed Edinburgh and District ARC, tells me
that a group of about 20 members meets every
Tuesday at 1930 at the club's rooms situated at the
City Observatory, Catton Hill, Edinburgh. One could
say that things are looking up! The club is active
from 2m to 160m with calls GM4AJV/A and
GM4BWT /A until they get their own call. Interested?
then write to Jim Martin at 22 Ross Gardens, Edinburgh EH9 3BR. Still in GM -land, the Aberdeen
ARS got all excited recently with a visit from the
BBC involving interviews with several members,
later broadcast on Radio Aberdeen. The producer
is interested enough to suggest a monthly spot on
Radio Scotland dedicated to amateur matters. In
the meantime more mundane meetings take place
at the hall to the rear of 91 Crown Street, Aberdeen.
On 8 April there's a demonstration of an automatic
CW reader and a try out of a new Jap receiver that
covers LW to 500MHz! On 15 April an RSGB Tape
Lecture will be illustrated with slides while 22 April
sees RSGB Council member GM3ZBE visiting the
club to talk of Society affairs. Secretary Stan Sutherland awaits your enquiries at 67 Greenfern Road,
Aberdeen or ring 691716.
Practical Wireless, May 1977
Back to regular correspondent Robin Bayley
A9203 who is now settled at Kemberton, near Shifnal,
Shropshire. He has been assessing his new QTH
from the DX aspect from 15 to 80m with the aid
of his EC10. With HKO's on 80, 40 and 15m and
KH6 on 20m things look promising. Andrew Work
A9091 in Beverley, E. Yorks, changed his 66ft wire
round the loft to a straight wire outside and
naturally found a big improvement in results including VP2 and VP5 on 80m. In Wallasey E. J.
Shaspe has progressed through a couple of receiver
kits to an Eddystone 670A which he found going
cheap. He's anxious to beg or borrow a handbook
on the same so if you can help write to 36 Warren
Drive, Wallasey, Merseyside L45 OJS.
Zone 23 is a very rare place and many aspirants
for the Worked All Zones award have had long
waits for a QSL from there. B. Harrison in Hastings
heard JT1KAA from Mongolia which is a good start
to getting a card. KC6 was another good catch in
the East Caroline Islands in the Pacific. Steve Budd
A8713 also on the sunny south coast, in Worthing,
has been logging stuff on the downlink from Oscar
6 10m and the 2m downlink from Oscar 7. However
he still did not desert the HF bands. Steve Cottis
A8961 seeks the DX from Harrogate and has QSL's
from HP7, VQ9 and VR8 to prove he has been
successful. I'd hesitate to attribute the improved
conditions on 15m to a general rise in sunspot
activity, Steve. Rather it is the usual improvement
as we move towards the summer in the northern
hemisphere.
David Peck BRS37621 has done us proud this
month from Cambridge with logs for SSB and RTTY
somewhat restricted by a move with all the gear
from the house to a shed in the garden!! David
started with a Creed 7B printer plus `RTTY the
Easy Way' built the terminal unit and he was away!
The receiver is a Yaesu FRG7 fed from a 135ft wire.
D. Anderson BRS36591 has not written for a while
from Brookwood, Surrey, but makes up this month
with a good log. Normally he tapes his DX but at
the moment the recorder is u /s. Dennis takes the
RAE next December and in the meantime G8LVB
is helping him with the necessary studies.
Now a note for all! The Annual Convention and
Exhibition of the Northern Radio Societies will take
place at Belle Vue, Manchester on Sunday 24 April.
See the box in the News feature of this issue for
further information.
Log Extracts
J.
R.
Taylor:- 20m KG4DHD VE8S0 7X2LTA
Bayley:- 80m AP2AD EA9CR FP8DX HKOCOP
JAIJRK
KH6PP
PY7PO
40m
CT2AP
EA9CF
HKOCAT 20m FP8DH KH6PA TG9TL VPBAA 15m
EA6DA FP8DA HKOKOC TG9TY ZL3AK
A. Work:- 80m VP2DAC VP5LDH
B. Harrison:- 20m FG7AK FM7WE FY7YM
HC1SC HKOBKX KG4PF PJ2FR' SVOWZ (Rhodes)
T12FM VP2EEQ (QSL WA6AHF) ZD7SD 40m
HC1DK VP2KF ZS3AW 20m P29PN S79P (Seychelles) 7P8AC 7Z1AB
D. Anderson:- 80m VS6DO 7Y4MD 20m C21PS
(Nauru) CP5GR HMOSM KC6KO P29BS VP2AG
ZP6KR
D.
Peck:-
20m KC4AAA KC4USD KL7IEU 15m
JR6HJJ WB2CJF/HZ1 20m RTTY ICBPOF K9KHI
OHONI UK3ACR WAOYDJ/4 YU2CE 9K2EP
65
N.
Braeman:-
80m
KP4AST
9Y4NP
20m
0E5GML/YK PZ1DR W6QL/VP2A(CW) YS7VI
S. Cottis:- 80m CT2BU KP4EBH 20m JW7FD
KL7IEU VR4DX 15m D2ASW FP8DX HP7XJS
WB6EWH/VQ9 (Chagos) 3B8CV 5U7AG
S. Budd:- 80m FM7WS JY9CR PJ8KG TI2FJC
6Y5EM 20m D2AFE (Ex-CR6FE) FR7ZL/T (Trognelin) TR8LE W6QL/VP2A YB2CR 8P7GN 15m N4PN
(USA) PYOZAE (QSL PY1CK) 7P8BC Oscar 6
(10m) GJ8EZA VE3EYR Oscar 7 (2m) CT1WW
HW6ADB IT9ZDA K4UQ TU2EF VE3FKU W2BXA
W9000
All SSB except where stated otherwise.
J
MEDIUM WAVE DX
by Charles Molloy
from Ralph Newman in Reading
mentions an unidentified station on 945kHz
between 2300 and midnight which created a
1kHz heterodyne with the Russian on 944kHz. The
writer has made a tape of the closedown announcement, which is in English, and although no location
was obtained, two frequencies on the medium waves
were referred, to 602kHz and 945kHz. The transmission ended with the Nigerian national anthem at
0002. The Western Nigeria Radiovision Service has a
10kW outlet on 602kHz located at Abafon and it
seems likely that they now have another on 945kHz.
Although the signal is quite strong at times interference makes reception difficult. DXers who use
communications receivers and a loop might like to
take up the challenge offered by this new broadcaster and try to obtain a more definite identification.
In a letter from Horsham in Sussex, Kes Otley
reports hearing CKVO Clarenville in Newfoundland
on 710kHz using his Roberts portable radio con nected to a long wire aerial and earth. He asks how
to use a loop with this receiver. From St. James in
Barbados, Paul Griffith poses a similar question when
he asks how can he connect a loop to a portable
receiver which has no external jacks for earth or
aerial. A number of DXers have written on similar
lines and the short answer is that a loop is really
unsuitable for use with a receiver that has an
internal aerial. Even if aerial and earth sockets are
fitted to the portable, they are intended for use with
a wire aerial and if a loop is connected to them then
poor results will be obtained.
The internal aerial in a transistor portable is
wound on a ferrite rod or slab and this type of
aerial is directional. There are two positions of
maximum pick-up at right angles to the rod and
two other directions of minimum pick-up which lie
along the length of the rod. A loop aerial which is
based on the frame aerial used in the early days of
radio, has similar properties and if an attempt is
made to use both aerials at once then problems will
arise. The loop may detone the receiver input causing
poor selectivity. If the null (direction of minimum
pick -up) of the loop is pointed at an interfering
Areport
66
station, there may still be pick-up from that station
via the internal aerial, the overall effect being to
reduce the directional properties of the loop.
One method of overcoming this problem is to attach
the receiver to the centre of the lobp in such a way
that the nulls of loop and receiver coincide. In most
cases this will mean that the receiver will be at right
angles to the plane of the loop windings. Coupling
between loop and receiver is inductive, so no direct
connection should be made between them. The loop
and receiver are rotated together to null out interference. This method should provide an interesting
field of experiment but at best it is only a makeshift.
The most effective DX tool on the medium waves
is a communications receiver and readers will note
that most of the DX reported in this column comes
from users of this type of equipment. Newcomers
to the hobby who are thinking of investing in a
receiver should think along the lines of a Realistic
DX160, Trio 9R59D /E or the Heathkit or Eddystone
range, rather than of portables or hi-fi tuners which
do not possess the selectivity or sensitivity required
by the serious DXer.
Robin Bayley has moved to a new QTH at Kemberton in Salop and is now the owner of an Eddystone
EC10. He reports hearing a DX programme from
Thames Valley Radio on 1430kHz during the Golden
Days programme which is on the air on Sundays
between 2200 and 2300. Another programme of
interest to the DXer is the weekly `Sweden Calling
DXers' which is on the air on Tuesdays at 2315.
Latin American medium wave stations come in
well in the UK, the long sea path across the Atlantic
favouring propagation from this area. Reception
from South America is often at its best when DX
from North America is poor so it is worthwhile investigating Spanish and Portuguese speaking
stations when DX from North America is absent.
It is unusual if there is no DX at all on the medium
waves! John Wildey who uses a Grundig Satellit 2000
in Doncaster says he has positively identified Radio
Margarita on 1020kHz but he finds that the fast
speaking style of South Americans makes identification difficult. He has heard a number in the 800
to 1000kHz and 1200 to 1400kHz areas.
Latin American countries most frequently heard
are Colombia, Venezuela, Argentina and Uruguay
where Spanish is the language and Brazil where
Portuguese is spoken. Although callsigns are allocated they are seldom used but most broadcasters
have names such as Radio Globo, R. Nacional followed by the location, such as Radio el Mundo
Buenos Aires (which is on 1070kHz). The `World
Radio and TV Handbook' gives a comprehensive
listing of LA stations both by frequency and country
together with station addresses. In answer to J. Williams of Frome in Somerset, the WRH is distributed
in the UK by Fountain Press and it can be ordered
through bookshops.
"Wonders never cease, I got a verification yesterday from Radio Sutatenza, Magangue, in Colombia,
HJHN on 960kHz" writes Harold Emblem from
Mirfield in Yorkshire. Latin American stations are
notoriously difficult to verify. Receiving a station is
only the first and usually the easiest part of the
exercise. They are unpredictable too. The DXer can
plug away for years with reports that are unanswered and then suddenly receive a cordial letter
with pennant, QSL card and detailed information
about the station and its locality. This appears to
have happened to Harold who now has details of
Practical Wireless, May 1977
.
15 -240
HY5
Preamplifier
Watts !
The HY5 is a mono hybrid amplifier ideally suited for all applications. All common Input
functions (mag Cartridge, tuner, etc) are catered for internally. Thedesired function is achieved
either by a multi -way switch or direct connection to the appropriate pins. The Internal volume
and tone circuits merely require connecting to external potentiometers (not Included). The
HY5 is compatible with all I.L.P. power amplifiers and power supplies. To ease construction and mounting a P.C. connector Is supplied with each pre -amplifier.
FEATURES: Complete pre -amplifier In single pack -Multi -function equalization-Low noise
Low distortion -High overload -Two simply combined for stereo.
APPLICATIONS: HI-Fl-Mixers-Disco-Guitar and Organ -Public address
-
SPECIFICATIONS:
INPUTS. Magnetic Pick-up 3mV; Ceramic Pick -up 30mV; Tuner 100mV; Microphone 10inV;
Auxiliary 3- 100mV; Input Impedance 4.7k0 at 1kHz.
OUTPUTS. Tape 100mV; Main output 500mV R.M.S.
ACTIVE TONE CONTROLS. Treble ± 12dB at 10kHz; Base A at 100Hz.
DISTORTION. 0.1% at 1kHz. Signal /Noise Ratio 68dB.
OVERLOAD. 38dB on Magnetic Pick -up. SUPPLY VOLTAGE ± 16 -50V.
HY30
Watts
into 8St
15
The HY30 is an exciting New kit from I.L.P. It features a virtually Indestructible I.C. with short
circuit and thermal protection. The kit consists of I.C., heatslnk, P.C. board. 4 resistors, 6
capacitors, mounting kit, together with easy to follow construction and operating instructions.
This amplifier is Ideally suited to the beginner In audio who wishes to use the most up -to -date
Available
June '76
technology available.
FEATURES: Complete Kit-Low DIstortion- Short, Open and Thermal Protection -Easy to
Build.
APPLICATIONS: Updating audio equipment -Guitar practice amplifier -Test amplifier
audio oscillator.
-
SPECIFICATIONS:
HY50
Watts
into Bit
25
OUTPUT POWER 15W R.M.S. Into 80; DISTORTION 0.1% at 1.5W.
INPUT SENSITIVITY 500mV. FREQUENCY RESPONSE 10Hz- 16kHz-3dB.
SUPPLY VOLTAGE A 18V.
Price ES 22 + 65p VAT P&P free.
The HY50 leads I.L.P.'s total integration approach to power amplifier design. The amplifier
features an integral heateink together with the simplicity of no external components. During the
past three years the amplifier has been refined to the extent that it must be one of the most
reliable and robust High Fidelity modules in the World.
FEATURES: Low Distortion- Integral Heatsink -Only five connections -7 amp output transistors-No external components
APPLICATIONS: Medium Power HI -FI systems -Low power disco-Guitar amplifier
SPECIFICATIONS: INPUT SENSITIVITY 500mV
OUTPUT POWER 25W RMS Into 80 LOAD IMPEDANCE 4 -160 DISTORTION 0.04% at 25W
at 1kHz
SIGNAL /NOISE RATIO 75dB FREQUENCY RESPONSE 10Hz -45kHz -3dB.
SUPPLY VOLTAGE +25V SIZE 1055025mm
HY I 20
Watts
into 8s2
60
Price £602 + 65p VAT PAP free.
The HY120 is the baby of I.L.P.'s new high power range. Designed to meet the most exacting
requirements including load line and thermal protection this amplifier sets a new standard In
modular design.
FEATURES: Very low distortion -Integral heatsink-Load line protection -Thermal protection
-Five connections -No external components
APPLICATIONS: Hi -FI-High quality disco -Public address -Monitor amplifier-Guitar and
organ
SPECIFICATIONS
INPUT SENSITIVITY 500mV.
OUTPUT POWER 80W RMS into 80 LOAD IMPEDANCE 4 -160 DISTORTION 0.04% at 60W
at 1kHz
SIGNALINOISE RATIO 90dB FREQUENCY RESPONSE 10Hz -45kHz -3dB SUPPLY VOLTAGE
A 35V
SIZE 114 50 85mm
Price £15 84 + £1.27
HY200
Watts
into 8Q
120
VAT PAP free.
The HY200 now Improved to give an output of 120 Watts has been designed to stand the most
rugged conditions such as disco or group while still retaining true HI -Fl performance.
FEATURES: Thermal shutdown -Very low distortion -Load line protection -Integral heatslnk
-No external components
APPLICATIONS: HI -Fi- Disco -Monitor-Power slave-Industrial -Public Address
SPECIFICATIONS
INPUT SENSITIVITY 500mV
OUTPUT POWER 120W RMS into 80 LOAD IMPEDANCE 4 -160 DISTORTION 0.05% at
100W at 1kHz.
SIGNAL/NOISE RATIO 96 dB FREQUENCY RESPONSE 10Hz- 45kHz -3dB SUPPLY VOLTAGE
+45V
SIZE 114 100 85mm
Price £2332 + £1 $7 VAT P&P free.
The HY400 is I.L.P.'s "Big Daddy" of the range producing 240W Into 40 It has been designed
for high power disco address applications. If the amplifier is to be used at continuous high
power levels a cooling fan Is recommended. The amplifier includes all the qualities of the rest
of the family to lead the market as a true high power hi- fidelity power module.
FEATURES: Thermal shutdown -Very low distortion-Load fine protection -No external
I
HY400
Watts
into 4i/
240
components.
APPLICATIONS: Public address -Disco-Power slave -Industrial
SPECIFICATIONS
OUTPUT POWER 240W RMS Into 40 LOAD IMPEDANCE 4 -100 DISTORTION 0-1%
at
240W at 1kHz
POWER
SUPPLIES
SIGNAL NOISE RATIO 94dB FREQUENCY RESPONSE 10Hz -45kHz -3dB SUPPLY VOLTAGE
+45V
.INPUT SENSITIVITY 500mV SIZE 114 x 100 x 85mm
Price £3217 + E2.57 VAT P&P tree.
PSU36 suitable for two HY30's £5 22 plus 65p VAT. P/P free.
PSU50 suitable for two HY50's £6,62 plus 0Sp VAT. P/P free.
PSU70 suitable for two HY120's £13 75 plus £1,10 VAT. P/P free.
PSU90 suitable for one HY200 £12 65 plus £1 -01 VAT. P/P free.
vtTT,.
PSU180 E2310 + £t
TWO YEARS' GUARANTEE ON ALL OF OUR PRODUCTS
£006 VAT.
B1 £0J6
t
Please Supply
Total Purchase Price
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Enclose Cheque
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NACKINGTON, CANTERBURY, KENT, CT4 TAD
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Practical Wireless, May 1977
67
600K5 for
Can YOUR
Antenna do all this?
Electronics Enthusiasts
A SMALL SELECTION FROM OUR HUGE FILE
OF TESTIMONIAL LETTERS ON THE JOYSTICK
VARIABLE FREQUENCY ANTENNA
30MHz).
(5-
-"I
Carl V. Guest, Mount Vernon, Ohio, writes
set the Joystick antenna on the floor of my operating
room which is at street level. On 40 meter CW
I
worked out to a distance of 700 miles in the
afternoon."
-"If
"CQ" Magazine
you are high enough the
antenna will operate (especially at IS - 20) as well as
the well -known 3- element beam with which we
compared it. The tests were 'operational, not
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K6MDJ- "Early results are astounding. I've been
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160
meters."
and 80
COMING SOON -Radio,
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Spring 77. 1,200 pages
This JOYSTICK
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WSCJV -"Do
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IN USE BY AMATUER TRANSMITTING AND
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COMING SOON- Beginner's Guide to Radio
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Gordon J. King
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Broadstairs,
1
ór'Borough Green, Sevenoaks, Kent TN 15 8PH
1
68
Practical Wireless, May 1977
the Radio Satatenza network in Colombia. Each
station calls itself Radio Satatenza following this
with the name of the town. HJCR Medellin is on
590kHz with 100kW, HJCX in Cali is on 700 with
120kW, HJCY in Bogota on 810 with 250kW, HJHN
in Magangue on 960 with 120kW and HJGL in
Barranquilla on 1010 with 10kW. HJHN in 960 is
often logged by DXers in the UK.
More LA DX comes from Ralph Newman in Reading with his homebrew receiver and loop which
pulled-in Radio Margarita on 1020 and Radio Vision,
the 50kW outlet in Maracay, Venezuela on 650kHz.
Roy Patrick who DX'es in Derby with a Trio 9R59D
and loop reports hearing Trans-World Radio Bonaire
on 800kHz at 0200. This station is on the island of
Bonaire which is part of the Netherlands Antilles
which lie off the northern coast of South America.
Multi-lingual programming, which includes English
is radiated from a 500kW transmitter and is mainly
of a religious nature.
SHORT WAVE BROADCASTS
by Derek Bell
must tie up a loose end from a month
or so back. Tony Cook had an HAC set that
was giving trouble on its band spread section
and thus thought it wise to ask, via this column, if
his confreres in the DX world could assist. As a
result a letter is before me from Joe Owens of
Dolgellau, North Wales who describes himself as
"an old time PW'er from the nineteen thirties ". He
suggests that it might be worth trying to connect
the BS capacitor to the main tuning capacitor via
a small series fixed capacitor. If Tony has not got
one of these he can twist two equal lengths of thin
wire together. Well there seems to be enough there
to pass a few happy hours tinkering! I hope that
it achieves the required result.
As a footnote Joe says that he bas six redundant
loudspeakers that need good homes and for the
price of the return postage he will pass them on.
If I may inject a personal note here it might be
nice if they went to school clubs or disabled or
pensioner DX'ers.
For once in my life, as the song says, I can be
in the forefront and let you have advance news of
a station. This rare event is due to the good offices
of Robin Bayley from Kemberton, Salop. Robin has
sent several items of station news the high spot
of which is that the Red Cross organisation is to
run one of its periodic station tests on 26, 28 and 30
July at 0600 to 0700, 1130 to 1230, 1700 to 1800
and 2200 to 2300 on 7210. These test transmissions
are to ensure that in the event of an emergency
the Red Cross has a viable means of world -wide
communication from Geneva. They will QSL if you
report to 7 Ave. de la Paix 1211 Geneva 8. Robin
also reports that the BBC is to supply Marconi SW
transmitters and aerials to Masirah Island station
by December and that Russia is supplying four
FIRST we
Practical Wireless, May 1977
250kW transmitters to Radio Prague between 1977
and 1980.
Our newcomers take the floor now led by Jeffrey
Raynor from Prestwich who runs a domestic radio/
cassette recorder. Despite the fact that this is hardly
a communications set Jeffrey says that he has loads
of fun listening to "the affairs of distant nations ".
He has connected a 25ft long wire and pulled in the
following :
Radio Pekin on 6100 at 0215
..Radio Norway on 6050 at 0030
Radio Sweden on 6850 at 0030
Voice of Turkey on 9550 at 2300
I can assure Jeffrey that he has not as he suspects
moved the cursor needle, the fact that his frequencies
are not spot on are a result of the crude calibration
of domestic receivers. This extra aerial, in my
experience, can throw the calibration by affecting
the oscillator. Lock on to a station of known
frequency and then add the aerial. When this is done
one finds the station again and notes the difference
remembering to take this difference into consideration when logging in that band.
Marcus Duncan from Thornaby also notices this
phenomena of calibration movement on his Alba and
seventy -foot long wire. He has made a start on the
PW General Coverage set with which project your
column wishes him the best of luck. He logs as
-
follows:-
Israel Radio on 7412 at 2250
Voice of Iran on 9005 at 2015
Radio Cairo on 9700 at 2210
WYFR on 11645 at 1810
Two rarely reported stations come from our old
friend Roy Patrick of Derby with his Trio 9R59 and
Joystick. In this lean spell Roy cheers us all up by
proving that some DX is still running by logging
Emissor Regional Dos Acores (Azores) on 4865 and
Radio Omdurman (Sudan) on 5039 at 1645. Coupled
with this may I include another old friend Bob
Burgess who writes but once a year but when he
does he brings good cheer. From his Chelwood Gate
QTH Bob and his Satellit 2000 bring a list `as long
as yer arm' of Latin Americans and Africans. While
1 admit that a Satellit is not a run-of- the -mill set it
is still a portable and Bob uses it as a bedside set
with all the hazards that local QRM can throw at
him. I wish that I could list all of the loggings but
space does not permit; however here is a handful:Radio Nacional Argentina on 11710 at 1900
Radio Nacional Brasilia on 11780 at 2300
Radio Nacional Chile on 9566 at 2300
Radio Rumbos Venezuela on 4970 at 2315
Conakry, Guinea on 4910 at 2245
Pointe Noire, Congo on 4843 at 2240
Bob mentions that Radio Nacional Chile is heavily
jammed from Eastern Europe. Bob is hoping to
retire shortly so we wish him well and wonder what
sort of a logbook he will have, with more time to
spend DXing.
We end this month on the subject of the Voice
of America. J. H. CoRick of Erdington would like
to get in touch with VOA regarding their Big Band
shows run by the veteran Willis Conover. The
address to write to is VOA US Information Agency,
Washington DC 20547 USA. This address also covers
QSLs. With that I will wish you best 73s and all the
best.
69
.:
J
by Ron Ham
,
WE start `down -under' with another interesting
letter from Anthony Mann, Western Australia, who tells of some mouth-watering DX
on Febuary 11 and 12, almost at the end of their
sporadic-E "season". The 12th was most unusual,
says Anthony, video signals on Ch0 (46.25MHz)
from eastern Australia (1900 miles) was received as
early as 0800, local time. Later, between 1240 and
1400 video was received from New Zealand on
45.25MHz (3400 miles). Prior to this a strong signal
from an Hawaiian amateur was heard on 10m
(KH6AHL working VK8AC). Around 1800 (1000
GMT) the 10m band opened toward Europe, with
both UK and French amateurs dominating the band.
At 1037 GMT the German beacon DLOIGI
(28.195MHz) was heard for less than a minute.
Anthony uses a Barlow- Wadley XCR -30 with a folded
dipole on 10m. While listening to an amateur broadcast he heard that, on January 24 and 25, the Great
Australian Bight between Adelaide in VK5 and
Albany in VK6 (1200 miles over water) had been
bridged on 1296MHz. Our congratulations to the
stations concerned.
In 14 years of routine observations the writer has
never known a month like February when the VHF
bands were so quiet. From the 1st to the 24th the
atmospheric pressure did not rise above 30.0 ", in
fact for 10 of those days it was nearer 295 ", so, at
no time was there any 'life' in the troposphere for
our radio signals. However, this has not daunted our
readers. George Zitterstein, G8ITS, City of London,
has now installed a barograph at his station, he was
lucky to find one with an electric motor to drive
the drum, to try and find out why the changing AP
can become frequency critical within the VHF /UHF
part of the spectrum.
Alan Baker, G8LGQ, our watchdog in Newhaven,
noticed a 'lift' on 2m around 1500 on the 12th, when
he heard signals from PAO, but this did not last long
and dashed the hopes of both Alan -and Ernie Hoare,
G8BDJ, Southwick, Sussex, of some good dx.
