Info

O 0304 0 047S 0 069 0096 0 83 2.1 4 7 2 Fig. 10. The E-I plot of a Thyrite varistor, Thyrite displays a negative coefficient of resistance versus voltage, like a thermistor, but differs in a very important way-The resistance value of the Thyrite varistor does not take seconds or minutes to be established, after application of voltage. This means that the Thyrite varistor fills the need for a fast limiter, one which will respond at the ac rate. This fast response shouldn't come as any surprise,...

Dx Mews

If a direct QSL address is not otherwise available. QSLvs for K and W TF amateurs operating in Iceland should be sent to Keflavik Amateur Radio Organization, Box 44, FPO New York NY 09571, Box 1058 Reykjavik is appropriate for QSL'ing to Icelandic nationals (TF ) only. Tell our Advertisers You Satv it in 73 1 have been very pleased with the good service in changing my address and getting me my 73 magazines. I subscribe to two other electronic magazines, and yours is the only one 1 have been...

Payne Radio

Days (615)384 5573 mgbts (615)384-5643 in-circuit characteristics. Collector current, Ic, is the most important. Link coupling is shown in the final, as in the other stages, for interstage coupling. Tapped coils can also be used, although with adjustment, links prove more effective. Bias resistor R3 resembles Lhe drivej resistor R2, and all comments apply. This value is not critical, as the resistor serves only to raise slightly the stage's efficiency by creating class C operating conditions....

Bottom View

CI - WIRE GIMMICK CZ TO IC7-MC 7B0P (MOTOROLA) CI-> jL 923 or HEP 503 QI-2N3646, 2N7Q6 Or HEP 50 more expensive than the Fairehild juA and Motorola MC numbers they replace, but the HEP parts are more generally available.) The other simplifying modification of the counter was the use of MC780P decade counter ICs, These ICs were unavailable when W1PLJ wrote the original article, They make the frequency standard divider section much easier to wire and eliminate any divider adjustments. The...

Hal Devices Model Electronic Keyer

The ESM 1 emergency signaling device is a self-contained pocket-portable unit that has a range of up to ten miles in fair weather daytime conditions. The device is solar powered and operates in the noncoherent light band. The emission is of the CW mode. Its dimensions are four by five inches, and about a quarter inch thick. Obviously it is solid state, very solid, with no moving parts of any kind, it must be very state-of-the-art you say No indeed, this device appears to be at least twenty...

Mtr Power Supplies

Regulated, overload protected 117V AC in 13.5V DC 3 Amp. out. Only 22.95 & 1.00 POSTAGE, Limited Quantity. Low, Low Prices on Japanese 2 mtr Gear, Free Catalogue. GLENWOOI) i RAD INC. CO., Box 1009, Blaine, Wa., 98230. TELETYPE Model 14 typing reperf, 28 CV-278 GRC late model ESK converter SI05 40 rolls 11 16 per forator tape, S8. Jim Cooper, FOB 73 M, Pa ramus, NJ 07652. DRAKE 2C Xtal Calb., with 2 CQ and Drake 2NT Xmtr. 5300.00. Like new Bart Burne, WN3QXU, 1725 Wyoming Ave.,...

Sign Eti Cs Phase Lock Loop

NE561B Phase Lock Loop 9.50 NE562B Phase Lock Loop 9.50 NE565B Phase Lock Loop 9.50 NE566V VCO (Function Generator) 9.50 NE567V Tone Decoder (PLL) . 9.50 MPS6571 .60 2N706 packet of 4 1.00 2N2218 packet of 2 1.00 1N4001 packet of 6 1.00 1N4002 packet of 6 1.00 1N4004 packet of 6 1.00 Motorola HEP Circuit-Stick - Plessey All devices are first quality and are fully guaranteed.

Liw

Used in many offices for 2-way messages. Complete with built-in ac 60 cy power supply. With schematic. Two for 27.50 HALHCR AFTER TRANSCEIVER TR35A (fac- > tory seconds) AM 2 to 9 MHz, 4 crysai controlled Sj channels. 35 watt transmitter. Receiver is super het. This unit is solid state except the final tube. > Also has a solid state 1 2V dc or I 10V ac supply. Unit may need some work. With schematic, as is, like new condition 39.50 > R390 COLLINS RECEIVER...

Ahw

Fig. h Typical Pierce crystal oscillator circuit. Cj feedback capacitor C4 rf bypass capacitors output tank capacitor Rj base bias resistor (see text) Lj output tank coil (see text) usually ferrite, 10K pot can be wired in during initial experimentation, adjusted, measured, and then replaced with the nearest fixed-value resistor. The value will usually be in the vicinity of 3K. Values shown in published circuits will seldom require adjustment. LI should similarly be tuned for the highest output...