During the 500th edition of World Radio Club,
broadcast by the BBC World Service on February
16th, the team was asked, "When is sunspot minimum?" and this prompted your scribe to examine
his records and put you all in the picture. After all,
we are at the beginning of a new cycle and as it
develops over the next few years, the increased solar
activity will affect our mutual interests with DX
again on the 10m band and more auroral activity
to upset our VHFs. The following figures show the
number of days each year that the writer's telescope
recorded solar radio noise during the old sunspot
-
cycle: -- 1969 -101, 1970-176, 1971 -203,
1972-
160, 1973 -118, 1974-140, 1975-65, 1976-72. The
peak activity was in 1971, followed by a downward
trend until the end of 75 and the- slight increase
shown in 1976 may well be the start of the new
cycle. Nigel Fisher, Co- ordinator of the Radio Astro-
nomy Group of the South East Essex Astronomical
Society, says that they have now completed their
solar radio telescope and made satisfactory tests.
70
.
The solar radio waves will be collected on a Yagi
aerial and fed to a Microwave Modules 136MHz
converter; an Eddystone communications receiver is
used as the IF amplifier and detector and an
integrated circuit DC amplifier drives an Evershed
and Vignoles pen recorder. Nigel's group will be
observing between 1000 and 1400 'hrs daily and will
be supplying both the British Astronomical Association and ourselves with information as soon as they
are properly organised.
Cmdr. Henry Hatfield, Sevenoaks, reports seeing a
tiny solar flare and a plage through his spectrehelioscope on the 8th and on the 13th he saw a
group of several sunspots. This accounts for the
solar radio noise recorded by your scribe at 136MHz
from the 10th to 13th inc. John Smith, Cranleigh,
Surrey, noted that the mean solar noise level had
increased at 140MHz over that period. John has been
making radio observations of the sun for more than
12 years.
No doubt some form of solar activity was responsible for the ionospheric disturbance reported by the
BBC World Service during the early hours of the
1st; this sort of information from the BBC is most
useful to those readers who use the DX bands.
Apart from a couple of short bursts of signals from
the Cyprus beacon, 5B4CY, (28.180MHz) at 0830
on the 16th and 0905 on the 19th, the 10m band has
been dead.
Did you know that the "hissing" which you can
hear above the background noise of your receiver
when the sun is "active ", was first discovered in
1935 by Denis Heightman, G6DH, on the 10m band?
Our readers are active in many fields. On February
18th Flt. /Lt. John Keegan, CO 2464 ( Storrington)
Squadron, ATC, used 5 vehicles, each equipped with
a Pye Cambridge, during a night exercise. These
mobile units were spread over a 10 mile area of
hills, vales, and woodland, not ideal for VHF communication with the short aerials attached to the
cars. In addition the AP was low and falling and a
moderate gale was blowing, but, despite this, and
the undulating terrain, good communications were
maintained throughout. On board each vehicle was
a cadet wireless operator, and each one a keen radio
enthusiast. After the exercise they were convinced
that the "low-band" frequency was much better than
the "high -band" frequency for reliable communications when conditions are bad.
The writer plans to be at the RSGB Convention at
Alexandra Palace on May 7th and will be pleased to
meet any of our readers who may be there. Thanks
again to all who have sent in reports.
BROADCAST BANDS
Short Wave Reports by the
15th of the month
to Derek Bell, 169 Max Rd., Chaddeston, Derby.
Medium Wave Logs to Charles Molloy, 132
Segars Lane, Southport, PR8 3JG.
AMATEUR BANDS
Logs covering any amateur band /s in band/
alphabetical order by the 25th of the month
to Eric Dowdeswell G4AR, Silver Firs,
Leatherhead Road, Ashtead, Surrey, KT21
2TW.
VHF
Reports on VHF matters to Ron Ham, Faraday,
Greyfriars, Storrington, Sussex RH2O 4HE.
Practical Wireless, May 1977
DRILL CONTROLLER
INFRA RED BINOCULARS
Slade for military purposes during and
Electronically changes
speed from approximately 30 revs to
maximum. Fall power at
.dl speeds by Boger-tip control,
Kit Includes all part., case,
everything and full imtructlons.
68.46 including poet & VAT.
Made up model 61.00 extra.
s TRANSISTOR PACK
Designed to operate translator sets and amplifier..
Adjustable output 8v., 9v., 12 volt. for up to
500mA (class B working). Takes the place of any
of the following batteries: PP1, PPS, PP4, PPS,
PP7, PP9 and other.. Kit comprises: main
transformer rectifier, smoothing and load resistor
condensers and Instructions. Real snip at only
61.60 VAT & Postage 50p.
RADIO STETHOSCOPE
Easiest way to fault find, traces
signal from aerial to speaker, when
signal stops you've found the
fault. Use it on Radio, TV,
amplifier, anything. Complete kit
rompriees two special transistors
and all parts including probe tube
and crystal earpiece, 1895, twin
atetho -set instead of
earpiece.
21.00
VAT and postage
incl.
MICRO SWITCH BARGAINS
Rated at 6 amps 260 volts,
Ideal to make a switch panel
for a calculator and for dozens
of other applications.
Parcel of 10 for 600, VAT and poet paid.
MAINS OPERATED SOLENOIDS
Model TT2 -sma8 but powerful
lin. pull -approx. size It x 11
x 1 In., 1.00
Model
4001 / -tin.
Model
11.10
pull. Size
21x2x141n.1.60
-1
in. pull.
x 2t x lin. 18.60
Prices include VAT
Size
3
@
postage.
SOUND TO LIGHT UNIT
Add colour or white light to your
amplifier. Will operate 1, 2 or 3
lamps (maximum 450W). Unit In
box all ready to work. 1796 plu'
Np VAT @ Postage
immediately after the last war to
sable snipers, vehicle drivers, etc. to
see in the dark. The binoculars have to
be fed from a high voltage source (5KV
approx.) and providing the objects are
in the rays of an infra red beam then the
binoculars will enable these objects to
be seen. Each binocular eye tube
contains a complete optical lens system
as well as the infra red cell, technical data on which is available. The binoculars
are unused, believed to be in good order. In fact they were never Issued, but since
they were made a long time ago they can hardly be called new. Bold without
guarantee. Price 617.60 per set. Post
VAT 22.60.
Pugh button gives 10 variations as follows (1) continuous hot water and con-
tinuous central heating (2) continuous bot water but central heating off at
night 01 continuous hot water but central heating on only for 2 periods during
the day (4) hot water and central heating both on but day
time only (5) hot water all day but central heating only for
2 periods during the day (8) hot water and central heating
on for 2 periods during the day time only -then for summer
time use with central heating off (7) hot water continuous
(B) bot water day time only (9) hot water twice daily (10)
everything off.
A baudsuure looking unit with 24 -hour movement and the switches and other
parta necessary to select the desired programme of beating. Supplied complete
with wiring diagram. Originally acid we believe at over 216-we offer these,
while stocks last at 1760 each Including VAT and postage.
MULLARD UNILEX
A mains operated 4
+ 4 stereo system. Rated one
of the foeet performers In the stereo field thin
would make a wonderful gift for almost any one in
easy- to- aasaemble modular form and complete
with a pair of Goodmana speakers this should sell
at about 230-but due to a special bulk buy and
as an incentive for you to buy this month we offer
the system complete at only 214.00 Including
VAT and postage.
2S0 WATT TRANSFORMER
Heavy duty power transformer which can be used for many part,>. Rated
at 250 watts it is very well built with frames for upright mounting and is varnish
Impregnated. Its primary is for 230/240 volts 50 cycles, it has four secondaries
each 10v very high current windings. Just a few of the circuits it can power are
10.0-10v at up to 12 amps, 20.0 -20v at up to 6 ampo; single 10v at 25 amps;
single 20v at 12t amps; single 30v at 9 amps, single 40v at 6.5 amps. The transformer can be used for power circuits (charging, etc.) or for amplifiers, there
being an earth screen between primary and secondaries. A transformer like this
today would cost at least 615 from the makers, however, we are making a
special offer at 26.96. Post @ VAT Paid. Grab some while you ran, our stock
may not last long.
SHORTWAVE CRYSTAL SET
RELAY BARGAIN
Type 600 relay with twin 500 ohm cod, which may
be joined in series or parallel thus relay will
operate off voltages between 6 and 80 volts DC.
Price 44p each, 10 for H poet and VAT paid.
-
8
drille,
planes, boats, etc., etc. 18.00.
Six speeds are available 600, 660
and 1,100 r.p.m. and 7,000, 9,000
and 11,000 r.p.m. Shalt is t in.
diameter and approximately 1 in
long. 230/240v. Its speed may be
further controlled with the use
our
POWERFUL BATTERY MOTORS
For modela, Meccano'.,
remote
control
ROTARY PUMP
Belt priming, portable fite drill or electric motor,
pumpe up to 200 gallons per hour depending upon
revs. Virtually uncorrodable, use to suck water, oll,
of
Thyrletor controller. Very
and useful motor else
approx, 2 in. dia x 6 In. long.
Price 1800 including Post & VAT.
petrol, fertilizer, chemicals, anything liquid. Hose
connectors each end. g2 00 Post Paid.
powerful
MOTORISED DISCO SWITCHES
SWITCH TRIGGER MATS
With alx 10 amp changeover switches. Multi
adjustable switches are rated at 10 amp each
so a total of 2000w'. can be controlled and
this would provide a magnificent display. For
mains operating 24,85 poet @ VAT Paid.
Ditto 9 switch 84.86 Post @ VAT Paid.
DITTO BUT 18 SWITCH 6676 POST @
V.'.
PAID.
So thin la undetectable under
carpet but will switch on
with slightest pressure. For
burglar alarms, ahoy doors.
etc. 24in x 18in 6888. Post
@ VAT 60p.
131n x 10in 11.85. Post @
VAT 50p.
MAINS RELAYS
SPIT MOTOR WITH CARTER
GEAR BOX
Probably one of the beet spit
motors made. Originally intended to be used in very high
priced cooker. however this
ran be put to plenty of other
uses, for Instance your garden
barbeque or to drive a tumbler
for stone polishing; In fact, there are no ends to
its uses. Normal mains operation. 83.26 including
POST @ VAT.
ROOM THERMOSTAT
Famous Batchwell, elegant design,
Intended for wall mounting. Will
switch up to 20 amps at mains voltage,
covers the range 0.30°C. Special snip
this month 1860, poet and VAT paid.
With triple 10 amp changeover contacts - ol. rating
coil wound for 230 volts AC, chassis mounting, one
screw fixing, ex unused equipment 60p each, 10 for 16
poet and VAT paid.
OUTPUT POWER PACKS
T
These have two separately B.C. smoothed outputs
so can operate two battery radios or a etereo amp
without cross modulation (they will of course
operate one radio /tape cassette /calculator, in fact any
battery appliance, and will save their cost in a few
months). Specs: Full wave rectification, double
insulated mains transformer -total enclosed in a
hard P.V.C. case -three core mains lead-terminal
output-when ordering please state output voltage
41v, 0v, 70v, 9v, 12v or 24v.
Price 1.95. Poet and VAT included.
CAR STARTER
MULLARD AUDIO AMPLIFIERS
All in module form, each ready built complete
with heat sinks and connection tags, data supplied
Model 1153
600mW
power output 61.60 including Post & VAT.
Model 1172 1W, power
output 1.86 Including
4
watt
power output 2890 including Poet @ VAT.
EP 9001 twin channel or
atereo pre -amp. 0590 Including Poet & VAT.
NEED A SPECIAL SWITCH
Doable lead contact. Very slight pressure, closes
both contacts 121' each.
Plastic pashrod supplied
for operating. 10p each.
00
1.0 for BSp.
Practical Wireless, May 1977
Most drivers who use their car around town find that on a very cold morning
they have difficulty in starting because the battery has not any charge lett in it.
This always seems to happen on the morning when you are in a particular hurry
so a charger /starter is well worth having. Our kit for this comprises: a heavy
duty 250w transformer and full wave rectifier which for short periods will
deliver 20 amps. This is usually enough to get the car started, directly it has
started of course it can be disconnected from the battery as the care internal
charger will take over. Special offer price of this is 28.50p including post and
VAT.
TERMS: Where order is under 88 please add 60p surcharge to
sepeme.
Out peeking
J. BULL (ELECTRICAL) LTD
103 TAMWORTH ROAD,
CROYDON CR9 ISG.
(Dept. P.W.),
Our monthly Advance Advertising
Bargains List gives details of bargains
arriving or just arrived -often bargains
which sell out before our advertisement
can appear-Its an interesting list and
its free -just and S.A.E. Below are a
few of the Bargains still available from
recent list.
100 watt Mains Transformer. 240v 5011. primary
wound in separate halve., primary screen. This
has three secondriee 24.0.24v, 0-49v and 0 -88v
tapped to 80v. Any one of these eecondrlee may
be loaded up to the 100 watts or the load can of
course be weed over to all the secondries.
Upright mounting. impregnated and varnished.
Size 4° x 31" x 3°. Price 88.60 + 28p Poet
80p + Bp.
Connector Strip for Push on tags. 7 pole, each pole
accepting 8 push on tags on strong plastic base
with fixing holes. Price 455 + 4p.
Stereo Flex twin screen fig. 8 type. PVC insulated
overall. 10 metres for 81 + 8p.
Latching Belay by Guardian Electric, mains
operated it is In tact two relays mounted on a
metal base plate. The relays being mounted in
such a way to ensure that when one closes the
other opens and vice versa thus when closed
relay A would remain locked until manually
released or electrically released by energising
relay B. Each relay has 2 sets of 10 amp changeover contacts. Ahould be ideal for burglar alarms
and similar applications. Price 11.95 + 182.
Connecting Win. 7 Stranded PVC insulated on
500 metre drums, 8 different colours available,
price 44 per 500 metres + 82p. Post 21 + 8p.
Please give alternative colours when ordering.
Mains Motor- double ended with normal mounting
feet, ideal for small fan heater, etc. Price 765 +
lip. Post 80p + Sp.
Mamnello Clutch rerun ref. nos. 121 5494 and
PN 886 -10. This is a two part device, the main
section with the coil fits to the spindle of the
machine and the break plate only has to be
mounted close to the main section. Price 86.00 +
24p. Poet 30p + 3p.
Photo Mnitipllar Tube. American RCA, their
type no. 4555. These tubes have a gain of
million or more, regular price over 220 but we
offer these brand new at lá60 + 86p.
Push Button Doable Changeover Switch. Honeywell type No. 14 DMG. Contact rated at 10 amps
250 volts, a tough spring return switch definitely
strong enough to be used as a foot switch. Price
50p
Although this tees no battery it given really amazing
results. You will receive an amazing assortment of
stations over the 19, 25, 31, 29 metre bands. Kit
contains chassis front panel and all the parts 21.90
crystal earphone 66p including VAT and postage.
MULTISPEED MOTORS
Poet @ VAT.
Model EP9000
@
SMITHS CENTRAL HEATING CONTROLLER
ITS FREE!
+
lap.
Clockwork Time Switch for delaying switch for
up to 12 hours. Being clockwork this is independent of the mains and le therefore ideal for
remote places, worked by batteries. Front dial,
which is calibrated In hours, is turned through
the required degrees together with preset time
up to 12 hours. Double pole switch rated 15 amps
30 volts. Price 88.00 + 84p.
Delay Switch electrically operated -will give
delay of up to 2 hours- contact suitable for
2 x 10 amp appliances. Price 75p + Op.
Open Type Relay with 10 amp Changeover
contacts. Mains operated coil, ex- equipment but
perfect. Price 60p + 4p.
Portable Radio Case. size 11" x 8" x 3I', mounting etude for standard 5° speaker and panel to
take the normal three controls. Price 8150 +19p.
Post 21 + 12p.
Tuning Dial, fits normal slow motion type condenser suitable for above cabinet. Price 8011 + 0p.
Self adhesive scale L & M, price 25p + 3p.
Disco Black Light Lamp, We have just received
a new delivery of these 176w ultra violet lamps
but regret to say that the price has Increased
and the new price Is now 2676 + 80p. Post
21.00 + 12p.
For the benefit of of our readers not knowing thin
lamp we wish to point out that it i. probably the
most useful ultra violet lamp available especially
for disco work as it does not require choke or
starter. It can simply be plugged into the nearest
lamp holder. It is a true black light and has
proper "Woods" filter glass.
Ferrle Chloride onions for etching copper,
making printed circuit boards, etc. Special
purchase enables us to offer this in lib bags at
60p + 4p + 20p + 2p.
7 Digit Counter. Another special purchase enables
us to offer thin mains operated counter for only
about a quarter of its proper price. It works off
240v 50h, mains and requires no step down.
There is only one point about this that le It
counts in even numbers only, 2, 4, 6, 8, 10, etc.
If you want to count single you must divide the
final figure by 2. Price 50p + 4p. Post 10p + 1p.
ßkw Heater Assembly. Spiral elements in metal
frame, size fit° x 21" elements centre tapped eo
can be used for 1kw or 2kw. Unusual shape,
looking at it sideways the frame looks rather like
ship's ventilator. Probably made for some
well known fan heater. Price
+ Sp. Post
30p + 3p.
e ram
1
Cabinet.
Long
low
modern
teak
veneered cabinet size approximately 4' 2° x
15' x 5' probable coat to make today over 220.
We have a few of these, they are slightly second,
at prices ranging from 86 each, depending on
condition -sorry but these are for callers only.
Digital Display Unit (Digivisor). A precision made
instrument which le basically a moving col
voltmeter. Instead of having a pointer, however,
the scale is punched out with numerals, 0, 1, 2, 3,
4 and eo on. When you apply a voltage for
instance 8 volts-fig. 8 comes in front of a lamp
and Is focussed on to the screen. This device
which must have cost a small fortune to develop
and make can also be used for a variety of other
purposes. Voltage regulation by making beam of
light trigger a photocell, etc., etc. price 25 + 40s,
Valves -send for your requirement., most types
In stock.
71
1
THE METAC DIGITAL
ALARM CLOCK
THE METAC DIGITAL CLOCK
* COMPLETE KIT *
Guaranteed *
Tested
* WITHBuilt,
SLEEP -OVER FEATURE
Pleasant Green display . 12/24 Hour readout
Silent Synchronous Accuracy . Fully electronic
Pulsating colon . Push- button setting
Building time 1 Hr. . Attractive acrylic case
Size 10.5 x 5.7 x 8 cm
Easy to follow instructions
Ready drilled PCB to accept components
KIT PRICE £9.60
+
76p
VAT
P &P
and
Fully
01.11111111111
inc.
Bright Orange 12 Hour Display or
Soft Green 24 Hour Display
Hour Alarm
10 Minute Repetition
COMPLETE CLOCK
Alarm Set Indicator
£1299
Timekeeping
Silent
Accurate
+£1.04 VAT P&P inc.
British Designed and Built
24
5
in. across, 3} ins. deep
name, address and card number
Cash, Cheque or Postal Order or If you wish to use Barclaycard or Access, simply quote
when ordering.
Direct from:
-
METAC ELECTRONICS AND TIME CENTRE
Tel.: Uxbridge (0895) 56961
3 NEW ARCADE, HIGH STREET, UXBRIDGE, MIDDX.
Tel.: Daventry (032 72) 76545
67, HIGH STREET, DAVENTRY, NORTHANTS.
WHY NOT PAY US A VISIT AND SEE FOR YOURSELF THE FULL RANGE OF TOP QUALITY
WATCHES, CLOCKS AND OTHER CONSUMER ELECTRONIC PRODUCTS.
P.E. ORION STEREO
AMPLIFIER & TUNER
INVERTORS
e
.../
II
purchased built up in metal case and ready
for use. Price list sent on receipt of s.a.e.
Prices include p. and p.
P.W. AUTOMATIC EMERGENCY
SUPPLY
watt Inverter with built in
battery charger. In event of power failure
switches over automatically from battery
240n -5OHz -150
charging to inverter operation. Cct. as
appeared in Dec. 72 P.W. Complete kit of
parts (excluding meter) £24-50 plus £1 70p.p
DIGITAL WATCH
FOUR FUNCTION DIGITAL WATCH
FOR ONLY CM with 1 Year Guarantee
HOURS . MINS.. SECONDS . DATE
American Design, UK Manufacture.
TRANSFORMERS AND COILS
ii
Both high volume and small order capacity
available.
Special offer. Miniature mains transformer
0.0-Sv.OvA. Up + 10p P. & P.
.
+ 20 Watts r.m.s. into 8 ohm load. Distortion
less than 0.01 % 100Hz- 10kHz. Frequency
response + dB 20 Hz to 20kHz. Hum level
virtually nil with volume full on.
This is a power amplifier of superb quality
features.
incorporating
9
9 the veryY latest design
P
Professional hi-fl enthusiasts have classed it
as fantastic and real value for money. The
CCT incorporates a low flux transformer and
inputs for disc, tape, tuner, etc.
kit of Pparts including9 slim line
Complete
P
bookend case, silk screened front panel and
knobs £4860 inc. VAT and p. & p.
The bookend case, I.C's and semiconductors,
board, Transformer, etc. may be
P.C.
purchased separately if desired. Send S.A.E.
20
1
.
for further information.
P.E. ORION TUNER UNIT
PARTS MAY BE PURCHASED AS FULL KIT OR
SEPARATE ITEMS. SEND S.A.E. FOR DETAILS.
N.B.- DELIVERIES ON ALL ITEMS MAY TAKE UP TO
DAYS. DEPENDING ON AVAILABILITY AND DEMAND.
CASH IN REGISTERED ENVELOPE OR POSTAL ORDERS
CAN REDUCE TIME by NOT HAVING TO CLEAR CHEQUES
24
ASTRO IGNITION SYSTEM
Complete kit of parts for this proven
and tested system £10 45 inc.VAT
Ready built with only two connections to alter £1375 inc. VAT.
Thousands have used this system
both home and abroad. Consider
these advantages -more power,
faster acceleration, fuel economy,
excellent cold starting, smoother
running, no contact breaker burning. Also because of the high
energy spark the fuel mixture can
be made weaker giving further
economy and fewer plug problems.
Fitting time when built 5 minutes
state whether
approx. Please
positive or negative earth.
TRADE and EXPORT ENQUIRIES
WELCOMED ON ALL PRODUCTS
MI
1.1
ASTRO ELECTRONICS
Springbank Road, West Park
CHESTERFIELD. 31475
1
72
;
_
IIIIRMilia4
a,,,,
240v -50Hz from your 12v car battery
300 watt (12v)- 423'08
25 watt -£4'75
400 watt (240- £3s.1:
40 wan -£11.27
500 watt (24v)- £4.1-11
75 watt- E12-03
1Kw(5O)-E127'00
150 watt-£21 27
300 watt (24v)-£2{451-5Kw(11Ov)-£145 110
All above invertors are In kit form but may be
ASTRO IGNITION
1
Practical Wireless, May 1977
NEW
& MAZ DA VALVES
All individually box ed.
EXPRESS
POSTAGE
Full trade discounts to
bona fide compani es.
Prices on application
DM70
DY86/7
DY802
0.14
0.70
EB91
EBC81
0 97
EBF80
EBF83
EBF80
0 63
ÉC6O1
ÉC7
ECC81
ECC82
ECC83
ECC84
ECC85
ECC88
ECC189
0 53
039
11.416
0.56
6.52
/.0
004
O41
8.70
0-70
0
70
0.63
1-52
122
11.77
ECFN
063
ECF82
0.14
0.70
ECFN
ECH81
173
ECH83
ECH84
ECL80
ECL82
ECL83
1.55
ECLN
150
1.02
0.14
0.93
EF80
EF83
EF85
EF86
EF89
EF91
0 62
1 10
0 70
1 73
1 73
1 35
EF92
EF95
EF183
EF184
EH90
EL34
1
ELM
ELM
1
EL86
EL95
1-40
EM81
EY51
EVN
EY86/87
EYN
EZN
EZ81
GY501
GZ34
OC83
PC88
PC88
PC97
PC900
51
163
9 93
093
1ß2
1
40
50
0 70
1
02
1ß1
0 60
O
1
1ß2
034
137
0.97
1
0-97
02
0 97
1 73
1
PCH200
PCL82
PCL83
PCL84
PCL85
0
0 72
0
40
1 40
0 70
q
0 97
3 05
1
23
1 40
PL81
123
PL82
PL83
PL84
PL500
0 48
1 73
1 02
N PL81A
1
1
N
1.00
1-N
1-41
1.50
N
CY31
1
DAM
0 40
0 N
DAF91
DCC90
DF91
DF98
DK91
DK92
DKN
1.15
0.40
0.60
0-50
1-00
0.75
EF80
0 35
EF85
0-45
EF86 USSR
0.11
EFN Mullard
2-04
EF89
0-35
EBFN
EBF83
EBFN
EBL31
ECC81
ECC82
ECC83
ECC84
ECC85
ECM
ECH35
ECH42
ECHO?
ECHM
ECLN
ECL82
ECL83
ECLM
EF37A
EF39
0 72
30C15/
PCF8001 ß2
129
30C17
30C18/
PCF8051 28
30F5/PF818
1
0.15
0'36
1.00
0.75
O -40
0-40
0-N
6.32
2-N
0-45
038
036
0 35
0-45
0-50
131
OSS
0-6S
0.40
0-40
O-N
3.19
0 70
PCCN
PCFN
PCF82
PCFN
PCF801
PCF802
5.60
EL37
3./0
PCFN5
PCF8N
EL11
1-20
1-65
0-35
0.69
PCF808
PCL82
PCL83
PCL84
PCL85
PCL86
EL/2
EL84
EL95
EMN
E14131
EM84
EM85
EM87
EY51
EYN
EZ40
EZ41
EZN
EZ81
GY501
3 -N
HN300
KT61
KT66
KT81
(7C5)
17$
0.45
PCC189
165
0.14
0.42
1.65
0.65
045
0-80
GZ30
GZ32
GZ34
/ -3S
0A2
082
KTM
0-SS
0-N
0-40
1.00
1.00
0-45
O-N
0-N
0.75
0.30
001
1-32
0.65
6.65
0-75
1-N
3N
4-00
2-N
4-75
0 40
0-42
0.65
O-N
0.72
1-21
0-N
1.28
0-45
0-70
0-N
0-N
0-N
PCL805/N
PCE8000 IS
30L17
UCH81
1
UCL82
UCL83
UL84
U785
6/30L2/
1
O
N
73
62
1.02
1ß3
0 73
ECC8011ß0
PCC805135
30PIMR
1ß2
30P19/
PC802
30PL11
136
PCL801135
30PL13/
PCL8001J7
PCL88
30PL15
30C1/PCF80
OJSM
OOS
0.55
0.45
U14
U25
U26
0 75
6.156
8J6
8.176
BJ7M
BKBGT
BK7G
8K7M
6K8G
8K8M
SLOG
2 50
1-N
0.85
0-75
UABC80 0.40
0-75
UAF42
U191
UBC41
UBC81
0-N
UBFN
0-50
0.50
0.50
UBF89
UCC85
UCH42
O-N
BX4
0.45
UY85
VR105/30 0.40
VR150/30 0.I5
0.50
0.40
0-40
3S4
3V4
5R4GY
5U4G
5U4GB
5Y3GT
SZ4G
0 50
0.05
1
20
1-25
0 70
0.6S
O-9S
6/30L2
0.90
6AK5 USSR
0.45
6A55 UK 1.65
BAM5
2
6A05
N
1.041
6AS7G RCA
4SO
O-5S
tt
BBHO
120
0.50
BBQ7A
Ó-N
55
0-S0
6BR7
6857
3.00
4.60
OBWB
3-00
BBW7
1
OC4
0.45
3.85
4.00
SO
12
0 03
6CD6GA 2-S0
PY81
OSO
OCHS
PY82
PY83
PY88
0-45
BCW4
PYSOOA
O-N
0-N
1
30
6F23
8-N
OF25
1041
0 96
6F28
R ST
Practical Wireless, May 1977
BLBGC
807G
OQ7M
6X56
6X5GT
786
7B7
7C5
7C6
7H7
7R7
7S7
774
12AT8
12AT7
12AU6
12AU7
12AX7
128A8
128E6
30C1
30C15
0.50 30C17
eA57G USSR 30C18
PL81
216
1-N
0-05
0.45
0.45
0-70
6VBG
BV8GT
O-SS
174
040
0 50
0-40
1-25
1R5
1S5
0.88
0.65
0.56
0.15
UCL82
UCL63
UY41
35
075
O-N
UL41
O
1.20
0-40
0-10
6SL7GT O SS
6SN7GT 0.55
OS07GY 0.40
BU5G
1.50
0-N
UCI-181
0.45
PL802
PY33
1
72
44
PYN1
6E1E6
PL509
1
PY81/800 0-50
0
1-32
1
12
63
116 30PL14/
OBAB
PLSO8
1
30PC8/01
6F23/EF812
0-85
0.63
O-N
20
0°65
PEN45
PL38
PL504
1
UBF89
UCC85
3-N 6AU6
O
144
080
0.88
0-40
PL84
02
UBC81
OATS
PL82
PL83
1
0-S6
117
II-60
PD500
35
30FL1/I
30FL2
30FL12
30FL14
0-N
0.00
0 45
0 45
OSS
0.80
0-N
2-00
1-N
0-90
130
2-2S
OW
0.45
0-4S
0
S
AA119
0.07
0.16
AAZ1S
AC107
AC128
AC127
AC128
AC178
AC187
S
AAZ13
AC/88
ACY21
ACY39
AD110
AD119
AD161
AD162
AF115
AF118
AF117
AFIN
AF239
ASY27
ASY28
BA102
BA115
BD131
BD132
BF115
BF107
BF173
BF179
BF180
-12
0.75
0.25
0.25
0.22
0.27
0.20
0ß6
1-00
11.311
0 63
BFS81
O-2S
0.65
0-45
0.45
0.25
0-25
0.25
BFS98
BFWIO
8.25
BFX29
BFX88
BFY50
BFY51
1-N
BR100
BY100
0.45
0.45
0-25
0-25
0.22
BC113
BC147
0 30
MJ E340
MJE370
MJE520
MPF104
MPF105
N KT404
OAS
0 7S
0.13
0-22
0.17
0A10
1-25
1.SS
0.75
016
0.26
0 22
030
0.35
0.36
9.16
0.25
9.37
1
1-00
N
120
30PL7
0-SS
0-95
0.95
30P4MR 1.30
1.00
30P12
30P19
0-95
1.44
30PL13
1 -N
30PL14
35W4
030
35Z4GT 0-70
50CD6G 2-N
807
1-00
813177 1750
813 USA 27.50
813USSR 0-N
866A
VALmVE
OC3S
OC38
OC42
OC44
OC45
0.75
0.75
0.56
0.46
0-45
OC71
0-25
OC72
OC76
0.45
5-45
OC77
0.75
0-56
Oß1
1.00
O-ss
1-50
0-56
075
001
OC81D
OC81Z
0013
0C140
OC170
6-N
OC171
0C200
0C201
ORP60
TIC11
9 6S
040
1.25
0-75
-
25
0-N
031
1-441
9-22
TIP42A
0-75
S-10
0-16
ZTX107
ZTX108
ZTX300
N40N
N4007
N4009
N4118
9-12
9-13
013 2N2005A 6.36
1-16
0
S
to
03O
0-07
0-07
0-N
6-N
0.09
6l9
0-11
0-0/
0q
0-06
52033
6-20
S2051 A 0-21
52100A 0.20
S921
S3010
2N696
2NN7
2N7N
2N706A
2N1132
2N1302
2N1303
2N1301
2N1305
2N1306
2N7307
2N1308
2N1309
2N1613
2N2147
N
1-N
TIL209
N914
N1001
N4002
N4003
N4004
N4005
1.75
0.0
0-40
ZTX503
ZTX531
ZTX550
2N1131
1
TIC2260
ZTX501
1-00
1
0-2S
0-20
0-17
012
0-12
0-23
0-30
2.00
SN7480
SN747o
SN7473
5N7474
36
0-41
0.42
5N7480
5
N
SN7483
1
10
Valves & Plastic
Transistors 121%
Integrated
Circuits & Metal
Can Transistors
8%0
149
O-N
1
SS
0-50
0.70
1.00
0-N
6-13
1-14
It
SN74191
6.16
0-16
0-16
0-12
S-4S
0.50
58
019
11.17
546
0-45
SN7/54
SN7497
SN74100
SN74107
SN74110
SN74118
SN74119
SN71121
SN74122
SN71123
SN74141
15
3 87
015
517
40302
40430
SN7492
/
0-15
9-N
0-37
0.22
SN74N
2N3990p0SyS
SN
40381
1-26
1-75
SN7112
SN7450
SN7451
SN7453
2N3003
2N3904
0-12
0'13
0'13
0-37
S6S
1.20
SN74145
SN741S0
SN7/151
SN74154
SN74155
SN71158
SN71157
SN74170
SN74174
SN71175
SN74170
SN74190
9-92
0-70
0.16
2143823
ON
1-30
1-75
0 47
N
6-N
2N3819
2N3820
0-13
3N141
40380
SN7486
SN7490
0
2113711
013
0-S0
0-21
0-40
0-16
0-37
1.90
0-70
0-79
2N3710
0-1S
3N/26
5N7428
SN7430
SN7433
5N7137
SN7438
SN7440
SN7494
SN7495
0'13
013
9.50
2N2904A 0-25
2N2905
0-30
SN7411.3
2143707
2113708
2113709
0.13
0-13
0.22
0.12
037
1-N
ON
0-17
0-55
0-N
2N361S
2N3702
2N3703
2N3704
2N3705
2N3700
2N4061
2N4002
2114209
045
0-N
ZTX302
ZTX304
ZTX500
SN7491 AN
1.60
0.111
0-19
0-12
0 07
2113614
031
0-45
0-45
OA79
oA81
OA91
0-1S
0.10
2N4058
2N40S9
2N4000
2N23NA P25
2N2848
2N2904
2N2926
2N30S3
2N30S5
2N362S
0-25
ZTX301
To be added
to all orders
30FL14
30L15
30L17
0-10
0-16
1-15
2-00
2.25
0-60
OCP71
ORP12
066
1.28
30FL2
0A200
0A202
0C16
0C20
0C23
0C25
0C28
0-42
VAT
1-N
Quantity discounts on
application.
0C202
0C203
0-3$
0.50
0.60
0.40
1-N
1-N
All transistors, I.C's
offered are new and
branded. Manufactured
by Mullard, Texas, RCA,
Ferranti, Motorola, ITT,
Fairchild, Lucas, etc.
O-SS
0 42
0.28
0.16
Oß5
0.30
0-45
SN7441 AN
0.42
025
0.23
0'40
MJE3056 0-75
MPF102 O-N
MPF103 0.40
0-75
0.16
0.11
0-21
M J E2955 1.2s
0-15
1.00
0.16
0.25
0.21
0.12
0-12
BFX61 series
0.20
BZYN series
0.12
CR51-05 0-4S
CRS1-10 0-60
CRS3-05 0.45
CRS3-40 0-75
013
SN7401
-29
BY127
0'10
BC1/8
O-N
BC189C 9-1S
BC182
0-12
BC182L 0-12
SN7402
SN7403
SN7404
SN7405
SN7106
SN7107
SN7408
SN7109
SN7410
0 61
BY12O
8.15
BCf 17
SN7420
SN7422
SN7423
0.11
BF200
0-15
SN7111
SN7412
SN7413
SN7116
SN7417
BF196
111
012
0.14
0.15
SN7/00
0-31
BF197
014
BD121
130124
0.30
0-30
BF181
BF194
0-SS
BC107
BC108
BC109
BC113
BC784L
BC338
BCY32
BCY33
BCY34
BCY70
BCY71
BCY72
BCZ11
0-40
5-45
0-20
0-20
0-25
030
30F5
30FL1
Climax
order In UK.
1Sp per
30L1/PCC84
0-63
30L15/
1.126
ULM
PCC89
ELM
EBC41
EBC81
0 72
1 22
UFN
165
0.70
E8C33
PY801
50
00
1
EF9S UK
0 47
9 SS
EABCN 0.38
EB91
1.60
7 50
1
0.62
0.55
O-6S
0.45
EAF42
N
0.15
N78
EF92
O-SO
EF95 USSR
EF91
0 45
0
KTW61
MU14
0.65
8.65
0.55
0.55
0-4S
DY87
DY802
DYN
DYN
PY500A
PY800
UL41
PC86
PC88
PC97
PC900
PCC84
EF98
EF183
EF184
EL32
E133
EL34
DL92
DL94
PL504
1 10
PL508
1 73
PL509
233
PL802
233
PY33
0 73
PY81/800 0 72
PY82
0 76
PM/7 70p
PY88
0 14
EXPRESS
POSTAGE
Valve
1.40
002
0 N
0 91
MOLLARD PRICES AVAILABLE ON REQUEST
NEW VALVES
Individually boxed and
guaranteed but of European or other origin at
greatly reduced prices.
Quotations for any
valve not listed.
AZ1
AZ31
CBL31
CL33
15p for 1 Valve.
Each additional
add 2p In UK.
N 191
U193
037
933
PCL805/
PD500
PFL200
PL36
10
130
PCF201
PCF801
PCF802
PCF806
850
32
0 96
1 17
U PCLN
0 70
0 01
0 14
0 70
1 73
1
22
0
031
PCC84
PCC85
PCC88
PCC89
PCC189
PCF80
PCF82
PCF86
PCF200
TRANSISTORS -INTEGRATED CIRCUITS
040
89
OßS
1N
2.01
1-0
1N
0-9S
2-52
SN71192 2.00
SN71103 2-90
SN74194 131
SN74195 1-10
SN741N 130
SN71107
XN74198
SN74190
1-25
2.77
2-S2
1.57
1-10
1.26
2-110
8 pin 15p
DIL
14 pin 15p
OIL
SOCKETS16 pin 17p
THIS MONTH'S
OSCILLOSCOPE TUBES
Types CV 1526,
VCR 139A
All at£8.00each,+ páp50p
Add 8°%, VAT
SPECIAL OFFER
TERMS OF BUSINESS: C.W.O. A /c's available to approved companies
on application. Telephone and telex orders accepted. Export and trade
enquiries welcome. Open daily to callers 9 a.m. -S p.m. Monday to Friday.
Prices correct when going to press.
Prices on application for any types not listed.
Obsolete valves a speciality.
RER
OD.
CO3
HouseMAIL
, Fallsbrook R
Streatham SW16 6ED
TELEPHONE
01 -677
2424
73
CRESCENT RADIO LTD.
FANE SPECIALIST RANGE SPEAKERS
designed to produce the individual
sound requirement for its purpose. Robust
Cast Aluminium Chassis
Rec. Price
12" DISCO /80 T,',r'; eaë E27. 95
164-166 HIGH ROAD, LONDON N22 6EJ 888 -3206
(also) 13 SOUTH MALL, EDMONTON, N.9 803 -1685
MAIL ORDER DEPT.
I ST. MICHAELS TERRACE, WOOD GREEN,
LONDON N22 4SJ
Phone 888 4474
ALUMINIUM BOXES +8%
Metal project boxes give your work a professional finish
AB7
ABS
AB9
AB10
AB11
AB12
AB18
AB14
AB16
AB16
AB17
A818
AB19
21
4
4
4
4
8
6
7
8
10
10
12
12
W
H
65
4
21
65
25
2
15
15
15
15
4
5
6
7
2
25
3
64p
63p
64p
68p
64p
46p
69p
84p
21.02
a
11011
2
1
dl86
61
11.60
61.60
"0100" 100 WATT AMPLIFIER
All built and tested, mounted on a plain aluminium
chassie which measure, 18" x 98^ x 4" and which you
can mount into a cabinet of your choice. Four controlled input,, master volume, treble, middle and base
controls. 8/e protected output. 100 watts clean into
Bohm L /8. Ideal for disco, music groupe, PA. and
clubs. A bargain at 648 + 81 cary. + 8% VAT.
P.O. ETCHING KIT
This kit contains all that the constructor will need to
etch the circuits of his own design.
Contente -Plastic etching dish. Sample copper clad
board. Laminate Cutter. I lb Ferric Chloride. Large
Plastic Spoon. Etch Resist Pen. Full Etching In-
¡tractions.
12" GUITAR /80L
you're not
FANE 'POP' RANGE
to
nettle for a
small male
and
SPEAKERS
poor
2" POP 33T 33w L14.95
2" POP 50/2 50w £16.99
2" POP 55 60w £22.95
5" POP 60 60w £25.95
5" POP 70 70w £29.95
8" POP 100 100w £46.95
ranges, then
read the
specilleatlons
for the
MM12, and send for onel
AC volte: 0 to 15, to 0 /600
in 10 ranges. DC volts: 0 to
0.5, to 0/600 In 12 rangea.
DC current: 0 to 25 µA, to
0 /10 amps
10 ranges.
Resistance: 0 to 100 ohms,
to 0 /16 meg ohms in 4
ranges. Decibels: -20 to
+62 db in 10 rangea. Sise:
65 x 45 x 2 1Inch.
Price 619.60 + 8% VAT.
BARGAIN PROJECT BOX
plastic box with moulded
extrusion rails for PC or
Chassie panels with metal
front plate fitted with four
screw, (all supplied). SIZE
(internai) 81mm x 51mrn x
A
28mm.
OUR PRICE
60p. +8%
TI MULTI-METER
Ideal teste for everybody interested In
electronics Weighing lees than 100
grammes and only 60 x 24 x 90 mm
Ranges: A.c. volt,: 0 -10V, 10V, 250V,
1,000V, D.c. volts: 0.10V, 80V, 260V,
1,000V. D.c. current: 0 -1mA, 0.100mA.
Resistance: 0.150 kohm.
Price 6660 + 8% VAT.
1.25.75
12 "PA /BO general purpose P.A.L25.95
15" BASS /85 85w
£39.95
For
15" BASS /I00
GuitarE42.00
cour work/
hobby and
prepared
FGu tard
2' GUITAR/80B 8;,, c;á £26.95
MULTI -METER Ml[16
60.000 o.p.v.
If you need
a good instrument for
Complete and Big Kit Value at 6426 + 8% VAT.
PP1 switched 3, 41, 6, 71',
9 and 12 volts at 500 m/a
with on /off switch and
pilot light. Sise: 130mm x
55mm x 76mm.
ONLY' 2550
Each
HIGH FREQUENCY
HORNS
J44
Range: 2.5KHz-I5KHz
Power: 50w with
HPX2
Power: 30w with
HPXI
Imp: 8 pohms
3} ^x
3
910/2
Range: 2KHz -I5KHz
Power: 50w with HPX
Imp: 8p-116 ohms
}" z 3" £7.95
J104
Range: 2K1-1z-I5KHz
Power: 50w with HPX
Power: 70w with HPX2
Imp: 8 ohms
Size approx
I
10 }
6}
£16.95
"x3} "x7}"
HIGH POWER
' CROSS -O V ERS'
HPXI 3 5KHz)
HPX2 (5K Hz)
£2.75
e
3
LI7.75
1
Rec. Price
}nrx
920/2
Range: KHz -18KH:
I
Power: (00w with HPX
Imp: 8 ohms
Size approx
0.,c
14 "x9"x 15"
Price £59.95
Rec Prices INCLUDE VAT. 2 years
guarantee on above speaker models
FANE SPEAKERS ARE SUPPLIED TO MOST LEADING
UK MFRS OF GROUPA DISCO
E
QUIPMENT
Distributors (Wholesale & Retail)
Rec. prices shown correct at 15.2.77.
LINEAR PRODUCTS LTD, ELECTRON WORKS, ARMLEY, LEEDS.
Manufacturers & Export enquiries to:FANE ACOUSTICS LTD,286 BRADFORD ROAD. BATLEY,YORKS.
FERRIC CHLORIDE
Anhydrous ferric chloride in double sealed one pound
poly pack,. Our Price 65p +P /P +VAT @ 8% per lb.
8 KILOWATTS PSYCHEDELIC
LIGHT CONTROL UNIT
Three Channel Base,
Middle, Treble, Each
channel has Its own
sensitivity control.
MICROPHONE
Cardlold and
W
Just connect the in.
put of this nuit to
M3 CONDENSER
onini- direc-
tional 600 ohm and 1501(
ohm impedance. 20- 18,000
Hs. On /off ,witch and wind
shield. Complete with stand
adaptor. Packed in presentation box.
Price 61460 + 121% VAT.
the loudspeaker terminals of an amplifier and connect three 260V up to
1000W lampe to the output terminal, of the unit, and
you produce a fascinating sound -light display. (All
guaranteed)
£18.50
plus 76p P.
&
P. +8 %
BARGAIN TRANSFORMERS
volt 500m/ti
12-0 -12
HEAVY DUTY 12 VOLT
POWER SUPPLY
240 volt primary transformer bargain.
at 12 volt power approx size
80mm x 40mm x 50mm
supply approx. sise 6" x
4" x 85 ". Ideal for Ping fixing centres 75mm
your car entertainment in Our Price
£1 C20 + 8%
the home from domestic
mains. Suitable for 8 track cartridge or 4 track casEFFECTS
sette machine,. Price 57.60 + VAT 8%.
1.6 amp
PROJECTOR
6 WAY AND S WAY CROSSOVERS +168%
NT206 2 -way network for 8 ohm speakers up to 30
watts. Price 68.00.
NT206H 2 -way, as above, 100
watts. Price 6226.
NT806
13-way network for 8 ohm speakers
up to 80 watts. Price 18 26.
NT806H
Sway, as above, 100 watts. Prim
£400.
TIE -CLIP CONDENSER MICROPHONE
Omni'Directional 600 ohm 40-15,000Hz.
Extra long lead. Ideal for stage work.
conferences, etc. Price 19.50 +125 % VAT.
be without our
new effects projector, we
believe that this is the
moat versatile machine for
projecting coloured images
to supplement your music.
Spec.-Volts 220/240 AC
60Es. Lamp A1/167 160
60 m /m.
Standard Lene-
sturdy metal construction and takes a range of
looses
and accessories.
Come, complete with 6"
liquid wheel and ready to
use. A bargain at 1127 +
A
VAT 8 %.
ABS PLASTIC BOXES
Randy boxes for oonstructlon project,. Moulded
extrusion rails for P.C. or ohaasis panel'. Fitted with
1mm front panel'.
1005 -106mm x 78mm
1008 -160mm x 74mm
1007 -186mm x 124mm
1021 -106mm x 74mm
(sloping front)
Q.E. CARRIAGE
5Op UNLESS
Any S-64p, 1041 .20, 50- 1.5.00.
Your choice from the list
below.
ECC82, EF80, EF183, EF184,
EH90, PCF80, PCF802, PCL82,
PCL84, PCL85, PCL86, PCL805,
PL504, PY81 /800, PY88, 30PL14, 6F28.
Colour Valves-PL508,
PL519, PY500 /A.
3Sp each.
x 46mm
x 47mm
x 60mm
x 48mm
60p
IlOy
61.80
Plus 8% VAT
OTHERWISE STATED
All
PL509,
tested.
Aerial Splitters -2 way,
OHMS, Inside Type, El 50
No Disco should
atte.
LOW NOISE LOW PERDE CASSETTE21+8 %
Good quality tape In well made screw type cassettes.
Presented ln single plastic cases.
C60 83p
C90 -41p
Cl 0 -60p
10% Discount on ten or more cassettes of one type
LOUDSPEAKERS +12}%
2 }" 8 ohm
90p
25" 40 ohm
90p
25" 80 ohm
901
6" 8 ohm
ceramic 5160
"160"
AERIAL
VALVE
BARGAINS BOOSTERS
Press
75
Aerial boosters can produce
remarkable improvements
on the picture and sound,
in fringe or difficult
I
For TH stereo and standard VHF /FM radio.
B I2
the
older VHF
BI
-For
television -Please state channel numbers.
B 45 -For Mono or colour this
covers the complete UHF
Television band.
All boosters are complete with
battery with Co -ax plugs &
sockets. Next to the set fitting.
E3.80
Button UHF Tuners-4 Button Transistor -British
made -E2 SO each.
60p BARGAIN PACKS
Packs Un -used Parts-PKI- 40 -C280 (Mullard) Axial Lead
Capacitor mixed values from Olaf to 47µF (250V /W). PK2 -30C281 (Mullard) Radial Lead Capacitors mixed values from 015µF to
I 5µF
(250V/W). PK3 -6 Co -ax. plugs. PK4-6 Co-ax connectors.
PK5- 8-5m /m formers with slugs, PK6-25 -ACI28 Transistors. PK7-3
BF200 (VHF) Transistors. PK11-2 BFI82 (UHF) Transistors. PK9
Any 6 Transistors BCI08, BCI 13, BC135, BC153, BCI71, BC172,
BF194, BF195, BF196, BF197. PKIO 8-1 amp 400 volts rectifiers.
PKI 14.5 pin din plugs (180°). PK12-5 PP3 Battery Connectors.
All
All prices include VAT. P&P 20p per order. Please send uncrossed
P.O. or Cheques for returning if we are out of stock of Bargain
Packs or older types of new valves.
ELECTRONIC MAILORDER LTD.
62 BRIDGE ST., RAMSBOTTOM, BURY, LANCS. TEL. RAMS. 070 682) 3036
ACCESS AND BARCLAYCARD ACCEPTED
VAT-All prias are exeluding VAT. Plus. add to each Item the VAT me Indleatd.
74
Practical Wireless, May 1977
LEKTROPACKS
17
TURNHAM
GREEN TERRACE.
Tel.
CHISWICK, LONDON,
01- 994 -2734.
IMUSICAL EFFECTS EQUIPMENT
I
...
complete
W.4
DIGITAL CLOCK KITS
TEAK CASES
NEW RANGE
MC350E ECHO CHAMBER
E7S.00
Top quality unit with endless play tape cartridge. Stationary play heads
ensure good reproduction and echo variance is achieved by changing
tape speed. Input Imp. 50K and 000 ohms. 240V a.c. operation.
PS
110
MINI FAZER
^
5
£27'N
GUITAR PICK-UP
Easy to Flt crystal unit complete with volume
control.
t
1
E4105
£10.65
+ VAT £0.85
1.,
ALARM
+ VAT £1.07
_
"DELTA
Including
P & P
GENUINE TEAK OR PERSPEX CASE
DELTA DATA: 4 Radiant Red } inch high LEDs. 12hr display with AM /PM
indication. Beautiful Burma Teak Case or Pretty Perspex in
White, Black, Blue, Red, Green, Power failure is indicated
by flashing display.
Kits can be bought without case: Non Alarm £9.00
MODULES:
READY BUILT:
lMICROPHONE MIXERS
1
MM2 MIXER
£12.00
Mono/Stereo 4 Channel Unit. Inputs 4 o S0KO. Gain 3dB.