Sale Sale

TS- 13 AP Signal Generator, 115V 1 ph 60-80 TS-15C AP Fluxometer, 40 35.00 ea. AS 580A ARN 30 Antenna, brand new, boxed, C 824 AIC-10 Controls complete, 100 4.50 ea. AS 578 ARA Antenna ) AS 5788 Antenna ) 50 total 9.50 ea. A 13B Antenna ) T-51 Chest Sets with band straps, new. PP-327B GRC-9Y new, 100 25.00 ea. Headset HS-38, brand new, U.S. mfr with 2 ea. ANBH-1, also cord and PL-354 pluq. CX 1120 with plug, clamp 4' 6, CX 2340, 100 CX 3977 Cable, 7 cond 18 - 6...

Homemade Radio With 1ad4

The solution for compact units is to enclose the outside of the winding with powdered iron as well as having a center core. This causes the magnetic field to curve back in a sense, into the coil again, instead of travelling through the near field'1 over to the base coil winding, where you most decidedly do not want it, These kind of cores are known as cup cores, and there are millions available practically for free. Most of the i-f transformers made for tube i-f's have some beauties in them....

Highsensitivity Widebawd Receiver

COMMUNICATIONS*BUG DETECTION SPECTRUM STUDIES 38-1000 MHZ AN ALR-5 Consists of brand new tuner converter CV-253 ALR in original factory pack and an exc. used, checked OK & grid main receiver Ft-444 modified for 120 v* 50 60 hz. The tuner covers the range in 4 bands each band has its own Type N Ant. input. Packed with each tuner is the factory inspector's checkout sheet. The one we opened showed SENSITIVITY 1.1 uv at 38.4 mhz, 0.9 at 133 mhzT 5 at 538 mhz+ 4Va at 778 mhz, 7 at 1 ghz. The...

Ant In

Car radio converter, by WA8ALL, from FM Magazine, June 196 7, reprinted in 73's FM Anthology I. There's no text or anything with the original, either. . .just the circuit. As a reader of 73 you may be interested in the newest FM bulletin . , . the Repeater Bulletin. This magazine is published by 73 Magazine just for the users of repeaters, particularly in the New England and Eastern New York areas and it carries news of activities of the repeaters covering this section of the country. In...

Semiconductor News

RCA says goodbye to germanium and silicon small-signal transistors, RCAs Solid State Division has decided to phase out over one hundred types of small-signal transistors. Included in the cutback is the whole line of small-signal silicon transistors, i he devices discontinued are as follows Silicon 2N2475, 2N3241, 2N3261, 2N35 I 2, 2N3932, 2N3933. 2N4068. 2N4069, 2N4074. 2N4259, 2N4390. 2N5180, 2N5183. 2N5 184, 2N5185, 2N5186, 2N5 187, 2N5188, Germanium 2N388. 2N398, 2N404, 2N1302, 2N1303,...

Qscil Loscopes

OSS U, 3RPJ TUBE, GENERAL PURPOSE, DC TO 2MHZ, PORTABLE CARRYING CASE, 115V 60CV . , . . , USM 24 2HZ TO 8MHZ VERTICAL RESPONSE SENSITIVITY 50MV, TRIGGERED SWEEP, BUILT-IN TRIGGER PULSES AND MARKERS, 3 CRT 95,00 USM-32 10HZ TO 4MHZ ,1 VOLT SENSITIVITY BUILT IN MARKERS, SWEEP 5MHZ TO 100KHZ USM-8 t h MILITARY VERSION OF TEKTRONIX 535 WITH DUAL TRACE PLUG-IN , , . , 1445,00 TEKTRONIX PLUG INS, MODELS K, E, OR Q . . , YOUR CHOICE 45,00 EA. TS-34 AP PORTABLE OSCILLOSCOPE, 2PPI WITH 2X MAGNIFICATION...

Meg

This switch is operated by body capacity t , , just touch the plate to operate the relay. How about this to turn the rig on and off You can use a latching relay, time delay relay, stepping relay, to do just about anything. Circuit courtesy Motorola HMA-33 Tips on using FETs, available free from Motorola, Department 73, Box 20924, Phoenix AZ 85034.