MM4 MIXER
£t 00
Mono 4 Channel Unit. 4 x 50K0 inputs. Gain 3dB.
MM3 MIXER
E21 00
Stereo 4 Channel unit with 2 level control meters. 4 dual impedance (50K0
or 6000) Inputs. Gain 13 or 8dB.
MIXER
r'
£13.43
effect foot switches 9V d.c. operation.
FY 2 FUZZ BOX
MUSS
Low priced 'Fuzz' effect unit with variable speed and volume controls and
on /off foot switch. 9V d.c. operation.
EA 45 ECHO REVERBERATION
Er. 00
High quality combined reverberation /mixer amplifier. Has 4 inputs and
separate control for reverb. section. 240V a.c. operation.
RT It RESLY TONE UNIT
E7t -00
Basically a Tremeioe /Phase Shifter/Revert,. Amp. all In one. A superb
multi -effect unit from which an infinite variety of sounds can be obtained.
240V a.c. operation.
12
z
prompt order
despatch
NON -ALARM
Li
WFS FUZZ WAH PEDAL
432.00
High quality professional standard unit, gives combined 'Wah Wah' and
'Fuzz' complete with 'Fuzz Adjust', Tone, Volume controls and Individual
MPl(
e,,,
,..
Low priced "Phase Shifter" activated byon/off foot switch. 91/ d.c. operation
RD 10 RHYTHM MASTER
£70.00
Provides 10 Percussion Rhythms (Waltz, Foxtrot, Western, Polka, March,
Rhumba. Bossanova, Cha -Cha, Mamba, Rock 1, Rock 2) as accompaniment
to other instruments. Has var. speed & tempo controls. 240V a.c. operation.
GP
-
ALARM
FEATURES:
"ALPHA"
E42. 00
Alarm
£1250 inclusive.
Buy a working tested module and fit your own case. Non
Alarm £9.50. Alarm £1300.
Complete Clock ready built 2 yr guarantee. Non Alarm
£1350 Alarm £1650.
Pulsed tone. Tilt operated 10 minute 'Snooze' period.
Single switch setting Optional extra mercury switch (45p)
allows Alarm reset by tilting clock. Digit brightness is
automatically controlled to suit lighting level.
Glowing Green }" high digits 12 or 24 hour. Non Alarm.
Built & Tested module plus perspex case.
Stereo 4 channel Mixer/Pre -amp. 4 Dual impedance (6000or 50K0)Inputs;
Stereo Phono (Magnetic) inputs. Output, 250mV. Mono or stereo.
4
MICROPHONES
£11'OO inc.
Clock chip AYS -1202 only £2-S0. Discount on ceders fore or more kits /clocks
Send payment with order. S.A.E. for complete range. Overseas: Add
£2 50 Airmail.
Suitable for P.A., Singing, Tape Recording, Groups, Disco's, Musical
Instruments, etc.
UDIS0 DYNAMIC CARDIOD
E12-N
Cardiod reic. with on /off switch. Supplied complete with jack plug /lead
and plastic mic. holder. Dual Imp. 50K0
6000.
ECM 070 ELECTRET CONDENSER
E1t-N
Dual Impedance 50K0 + 6000 :Detachable lead. Freq. response20- 25,000Hz
-i 2dB. UM- DirectIonal Cardlod. Cplt. with w /shield, Mic-holder, Battery.
FLEXIBLE METAL GOOSENECKS
200mm. £2.50; 330mm. E3.50; 550mm. ES Si.
All prices include V.A.T. and U.K. postage.
t
PULSE ELECTRONICS LTD
DEPT. PW4, 202 SHEFFORD ROAD,
CLIFTON, SHEFFORD, BEDS.
Telephone Hitchin (OW) 814477
A MINIATURE POWER TOOL
Please
mention
to speed your building
Super 30 Kit (30 Tools) (incl.
drill without stand)
£1762 plus P. & P. 85p
Mk. II Drill Stand
£4.40 plus P. & P. 35p
Practical
Wireless
Mk. Il Drill only
£8.79 plus
P. & P. 35p
Flexible Drive Shaft
£5.46 plus P. & P. 25p
Transformer 240V a.c./12V d.c.
£6 plus P. & P. 70p
when
replying
to
Advertisements
Variable Speed Transformer
£8.25 plus P. & P. 70p
Replacement drills, stones, burrs,
etc. 40p each. Circular saw blades
50p each. £2 per set of 4 sizes.
P. & P. any quantity 20p.
All VAT inclusive
PRECISION PETITE LTD.
119a High Street, Teddington, Middlesex TW11 8HG
Tel. 01 -977 0878 (24 hour answering service)
9" x 4"
Practical Wireless, May 1977
S.A.E. please for leaflet and order form
75
ijjjri it
'lost Equipment
.
ÎtEI1P1Eu
helps!
Practical Electronics 8 -page
supplement on wiring,
prototyping systems, circuit
boards and housings is an
invaluable practical guide for
all constructors.
SPECIAL PROJECTS IN THIS ISSUE
Milkimeters
The Eagle range of multimeters
covers every possible need of the
electrical or electronic engineer.
They cost from about £6 to £58
(inc V.A.T.). There's at least one
which suits your job precisely.
We have a lot of other test equipment too.
Send the coupon and we'll send you our
complete catalogue.
Please send me details of all your test equipment.
NAME
ADDRESS
Eagle International, Precision Centre, Heather Park Drive,
Wembley HAO 1 SU Tel. (01) -902 8832
L
CMOS Day -of- the -Week Indicator
that functions for one year on a
a
battery of manganese cells
IT'S
WHAT IS
-
A QUARTZ DIGITAL CLOCK
Hrs., Mins., AM /PM, Day, Date
AN ALARM CLOCK
4 Alarm Memories
IT?
A STOPWATCH
To 9 hrs., 59 mins., 59.9 secs.
A CALCULATOR
a transient generator which
produces keyboard triggered
envelope profiles, for use with
synthesiser VCAs and VCFs
Time and Date calculations
ANOTHER WORLD FIRST
FROM CASIO
THE CQ -1 In grey or white
ONLY 1" x 21" x 51 ". ONLY 5.2 oz.
ONLY £29.75 (R.R.P. £3595)
AC adaptor £3. 20
NEW
1977
Casio Caslotron Watches
functions and backlight
Stopwatch. Dual time zones
0
Arguably the best watches in the world -at any
price. Certainly the most versatile.
R15B (R.R.P. £7595)
S16B (R.R.P. £8995)
SI5B (R.R.P. £9995)
(Illustrated)
o!n CASIOTRON watches
r
mains -powered 3} -digit
voltmeter based on the Ferranti ZNA116
dual -slope integration DVM chip
AND
Part 2 of this vital series
Microprocessors Explained
a
-
Progress with
PRATICAL
£59.50
E6650
ET.. 50
from £39
50
Fairchild Timeband L.C.Os.
Battery Hatch for Self -change
Free Replacement Battery
Lower prices -Higher quality
5 +4 functions. Round watch on strap.
TC411. Chrome £2595. TC410. Gold E2995.
5 +4 functions. Illustrated.
TC413. Chrome £31 00. TC412. Gold £3395.
NEW. TIMEBAND DIGITAL ALARM CLOCK with snooze button £14.95
NEW
Send 10p for our ILLUSTRATED CATALOGUE. Probably the WIDEST
RANGE of the BEST watches at the LOWEST prices. Accurist, Ibico,
National Semiconductor, Optim, SEIKO, Texas, etc. Also LADIES' Watches
C
ELCETRONICS
TEMPU
Dept. P.W.
Fitzroy Street
Cambridge CBI f EH
Telephone: 0223 312866
19-21
APRIL ISSUE ON SALE FRIDAY 11 MARCH 40p
76
Practical Wireless, May 1977
STATION ROAD,
860185 (2 lines) TuesdaySto Saturday
Telephone:
one 5E
BAM B E R ELECTRONICS
B.
3)
PLEASE ADD 8% VAT UNLESS OTHERWISE STATED
PLEASE ADD 8% VAT UNLESS OTHERWISE STATED
MAINS ISOLATION TRANSFORMERS. Tapped
mains input. 240V at 3A + 12V at 500mA output.
New :boxed, made by Gardners, f12.
MIXED
PACKS, containing
resistors, capacitors, pots. etc. All new. Hundreds
of items. £2 per pack, while stocks last.
A LARGE RANGE OF CAPACITORS AVAILABLE AT BARGAIN PRICES, S.A.E. FOR LIST.
4MHz XTAL PACKS
AW -SOL ALUMINIUM
PLUGS AND SOCKETS
SPECIAL OFFER...
STARPHONE HIGH BAND RF PC BOARDS,
with conversion data for making into a good 2M
xtal, 7 caps.
Converter. (All that is needed:
2 resistors, and 9V DC.) PCB contains 2 Dual gate
Moe Fat RF stages 13N1401, Diode ring mixer,
PCB,
approx. size
All
on
one
3 stage OsclMultiplier.
6" e 1}',
t. connections. 9V DC supply. AGC
(can be left x fixed bias, or RF gain control) Ant.
input, IF output (works from a few MHz to over
30MH :1. All Brand New. £6.50 each, while
stocks last.
1
TELEPHONE HANDSETS with "PRESS -TOTALK" buttons, on curly lead, brand new, 13.50
(few only).
GARRARD 9V DC MINIATURE MOTORS,
Type 31BM, 3200 RPM governed. size approx.
n. high. with 2mm spindle. Brand
1in. dia. e
New 8Op each or 2 for f1.
1
1
CIO assorted orals between
4MHz and 6MHz), our selection only. £1 Pack.
MINIATURE PLIERS. High
made in USA. £4 35 +VAT (36p)Ú
SIDE CUTTERS. High quality, £370
normal displays. All brand new. AT THE BARGAIN
PRICE OF 50p PER DIGIT. TYPE 332 (two digits
In one mount) £1 each. (Sorry, no single digit
avallable.) Data supplied.
BSX20 (VHF Osc/Muld. 3 for 50p.
BC108 (metal can}, 4 for 50p.
PBC108 (plastic BC1081, 51for 50p.
BFY51 Transistors, 4 for 60p.
BCY72 Transistors, 4 for Sop.
PNP audio type 105 Transistors, 12 for 25p.
0E152 (UHF amp/mixed. 3 for 60p.
2N3819 Fet., 3 for Bop.
8C748 NPN SILICON, 4 for 5Op.
BC158 PNP SILICON, 4 for Sop.
BAY31 Signal Diodes, 10 for 36e.
BA12 t Varicap Diodes, 4 for Sop.
SILICON HIGH VOLTAGE RECTIFIER STICKS,
each, BY140
BV185 Inew) 35kV 2 5mA
lee-equip) 12kV 2.5mA 46p each.
fl
VARIABLE STABILISED POWER SUPPLY,
mains input. 0-24V output, stabilised and current
+ 32V at 50mA. Brand new by
21 e 4in.
British m manufacturer. Size approx. 71
completee with external
3 -turn pot e for voltage
control. Connection data supplied. £7.
limiting at 500mA
5k
5 to 12V DC, 450 ohm
coil. Designed to work directly from TTL Logic,
Single Pole Change over, Contact ratings 26VUV IA
3W. f7.75 each.
14 DIL REED RELAYS,
SOp each.
2N3055 type Transistors. O.K.. but unmarked,
5 for
9
m
switches
for
(suitable
mains operation)
with 9ro rotating cams. all individually adjustable.
Ieal for switching disco lights, displays, etc.,
or industriel machine programming. (Need slow
motion motor to drive cams, not supplied,) 9 switch
version £1.60.
VOLTAGE
LOW
PACK
OF
B ARGAIN
ELECTROLYTIC CAPACITORS. Up to 50V
working. Seatronic Manufacture. Approx. 100, £1.50
per pack . 121% VAT.
SOLDER SUCKERS (Plunger Type/. Standard
Model, £4.50. Skirted Model, LA -95. Spare
Nozzles bop each.
Converters. 24V DC input 13 8V at
approx. 3.4A DC output. fully stabilised. f3SO each
(ideal for running 12V car radio from 24V lorry
battery).
WELLER SOLDERING IRONS
EXPERT. 8ulh- inspotllght illuminates work Pistol
Mobile
123% VAT.
1
x
PERSPEX TUNER PANELS (for FM Band 2
tuners) marked 88- 108MHa and Channels 0-70,
Lead suppressors (10kohm) for mobile plug loads,
4 for 50p.
HEAVY DUTY RELAYS, 24V d.c. operated will
work on 18VI 3 heavy duty make contacts (around
break
10A. rating) e 4 change over ontacts +
New, complete with cmounting bracket.
contact.
m
(Ideal for switching HT on Linear..) Many uses for
1
this high quality unit. 11.50 each.
1
123% VAT.
£980
£2.22
Dubilier Electrolytic., 50pF, 450V. 2 for Bop.
Dubilier Electrolytic., 100yF, 275V, 2 for Bop.
Plessey Electrolytics, 470yF. 63V, 3 for Sop.
TCC Electrolytics, 1000yF, 30V. 3 for Bop.
Plessey Electrolytic, 1000pF, 180V, 40p each
13 for 111.
Dubilier Electrolytic., 5000pF, 35V, 50p each.
Dubilier Electrolytic., 5000yF, 50V, Bop each.
ITT Electrolytic., 6800pF, 25V, high grade, screw
terminal.. with mounting clips. 50p each.
Plessey Electrolytic., 10,0000F at 83V, 7Sp each,
Plessey Cathodray Capacitors, 0-0 .40F at 12 5kV
DC. Screw terminals. El 50 each.
PLEASE ADD 12}% VAT TO ALL CAPACITORS.
TV Sockets (metal type), 4 for 50p.
TV Une Connectors (back-to-back sockets), 4 for Sop.
EXPERT SOLDER GUN. 16.80 + VAT (54p).
EXPERT SOLDER GUN KIT Ispere bits case,
+VAT 178p).
SPARE BITS, PAIR. 30p e VAT (2p).
MARKSMAN SOLDERING IRONS
SP150 15W £3 + VAT 124p1.
SP25D 25W £3 o VAT 124p1.
SP250K 25W + bits, etc.. kit E3.86 + VAT (31p).
SP40D 40W £3.44 + VAT 128pí.
BENCH STAND with spring Marksman Irone,
for 50p
TV PLUGS AND SOCKETS
TV Plugs (metal type), 5 for 50p.
grip with fingertip trigger. High efficiency copper
soldering tip
etc.).
i
2
high.
Lin. o }in. x
ound 3 5-5MHz. 2 separate transformers in
rcan. internally screened, 5 for 50p + 121% VAT.
Mom add
103 transistor insulator sets. 10 for 60p.
Plugs 50 ohm, 8011 each, 3 for £1.50.
PL259 Plugs IPTFE). brand new. packed with
reducers, Shp or 5 for f3.
50239 Sockets IPTFEI, brand new 14 -hole fixing
type), 50p each or 5 for £2.25.
VARICAP TUNERS Mollard Type ELC1043/05.
Brand New, £4.40 o 121% VAT.
TWIN I.F. CANS, approx.
clear numbers, most blacked out, smart modern
appearance, size approx. 84in. x 1-lin., 2 for 36p.
PROGRAMMERS (magnetic devices). Contain
N -Type
1
Miniature earphones with min. jack plug,
ideal for radio, Hi -Fi inputs, etc.), approx. }In,
t }in., 3 for 60p.
4 for Sop,
SOLDER (made by Multi ora). Solders aluminium to itself or copper,
brass, steel. nickel or tinplate, 16 s.w.g. with
multicore Rue, with instructions. Approx. metre
coil 40p pack. Large reel £2.75.
We now stock Spiralux Tools for the electronic
enthusiast. Screwdrivers, Nut Spanners, BA and
Metric sizes, pop rivet guns, etc. S.A.E, for Ilst.
SMALL MAINS SUPPRESSORS (small chokes.
ft.
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+ VAT 3Op.
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l
PLASTIC BOXES 33' square, 11" deep Iwallounting type) with 5-pin din plug on front penal.
q ality "Crescent'.
COMPONENT
+
VAT 118p1.
SPARE BITS
MT8 for 15W, 48p + VAT (40.
MT4 for 25W, 38p o VAT (3c.).
MT10 for 40W, 42p n VAT I3pl
TCP2 TEMPERATURE CONTROLLED IRON.
Temperature controlled iron and PSU. £27 r VAT
(£2.181.
SPARE TIPS
Type CC single flat, Type K double flat fine tip,
Type P. very 8ne tip. Et each + VAT (SP).
MOST SPARES AVAILABLE.
MULTICORE SOLDER
Size 5 Savbit 1E1 e.w.g. in alloy dispenser. 32p
VAT (3p).
Size CI SAV 1 B Savbit 18 s.w.g.. 58p + VAT (4p).
Size 12 Savbit 18 s.w.g. on plastic reel £1.80
VAT (1601.
} Kg. I1 116) 80 x 40, 20 s.w.g. on plastic reel C3.
Terms of Business: CASH WITH ORDER. MINIMUM ORDER f2. ALL PRICES INCLUDE POST & PACK/NC (UK ONLY). SAE with ALL ENQUIRIES P/ease
PLEASE ADD VAT AS SHOWN. ALL GOODS IN STOCK DESPATCHED BY RETURN. CALLERS WELCOME BY APPOINTMENT ONLY
A. Marshall (London) Ltd Dept: PW
Cricklewood Broadway London NW23ET Tel: 01 -452 0161/2 Telex:21492
'8. 85 -West Regent St Glasgow G2 2QD Tel: 041 -332 4133
6 1 Straits Parade Fishponds Bristol BS16 2LX Tel: 0272- 654201/2
C'a rear-deal j,/ro"c
40 -42
s
rsIvlIIrlc:::I
CATALOGUE NOW IN
STOCK PRICE 55p post paid
(40 to callers
1977
Call in and see us
9-5.30 Mon-Fri 9-5.00
a
Our range covers over
7,000 items. The largest
selection in Britain.
TOP 200 IC's TTL, CMOS & LINEARS
CA3020A
CA3028A
CA3028B
CA3030
CA3080A
CA3045
CA3046
CA3048
CA3049
CA3052
CA3053
CA3080
CA3080A
CA3086
CA3088
CA3089
CA3090
CA3130
LM30IA
LM301N
LM304
LM307N
LM308N
LM309K
LM317K
LM318N
LM323K
LM339N
LM348N
LM360N
LM37oN
LM371 N
LM372N
LM373N
LM374N
LM377N
LM378N
LM380-8
2.29LM380N
1.01 LM381A
1.29LM381N
1.14 L1h382N
1.89 M384N
1.40 M386N
89p M387N
2.23 M388N
-66,LM389N
98pMC1350
2.43MC1351
1.60MC1352
1
75pNE567
65pSA5560
45p SA5570
60pSO42P
60p76001 N
85p76003N
75p76008K
I.88LM710C
51p LM710N
-59LM723C
1
2.52LM723N
3.80 LM74 C
94pLM74IN
65p 76013N
TBA7000
I
I
1
.OSTAA521
.30TAA522
65 TAA550
I'BOTAA560
TAA570
TAA611B
OOTBA820
1.03
1.90 TBA920
1.79
60p TBA920Q 1-99
I -60TBA940
1.62
1.30 TCA I60C
SS
I
.85TCA1608 1.61
TAA621
2.15 TCA270
2.25
1'57TAA66IB 1.32TCA280A
30
TAA700 3.91TCA290A 3.13
1.50 TAA930A I OOTCA420A 144
I70
1
1
1
1
1
1
-91
LM3900
2.75 LM3905
00 LM3909
2 25 M C I 035
7Sp 76227N
75p76228N
1.6076530N
3
2 15MC1303
1 15 MC1305
1 25 MC1306
75MC1310
I
2d5
MC1312
9SMC1327
90p MC1330
3
I
I
68p 76532N
75 76533 N
4776544N
I 8576545N
9176550N
1
76546N
1
I
1
9876552N
76570N
92p76620N
1.
I.5ITBA530
17S TBA530Q 2.07
221
91 9 TBA540
I 50 TBA540Q 1.30
3.13
30 TBA550
1
1
CD4006
CD4007
CD4008
CD4009
CD4010
.44T5A550Q 321CD4011
2 09TBA560Q 3 211CD4012
44TBA570
I 29CD4013
41pTBA570Q
38 D4014
6SpTBA641Q 1 50 04015
2 0i,TBA651
1.80 04016
101TBA700
52CD4017
I
1
1
1
AT THE ALL ELECTRONIC SHOW
GROSVENOR HOUSE 19-21 APRIL
SEE US
Practical Wireless, May 1977
2 07
1.20
1.16
1
I -05TCA730
50p760I3ND 1.57 TAA930B
TAD 100
I
65p LM741-8
40p 76018K
2-S0 TBA120
6SpTCA7S0
44pLM747N
90p76023N
1-70 TBA400
I .á8TCA760
2.45LM748-8
50p76023ND
57TBA500
TCA800
65ppLM748N
90p76033N
i;SlTBA5000 2.21
1.30UAAI70
1- 17 LM I800
1-7676110N
713A510
1'll UAA 180
2-10 LMI808
1-9176115N
.87
2,TBA510Q
2.30CD4000
3.00 LM 1828
1-7376116N
.30TBA520 2.21 C04001
N
N
I
6.
LM3302N 1
76226N
94T5A520Q 2.30 04002
1.75 LM3401 N
1.61
60p 71$4720Q 2.30
92p TBA750
1.98
45TAA310A 1.50 TBA750Q
9IpTAA320A IISTBA800
53pTAA350A 2.48TBA810
1
62LM702C
60pLM709C
68p LM709N
10
1
45MC1458
80p NE555
-OS NE556
1.00 NE565
1-00 NE566
I
1.2076660N
97p 76666N
1-23 MC1357
1
I
75p 76650N
3.22
2-76
2.30
1.38
3.13
2-00
2 00
lÓp
20p
1.10
lop
97p
ióp
20p
S7p
1.01
1.01
101
POPULAR SEMICONDUCTORS
2N6%
lSp
2N697
2N698
2N699
2N706
2N706A
2N708
30p
62p
55p
14p
12p
21p
214709
SOp
2N718
2N718A
2N720A
2N914
2N916
2N918
2N929
2N930
27p
Sop
80p
3Sp
30p
38p
25p
28p
60p
60p
2NI132
2N1613
2N1711
2N1893
2N2102
2N2218
2N22 8A
3Sp
37p
30p
60p
33p
37p
30p
2N2219A
2N2220 33p
2N2221 12p
2N2221A 26p
25,2222 25p
2N2222A 25p
2N2368 Up
2N2907
2N2907A
2N2924
2N2926
2N3019
2N3053
2N3054
2N3055
2N3390
2N3391
21p
22p
2N3394
2N3439
2N3440
2N3904
2N3908
2N4036
25p
ISp
ISp
Bip
64p
85p
2N3442 135
2N3638 16p
2N3638A 16p
2N3639 30p
2N3641 20p
2N3702 17p
2N3703 16p
ISp
16p
ISp
16p
73p
2N4037
12p
67p
55p
20p
20p
40362
40363
40406
40407
40408
40409
40410
17p
40411
2N4058
2N4060
2N4061
2N4062
2N4126
2N4289
2N4919
2N4920
2N4921
2N4922
2N4923
2N5190
2N5191
2N5192
2N5245
2N5294
2N5295
2N5296
2N2905A289
STOCK"
Price.
at 18th. Feb.,
25p
2N2369A 25p
2N2646 73p
2N2647 1.40
2N2904 36p
2N2904A 37p
2N2905 37p
ISp
2N3823
2N5298
16p 2N5447
2N3711 lip 2N5448
2N3712 1.10 2N5449
2N3713 130 2N5457
2N3714 2 45 2N5458
2N3715 2 55 2N5459
2N3716 2.80 2N5484
2N3771 1.83 2N5486
2N3772 2.00 2N6027
2N3773 1.90 2N6101
2N2369
2N3709
2N3710
2N6121
60p
70p
25p
30p
2N3441
2N3705
2N3706
2N3707
2N3708
310
55p
2N3391A 23p
2N3392 16p
2N3393
2N3791
2N3792 3.50 2N6122
2N3794 20p 2N6123
2N3819 36p 2N6126
2N3820 311p 40361
15p
12p
lIp
ISp
38p
4Ip
43p
4Sp
45p
48p
1.20
Up
459
65p
65p
65p
2 85
at
BC107
BC108
BC109
BC! 13
BC115
BC116
BCI16A
BC 117
BC 118
BC119
BC121
15p
ISp
15p
17p
19p
19p
20p
22p
16p
30p
4Sp
BC132
BC134
BC135
BC136
BC137
30p
BCI41
B('142
4Sp
15p
16o
19p
40594
40595
40673
AC126
AC127
75p
86p
73p
37p
44p
SSp
AC151
35p
Sep
BC143
BC147
BC148
BC149
BC153
30p
7Sp
AC 187K
SSp
ACI88K 55p
12p
AD161
AD162
AFI06
85p
85p
BC158
BC159
AF109
15p AF124
19p AF125
AF126
22p
33p AFI27
39p AF139
34p AF186
AF200
53p AF239
63p AF240
42p AF279
41p AF280
75p
6Sp
63p
65p
6Sp
69p
50p
70p
74p
BC161
BC167
17p
20p
65p
70p
50p
70p
60p
70p
75p
40p
40p
40p
40p
1Sp
lip
AC128
37p
AC152
49p
AC153
AC153K SSp
40p
AC176
S5p
BC/60
BC168
BC169
BCI70
14p
40p
30p
12p
11p
139
27p
Ilp
SOP
50p
Ilp
12p
12p
16p
14p
BC171
BC172
BC177
BCI78
BC179
BCI82
12p
100
20p
239
lip
BCI02L 149
lip
80p BC183
2N2906
2143789 2-90 2N6I07
BSp BC183L 14p
2N2806A 25
2N3790 3.10 2N6109
"FULL RANGE OF THYRISTORS TRIACS DIACB, iENERS, CAPACITORS RESISTORS, SOLDERING IRONS, TOOLS ETC., ALWAYS IN
lip
1977,
but
1111
98p
BCI40
exclusiva of VAT. P. &
P. 30p
77
SMALL ADS
CONDITIONS OF ACCEPTANCE
OF CLASSIFIED ADVERTISEMENTS
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that
the
Advertiser
understanding
warrants that the advertisement does not
contravene any Act of Parliament nor is it
an infringement of the British Code of
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2. The publishers reserve the right to
refuse or withdraw any advertisement.