Labs

MOLLIS, N.Y.11423 196-23 JAMAICA AVE. MOLLIS, N.Y.11423 Easy reading, 7 segment display tubes. Solid State MSI 1C electronic components,. Accurate 60 cycle line time reference. Simple, push button settings. Clock displays hours, minutes and seconds, 10 minute timer, with seconds available. Clock kit 74.50 ORDER TODAY Tlmfir . Sf t ,n OR WRITE USE YOUR Timer k,t i54'50 FflR flFTAII lt s MASTER CHARGE Add choice of cases rurt uuhiuo or BANKAMERICARD Metal clock case 10, Walnut...

Dycomm Fm Booster

10-15 watts drive produces 90 100 watts output. All solid state. Requires 13.5 VDC power, automatic Xmit Rec. switching- Small 5x5x8. Fantastic warranty. Get yours now for only 195.00 P1416 15 amp ac supply for your 10-0 10-15 watts input - 40-55 watts out 13.5 VDC required auto switching ready to Boost your 1 3.5 watt rig to 20 30 watts out. 13.5 VDC at 3.5 amps S79.95 Use your 1 3 watt rig amp get 40 50 watts out 13.5 VDC at 6.5 amps 99.95

Jensen High Compliance Speaker Systems

A local manufacturer went out of the speaker enclosure bu si ness, and we were lucky enough to buy his inventory of Jensen high-com-pl i ance acoustic suspension speaker systems. These systems consist of a 12 extended range woofer, ahemi-spheric dome tweet er, plus crossover. The dome tweeter response extends into the supersonic. The dome shape provides an ideal polar pattern response. The system is ideal for use with our Sanken Amplifier Systems, or any system capable of putting out at least...

Radio Receivers And Transmitters

COLLINS R 389 URR VLF RECEIVER TUNES 15KHZ TO 1500KHZ, DlGiTAL REAO-OUT 115V 60CYr 19 RACK MOUNT COLLINS R 388 URR, MILITARY VERSION Of 51J 3 RECEIVER, TUNES 500KHZ TO 30,5MHZ, 19 RACK MOUNT, 1SV 60CY KAMM AR LUND SP 600JX VLF RECf I VER, 10 TO 540KHZ IN 6 BANDS, 1 15W60CY, 19 RACK HAMMARLUND SP 600JX TUNES S40KHZ TO 54MHZ IN 6 SAND, 1 15W60CY 19 RACK MOUNT AN URR 13 RECETVER TUNEABLE UHF 22h 400MHZ, USED TO MONITOR MILITARY AND ASTRONAUT FREQUENCIES, AM CW, 115V 60CY AN URR 27 RECEIVER...

National Devices

LM370 AGC Squelch amp 4.85 LM373 AM FM SSB strip 4.85 LM309K 5V, 1 A regulator. 3 lead TO-3 case. Easy to use. Recommended for all TTL circuits DIGITAL BARGAINS FACTORY FRESH TTL IC's FIRST QUALITY Tl amp NATIONAL DEVICES 7447 Decoder driver for the digital readout or other 7 segment displays 2.25 7400 gates .35 7441 NIXIE driver 1.95 7490 decade counter 1.40 7475 quad latch 1.40 7495 shift Reg 2.00 7493 divide by 16 1.90 74121 monostable 1.80 7473 dual flip-flop .85

Real Down To Earth Prices

TEK 80 vertical plug in less probe 25.00 TEK 80 vertical plug in with probe 35.00 TE K TU2 test toad plug in 35.00 TE K 536 wide band caiib, pre amp 65.00 TEK 53D diff. high gain calib. pre amp . 65.00 TEK 53 54K fast rise calib, pre amp 65.00 TEK G wide band diff, callb. pre amp 65.00 TEK N sampling plug in 100.00 TEK P plug In test unit 25.00 TEK R transistor rise time 1 10.00 TEK 121 wide band pre amp 5 CPS to 12 MC TEK 122 pre amp 0.2 Hz to 40 kHz . . . . 50.00 TEK 105 sq. wave gen. , . ....

Iv

100 W. 18th Street Erie, Pennsylvania 16502 SSB. The first project on the agenda, therefore gt was the conversion of the 75A2 I purchased from a local ham. Of course, a mechanical filter. And a crystal lattice for CW And a good product detector and age system. with suitable noise limiting. This article is devoted to all of those who have failed to achieve the desired results when tackling a similar conversion. Most such failures lie in the area of the product detector and age. The installation...