3. Although every care is taken, the
Publishers shall not be liable for clerical
or printers' errors or their consequences.
The prepaid rate for classified advertisements is 17
pence per word (minimum 12 words), box number
40p extra. Semi -display setting £14.00 per single
column inch (2.5cm). All cheques, postal orders
etc., to be made payable to Practical Wireless and
crossed "Lloyds Bank Ltd ". Treasury notes should
always be sent registered post. Advertisements,
together with remittance, should be sent to the
Classified Advertisement Manager, Practical
Wireless, Room 2337, IPC Magazines Limited,
King's Reach Tower, Stamford St., London,
SE1 9LS. (Telephone 01 -261 5846).
MULLARD 0C28 TRANSISTORS complete with
mounting nuts and bolts. Ex equipment but
FULLY GUARANTEED.
NOTICE TO READERS
20p each, 90p/5, £8/50
Receivers and Components
"4'
-
SEMICONDUCTORS: 1N914E 3p each,
1
amp
£180/100, £13 /1,000 800v
(1N4006 equiv.) 5p each, £4/100, £35/
1,000. Zeners:- 2.2 -36v 5p each, £4/
100 (no mix), £4.50/100 (mix). G.P.
Silicon Diodes:- 2p each, £1.30/100,
£10 /1,000. 0A90/91 etc 4p each, £3/100.
Ltd Qty. Branded Transistors:- BC212L
9p each, ZT 212 lop each, 2N2955 £1
each, 2N3054 £0.40 each, 2N3716 £1.50
each. CZ11 Thermistor 20p each, 10
for £1.50. S.A.E. for lists. P +P 20p
components,
service
2.2, 4.7 6 lOmfd. -5p. 22, 47-51p. (50V-6p).
100-7p (50V -Sp) 220 -Bp. (50V-10p) 470 -11p.
(50V -16p) 1000/16V -15p, 1000 /25V -18p. 1000/
50V -22p.
data,
historical research, books, magazines, repairs
and restorations. A complete service for the
collector and enthusiast of vintage radio.
S.a.e. with enquiries and for monthly newsheet.
Full 1979 catalogue, 50p post paid.
TUDOR REES (Vintag Services), 54, Broad
Street, Staple Hill, Bristol, BSIS SNL. Tel.
Bristol 565472.
rrr
5870ST
SP- 425-09 (9
N1XI +Data, 50p. Sperry
digit display) +data, £1.
SKT 50p. 747 (Class II), £1.35. MM5314
+data, £3.35. SKT, 45p. TIL209, lop.
BC108, 10p. IN4148, 3p. EX7001 (CT7001),
£5.50. 741 DIL, 18p. TO99, 20p miniature 5 position toggle, £1. P/P 10p. LB,
43 Westacott, Hayes, Middx UB4 8AH.
VALVES
T.V. - Industrial - Transmitting
We Dispatch Valves to all parts of the world
by return of post, Air or Sea mail, 2700
Types in stock, 1930 to 1976. Obsolete types
a speciality. List 20p. Quotation S.A.E.
Open to callers Monday to Saturday
9.30 to 5.00 closed Wednesday 1.00. We
wish to purchase all types of new and
boxed Valves.
-
COX RADIO (SUSSEX) LTD.
Dept. P.W. The Parade, East Wittering,
Sussex P020 8BN West Wittering
2023 (STD Code 024366)
Subminiature bead tantalum electrolytics-
0.1, 0.22, 0.47, I .0, 2-2 @ 35V, 4.7/25V -11p.
10;25V -13p. 22/16V, 47 /6V, 6 100/3V -15p.
Millard miniature ceramic E12 series 2% 63V.
lOpf. to 47pí -3p. 56pí. to 330pí. -4p.
Vertical mounting ceramic plate 50V.
EIS series 225f- 1000pí. E6 series 1500pf -47000pí.
-2p.
Polystyrene E12 series 83V horizontal mounting. lOpf to 1000pf-3p 1200pí. to 10000p1-4p
Mallard polyester 250V vertical mounting ES
series. 0.01 to 0.1-4p. 0.15, 0.22- 5p.0-33, 0.47
Sp. 0 68-11p. 1.0 -13p. .5 -20p. 2.2-22p.
Mylar(Polyester) Film 100V vertical mounting.
-
1
0001, 0002, 0005 -3p. 0.01, 0.02-4p. 0.04, 0.05
--4ip.
Miniature resistors Highstab E12 series 5 %.
Carbon Film 0ß5W 10 to 10M0. (10% over
1M0) -1p. Metal Film 0.125W, 0ß5W 6 0.5W
100 to 2M20. -14p. Metal Film 1W.27 0 to
10M0. -2p ea.
1N4148-3p. 1N4002-5p, 1N4006-7p. 104007-8p.
BC107/3/9, BC147/8/9, BF157/8/96 BF194 6197-Op.
Fuses 20mm. glass. 14" glass 6 1" ceramic. 21p.
Post 10p. (Free over £4.00) Prices inclusive of
VAT.
THE C. R. SUPPLY CO.,
127, Chesterfield Rd., Sheffield
Primary windings for 000 ohm. 200 ohm and 60
ohm with Secondary loadings from 2K ohm to 10 K
ohm Frequency response plus /minus ¡dB 20 Hz
to25 KHz. Contained in well finished Mumetal box,
33mm diameter by 22mm high, with colour coded
end leads, low distortion. Delivery (smell quantities) EX STOCK, HIGHLY COMPETITIVE PRICE
FULL DETAILS ON REQUEST.
A. SOWTER LTD., Dedham Place, Ipswich,
1P4
CARBON FILM RESISTORS. 0.33W
5% Hi- stability E12 series 4.711.1M. Any
selection 0.9p each, 0.8p 100 +, 0.75p
1,000 +. Inclusive prices. P &P 15p.
C. N. Stevenson (PW), 304 Avery Hill
Road, London SE9 2JN.
78
SB.
SOWTER TYPE 3070
MULTITAP MICROPHONE TRANSFORMER
E.
IJP. Telephone
modules. Small superhet circuit boards
requiring only controls and tuned
circuits. 9 volt. Mosfet mixer, IC IF,
BFO, PROD. pet. Excellent AM /CW/
SSB results reported by delighted
users. SAE details. PR Golledge Electronics, Millend, Stonehouse, Glos.
Precision Polycarbonate Capacitors
All High Stability -extremely Low Leakage
03V DC RANGE
440V AO RANGE
Value
Dimes- Price
dons lmm) each
D
L
0'1µF
27
27
93
99
23
33
93
(µF)
046µF
0ß2µF
O'25NF
o 330F
0470F
060F
68µ1r
i'OyuF
5
12'7
68p
809
860
92p
090
127
16
16
16
19
19
60 8 19
60 8 19
1110
11 10
0126
9187
Value(PF)tl% ±2% ±5%
0.01 -0.2
0ß2-0.47
0.68µF
1-0/F
160F
2ß1aF
33µF
47µF
88HF
101.LF
61.28
6152
11.44
75p
77p
840
6166 91p
1174 1116
909
61p
660
80p
67p
6198 6182 70P
99p
6240 1160
12.82 0188 11.22
2248 1039 0147
0498 43.32 9201
07 14 04'76 02'88
15µF 60'8 25.4 11'84 050.F
99.88 £8.44 £390
2.00° 60.8 25.4 01.96 2'2µF
TANTALUM BEAD CAPACITORS -Value available:
1.0, 2.2, 3.3, 4.7, 6'80`
0.1, 0ß2, 0.33, 0.47, 0 6
15V /25V or 30V: 10'0µF at 16V /'20V or 25V; 22.OyuF
6V/10V or 16V; 33.00yuF at 6V or 10V; 470µF at 3V
6V; 100'0µF at 3V. All at 12p each, 10 for 6110,
for 26, 100 for
,
Electrolytic capacitors 16V, 25V, 50V. -0.47,1.0,
VINTAGE RADIO
1920 to 1950
valves,
Dalton
BRAND NEW COMPONENTS BY RETURN.
0024
Receivers,
Radio
All prices include VAT.
class) 20p. C.W.O. S.A.E. for full lists.
J. C. JONES (WS1)
Mall order only
46 Burstellars, St. Ives, Cambs. PE77 4XX
P. 6 P. (I at
Bale Electronics, "Nanock,"
Lockerbie, Dumfriesshire.
RECEIVER
COMMUNICATIONS
SPECIAL OFFER
When replying to Classified Advertisements please ensure:
(A) That you have clearly stated your
requirements.
(B) That you have enclosed the right
remittance.
(C) That your name and address is written
in block capitals, and
(D) That your letter is correctly addressed
to the advertiser.
This will assist advertisers in processing
and despatching orders with the minimum
of delay.
1.
0473 52794
V.H.F. /F.M, Aerials. British made by
Panorama (communication aerials
specialists). Chrome with black base
settable V, L or dipole. Specify 75 or
3000. £1.95 inclusive. P. Baker, 6
Serpentine Road, Sevenoaks, Kent.
I9.
TRANSISTORS a I.e.Y
BC212/212L 12p
BC107/8/9
92
13C218/2134 11e
12p
BC114
BC147/8/9 10p
l6p
BC169
BC164/7/8/9 lop
BC214/214L lip
BF194/5
12p
BFY60/1/2 gap
2N3055
at
at
or
60
609
20P
0044/45
0071/2
20p
NE655 Tinier 91p
741C8 pin D1182p
ZN414
6115
ÁF078
40p
SN76013ND
AF239
88p
3N3702/4
llp
01.60
POPULAR DIODES -1N914 8p, for 8 450, 18 for 00p
114916 Op a for 45p, 14 for 90p; 1844 6p, 11 for 60p;
28 for 0100, 1N4148 6p. 6 for 27p. 12 for 48p; 1144001
65p; 002 6p; 003 65e; 004 70; 006 71p; 006 Sp; 007 940
LOW PRICE ZENER DIODES-400roW, Tol. ±5% at
5mA. 9V; 3V2; 3V6: 4V7; 6V1; 6V6; 61,2; 6V8: 7V5;
8V2;9V1;10V; 11V; 12V; 13V; 13.0V; 15V; 16V; 18V;
20V; 22V; 24V; 27V; 30V; 33V. All at 7p each, 6 for 830,
10 for 65p, 60 for 13.12. SPECIAL OFFER: 100 Zeners
may be mixed) for 16.00.
RESISTORS -High stability, low noise carbon elm 6
OW at 40 °C, tW at 70 °C. 512 series only -from 2ßtì to
2.215a. ALL at 1p each. Op* for 10 of any one value,
7001 for 100 of any one value. SPECIAL PACK; 10 of
each value 2'2n to 2ßM 17 (730 resistors) I51.
SILICON PLASTIC RECTIFIERS -1.6 amp, wire -ended
D027: 100 P.I.V. 7p (4 for 26p); 400 P.I.V. Sp (4 for 30p)
BRIDGE RECTIFIERS -24 amp: 200V 400; 950V 40p;
llp
5C182/182L
BC183/183L lip
BC184/184L 12p
60011 56P.
SUBMINIATURE VERTICAL PRESETS --0-1W only:
AU at 6p° each; 50; 100; 220; 470; 880 ohm; 1k; 2k2;
4k7; 6k8; 10k; 15k; 22k; 47k; 100k; 220k; 680k; 1M;
2M6; 6M.
PLEASE ADD 20p POST AND PACKING ON ALL
ORDERS. EXPORT -ADD COST OF SEA /AIRMAIL.
Add 8% VAT to all items except thoae marked with
which are 125 %.
Send B.A.E. for additional etock lists.
Wholesale price lists available to bona Ode companies.
MARCO TRADING (Dept.
P4),
The Old School, Edstastos, Wem, Shropshire.
Tel: Whitell 404/465 (STD 004 878)
( Propre. Minieoet Trading Ltd.)
AMPLIFIERS,
working
1
NEW,
watt audio.
Boxed,
Guaranteed,
AMPLIFIER PANELS with 2 speed motor controller incorporated uses IC Type LM380N and
runs from 9 volt P/Supply. Only £1.00 each inc.
VAT /P 6 P etc. Drawings + IC Data add extra
60p to order from:
-
INDUSTRIAL RF SERVICES, 51 Deptford
Broadway. London SES 4Pµ. Phone 992 -4224.
Practical Wireless, May 1977
TOUCH CONTROLLED
LIGHTING KITS
Service Sheets
These KITS replace conventional light switches
and control 300W of lighting. No mains rewiring
required. Insulated Touchplates. All with easy
to follow instructions.
NEWI TSD300K-TOUCHSWITCH and DIMMER
combined. ONE touchplate to switch light on or
off. Brightness controlled by smell knob. ONLY
£5 95.
TS300K- TOUCHSWITCH. TWO
SERVICE SHEETS- COLOUR TV SERVICE
FERGUSON H.M.V. MARCONI AND MANY MORE
Please send a Stamped Addressed Envelope fora prompt reply.
touchptetes
Let us quote you.
ON and OFF-ONLY £3.87.
TSA300K- AUTOMATIC. ONE touch plate. Light
Also comprehensive T,V. repair manuals by J. M. Court. S.A.E. for details.
G.
turns off after preset delay £3.67.
LD300K- LIGHTDIMMER KIT -£2.45.
10
CMOS (Motorola)
4000
11Ip
4001
ISp
4002
4007
111p
4011
4012
16p
18p
17p
51p
91p
51p
91p
17p
17p
4013
4015
4018
4017
4023
4025
TRIACS 400V TO220
Case Isolated TAB
6.5A Sep 8 5A 15p
Disc 21p
4040
4049
4077
4501
4519
4566
B pin DIL
pin DIL
NE555
741 B
2N6027 (PUT)
2N3055
97p
41p
45p
20p
56p
155p
P &P.
34
Mail Order Only to:
PLEASE ENCLOSE LARGE 8.A.E
WITH ALL ENQUIRIES & ORDERS "
Otherwise cannot be attended to
ROCKBOTTOM PRICES
BEAUFORT PARK
LONDON, N.W.11 0ßX
71
We have the largest supplies of Service
Sheets (strictly by return of post). Please
state make and model number alternative.
Free TV fault tracing chart or TV list on
request with order.
Mall order or phone 01 -458 4882
Large Stocks of Colour Manuals
NO OVERSEAS MAIL PLEASE
available from April 1974 edition up
to date. Price 55p each:- Bell's Television Services, 190 Kings Road Harrogate, N. Yorkshire. Tel (0423) 5885.
bound, 49 unbound with indexes.
each including postage. Colm Nolan,
Beech Park, Athlone, Ireland.
WIRE Recorder Webster 1947 Working
with wires. OFFERS Bristol 0272550876 Office Hours.
48,
£4
25
NUMBER of magnificent informative
SONY radio- cassette-corder, t /recorder
service manuals for sale. 01 422 5185.
S.T.C. (Mono) AMP, Complete with
8 speakers, Reslo /Mike, Garrard Deck
T /Base S /Tint cover, complete with
stand. Ramsbotton (Lancashire) 2858.
Only £130.
Wanted
TRANVALVES,
WANTED-NEW
SISTORS. TOP PRICES, popular types.
Kensington Supplies (C), 367 Kensing-
ton Street, Bradford
8,
Yorkshire.
WANTED. Codar P. R. 40 R.F. PRE SELECTOR. Meek, 4 Byways, Strode
Road, Clevedon, Avon.
Educational
Principal, Nautical
Fleetwood FY781Z.
College,
Rar'n
1971
dio Receiver
rain{ IC, a.
.
.
Write:
Broadwater
Practical Wireless, May 1977
.
.
Electrical
4EE.
.
ÍSea)
L
Miscellaneous
-55
CO-SS
(0-95
0-95
Electronic Novelty Circulas
Audio Enthusiasts Handbook
T9
C('
LOAM
Radio Manual
Sore Su,. Power Supply Handbook
IC, & Transistor Gadpu Construction Handbook
Inn {nod Circuit, E9uir & S,,b&,,, ., Handbook
Home
Electro
Electrenic Circuits for.
Electronic Gad {ats a Game,
PRICES INCL. P&P. SEND 5 A.E. FOR FULL LIST.
1
LO-CS
Radie Antenna H'book for Lon{ Dia. Receptn
Th Compta, Car
SOMERSET
(5 -75
.
rn. umoaa Ra o,tnio,,Vv. ana .n u,.,
I,t & 2nd
Conman,' E9ui. & S. bane,,,
LAMBDA ANTENNA STUD FARM
WHITEBALL, WELLINGTON,
etc. For the best at keenest prices send
S.A.E. for free illustrated list to:
Felstead Electronics (PW), Longley
Lane, Gatley, Cheadle, Cheshire. SK8
RADIO BOOK SERVICE
World Radio TV Handbook
TXers and S.W.L's. -Have a proper aerial
system, anti -TV I, individually designed,
purpose built for your particular interests,
QTH and Equipment by an ex -BBC Transmitter and Aerial Engineer.
Details large S.A.E. and 3 84p stamps.
STYLI, CARTRIDGES & AUDIO LEADS
Books and Publications
(0-
LO -7950
(0 -95
Lo-bo
(0.95
NOTE NEW ADDRESS
4 CNILCHESTER COURT,WICKHAM RO.BECKENNAM KENT BR32QW
SIMPLIFIED TV REPAIRS. Full repair
instructions individual British sets
£4.50, request free circuit diagram.
Stamp brings details unique TV
Publications (Ausepw) 76 Church
Street, Larkhall, Lanarkshire,
START YOUR OWN BUSINESS
REWINDING ELECTRIC MOTORS
This unique Instruction manual shows step by
step how to rewind motors, working pert or full
time, without previous experience. Everything
you need to know easily explained, Including
where to obtain materials, how to get all the work
you need, etc. A goldmine of Information and
knowledge.
Only E3 90 plus 26p P &P.
Magnum Publications Dept PW5
GO TO SEA as a Radio Officer.
G2DYM AERIALS
C. CARANNA
NEW ISSUES of "Practical Wireless"
PRACTICAL WIRELESS. Vols. 46, 47,
ext. up to 6212 ft. The Ladder Centre
(WLS) Halesfield (1) Telford, Salop.
Tel: 586644. Callers welcome.
Aerials
PLEASE NOTE
We operate s "by return of post" service. Any
claims for non- dellvery should be made within
7 -dey, of posting your order.
15379, equiv. to 2N 3819 -15p. 2N
BC 184 -5p.
107 -6p.
697 -1Op. BC
BC214 -5p. TIP 31 -35p. T05. HT.
For Sale
LADDERS. Varnished. 20ft 91n extd.
£2533. Carr. £1.90. Leaflet. Also alloy
(Uncrossed P.O., please, originel
returned If service sheets not available.)
brand new, by return FET.NSSF
Aldershot, Hants.
Ladders
In stock.
"
etc.,
and s.a.e.
HAMILTON RADIO, 47 Bohemia Road,
St. Leonards, Sussex.
CAR RADIOS, TUNER SHEETS)
20p).
DECTRONICS,
275 Vale Road, Ash Vale,
SHEETS, Radio, TV
50p and s.a.e. Catalogue 20p
ALL AT 7Sp EACH (Except colour) & CAR RADIOS
Please state If Circuit will do if Service Sheet not
Britwell Estate, Slough, Berkshire
& Postage
( +VAT at High rate 1212`2
Sinks -6p. Post at VAT inc. CWO/
S.A.E. enquiries to:-
BELL'S TELEVISION SERVICES For
Service Sheets on Radio, TV, etc., 75p
plus S.A.E. Colour TV Service Manuals
on request. S.A.E. with enquiries to
B.T.S., 190 Kings Road Harrogate, N.
Yorkshire. Tel: (0423) 55885.
SERVICE
(T.V., RADIO, TAPE RECORDERS,
RECORD PLAYERS, TRANSISTORS,
STEREOGRAMS, RADIOGRAMS,
Studley Grange Road, London, W7 2LX
RESISTORS: AEL2 Type. Carbon Film
High stab. 57 E24 range. Sold in
units of 10. '4w (4E7 to 2M2) 8p per
10. 12w (10E to 10M) 9p per 10. Also
Transistors BC 108/9 75p per 10. LEDs
TIL209/FVL117 Red 12p, Grn &yell 20p.
SAE for more details to CW Electronics Dept PW 10, Kingsley Path
MAIL ORDER ONLY
LARGE SUPPLIER
OF
SERVICE SHEETS
24p
34p
36p
T. K. ELECTRONICS (PW)
106
T. TECHNICAL INFORMATION SERVICE
119 OXFORD ST., LONDON WIR IPA
DRYDEN CHAMBERS,
SERVICE SHEETS, radio, TV etc.
10,000 models. Catalogue 24p, plue SAE
with orders, enquiries. Telray, 154
Brook Street, Preston PRI 7HP.
QUANTITY DISCOUNTS ON REQUEST.
ADD 8% VAT plus 25p
MANUALS
Service Sheets for Mono TV. Radios, Record Players and Tape Recorders 7Sp.
Please send large Stamped Addr
d Envelope.
We can supply manuals for most makes of Colour Television Reclevers by return of post.
B.R.C. PYE ECKO PHILIPS ITT/KB SONY G.E.C. HITACHI BAIRD ULTRA INVICTA
Brinksway Trading Estate, Brinksway,
Stockport SK3 OBZ.
Overseas Distributors wanted.
MAGNETIC MICROPHONE SPEAKERS
Inserts, Ideal for all sound speaking and
listening applications.
Very rugged -d.c. resistance 20 ohms.
4T
Size: 11" die.
I"
deep.
Op ea. + 10p PIP.
6 for £2 20 + 20p P & P.
12 for E4 50 P & P free.
S.A.E. for list of many other Items.
Trade enquiries we /come.
B .B. Supplies, 141 Shalmsford Street,
N r. CANTERBURY, Kent CT4 TQZ.
LOW-COST I.C. MOUNTING for any
size DIL package. 100 Soldercon
sockets 65p. 7 and 8 hole plastic
supports 5p /pair. Quantity rates. SAE
details and sample. Trial pack 65p.
(P & P 10p /order). P.K.G. Electronics
Oak Lodge, Tansley, Derbyshire DE4
:FE.
H. M. ELECTRONICS
275a
FULWOOD ROAD, BROOMHILL,
SHEFFIELD 810, 3BD.
SEC CABINETS (Illued)
METAL CASES
DRY TRANSFER LETTERING
SendlOp for leaflets (Refundable)
Trade enquiries invited
79
Miscellaneous
LOUDSPEAKERS
- IT - YOURSELF
for hi -fl are our speciality. Full range
of components and accessories including chassis speakers, crossovers,
sound absorbent, grille fabrics etc.,
We
stock the
always available.
fabulous value Helme speaker kits
instruceasy
with
full
and
complete
tions, also Peerless and Wharfdale
kits. Just about the lowest prices
anywhere! Send 812p stamp for bargain list to: Audioscan, Dept PW-577
4 Princes Square, Harrogate, North
Yorkshire.
DO
(
continued )
4oz
2oz
lb
8oz
-09
-50
2.40
1-20
2.45
-$2
.59
1-1f0
.w
2-00
1.70
'N
2.95
1.04
75
1.90
Inclusive of p &p and VAT.
resistance
SAE brings Catalogue of copper and
1
THE SCIENTIFIC WIRE COMPANY
PO Box 30, London E4 9BW
Reg. Office: 22 Coningsby Gardens,
-
Musical
MISSING L.F.?
NOW you can LISTEN right DOWN TO 100KHz-
£22
on YOUR receiver. 100-000KHz CONVERTER has
20dB gain, antenna matching and 3-5-4MHz
output. ALL parts, colts, printed circuit, 1 }" x
3" x 5" case, battery etc, Instructions, money
back assurance, SEND £9.90 NOW.
MIMI
!
®
using some of the huge range of DEWTEON
modules. Or build fuzz or was-was st budget
prices using special kits.
325
D.E.W. Ltd., 264 Ringwood Road, Ferndown,
Dorset 5H22 OAR.
BAND. British campaign
for public 2 -way radio. Citizens' Band
Association, 16 Church Road, St.
Marks, Cheltenham, Glos.
Fore Street, London, N9
Tel. 01-807 3719
INSTRUMENTS CASES by
Bazelli, manufactured from heavy duty
PVC faced steel. Hundreds of people
and industrial users are choosing the
cases they -require from our vast
range, competitive prices start at a
low 82p. Examples: width, depth,
height, 8in x 5in x 3in, £1.70. loin x
6in x 3in £2.42. loin x 8in x 3in £3.02.