Handmike

Rugged, heavy-duty carbon handmike with press-to-talk switch Equipped with 4 ft cord amp phone plug- SPECIAL NEW, boxed Eoch 1 88 2 for J3.25 Mounts in 2-1 8 hole. Flange diameter 2-5 8 Two scales 0-15 and 0-600. Calibrated for use an iteel panel. Standard brand. SPECIAL NEW, boxed Each SI.75 2 for 3.00 BC-733 RECEIVER Receives radio signals being transmitted by US satellite on apprax, 108 Mc. AM, crystal-control led on 6 preset fre lt p. in 108.3 to UO.3 Mc range. Operate on 12 24 V DC amp 220...

Umf

A sefection of E-l pJois cont. So far, we have seen lamps used as stabilizing elements in oscillators and as elements in bolometers for power measurement. A similar use of lamps is in the application of current limiters or fuses. In many circuits which may be subject to expensive failures, lamps may be used to slow down destructive runaway currents, and then open ' fuse-like, if the runaway continues uncontrolled. One such application is in push-pull or pseudo-push-puli transistor...

Telephone Type Relay

NEW 3.45 AN APR 4Y FM A AM RECErVER FB for Satellit Trocklngl High precision lab insrrument, far monitoring and measuring Frequency and relative signal strength, 38 to 4000 Mc, in 5 tuning ranges. For 110 v 60 cycle AC. Built-in power supply Original circuit diagram included. Checked out, . _ _ Perfect, LIKE NEW 88-50 AM tuning unit available for above. P U.R. R48 TRC-8 UHF FM RECEIVER 230 to 250 Mc. Variable tuning, one bond. 7 i5 230 V 60 cy, Complete with speaker,...

Ox Handbook

This 300-plus page book has material on basic FM repeaters, national standards for FM repeaters, carrier operated repeaters, tone decoders for repeaters, controlling repeaters with tones, improving repeater intelligibility, minimizing desensitization, solving intermoduiation problems, digital identification, the WB6BFM identifier, a computer-optimized digital identifier, WAOZHT design data, the Curtis identifier, the K6MVH auto patch, the Zero DKU autopatch, the touchtone autopatch, setting up...

Jennings Ucs Mmfd Vacuum Variable Capacitor Kv With Gear Drive

POPULAR FOR LINEAR BUILDING 29.50 NEW FACTORY EI MAC YELLOW BOXED TUBES. FACTORY GUARANTEED El MAC 3 4002 EIMAC 3 5002 El MAC 3 10002 EIMAC 4 400C . EIMAC 4 1000A EIMAC EIMAC 4CX1500A EIMAC SK 510 SOCKET 3-10002, 4 EIMAC SK-410 SOCKET 3-4002, 3-5002 10.50 EIMAC SK-650 SOCKET 4X150A, 4CX250B, NO SCREEN BY PASS 12.00 EIMAC S K -620 SOCKET 4X150A, 4CX250B, HAS SCREEN BY-PASS 14.00 EIMAC SK-516 CHI ME NY FOR 3 1 EIMAC SK-416 CHIMNEY FOR 3 4002, 3 500Z 7.00 EIMAC SK-626...

Report On Huntoon Talk

John Huntoon, ARRL General Manager, recently spoke before the Pueblo CO Ham Club, He commented on League activities and policies, and made some interesting comments about the 200 Mil band. After saying that the CBers stand a 50-50 chance of getting part of the band, he went on to say that rhe League lias not filed against the proposal and thai the FCC has not definitely recommended it If it conies to be, it will hurt, but won t hurt much since the advent of two meter FM If you object, please...

Integrated Circuits

SHEETS FAIRCH1LD PHILCO RCA MOTOROLA NATIONAL UL 900 Buffer 80 10 5.50 UL 914 Gat _ 80 10 5.50 UL 923 JK Flip-flop ________________ 1.50 10 8.50 MC 790P Dual JK Flip-flop 2.00 10 18,95 MC 890P Dual JK Flip-flop 2.00 10 18.95 MC 767P Quad Latch 3.00 MC 9760P Decade __________________5.00 7400 Quad 2 Input NAND Gate 65c 10 5,95 7404 Ha Inverter 65c 10 5,95 3,50 10 29.95 NEW 7447 7 Segment Decoder Driver 7473 Dual JK Flip-flop 1.30 10 10.95 7475 Quad Letch 2.10 10...

Level Adjust

K6ASK single tone encoder see above . 4CX250 amplifier for six and two meters, using single pole switching. By K1CLL, from 73 Magazine,T ApriJ, 1966- Simple modifications by Fritz Hervey K4ETZ forget the 6 meter coil and use smaller PA tuning capacitors, Class C bias and a grid tank allow 10W drive, 200-250W out with enough air on the anode, Amplifier should have a screen clamp tube with G2 supply bled down from high B for best results, says Fritz and he suggests a TV power transformer with a...