12in x loin x 3in £3.96. 8in x 4in x 4in
£1.98. loin x 6in x 4in £2.97. 12in x
8in x 4in £3.96. 7in x 7in x 5in £291.
8in x loin x 6in £3.96. 12in x Bin x 7in
£440. 12in x 12in x 7in £4.84. Plus 85p
carriage and 8% VAT. Over 400 models
to choose from. Prompt despatch. Free
literature (stamp would be appreciated). Bazelli, Dept No. 25, St.
Wilfrid's, Foundry Lane, Halton, Lan-
OPE
AERIAL WIRE. High quality p.v.c.
covered multi-strand copper. 50ft, 85p
(15p) 75ft, £128 (17p); 100ft, £167
(23p) 150ft, £2.51 (34p); 200ft, £3.36
(39p) 250ft, £419 (46p); 300ft, £4.97
(48p) P &P in brackets. A.1 Radio
Components, 19 The Borough, Canter-
bury, Kent
0#\04/1
CAMBRIDGE KITS
(PS) Old School Lane, Milton, Cambridge.
SUPERB
TELERADIO ELECTRONICS
-
CITIZENS'
45
RANGE: I0Hz to I00kHz. OUTPUT: IV,
sine /sq. DISTORTION: less than 0.02 %. 9V
battery. Also available in Kit form at L17.
Add 8% VAT. P. & P. and ins. 75p.
Leaflet available, also F.M. Signal Generator,
Millivoltmeter, freq. meter, THD analyser,
P.S. Units. S.A.E. please for literature.
Build your own synthesiser or musical effects
Bend 26p for Catalogue from
9764.
HIGH EFFICIENCY
AUDIOOSCILLATOR
by Dewtron
wanted, 50p for 'Nickel Cadmium
Power' booklet. Sandwell Plant Ltd.,
Denholm Road, Sutton Goldfield,
1
West Midlands B73 6PP. Tel: 021 -354
wires In all coverings.
LOW COST
Miracles
RECHARGEABLE NICAD BATTERIES
'AA' (HP7), £126; 'Sub C', £129; 'C'
(HP11), £238; 'D' (HP2), £292. PP3,
£4.98. Matching chargers, respectively,
£448, £4.48, £524, £5.24, £398. All
prices include VAT. Add 10% post and
package. SAE for full list, plus, if
ENAMELLED COPPER WIRE
nwg
14-19
20-29
30-34
35-40
caster LA2 6LT.
CT1 2DR.
Computer parts for hobby,
experimental,educational
and professional use.
FRESH STOCKS OF THE POPULAR
CLARE -PENDAR ASCII KEYBOARD
TYPE KB6 NOW TO HAND
ASCII -Coded 77i-compatible 4 -bank alphanumeric reed-switch keyboards
with ROM encoder chip, strobed output, two -key rollover and debounee.
Standard 7 -pit ASCII code (no parity). Supplied complete with circuit diagrams and code chart.
t15% 10mA
SPECIFICATIONS Power Supply: + 5VDC t5% 150mA; -12VDC
through 7.0v "0" 45V; 2-5v "1" 5.05V Fan Out: One
Output Logic Levels: Data Bits
standard TTL load. Strobe: 2-6v "1" 5-25V; Ov "0" 46V. Fan Out: 10 standard TTL loads.
Strobe signal delay 10 milliseconds nominal to allow date to stabilise.
KB9: 56- station standard Teletype layout. AS RECOMMENDED FOR PRACTICAL
WIRELESS VIDEO -WRITER PROJECT. Price £3g -50 plus £1 P &P + 8% VAT (send
1
£43.74).
ALSO AVAILABLE
SPECIAL LOW COST KEYBOARDS
KBS: 3 -bank alphanumeric Baudot-coded 36- station keyboard. TTL compatible, strobed
output. Pries £2000 plus LI P&P + 8% VAT (send £22.68).
NEW ARRIVALS
I
11111
n
ELECTRONIC BROKERS LTD
FABULOUS NEW 96- STATION CRT DISPLAY KEYBOARDS 8 -bit ASCII code, upper
and lower case output PLUS separate numeric pad. TTL logic. Delayed strobe signal
and two -key rollover feature. Mounted in attractive box, overall dimensions 201 x 71 x
31 ". Price £95190 + £3 carriage + 8% VAT (Send £7344).
BCD -coded keyboard, upper and lower case outputs. 54 Key -stations PLUS 5 indicator
lamps and on /off switch, Set in attractive mounting panel, dimensions 15+ x 5 x 2E ".
Price £39.50 + £2 P&P + 8% VAT (send £44 82).
Also available a few only of above model WITHOUT ENCODING, Price L2S 09+£1 50
P &P + 8% VAT (Send £2882).
FOR THE EXPERIMENTER
Single plane core memory Ideal for experimental and Instructional applications.
buffer.
42 x 52 cores storage capacity with 230 °A10 diode -loaded
£2 00 plus 40p P &P + 8% VAT (Send £2.59).
Ferrite core memory plane mounted on plastic frame
5 x 8" consisting of matrix 40 x 52 x 4 cores, divided
Into tour individually addressable planes with separate
sense and inhibit wires per plane giving 1000 bits capacity, comprising of a grid of wires passing through
ferrite cores at a 90 angle. 22.50 plus 40p + 8% VAT
49/53 Pancras Road
London N W12AB
TeI:01-837 7781
80
<.,,..
..
(Send £3.13).
Practical Wireless, May 1977
GRUN DIG
Cassette Recorders, Cassette Recorders, Microphones, etc., etc.
Please write (send S.A.E.), phone or cell for full
details and prices.
CHURCH ST.,
BLACKBURN
Tel: 511182
77
oRne
10 each of any value
Satellit 2100, 21 Wave Band Radio, TK547 and
TK747 Stereo Tape Recorders, Radios, Radio/
42.44
1M
7SP
100 RESISTORS
5w 5% C /Film 2.2 (2 -2-2M fl (E12)
GORSE'S
MAIN STOCKISTS FOR
THE MALL
BURNLEY
Tá:35229
TELEPHONE
PICK -UP LEADS
Jack.
Phone sucker in either 3 DIN
3.5 Jack Phono or Philips EL3581/3582/84
or other Philips models. Please state which
one.
C60 CASSETTES 32p Casealihe
in dexlaenld
w
C90 CASSETTES 45p Screwed Assembly.
All prices Include VAT Add Postage 10p in L1
Quantity Discounts. SALOP
LOP ELECTRONICS
10 Units 5%
SHREWSBURY
50 Units 7%
Tel. 53206
100 Units 10%
.
AT
DISCOUNT
SPEAKERS
WILL BUY. Radio Equipment from
World War I and the 1920s. Crystal
sets; Valve transmitters and receivers, Test sets; Speaker and good
old components. Spark Sets also
sought. Diagrams sketches and information to G3SYX Box No. 136.
ARMATURE & COIL WINDING
ENAMELLED COPPER WIRE
Only top quality materials supplled.
24 hrs.
All orders dispatched within
lb reel
£2.95
S.W.G.
10
20
30
35
ONLYPOST£199
sHIFI DISCOUNT CENTRES
to
to
to
to
19
29
34
40
£1.80
£3.15
£1.80
£3.45
£2.10
£3.65
All prices are inclusive of P. & P. in U.K.
COPPER SUPPLIES, 102 Parrawood Road,
Withington, Manchester
20.
Tel:
TITAN
061-US 8753
1
List
501 'lid or Full range Sp. Price
5" lOw Various makes
Sp. Price
8" A.F. Model 80
Sp. Price
8" A.F. Model 83
Sp. Price
FANE 8" 808T
Sp. Price
FANE 8" 807TP
Sp. Price
8" WHARFEDALE LINTON KIT Pair
8" FANE MODE ONE KIT Sp. Price Pair
8"
NOTICE TO READERS
Tel: 01 -458 4755
PRINTED CIRCUITS
and HARDWARE
of goods shown
in
classified advertisements are correct at
the time of closing for press, readers
are advised to check with the advertiser
both prices and availability of goods
before ordering from non -current issues
of the magazine.
0" WHARFEDALE GLENDALE XP
KIT
Sp. Price Pair
0" ELAC Model IORM
Sp. Price
4879
MATERIAL. Assorted panels
copper clad laminate. 1 /16in and 3/32in.
Paper/glass.
sided.
Single /double
Minimum 212 in x 5in. Approx 2 sq ft
per pack. £1.90 inc. p & p. Peter
Jones, 2 Princes Street, Southend on
Sea, Essex.
P.C.B.
.,
MK III
Metitl Locator
Varicao tuning
-__
Britain's best selling metal
locator kit; 4,000 sold
Weighs only 220r. Fitted with
Faraday shield.
J
Complete
Kit
Post LI
00
£14.75
.
[I- 10 VAT
sum
&
£19.75
tested
Post £l.
00
-
£1.58 VAT
MINIKITS ELECTRONICS,
6s CLEVELAND ROAD,
(Mail order only)
LONDON, EIS 2AN
Practical Wireless, May 1977
£36.00
Price
Price
Price
Price
Price
Price
L24 75
L25-95
£24.75
DISCO 80
GUITAR 80L
GUITAR BOB
2"
2"
2"
2" FANE CRESCENDO 12A
12L
2" FANE
..
12 BASS
2" FANE
TITAN 715160 60w
TITAN T15/70 70w
TITAN T15/100 100w
GOODMANS
218-95
e--
+ V.A.T. £1.62
Solve your communica-
tion problems with this
46tation Traeatabr Intercom eyetem (1 muter and
8 Bab), in robust plastic cabinets for desk or wall
mounting. Call/talk /listen from Muter to Bobs and
Subs to Muter. Ideally suitable for Business, Surgery, Schools, Hospitals and Office. Operates
on one 9V battery. On /off switch. Volume control
Complete with 3 connecting wires each 6610. and
other accessories. P. a P. 90p.
MAINS INTERCOM NEW MODEL
in
per pair P. a P. 90p.
NEW /
AMERICAN TYPE CRADLE
TELEPHONE AMPLIFIER
LY
13-95
VAT 41.12
Latest transistorised Telephone Amplifier
with
detached plug -in speaker. Placing the receiver on
switch for Immediate
to the cradle activates
two -way conversation without holding the handset.
Many people can listen at a time. Increase efficiency
in office, shop, workshop. Perfect for "conference'
calls: leaves the user's hands free to make notes,
consult files. No long waiting, saves time with
long.dietance calls. On/Oa switch. volume. Direct
tape recording model at 41668 + VAT 61.36
P. a P. 75p, 10 -day price refund guarantee.
WEST LONDON DIRECT SUPPLIES (PW5)
LSISINOTON HIGH STREET, LONDON, WB
In
[3.35
0.95
[6
95
L3 95
[4.75
£295
L19 75
L53 9S
0.85
L7.95
159.95
[9.95
[10.95
[12.95
0.2 95
L12.99
[1595
[1650
[1795
L1795
117 95
£24.95
C56.70
[3995
[3995
L5735
L5995
£28.00
028.00
C41-00
L3995
BASS 100
Price
[4.95
[16.95
£179S
L1695
[16.95
FANE 'SPECIALIST' BASS 85 £3775
HORN UNITS
Speaker and earphone operation
Knocks down to only 171e.
Prebuilt search coil assembly
Thoroughly professional finish
As seen on BBC! and BBC2 TV
You only need soldering Iron,
screwdriver, pliers and snips
Five transistor circuit
Send stamped. addressed
envelope for leaflet
2" GOODMANS 12 PD
2" GOODMANS 12 PG
2" FANE 'SPECIALIST' P.A. 80
L22 50
Sp.
Sp.
Sp.
Sp.
Sp.
Sp.
8" FANE CRESCENDO IBA
C101 95
8" FANE CRESCENDO BASS 09.95
8"
'COLOSSUS' 200w
L1I5.00
batteries -no wires. Just plug in the maim
for instant two -way, loud and clear communication.
74
On off switch and volume control. Price
TREASURE TRACER
2" CELESTION G12/50TC
5"
5"
5"
5"
L1580
12/45545w
15P
Sp. Price
CELESTION GISC
Sp. Price
FANE CRESCENDO I5 /100A L7295
FANE CRESCENDO BASS
£76.00
5 ".
15 /100LT £74.69
5"
COLOSSUS 200w L10800
8" TITAN T18/100 100w
C47.00
8" GOODMANS 18P
Sp. Price
8" CELESTION GI8C
Sp. Price
110
BUILD
Sp. Price
Sp. Price
Sp. Price
2" TITAN 711/60A 60w
2" TITAN T12/100A IOOw
2" CELESTION G12M
2" CELESTION G12H 30w
2" CELESTION G12150 50w
5"
5"
5"
5"
Ramar Constructor Services,
Masons Road, Stratford on Avon,
Tel.
"TITAN
5"
Readily available supplies of Cor structors' hardware, Aluminium sheet
and sections. Printed circuit boards,
top quality for individual designs.
Prompt service. Send 15p for catalogue.
Warwicks.
x
I
2
Whilst prices
years
ALL PRICES
INC. VAT sonic
2" FANE 121115LR 20w
2" FANE 122110 25w
2" FANE POP 25T
FREE
Dept. P.W., 1115, Finchley Road,
Temple Fortune, London N.W.1I.
5
FANE 2 yrs
OTHERS year
5' FANE
lb reel
£1.60
5
1
or I50 as app.
Guarantees:
imp
CELESTION MHI000
FANE 910 MK II
FANE 920
FANE J44
FANE 1104
Sp. Price
F.A.L. 'Add -on'
TITAN TIM 70w
TITAN TS2H IOOw
Sp. Price
Sp. Price
Sp. Price
437.95
L18.95
£19 95
L28.95
L28.95
[29.95
£2250
L26.95
[4995
[4995
[49.95
169.95
L33-95
L38.95
[3450
[66.95
[5995
[6995
L13 75
[1775 [1099
L59-95
C7.95
L16.95
[39
HI -FI SPEAKER SYSTEMS
LEAK 3020
LEAK 3030
LEAK 3050
CLESTION DITTON 15
CELESTION DITTON 33
95
L595
[195
HIGH POWER 'CROSS OVERS'
FANE HPXI or HPX2
C2.75
LI
'ADD -ON' HIGH FREQUENCY UNITS
75
[395
L25.95
L25.95
Pair 0119.42 [87.95
Pair £157.50 L117.95
Pair L218-00 [1695
Pair (124 15 L85.95
Pair C190.57 £129.95
WHARFEDALE CHEVIN XP Pr. 040.12 L28.95
WH'FEDALE DENTON 2XP Pr. C59-IS [4295
WH'FEDALE LINTON 3XP Pr. C84-62 L59-95
WH'FEDALE G'NDALE 3XP Pr. El IS 16 031.95
WH'FEDALE D'VEDALE SP Pr. C197-24 4142 95
WH'FEDALE L'TON 3XP kit Pr. £4790 [34.95
Extra Special prices for quantities.
MANY
OTHER DISCOUNT LINES
(for personal callers only)
AMPS,
T'TABLES,
JINGLE
MACHINES,
DISCO CONSOLES, LIGHTING, CABINETS,
CREDIT TERMS AVAILABLE orders
over ít20
Phone orders accepted from Access & Barclay
card holders.
Please send stamp for leaflets or with enquiries.
Prices correct at 15.2.77.
Branches at
403 SAUCHIEHALL STREET
Tel: 141 332 0700
59 Grainger Street
Tel. 0632 21469
106 NEWPORT
ROAD
GLASGOW
NEWCASTLE
MIDDLESBROUGH
Cleveland TS' 5JF. Tel: 0642 217401
Mail Orders & Exports enquiries to Middlesbro Branch Add 75p carr. on orders under C7.
Cabinets for personal shoppers only.
81
TRANSISTORS
AC717
AC123
AC126
AC127
AC128
WATFORD ELECTROJICS
33/35, CARDIFF ROAD, WATFORD HERTS, ENGLAND
MAIL ORDER, CALLERS WELCOME. Tel. Watford 37774
ALL DEVICES BRAND NEW, FULL SPEC. AND FULLY GUARANTEED.
ORDERS DESPATCHED BY RETURN OF POST. TERMS OF BUSINESS:
CASH /CHEQUEIP.O.s OR BANKERS DRAFT WITH ORDER. GOVERNMENT
AND EDUCATIONAL INSTITUTIONS OFFICIAL ORDERS ACCEPTED.
TRADE AND EXPORT INQUIRY WELCOME. P & P ADD SSp TO ALL
ORDERS UNDER E10 00. OVERSEAS ORDERS POSTAGE AT COST,
AIR /SURFACE. SEND SAE FOR OUR FREE LIST.
Export orders no VAT. Applicable to U.K. Customers only. Unless
stated otherwise, all prices are exclusive of VAT. Please add 0%
to Bevies, marked To the rest add 12t %.
We stock many more Items. It psys to visit us. We are situated behind Watford
Football Ground. Nearest Underground /Br. Rail Station: Watford High Street.
Open Monday to Saturday. Ample Free Car Puking space available.
V AT
.
POLYESTER CAPACITORS: Axial lead type. (Values are In pi).
400V: 0001, 0 0016 0.0022, 00033 7p; 0 0047, 00008, 0.01, 0015, 0'018 0p; 0 022,
0.033, Sp; 0.047, 0068, 0.1, 11p; 0.15 0.22, 18p: 033, 047 Up; 068 Up.
1114V: 0-039,0 15, 0.22 11p; 0.33,0.47 Ifp; 068, 1.0 22p; 1:5 29p; 2 2 32p; 4 7 34p.
DUBILIER: 1ONV :0.01, 0.015 111p; 0.022 10p; 0 047 1Sp; 0 20p; 0.47 43p; 0, Up.
1
1
FEED THROUGH
In uf). 254V:
0015 Sp; 0022, 0.027 Sp; 0033, 0047, 0068, 0.1 7p; 0.15
0 6818p; 1:0 21p; 1.5 24p; 2 220p.
POLYESTER RADIAL LEAD (Values
0 01,
CAPACITORS
1000pF/350V
19P:0 22, 0.33 12p; 0.4714p;
Op
ELECTROLYTIC CAPACITORS: Axial lead type (Values are In pF)
2511V: 1000, 40p; 1011V: 20, Op; 63V: 0.47, 1:0, 1.5, 2 ß, 2:5, 3.3, 4.7. 6.8 7p; 8, 10,
15, 22, Sp; 47, 32, 50, 10p; 63, 100, 12p; SOV: 1.0, Sp; 50, 100, 10p; 220, 10p; 470, Up;
1000, 43P; 2200, 48p; 40V: 22. 0p; 100, 10p; 3300. 52p; 35V: 10. 33, 7p; 330, 470, 27p:
1000, 38p; 20V: 10, 22, 47, Sp; 80, 100, 160, Op; 220, 250, 13p; 470, 640, 25p; 1000, 27p;
1500, 3613! 2200, 34P; 3300, Up; 4700, 47p; 16V : 10, 40, 47, 88, Sp, 100, 125, 7p; 470, 12p;
1000 1500 111p; 2200, Up; 10V: 4, 100, Sp; 840, 10p; 1000, 14p.
TAG -END TYPE: 75V: 4700, 121p; NV: 3300, 94p; 10000 166p; 44V: 2500, 55P;
25V: 4700, 40p; 15V: 4500 3$p; 40V: 2000 +2000 Np.
POTENTIOMETERS (AB or EGEN)
Carbon Treck, 0.25W Log 0 0.5W
TANTALUM BEAD CAPACITORS
35V: 0.1 uF, 0.22, 0'33, 0.47, 0.68, 1.0,
2ßµF, 3.3, 4.7, 6.8. 25V: 5, 10. 20V:
1.5. 10V: 10µF, 47. 10V: 4.7, IS, 25, 33.
SV: 22, 471'F, 68. 3V: 100µF. 12p each.
Linear velues
K 002K 0 (LIN. ONLY) Single gang 24p
24p
5K0 -2M0 single gang
5K0 -2M0 single gang D/P switch Np
SSp
5K(1-2M0 dual gang stereo
1
1
MYLAR FILM CAPACITORS
190V: 0001, 0002, 0005, 0.01pF
Sp
0015, 0.02, 0.03, -0.04, 0.05, 0058uF Sp
SOV: 0.47pF 10p
0.1 pF, 0.15, 0-2 7p.
SLIDER POTENTIOMETERS
0.25W log and linear velues 60mm
5KO -500K0 single gong
10K0 -500K0 Dual gong
50KO Lin 150mm WS 150
CERAMIC CAPACITORS 50V.
Range: 0.5pF to 10,0000F
0.01501, 0.022uf, 0-033p1, 0.047uí
4p
TETFER Trimmer (Jackson)10pF, 580.
RESISTORS -Erie make 5% carbon
JACKSONS VARIABLE CAPS.
Dielectric
195p 6:1/36;1
12544 0- 1 -365pF
bILEMIN
00 2 385pF
300pF /500pF
185p 00 208/176
2 speed
with
4832/2K
100 /300pF
coupling
Miniature High Stahifity, Low Noise
Dial Drive 4103
Drive Unit complete
with knobs and
350p
5211p
1611p
275p
28Sp
slow
motion drive
305p
C804 -5pF; 10; 15; 20;
135p
25; 5OpF
100, 150pF 195p
Drum 54mm
35p
420p
'L' 3x310pF
6:1 Bali Drive
107p 00-3x25pF
4511/DAF
306p
SILVER MICA (pF)
3-3, 4.7, 6.8, 10, 12, 18,
22, 33, 47, 50, 68, 75, 82,
85, 100, 120, 150, 200.
250, 300, 330, 360, 390,
800 0 820pF
Sp each.
1000, 22002F 12p each.
COMPRESSION
TYPE
22p
8-80pF
20- 140pF; 50 -2000F 33p
Up
00 -500pF 1250pF
3 -4OpF;
AUDIBLE Warning
135p
Devices 12V
Val. 1 -99 100+
RANGE
1p
0ß5W 220 -4.7M E24 1 Sp
1 'Sp
2.20 -4.7M E12 2p
C' SW
1W
220 -10M 612 Sp 4p
Sp
2% Metal Film 100 -IMO
DENCO COILS
HEAT
SINKS.
7002
Sp
9P
Sp
TO5
TO18
T088
CRYSTALS
3Np
100KHz
1MHz
323p
395p
1.6MHz
32768
SNP
Holder HC6U 1SP
AMP
CERAMIC TRIMMER REVERE
Short spring -line
CAPACITORS
448p
2 -7pF; 4 -15pF; 6 -25pF; Unit
20p Complete Klt
8-30pF
available. Send
for
list.
SAE
MINIATURE TYPE:
2.5 -6pF; 3 -10pF;
10Sp
S-DEC
22p
3-3OpF; 10-40pF
5 -25pF; oOpF; 88pF Up
Np
70p
E4-50
PRESET POTENTIOMETERS
0.1 W 500 -2.2M Mini. Vert. 0 Horiz. 7p
0.25W 1000 -3-3M0 Horiz.l larger 8P
Ep
0ß5W 2500 -4.7MO Vert. Í
Sp
T-DEC
3Np
U -DEC 'A'
375p
U -DEC 'B'
155p
16 DIL Apeptor
17044
Adaptor 15p
Single end
TOO
!
lead
D'ble end leadlllp
Sp
1mm plug
22p
22p
22p
TO3
T066
I-nsulation Kit
Mice plus
2 Bushes for
Dual Purpose 'DP'
Rn0.1.5 B,Y,R,W Np
1
6.7 B. Y,
-5 Green
70p
9Sp
R
'T' Type (Tr. tuning)
Rng.
1
-5 B, Y, R,
W
W
BOA Valve Base 23p
RDT2
RFC 5 chokes
SOP
Up
Np
RFC 7(19mH)
IFT 13/14/15/16117 791)
T03/T066 or IFT 18/1.6 or 485 9Sp
PlesticTrna5p TOC1
NP
76
MW 5FR
Silicon
9Sp
Grease 120p MW /LW 5FR
OIL
Terminals*
EARPHONES
Magnetic
Sockets
Low
í8p (Texas)
3.5mm
Crystal
33p Bpin
14pin
FIGARO Gas lopin
0 Smoke
Detector
812
24pin
28pin
4044111
or 813
Socket
Screw type
Red, Black,
ISp profile
2.5mm
"Sp
NO
lip
12p
13p
Yellow 21p
BATTERY
CLIPS
Up Polorised
¿Sp PP3
Np PPO
-
SOLDER-CON
100
50p;
Sp
10p
PINS
1000 400p
TRANSFORMERS (Mains Prim. 220-240V) PW PROJECTS
100mA
5-0-8V
Np 15 -0-15V A 245p+ Easlbulld Organ, General
1
75mA
9-0-9V
12 -0-12V 100mA
16 -0.18V 100mA
0-12 0.12V 100mÁ
0-0 0-5V 280mA
SSp
SSp
185p
8 -0-18V 1A 27Sp+
30-0-30V IA 295p+
Coverage
Receiver, Transistor Tester, Chrome chase, Stereo Touch Tuner. Tug-0War, Smoke Sensor Alarm, Reverb
Amp, Metal Detector 2 -way Intercom.
Send SAE plus Sp per list.
8-0-6V 1.5A 345p 1154p 9-0-9V 2A 270p+
240p+ 30-25-20-0-20 12 012V 0-5A
15.0 -15V 0 -SA 220p-f25.30 SA
4S7p+
220p+ LT44
20-0-20V SVA
54p
240p+
24 -0-24V 0.5A
to
245pí LT700 Min. 0/1. Pri, PW RHYTHM GENERATOR
9-0-9V
-12V
to 245p+ 12K, Sae. 3ß0 Sop We are the sole suppliers of the
0. 120
30.24- 20- 15 -12 -0 1A
complete kit Including the 3 re- designed
Multi tappings 360p+ MOT Mln. 0/P Prl circuit boards. PRICES including VAT
1ßK, Sec.
42p
30- 24- 20- 15 -12-0
Complete Kit E.44.95. Ready Built Unit
445P+
2A multi tap
(Please odd 450 440p charge to all prices ES4 -95 (add E1 20 P. 0 P. and Incur.).
\marked 4-, above our normal postal charge.) Demonstration on at our shop.
144p
In
82
111
21
TO
24
39
44
BC113
BC114
BC11S
BC116
BC117
8C118
BC119
BC135
BC136
BCI37
BC740
RC142
BC143
BC147
BC148
BC749
BC753
IS
IS
BF244
BC182
BC182L
BC183
BC183L
BC184
BC184L
BC180
10
12
10
11
11
12
22
25
12
13
11
13
14
16
15
18
30
BC441
BC461
BC4e2
N
30
15
BC547
BC548
BC549C
BC557
iS
15
20
BCY30 55
BCY32 55
BCY34 t0
BCY39 tOp
BCY40 90
BCY55 201
BCY59 18
BCY70 17
BCY71 20
BCY72 IS
BD116 52
BD121 N
BD123 95
BD121 105
BD131 SS
BD132 30
BD133 55
9
5
12
12
5
12
12
15
45
40
BD135
15
150138
18
18
20
15
25
13
15
B0137
BD138
42
17
54
57
53
130139
130140
130142
BD145
BDY17
BDY80
BDY61
BF115
BF154
BF156
BF773
BF177
BF178
1S
34
24
21
7
7
N
7401
7402
7403
7404
7405
7405
7407
7408
7409
7410
7411
7412
7413
7414
7418
7417
7420
7421
7422
7423
7425
7426
7427
7428
7430
7432
7433
7437
7438
7440
7441
7442
7443
7444
7445
7446
7447
7448
7450
7451
7453
7454
7460
7470
7472
7473
14
14
15
18
20
22
44
44
22
22
15
25
25
40
74
35
39
15
29
24
30
3
35
35
N
18
28
45
se
33
17
74
74
1311
122
94
11S
02
Si
17
17
17
17
17
32
as
32
474
475 476
480
481
482
7483
484
485
7186
7489
7490
7491
7492
7493
494
495
496
407
4100
4104
74105
74107
74109
74110
4111
4116
4118
4120
4121
4122
74123
71125
74125
74128
74132
74141
55
01
7S
72
74142
74143
315
4144
314
74145
74147
74148
74150
74151
74153
74154
314
N
275
150
123
79
82
150
BF256
BF257
BF258
BF259
BF5O4
10595
BFR39
SFR40
BFR79
BFR80
BFX18
BFX29
BFX38
BFX53
BFX55
BFX64
BFX81
BFX84
BFX85
BFX86
BFX87
BFX88
BFY50
BFY51
BFY52
BFY65
BSY26
BSY29
33
33
33
33
21
30
10
10
14
15
15
37
15
34
34
34
32
48
30
21
22
25
2S
25
54
2$
38
N
45
30
141
24
25
25
23
2s
MPSU52 IS
MPSU55 SO
MPSU56 82
OC25
OC28
OC28
OC20
OC35
OC38
OC11
0070
OC71
0072
17
35
25
23
27
OC77
OC79
OC84N
OC123
OC130.
OC140
OC141
OC170
OC171
OC201
OC202
OC204
TIP29
TIP29A
TIP29C
52
50
54
74
52
54
OS
51
62
63
119
115
7464
121
74 55
120
74 66
74167
151
74172
74 73
74 74
74 75
74176
74 77
74 80
74 81
74 82
74 84
74185
74 88
71190
74191
74192
74193
74184
71195
74196
74197
74198
352
514
176
173
90
120
116
101
299
OS
154
140
855
161
155
125
125
125
OS
114
118
245
CMOS*
(RCA)
4000AE IS
4001AE 15
4002AE 15
/000AE 115
4007AE
4009AE
4010AE
1011AE
4012AE
4013AE
4015AE
4018AE
4017A
17
55
55
111
18
55
99
SS
OS
4018AE 52
2N2221
TIP2955
73
70
02
49
T1S43
SS
27
TIP3p65
4019AE
4020AE
4021AE
4022AE
4023AE
4024AE
4025AE
4026AE
4027AE
4028AE
4029AE
4030AE
4033AE
4034AE
4040AE
4042AE
4043AE
4044AE
45
105
103
95
II
75
17
2N2614
N
4071AE 20
4072AE 25
4076AE 155
1077AE N
4078AE 22
/081AE
4082AE
4510A5
4511AE
4516AE
4518AE
4520AE
4528AE
4585AE
2N2926G 10
2N28260
S
2N2926R
0
LINEAR IC'S
78L82A W C 19p
709C 14 pin 27p
710
41p
711C 8 pin 22p
747C
72p
748C
36p
753
15p
AY-5-1224 349p
4070BE
22
20
140
155
149
140
135
145
104
AY-1-0212
AY-1-5051
345p
S76p
123p
AY-1-87216 19Sp
AY-3-8500 792p
AY-5-3507 110p
CA3011
82p
137p
CA3011
CA3018
72p
CA3020
145p
CA3023
14Sp
CA3028A
CA3035
CA3036
CA3043
CA3046
CA3018
CA3075
CA3080
CA3081
CA3089E
Np
115p
147p
11Sp
Np
21Sp
1Np
Np
1Np
205p
CA3090A0 39Sp
CA3123E
CA3130
CA3110
LM300H
LM301
LM308
LM318
LM379
54
41
2N2646
2N2901A24
2N2905 20
2N2906 1S
2N2907 25
2N2907A22
95
109
52
130
104
99
4046AE
4047AE
4048AE
4040AE
4050AE
4054AE
4055AE
4056AE
4060AE
4067AE
4068AE
4068BE
/045AE
A21
8038CC
57
55
145
127
55
50
52
55
120
134
134
112
350
22
25
45
20
175
55
S5
45
32
37
37
2N2222 21
2N2303 230
2N2388 14
2N2483 30
2N2484 30
TIP35C270
TIP3sA34S
MPSA05 32
MPSA06 32
MPSA 5 30
MPSA56 30
MPSA 0 34
MPSUO2 55
21
2N2218A2S
2N2219A24
2N2220A20
OS
SS
19
23
25
2N1671 B 190
2N189. 27
2N2160 80
2N2217 40
TIP34A1I5
TIP34B 140
TIP35 215
TIP41A
TIP41B
TIP12A
TIP42B
N
2N1671 150
$3
00
03
SO
N
2N1613
TIP33B112
TIP33C125
TIP34 110
38
35
21
2N1131
2N7132
2N1302
2N1303
2N1304
2N1305
2N1306
2N1307
2N1308
TIP31B N
TIP31C 55
TIP32 5/
TIP32A
TIP32B
TIP32C
TIP33
TIP33A
15
2NN1
SI
TIP31
TIP31A
2N3011
2N3053
2N3054
2N3055
2N3525
2N3614
2N3615
2N688 39
2N685 45
2N706 17
2N706A 19
2N707 N
2N708 19
2N914 IS
2N516 27
2N918 34
2N820 {1
2N530 10
IS
TIP30A
TIP3oB
TIP30C
2N2926Y pd
10
47
47
24
12
11
15
14
14
19
22
24
15
24
20
17
IS
2N6N
2NN7
115
145
125
157
40
12
125
135
150
150
43
MPF10
95
225
114
114
2N526
u
44
0C5t
27
ZTX314
ZTX341
ZTX500
ZTX501 IS
ZTX502 19
ZTX503 19
ZTX504 51
ZTX531 21
ZTX530 IS
24
21
25
35
20
OC82
OC82D
OC83
MPFi06
N
ZTX3II
SS
00810.
TIP35A 225
76
ZTX302
ZTX303
ZTX304
SS
0081
35
36
50
55
56
57
59
ZTX301
N
OC15
OC18
MJ481 1N
MJ2956 120
MJE340 45
MJE370 N
MJE371 SS
MJE320 55
MJE521 74
MJE295590
MJE305502
MPF102
MPF103
MPF104
MPF105
55
70
70
70
OC/2
OCU
TIP30
ZTX108
ZTX109
ZTX300
OS
17
17
25
IS
TIS91
ZTX107
39
MPU131
OC203
25
20
BSY95A 10
BUM. 168
E5567
48
MD8001
ISO
MJ400 90
TIS44
TIS46
TIS50
TIS74
MPSUO6 32
17
17
17
25
40
BSX20
22
22
29
25
26
20
74
74
74
74
74
74
74
74
p
23
BSY78
195
128
147
36
35
36
60
114
82
55
95
125
34
390
43
55
53
10
05
73
52
262
135
45
45
33
64
54
75
198
115
155
34
50
73
SI
BF224A
SS
TTL 74*
7400
BF182
BF183
BF184
BF185
18
BC212
BC212L
BC213
BC213L
BC214
BC214L
BC307B
BC328
10
BF181
8C177
BC178
BC179
BC10r
AD149
AD161 311
AD162 30
AF114 20
AF115 20
AF116 20
AF117 23
AF118 47
AF121 39
AF124 30
AF125 30
AF126 30
AF127 36
AF139 33
AF178 70
AF179 70
AF180 70
AF181 45
AF185 N
AF186 48
AF239 3!
ASY26 33
ASY29 40
BF179
BF180
BF194
BF195
BF796
BF197
BF198
BF200
11
11
11
BCi72
35
28
25
24
25
16
BC107
BC107B
BC108
BC108B
BC108C
BC109
BC109B
BC109C
12
13
32
12
12
14
BC187
BC788
BC169C
BC170
BCi71
AC141 KU
AC142 21
AC142K N
AC176 18
AC187 18
AC188 18
ACY17
ACY18
ACY19
ACY20
ACY2I
ACY22
ACY28
ACY39
ACY40
ACY44
1/
BC160
10
22
ACI41
20
BC754
BC157
BC158
BC159
35
22
18
A
LM380
LM381
LM382
LM3900
LM3909N
180p
54p
9Sp
179p
3Sp
120p
ISSp
3951)
98p
170p
150p
45
49
55
149
135
32
2N3683
2N3702
2N3703
2N3704
2N3705
2N3706
2N3707
2N3708
2N3705
2N3710
2N3711
11
12
11
12
/4
11
9
9
12
12
2N3771. 154
2N3772 175
2N3773 575
22
2N3510
44
2N3S20
2N3823 N
2N3824 09
2N3866 Si
2N3503
pN3901
2N3505
2N3505
1S
18
18
18
2N4037 35
2144053
2N4061
15
13
24
35
34
12
12
12
40
2N4289
2N4855
2N4571
2N6133
RN6135
2N5138
2145175
Si
2N5180
2N5101
2N5305
2N5457
2N5458
2N5455
2N5485
IS
40
-3S
35
36
42
Si
2N11027
40311
40313
10318
40317
42
114
N
42
103'!6
12
N
10327
40347
40348
55
53
35
38
43
264
42
175
00
95
62
115
55
/0380
10361
40362
40411~
40112
40478
40594
40585
40503
40538
40673
Matched
Pair
10p extra
MC1303L
MC1304P
MC1310P
148p
mop
tSóp
MC1312P0 170p
MC1458P 77p
MC14N
91p
MC7710CG
79p
MFC6040
97p
MK50253 5611p
MM2112N 350p
NE350
NE518A
1Np
NES61
395p
216p
NE555
Itp
NE556DB S9p
NE560
325p
NE662B
NE606A
396p
176p
170p
182p
RAM2102-2 250p
NEW*
NE567V
ROM2513 7Np
255p
SG3402
SN72733
SN76003
SN78013
SN70023
SN78033
SN78115
SN78221
TAA621A
TAANIA
125p
sap
160p
106p
233p
21Sp
176p
S76p
155p
TAA700
253p
TAA960
2Np
TAD100
1Np
TAD110
176p
TBA120S
Np
TBA5400 125p
TBA5500 SUP
TBA841BXI225p
TBA641 B11 225p
TBA851
1Np
Np TBA800
TBABIOS
78p
30
16
Np
105p
Np
71110p
TBA820
M253
MC724
7S0p
175p
TBA0200
350p
TDA2020
MC845P
1SOp
214414
7Np
/10p
M252AA
Practical Wireless, May 1977
VEROCASE
ALUM. BOXES
WATFORD ELECTRONICS
(Continued from opposite side)
BRIDGE
DIODES
AA119
AAZ15
15p
15p
AEY11
RECTIFIERS
(plastic case)
SOp
BA100
BA102
BY700
BY126
BY727
10p
24p
12p
12p
1ASOV
1 Al 00V
10p
0A9
IA400V
1A600V
2A50V
2A100V
2A200V
2A400V
4A100V
4A /200V
4A400V
4A800V
6A100V
6A /200V
6A400V
6A1600V
Sp
Sp
OA70
0A79
12p
10p
12p
OA81
0A85
ip
OA90
0,491
lip
0A95
Sp
Sp
Sp
0A200
0A202
4p
N914
N916
N4001/2
N4003
N4004/5
N4006/7
N4148
S44
3A/100V
3A/400V
3A/600V
20p
1A200V
S
0A47
1
34p
3ASOV
3Sp
3A100V
46p
3A400V
3A800V í20p
5A400V 120p
7A400V 12Sp
BT706
1509
53p
72p
75p
70p
1211p
73p
78p
sip
Sip
1.3W
17o
V ARICAPS
MVAM2 1359
BB104
BB105B
BB106
3A/1000V 30p
6A/600V Sop
40p
30p
45p
Noise Diode
Z5J
ABOOV
CI 06D
TIC14
Sip
TIC45
asp
45p
2N4444
101p
105p
TRIACS
3A400V
6A400V
8A400V
10A500V
15A400V
113p
140p
160p
10Sp
200p
15ASO0V 21159
30A400V 391p
40430
40689
9119
99p
{"
4x5
4x2
"
}"
x1
x2"
5x4x2"
6x4x2"
F.2
Sap
Sap
Sap
70p
Sap
19mm
"; 2)"
124p
14ip
190p
£7.92* only
80 5W
"x4"
117p
127p
205p
7
180 5W
7 x
single dble/
6 "x12"
11Sp
sided
4"
sided
25p
205p
(for limited period)
7
140p
}"x8}"
411p
FERRIC CHLORIDE. 111) beg
Anhydrous 6Sp + 30p p. & p.
DALO ETCH RESIST
apare tip
PEN +
This is an easy to build no compromise kit using the very latest
Integrated Circuit only just available from the United States. Simply
plug into the U.H.F. Aerial socket of any standard Television
Receiver, sit back in your favourite armchair and spend countless
hours with the family playing any of the six games available.
The central Control Unit provides Game selection with switching
for Bat size, Angle and Ball speed adjustment. The Bat position,
Score reset and Serve controls being remotely connected allowing
players to be many feet apart. The Unit is mains powered (no expensive batteries to buy) and incorporates the unique "Ventriloquist" audio system which produces realistic Game sounds from
your Television speaker.
Also included are instructions to build the "Sure Fire" rifle. A
simple design which is made foolproof by the "On Target" detector
incorporated in the electronics. Complete kit £27.85 Incl. VAT.
(P&P insured add 85p)
Send SAE for details. (Demonstration on at our shop).
7ip
VEROBOARD Pitch
0-1
0-IS
0.15
(co36p clap (plain)
2 x 3t"
19p
2
3
3
2
x
x
x
x
x
x
3
4
5"
3f"
439
43p
5"
alp
17"
17"
134p
173p
222p
17^
24p
311p
40p
53p
107p
143p
34p
73p
95p
1459
-
Zip
69p
lip
Pin insertion tool
OPTO ELECTRONICS*
LEDS + Clip
7 Segment Displays
TIL209 Red
13p TIL312 3" C.An
2Sp TIL313 3 "C.Cth
TIL220 Red
20p TIL321 -5" C.An
2" Red
179 TIL322 -5" C.Cth
Yellow, Green,
DL704 .3" C.Cth
Amber
21p DL707 .3" C.Anod
OCP70
40p DL747 .6" An
ORP12
Gip MAN3610 C. An
MAN3640 C. Cath
TIL211 Gm
OPTO
ISOLATORS
TIL111/2
TIL114
TIL117
MINITRON 3015F
2N5777
105p
110p
164p
DRIVERS
75491
75492
VOLTAGE REGULATORS
459 Plastie Cass
125p 723 DIL
53p Plash WC IA
125p 723 TOS
12Sp
T3Á6258 9Sp MC7805
1259 TO3 Can
99p 1A 5V
99p IA 12V
1909 IA 15V
2S0p 1A 18V
260p LM309K
240p LM323K
54p MVR5
MVR12
30p IA -SV
909 IA -12V
Type MC7812 1 A 12V
SV 135p
135
170p MC7815 IA 15V
1í0p FTSN24 lA 24V
190p Variable Typa
215p LM325N ±15V
1S0p LM326N ±12V
625p LM327N ±5 -12
1110p LM317K 20W 1-5A
1809
+1 -2V to 37V
220p LM317H 5W 1.5A
220P
+1-2V to 37V
135p
135p
140p
240p
240p
260p
350p
320p
SUB -MIN TOGGLE
TOGGLE: 2A, 250V SP changeover 59p
Sop
SPST on /off
2Sp
SWITCHES*
Flairline
...
...
...
10
A. H. Supplies
Alban Engineering
G2DYM Aerials & Project
...
...
79
Greenway Electronics
...
...
Greenwald Electronics
...
...
G.T. Technical Information Service
...
...
...
64
H.A.C. Short -Wave Supplies
Harverson's
...
...
...
H.M. Electronics
Heathkit Ltd.
...
..
Home Radio
...
...
...
...
10
I.L.P. Electronics Ltd.
Industric I.C.S.
Industrial R.F. Services
...
...
...
...
...
...
...
67
"'
..
78
...
...
...
78
Alton Instruments
Ambit International
Astro Electronics ...
Bamber B. ...
...
BarclayY Electronics...
Barrie Electronics ...
B. B. Supplies
...
Bentley Acoustic Corp.
Bi -Pak Ltd....
...
Birkett
...
....
British National Radio
J
.
School
...
...
Brewster S. & R. ...
J. Bull (Electrical) Ltd.
Cambridge Kits
...
Caranna C.
Chromasonics
...
Copper Supplies ...
Cox Radio (Sussex) Ltd.
C. R. Supply Co. ...
Crescent Radio Ltd.
Crofton Electronics
Dettranics ...
D. E. W. Ltd.
Eagle International
...
...
...
,..
...
...
...
...
14
...
14
..,
6
72
...
...
...
...
...
...
...
...
...
...
77
..
...
...
...
9, 81
...
84
79
12
18, 19
...
8
Electronics
17, 63
...
...
...
6
71
...
80
79
63
...
...
...
...
...
...
...
...
...
...
...
78
78
74
...
...
64
81
...
...
Electronic Design Assoc....
Electronics Brokers Ltd. ...
Electronic Mail Order Ltd.
Electrovalue Ltd. ...
Practical Wireless, May 1977
...
...
...
...
.
,
...
...
...
...
...
...
)ones
J.
C.
...
Linear Products
Lectropaks ...
Lynx Electronics
...
...
...
...
...
...
...
...
...
74
...
75
32
80
...
...
...
76
Newmart Electronics
Newnes- Butterworth
...
...
Orchard Electronics
...
...
...
2
8
...
...
...
6
...
...
79
79
cover iii
... 79
... 63
... 36
Manor Supplies
...
...
Magnum Publications
...
Maplin Electronic Supplies
Marco Trading
...
Marshall, A. & Sons
...
Metac Ltd. ...
...
...
Minikits Electronics
...
...
13
...
...
16
79
SOCKETS
JACK PLUGS
Screened Plastic
body
chrome
SPST
78p 2.5mm
DPDT 6 tag
DPDT
35p
3.5mm
DPDT Centre off 92p MONO
4 polechangeoverSSp
DPDT Biased 115p STEREO
INDEX TO ADVERTISERS
....
"OLYMPIC" TELEVISION GAME
S.R.B.P.
lip
64p
'The
AY-3-8500
2.5; 3"
589
640 2-5" 65
Fibre
glass
6 "x6"
.
65p
2
MP
10x7x3"
10x41x3"
12x5x3"
12x8x3"
.
IC
8003W
91p
7x5x2J1"
.
Sp
SPEAKERS
Sip
8x6x3'
It's here!
35
Vero-Standoffs
Pkt of 36 pins
Spot face cutter
DIAC
ST2
65 -2520,1
21x5 }x1
4x4x1
4x2 xt
Up COPPER CLAD BOARDS"
110p
SOP
ZENS RS
Rng:3.3V-33V
400m W
Op
6p
7p
4p
20p
18p
20p
27p
42p
47p
52p
70p
31p
1A100V
1 A200V
1 A400V
22p
2Sp
20p
lap 3A200V
BY164
Sp
Sp
Sp
SCR's.
Thyrlstors
with 11d
P.B. Electronics
Precision Pettite
Pulse Electronics
10p
14p
10p
2/p
...
...
...
Open
metal
Moulded
with
Sp
Sp
contacts
Sp
10p
1Sp
lip
break
20p
24p
13p
15p
...
...
...
15
...
...
...
75
75
...
...
...
...
...
...
...
...
Radio Book Services
Radio Components Specialists
Radio Exchange Ltd.
...
Radio Society of Gt. Britain
Ramar Construction Services
79
11
cover ii
2, 60
...
.........
81
R.S.T. Valve Mail Order
Radio & T.V. Components Ltd. ...
...
5
Salop Electronics ...
Saxon Entertainments
...
...
81
...
80
...
...
Scientific Wire Co., The ...
Selra Book Co. ...
...
Sintely
...
...
...
Sonic Hi Fi ...
...
Southern Valve Co.
Sowcer E. A. Ltd. ...
Stirling Sound
...
...
...
...
...
Swanley Electronics
...
...
...
Tamba Electronics ...
Tempus
..
...
Technomatic Ltd. ...
...
...
73
31
36
...
...
...
.
81
IO
...
78
7
32
...
...
76
...
...
...
...
10
Teleradio Electronics
...
T.K. Electronics ...
...
Trampus Electronics
Tudor Tees (Vintage Services)
..
Watford Electronics
...
West London Direct Supplies
Wilmslow Audio ...
Williams Mick
...
...
...
8
68
82, 83
... 81
... 35
...
4
...
14
Xeroza
...
68
Z. &
cover iv
... 78
... 77
... 72
... 81
...
...
80
79
16
78
...
...
...
...
59
Aero Services
...
...
...
84
...
74
16
Partridge Electronics Ltd.
1.
83
z & A E R O SERVICES LTD
:s:o:R;a::;:t
BS TOTTENHAM
L
Tel: SRO 8403
Open all day Saturday
1
pondence and Mail-Orders to Head Office
Please send all
Tel: 727 5641/213
AC /DC TAUT SUSPENSION MULTIMETERS (Made in USSR)
TYPE
U4312
Sensitivity D.C. 667 o.p.v.
Sensitivity A.C. 667 o.p.v.
300 AA-6A
D.C. Current
1 5mA -6A
A.C. Current
75mV -900V
D.C. Volts
300mV -900V
A.C. Volts
-
-`
-
Resistance
Capacity
0'02-3kSl
Accuracy
1% D.C.,
1.5% A.C.
U4313
U4315
20,000 o.p.v.
2,000 o.p.v.
6OuA -1 5A
20,000 o.p.v.
2,000 o.p.v.
501A A -2 5A
0.6mA -1
5A
TYPE
0.5mA -2.5A
75mV -600V
15V -600V
1K -1M
75mV -1000V
1V -1000V
0.5µF
1.5% D.C.,
2.5% A.C.
0.5µF
2.5% D.C.,
4% A.C.
30052 -500kí1
4
b
Ranges:
D.C. current: 0 060 6-8- as -600mA
A.C. current 0-3-3-30
300mA
D.C. Voltage:
U4324
-
3-1.5
-8-30-60-150-300-
J
0
900V
41
A 300-1V50í300 -750V 7
Resistance: 2.20 20okn -2Mo
collector
Translator
cut-off current 60uÁ
Trenaletor D.C. cur -
-,
two
rent gain In
ranges 10-350
Accuracy: 2.5% D.C.
4-0% A.C.
_
1111
0.06- 0.6- 60- 600mA -3A
0.3- 3- 30- 300mA -3A
0.6-1.2-3-12-30-60-120-600-1200V
3- 6-15 -60 -150- 300 -600 -900V
5000- 5- 50- 500kS2
D.C. 2 5%; A.C. 4% (of F.S.D.)
D.C. Current:
A.C. Current
D.C. Voltage:
A.C. Voltage:
Resistance:
Accuracy:
¡"
1870011/V D.C.,
33013/V A.C.
'
Y
Price complete with pressed
steel carrying case and test
£1495
£1750
£1450
leads.
TYPES U4313 AND U4313 ARE PROVIDED WITH ANTI- PARALLAX MIRROR
SCALES
TYPE
U4341
Sensitivity:
ur D.C.
5%r D. gain
curent
Power supplies: 4.5V
battery
(Eveready 1289)
Complete with steel carrying case, test
lead, battery and instruction manual £14.50
OVERLOAD PROTECTION l5
INCORPORATED IN THESE INSTRUMENTS
NO
PRICE complete with test leads and fibreboard storage case £1450
PER INSTRUMENT
THE ABOVE PRICES ARE EXCLUSIVE OF VAT (at present 8%) HANDLING AND POSTAGE CHARGES £1 .25
FOR £0.30
OUR NEW 1976/1977 CATALOGUE IS NOW READY AND WILL BE SENT ON RECEIPT OF REMITTANCE
TRANSFORMERS
Ref
L
(Watts)
64
20
75
4
150
113
0- 115 -210 -240
2.81
0 -115- 200 -220.240
.,
,.
6.24
8.62
4 6S
60
SCREENED MINIATURES
VOLT RANGE
66
67
84
300
500
13-10
Prim. 220 -240V
3
1500
23.62f
Sec.
Ref.
73 3000
45-76t
24
26
27
25
23
40
20
0-24-30-40-48-60V
Ref mA
238 200
212 IA, IA
Volts
L
2.50
2.97
3 -0 -3
0 -6, 0 -6
9 -0-9
0 -9, 0 -9
VOLTS
SEC 120/240V
CENTRE
2'28
2.39
TAPP
WITH
SCREEN
Vg(Outts)
Ref
20
071
60
49
L
3
4
85
70
108
5
7.65
I1 95
CASED AUTO TRANSFORM
11.00
13-07
240V cable in and USA 2 pin out.
14 20
Ref 113W
L 4-95
20VA
16-64
Ref 4W
L 8-94
150VA
19.56t
21
Ref 67W
LIS-11
SOOVA
24-09t
22
10.0
Ref 84Wt
I000VA
L22-84
315
25.16t
12-0
89
Ref 95Wí
L3566
2000VA
DECS
TEST METERS
30 VOLT RANGE
Solderless Bread boarding
167.33
AVO 8 MK5
Prim. 220 -240V
L2-41
S Dec 70 contacts
626.86
Sec. 0-12-15-20-24-30V AVO72
T Dec 208 contacts L3.92
623.48
AVO MM5
L
Ref.
Amps
6458
U Dec 'A' for IC's
628-94
AVO
TT
169
0-5
3.15
112
U Dec'B'for IC's etc. L7.82
¿1393
4.00 U4315
1.0
79
Stab 3-6-9V 400mA 66.95
2.0
5.55 (USSR) inc. Steel carry case
3
6.87
3.0
20
ELECTRONIC CONSTRUCTION
MINI -MULTIMETER
4.0
7.93
21
KIT
D.C.- I,000V. A.C-1,000V, 1,000 9.55
51
5.0
(3lV
10 projects (including Electronic Organ).
10-69
117
6.0
D.C.I -IOOreA Res.- ISOkfl £621
Ideal gift at L8-63 (no soldering)
14.15
88
8.0
89
10.0
1451
AUDIO KIT 23W
COMPONENT PACKS
25W Amplifiers, I + Pre -Amp
BRIDGE RECTIF'S 2 + Power
200 Mixed value resistors (count by
supply, I + Transformer
0-67 I +
200V
2A
weight)
Panel.
I
Front
+
400V
2A
0.72
150 Mixed value capacitors (count by
+ Kit of parts to include on /off
4A
0-89
200V
weight)
ind. Stereo headphone
500V
IOA
2.70 switch, neon
value precision resistors W
Mixed
30
socket Plus Instructions book [32.18
2%
POWER UNITS
TEAK
AUDIO
KIT
23W
15 Assorted pots and pre -sets
CC 12 -05. 3-6.5-6 veneered cabinet
10 Reed switches
7-5 -9 -12V at 500mA Teak
Aluminium chassis, heat sink and
3 Micro switches
63.18
front panel brackets plus back
mixed
wound resistors
15 Wire
STABILISED 3-ó- panel and sockets etc. L11-21
wattage
7.5-9V
at
400mA
metres, assorted
wire
50
TUNER
WITH
I
Pack
FM
STEREO
66.98
colours
3300. Fits into 13A PHASE -LOCK LOOP
REQUIRED
stations supply
PLEASE
STATE PACK
socket 6-7-5-9V 300 - 4 Pre -selected
90p PER PACK
20-35V 90mA Max. 634.11
mA 63.59
53
27 25t
37.971-
1500
43.33t
2-0
3.0
4.0
5-0
6.0
8.0
7-65
13
100
235 330,330
207 500, 500
208 IA, IA
0-8 -9, 0-8-9
0-8 -9, 0 -8 -9
236 200,200 0- 15.0 -15
214 300,300 0 -20 0-20
221 700 (DC) 20- 12- 0 -12 -20
0- 15 -20, 0 -15-20
206 I A, I A
203 500, 500 0 -15- 27.0 -15-27
0- 15 -27, 0 -15 -27
204 I A, A
12, 15,20, 24, 30
5112 500
I
IPLUS
1
-
Prices Include VAT and P & P except t where carriage will be
according to weight and distance. Electrosil Resistors, Semiconductors, Multi- meters, wide range of Panel Meters, Audio
Accessories, send stamp for lists. Prices correct at 21st January 1977.
4.51
2.28
3.22
3.66
5.37
4.77
6.00
52
54
55
56
57
2000
5
59
I
3000
14-47
17-14
19 73
48-34
8.361-
ISV or 240V Sec. only.
HIGH VOLTAGE
Maine Isolating
Prim. 200/220 or 400/440
Sec.
100/120
VA
Ref.
60
350
1000
243
247
250
252
2000
I
2
100
5-43
213
18
200
250
350
560
750
1000
L
3-94
or 200/240
L
6.62
gmps
24V
L
0 0 5
3.01
0.5 025 130
68
51
1.0
Volt
12V
III
71
50
0-5
Ref.
4 57
6 68
3.14
amiss
and or 24
PRIMARY 220 -240V
PRIMARY 220 -240
PRI.120/240v
DAY DESPATCH
ALL EX -STOCK
i
12
MAINS
ISOLATING
TRANSFORMERS
-SAME
Auto Tops
VA
3.68
5 I0
I
2
-
458
S-61
3
6.36
8
10
12
16
4
7 34
115
187
20
15-42
30
10
15
226
60
30
21.941'
6
72
116
17
SO
7.86
8.39
1048
5
6
8
VOLT
1950
RANGE
Prim. 220 -240V
Sec. 0- 19- 25- 33- 40-50V
Ref.
L
No.
Amps
4.07
02
0.5
5.27
03
1.0
04
7.17
2.0
8.77
05
3.0
06
07
15.13
32.613t
18
19
54.801
HIGH QUALITY MODULES
4.0
6.0
8.0
10.0
1126
I729
1867
22.041
CARTRIDGES
13 93
RMS AMPLIFIER
L2-78 AT55
RMS AMPLIFIER
63. 17 Sonotone
V100 64.87
RMS AMPLIFIER
E3-51
9TAHC L3 01
25
RMS AMPLIFIER
¿4.67
E17-SO ACOS
125W RMS AMPLIFIER
PRE -AMP for 3 -5-IOW
£7.50
GP93-1 E2'ó0
GP96 -I Lí92
PRE -AMP for 25W
LI5 79
POWER SUPPLIES 3 -5 -10W LI 54 B.S.R.
SX6M L275
POWER SUPPLIES 25W
¿3.56
SCI2M 13.50
TRANSFORMER 3W
L2 54
3
5
IO
Watt
Watt
Watt
Watt
TRANSFORMER 5-IOW
TRANSFORMER25W
L2-99 GOLDRING
63.38
ANTEX SOLDERING IRONS
15W 14.08 18W L4-08 25W
6380
SOLDERING IRON KIT L3-80
STAND FOR ABOVE 6I .84
0800
G850
Shure
LS 96
L4.44
M75-65
612 -S0
MISE 114 19
Barrie Electronics Ltd.
3, THE MINORIES, LONDON EC3N 1BJ
TELEPHONE: 01 -488 3316/7/8
NEAREST TUBE STATIONS: ALDGATE 6 LIVERPOOL ST
by Lodes Printers.
Published on approximately the 715 el each month by Il'C Siagazlnen Limited. Yleetway House, 0arringdon Street, London EC4A SAL. Printed to Englan.1
le NOW subject
Dunstable, Beds. Sole Agente for Australia and New Zealand- Onrdon and otch (Asia) Ltd.: South Africa--Central News Agency Ltd. PRAorw u. Wioocree
of
at
to the following conditions, namely that It hall not. without the written consent of the Publishers ant baying been given, be lent, resold, hired out or otherwise disposed of by way Trade
dlepaed
more than the recommended with,, prir, -town or, the cover, excluding Eire where the selling price la eublect to V.A.T., and that It shall not be lent, resold, hired out or otherwise
of In mutilated cowl Moil or In ally unauthorised corer by way of Trade or affixed to or se part of any publication or advertising, literary or pictorial matter whatsoever
1
SUPERSOUND 13 HI -FI MONO
AMPLIFIER A superb solid state audio ampli-
HARVERSONIC SUPERSOUND
10 -1 IO STEREO AMPLIFIER KIT
MAINS OPERATED SOLID STATE
AM /FM STEREO TUNER
Brand new components
throughout. 6 silicon transistors plus 2 power output
fier.
transistors in push -pull.
Full wave rectification.
Output
13
approx.
watts r.m.s. into
8
ohms. Frequency response 12Hz 30KHz
3db. Fully integrated
pre -amplifier stage with
separate Volume. Bass boost
and Treble cut controls. Suitable
for 8 -15 ohm speakers. Input for
ceramic or crystal cartridge. Sensitivity
approx. 40mV for full output. Supplied ready built and
tested, with knobs, escutcheon panel, Input and output
plugs. Overall size 3" high x 6" wide x 71" deep. AC
2001770V. PRICE £1375. P. & P. £1.00.
t
LATEST ACOS GP91 /1SC mono compatible cartridge with
t/o stylus for LP /EP /78. Universal mounting bracket.
61.60. P. & P. 18p.
CERAMIC STEREO CARTRIDGE. Universal mounting
brackets and turnover stylus. 70mV per channel output.
ONLY 0190. P. & P. 18p.
SONOTONE9TAHC COMPATIBLE STEREO CARTRIDGE
T/O stylus Diamond Stereo LP and Sapphire 7h.
ONLY £2.38. P. & P. lop. Also available fitted with twin
Diamond T/O stylus for Stereo LP. £2.86. P. & P. 18p.
LATEST
CRYSTAL T/0
STEREO /COMPATIBLE
CARTRIDGE for EP /LP /Stereo 78. £180. P. & P. 18p.
LATEST T/0 MONO COMPATIBLE CARTRIDGE for
playing EP /LP /78 mono or stereo records on mono
equipment. Only £1.58. P. & P. 18p.
HARVERSONIC STEREO
A
44
solid state
stereo amplifier chassis,
with an output of 3 -4
watts
per
channel into
8 ohm speak,. Using the latest high technology integrated circuit
amp ifiers with built in short term thermal overload
prof atom. All components including rectifier smoothing
capacitor, fuse, tone control, volume controls, 2 pin din
sock is & 5 pin din tape rec. /play socket are mounted on
the printed circuit panel size approx. 95" x 21° x 1" max.
dep h. Supplied brand new & tested, with knobs, brushed
ano, iced aluminium 2 way escutcheon (to allow the
amplifier to be mounted horizontally or vertically) at
only £900 plus 50p P & P. Mains transformer with an
output of 17v a/c at 500m /a can be supplied at 1160+
40p P & P if required. Pull connection details supplied.
LIMITED NUMBER ONLY ut
1
Secondary combination 0- 5- 10- 16- 20- 26- 30- 35- 40 -60v.
half wave at I snip. or 10 -0-10, 20 -0 -220, 30- 0 -20v. at
2 amps full wave. Size lins long x 35111. wide x 3111. deep.
Price £2 90 P. & P. 90p.
MAINS TRANSFORMER. For power supplies.
Prl. 200/240v. Bec. 9-0 -9 at 500 mA. 8160. P. & P. 60p.
Prl. 2001240e. Sec. 12 -0-12 at 1 amp. 6186. P. & P. 60p.
Prl. 200/240v. Sec. 10 -0-10 at 2 amp. 6285. P. & P. 90p.
Prl. 200/240V Sec. 23V at 1-5amp, 6V at .6 amp, 8V at
501nÁ. 0200 + 655 P. & P.
ALL -PURPOSE POWER SUPPLY UNIT 200/240v.
A.C. Input. Four switched fully smoothed D.C. outputs giving 6v. and 75v. and 9v. and 12v. at 1 amp
on load.
Fitted insulated output terminals and pilot lamp
Indicator. Hammer finish metal case overall size
6" x 35" x 25". Ready built and tested Price £6.76
P. & P. 85p.
STEREO -DECODER
SIZE 2" x 3" x 5" ready built. Pre
aligned and tested. Sens. 20-660 mV
for 6 -16V neg. earth operation. Can
be fitted to almost any FM VHF radio
or tuner. Stereo beacon light can be
fitted if required. Full details and
Instructions (Inclusive of hints and
tips) supplied. £568 plus 201, P. & P.
Stereo beacon light If required 40e
extra.
QUALITY
Open 9.30 -5.30 Monday to
Friday. 9.30 -5 Saturday
Closed Wednesday.
All prices and specifications correct
at time of press and subject to
alteration without notice.
&
P.
Pye VHF /FM Tuner Head
covering 88 -108 M /Hz. 10.7
M/Hz I.F. output. 7.8 Volt+
earth. Supplied pre -aligned,
with full circuit diagram.
Connection details supplied.
Beautifully
made
with
precision- geared FM gang
and 323Pf + 323Pf A.M.
Tuning gang only 83.15 +
P.
&
SPECIAL OFFER -only E2375 if all
ordered at one time plus El p. & p.
P. 35p.
3
items
Full after sales service
PRECISION MADE
Push Button Switch bank. 8 Buttons giving 16 S/P C/O
Interlocked switches plus 1 Cancel Button Plus 3 d/p c /o.
Overall size 5" x 25" x 1 ". Supplied complete with
chrome finished switch button.. 2 for £160 + 20p P & P.
HI -FI LOUDSPEAKER SYSTEM MK I
I
Beautifully made, siumlated teak finish enclosure
with attractive slatted front. Size 165" high x 101"
wide x 9" deep (approx.). Fitted with E.M.I.
Ceramic Magnet 13" x 8" bass unit, H.F. tweeter
unit and crossover. AVAILABLE IN NOMINAL
4 Ohm, 8 Ohm or 16 Ohm impedance (state which).
Handling power 10 watts R.M.B.
PRICE LI2.80 each.Carr.81.90 ea.
Cabinet Available Separately 47 60, Carr. 81.40 each.
Also available In 8 ohms with EMS 18" x 8" boas
speaker with parasitic tweeter 61140, Carr. 51'90 ea.
Also available ready built and tested 63125. P.
8 -VALVE
&
P.
£I.
AUDIO
AMPLIFIER HA84 MK II
Designed for HI -FI reproduction of records. A.C. Mains
operation. Ready built on
plated heavy gauge metal
chassis, elle 75 "w. x 4"d. x
45 h. Incorporates ECC8S,
EL84, EZ80 valves. Heavy
duty, double wound main.
transformer and output transformer matched for 3 ohm
epeaker. Separate volume control and now with Improved
wide range tone controls giving base and treble lift and
cut. Negative feedback line. Output 45 watts. Front
panel can be detached and leads extended for remote
of controls. Complete with knobs, valves, etc.,
wounting
ired and tested for only £1120. P. & P. £1.00.
ROL "FOUR" AMPLIFIER KIT. Similar In appearance
to HA34 above but employe entirely different and
advanced circuitry. Complete set of parte, ete £7.80
-
OUR
LOUDSPEAKER BARGAINS
in. 3 ohm 6200. P. & P. 30p. 7 x 4111. Bohm 4236, P. & P.
48p. 10 x 61n. 3 or 16 ohm 13 00, P. & P. 76p. 8 x 61n.
B ohm with high flux magnet 4300, P. & P. 60p. Tweeter.
Approx. 55 ". Available 3 or 8 or 16 ohm., 0200 + 26p,
P. & P. 2" Plastic Cone HE Tweeter 4 ohm 13-50 per
matched pair + 50p P. & P.
"POLY PLANAR" WAFER -TYPE, WIDE RANGE
ELECTRO -DYNAMIC SPEAKER
Olze 111" x 1411" x 1 4" deep. Weight l9oz. Power
handling 20W r.m.,. (40W peak). Impedance 8 ohm only.
Response 40Hz-20kHz. Can be mounted on ceilings,
walls, doors, under tables, etc., and used with or without
battle. Send O.A.E. for full details.
Only £240 each + p. & p. (one 75p, two 90p).
Now also available 8 ".
8 ohm 10 watts, r.m.a. 20
watt peak 40 Hz- 20,000 Hz. Overall depth I ". Ideal for
HI-FI or for use in ears 4510 + p. & p. (one 31p, two 65p).
-
OFFERED
TOCKEAVAILABILITY
Limited number of British manufacturer's surplus
professional 100 watt RMS slave amplifiers. Special
feature., 2 separate power modules, 1 for Bass response
and 1 for midrange /tweeter. 6 stage LED display for
power o/p indication. A/C mains i/p switchable for 110
or 240v. Can easily be converted to Stereo. AVAILABLE
TO PERSONAL CALLERS ONLY, PLEASE PHONE TO
CONFIRM AVAILABILITY. Brand new & tested only
£3375.
SPECIAL LINES
watt RMS Solid state power amplifier module. Fre.
Resp. 35 Hz. -20 KHz. Power requirements 40 volte Q
1.5 amps. Full c/d & connection details supplied. 11120
26
PLAYER AMPLIFIER MK. II
A top quality record player amplifier employing heavy
duty double wound mains transformer, ECCA3, EL84,
and rectifier. Separate Bue, Treble and Volume control..
Complete with output transformer matched for 3 ohm
speaker. Size 71n. wide x Sia, deep x 61n. high. Ready
brtllt and tested. PRICE 0700, P. & P. 90p.
ALSO AVAILABLE mounted on board with output
transformer and epeaker. PRICE 68 00, P. & P. £l.
RECORD
+ £1 30 P.
SPECIAL OFFERS
yd.). B.A.E. for samples.
BRAND NEW MULTI -RATIO MAINS TRANSFORMERS. Giving 13 alternatives. Primary: 0- 210 -240e.
£28'00
Mallard LPI159 R.F. -I.F. Double Tuned Amplifier
Module for nominal 470 KHz. Size approx. 21" x 15" x
9" 7.6 Volt + earth. Brand new pre. aligned. Full specification and connection details supplied. 11225. P. & P. 12p
VYNAIR & REXENE SPEAKERS & CABINET FABRICS
app. 54 In. wide. Our price 61-50 yd. length. P. & P. 50p
per yd. (min.
really Drat-class HI -FI Stereo Amplifier Kit. Uses 14
transistors including B:licon Transistors in the first five
stages on each channel resulting in even lower noise
level with improved sensitivity. Integrated pre -amp with
Base, Treble and two Volume Controls. Suitable for use
with Ceramic or Crystal cartridges. Very simple to
modify to cult magnetic cartridge-instructions included.
Output stage for any speakers from 8 to 16 ohms. Compact
design, all parts supplied Including drilled metalwork
high quality ready drilled printed circuit board with
component Identification clearly marked, smart brushed
anodised aluminium front panel with matching knobs,
wire, solder, mute, bolts -no extras to buy. Simple step
by step instructions enable any constructor to build an
amplifier to be proud of. Brief specification; Power
output: 14 watts r.m.e. per channel into 6 ohms. Frequency response f3dB 12- 30,000 Hz Sensitivity:
better than SOmV into IMO. Full power bandwidth:
f3dB 12- 15,000 Hz. Base boost approx. to ±12dB.
Treble cut approx. to -16dB. Negative feedback 18dß
over main amp. Power requirements 36v. at LO amp.
Overall Size 12 "w. x 8"d. x 21 "13.
Fully detailed 7 page conetructicn manual and parte
list free with kit or send 26p plus large S.A.E.
AMPLIFIER KIT
113.50 P. & P. 65p
(Magnetic input components 33p extra)
POWER PACK KIT ..
..
4550 P. 5 P. 85p
CABINET
..
..
..
£6.60 P. & P. 85p
A
200/240V Mains operated Solid State F/M A/M Stereo
Tuner. Covering M.W. A.M. 540- 1605KHz VHF /FM
88- 108MHz.
Built -in Ferrite rod aerial for M.W. Full AFC and AGC
on AM and FM. Stereo Beacon Lamp Indicator. Built
in Pre -amps with variable output voltage adjustable by
pre -set control. Max o/p Voltage 600m/v RMS into 20K.
Simulated Teak finish cabinet. Will match almost any
amplifier. Size 85 "w x 4 "h x 95"d approx.
+ 30p P/P.
HI- FIDELITY STEREO HEADPHONES with Standard
Stereo Jack Plug. 4360 + lOp P. & P.
P.
&
P. £1.00.
10114 WATT Hl -FI
AMPLIFIER KIT
A etyllshly finished
monaural amplifier
with an output of
14 watts from I
EL84. in push -pull.
Super reproduction
of both music and
speech, with negligible hum. Separate
Inputs for mike and
gram allow recorde
and announcements
to follow each other.
Fully shrouded section wound output transformer to
match 8 -15 n speaker and 2 independent volume control.,
and separate bass and treble controle are provided
giving good lift and cut. Valve line -up 2 EL84s, ECC88,
uction booklet
EF88 and E 780 rectifie r. Simple Instruction
26p }SAE (Free with parte)' All parte sold separately.
ONLY 012 00 P. & P. £1.36. Also available ready built
and tested 016.60 P. A P. £1.36.
GENERAL PURPOSE HIGH STABILITY
TRANSISTOR PRE -AMPLIFIER
For P.U. Tape, Mike, Guitar, etc. and suitable for
use with valve or transistor equipment. 9-18v.
battery or from H.T. line 00/300v. Frequency
response 1511z- 25KHz. Gain 26dB. Solid encapsulation size 15" x le" x 1 ". Brand new complete
with inetructione. Price 0180 P.& P. 15p.
Prices include VAT at Current Rate
I
HARVERSON SURPLUS CO. LTD.
(Dept. P.W.) 170 HIGH ST., MERTON, LONDON, S.W.I9 Tel.: 0I -540 3985
4
/rte .,,tenter froar Sonst 8 i,ebledoa Tube Sialion.
SEND STAMPED ADDRESSED ENVELOPE
WITH ALL ENQUIRIES
(Please write clearly)
PLEASE NOTE: P. & P. CHARGES
QUOTED APPLY TO U.K. ONLY.
P. & P. ON OVERSEAS ORDERS
CHARGED EXTRA.
The only organ you can build in stages
and tailor to your requirements as you go
along -and at each stage you'll have a fully
working instrument! We haven't got the
gimmicks (yet- they're coming soon), but we
have got the most beautiful sounds -you
won't find them on any organ less than twice
our price. So get our MES50 series leaflets
now! 65p buys the three available so far.
UnP.--.:.
9 a a 9
-N(# (
This high quality Graphic Equaliser will enhance even the most
sophisticated system at a traction of the cost of a ready -made
equaliser of equal quality. You can get all the parts from us
(except woodwork) including drilled and. printed metalwork.
Construction details in our leaflet: 15p.
9
(((((t((11(tttt n.
44MMg
We stock a wide range of switches
including a really low -priced high
quality interlocking push- button
switch system, which is extremely
versatile. We've Out toggle
switches, slide switches, push
switches, rotary switches -there
are dozens to choose from, but it's
only a tiny part of our. fantastic
range.
A completely self -contained pedal
unit. 13 -note, 2- octave range,
organ stops. It can be added to
any organ! A really unusual extra
Is the bass guitar stop which uses
four envelope shapers to give a
real bass guitar sound. A must for
the solo guitarist. Full construction
details in our cataloóue -post the
coupon below now!
4
Play fascinating games NOW on
your own t.v. in your own living
room. The kids will think it's magic
when the scores pop up on the
screen. Lay your bets- anyone
could win -with Mapiin's prices
everyone can win. Get the May
edition of Electronics Today
International now -then get all the
parts from us at a remarkably low
price (I.C. alone £11.99). All
prices include VAT and
P & P.
AY- 3-8500. Special offer price £899
inc. VAT and P &.P.
IT'S A FANTASTIC BESTSELLER!
216 big (11"' x 8 ") pages! Over a thousand illustrations!
Over 30 pages of complete projects to build!
Thousands and thousands of useful components described
and illustrated! No wonder it's a bestseller!
DON'T MISS OUT! SEND 50p NOW! '
r
Our bi- monthly newsls. ter keeps you up to date with latest
guaranteed prices - at.r latest special offers (they save you
pounds) - details of new projects and new lines. Send 3Cp
for the next six issues 15p discount voucher with each copy).
I
immediately
I
Telephone Eouthend (0702) 715155
'Closed on Monday; Telephone Southend 107021 473 79
NAME
ADDRES
BOX 3 RA'{LEIGH ESSEX SS6 8LR
Shop. 284, L:)nda7 Road, Westtuff -on -Sea, Essex
YOUR COPY OF OUR CATALOGUE
PRICE 50p
;71:3R
Please rush me a copy of your 216 page catalogue by return of post.
enclose 50p, but understand that if am not completely satisfied may
return the catalogue to you within 14 days and have my 50p -efunded
MAPLIN ELECTRONIC SUPPLIES
P.O.
POST THIS COUPON NOW
I
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