Info

146 25 1 SS 223.26224.BS 47 435 46.40 14fl.ai-14K.6T 223.26 224.86 T .8 147.fl7M7.2T 146,055-146.5 55 147.12 147 72 444.5-449.5 W2.t 146,34 146.34 146.28 146.86 1 14-146.78 443 7S-448.75 (fmm call WA9WVC Ml KBWNJ hUtishpQon Mi WABPUD Glfnti Rapnfs MI W BttEE WliiEinure Lsko MI WRBAAA Milford ML WRBASI Katamazoo (forme r call K8T1W) Mt WRBABZ Jacken ffnnner ctf WB0CSQ) Mi WfiBACf Dtlrorl ftornwr call KBVLN) MD WRflACT Inden einte nee MS WR5ACC Jackson MS WA5ABT Jackson tJS WftlABA Bellcvut NJ...

Digital Rf Wattmeter

The model 4371 THRU LINE Directional High-Power Wattmeter is the first digital insertion instrument for measuring Forw rd or reflected CW power in coaxial transmission lines. It accurately measures power flow under any load condition from 25 to 520 MHz and from 1-1000 watts in six ranges. Model 4371 is also the first High-Power Directional Wattmeter which the user can calibrate in the field to known RF power standards, eliminating weeks of transit for periodic certifications. This Wattmeter...

Linear Ic Data Book

Motorola's 3rd Edition of the Linear Integrated Circuits Data Book is just off the press and has been expanded to over 800-pages, 100-pages more than the previous edition. In addition to device listings and data sheets, an interchangeability guide and listing of available Appirca-tion Notes is included. Package out lines, pinouts and numerous schematics are abundantly provided. At S3 per single copy it is a bargain buy for the solid state bookshelf. The Linear Integrated Circuits Data Book may...

Decoder

A KIT QESIGNEP TQ PftQVIPE INEXPENSIVE SELECTIVE CALLING ons- 4-oigil TOUCH-TONE i qu nc** islet F-H-fJ b irilnrrwit tlrQppirtg * U *s a-.do Irom diitriiiiinoF f or ip lt r ovtpuF * Speaker i tichiruj relay intludtd * L< ii ' iman te d c ir m i J Frehnok g * Fpiy GOMtruchcm und inifdllaliDri Compta Ft kit rncluttai c bimH . switch, and L O indicator * P wtr rtpul t v6< ne atitf g*OUr> d Sing e osciiJator and diode provide two injection frequencies for dual conversion receivers. Transistor...

Fight Lung Cancer Subscribe To

73 Magazine has many qualities that I admire, but unlike the others that cross my desk, it doesn't have any cigarette commercials, . .hi I know the other ham magazines don't carry them either, but they might someday, .and ) hope you hold out against blood money. Raise your subscription price, or anything else, but let's keep lung cancer out of our hobby. lltk Vndersoii K6BBQ KCBS Radio San Francisco < BUY A LIFETIME SUB -And Help Build a Nuclear Power Plant Here is a picture of Earl Carrier...

Bassett Vacuum Trap Antenna System

Complete packaged multi-band antenna systems employing the famous Bassett Sealed Resonators and Salun from wti ch air has been removed and replaced with pure helium at one atmosphere. Operating bands are indicated by model designation. The famous seated helium filled BaJun , . employed with the OGA Series Antenna Systems. Solrierless center insulator and easily handles more than full legal power while reducing unwanted coax radiation. Equipped with a special SO 239 type coax connector and...

Atv

Terry Fox WB4JFi 3672 Barer oft View 302 Baileys Crossroads VA 22041 ATV may be the most exciting new facet of amateur radio, The word new is emphasized because ATV has been around for over 25 years. As a matter of fact, hams were among the pioneers in television, both color and black andi white. Unfortunately, except for a few isolated pockets of activity, ATV has never really caught on. Two major reasons for this come to mind. First, there seems to be a fear of television by amateurs, both in...

Telephone Unit

Capacitors should be mylar. Half of one 88 mH toroid is shorted our. attenuation of the frequencies higher than about 100 Hz. Also, although i heoretically it shouldn't have been the case, the filter seemed to have too much insertion loss even at the very tow frequencies requiring that the volume control on the transceiver be run wide open. The answer was to build a good low pass filter from LC elements. Building such a filter at the high impedance levels...

Regulated Oscillator Screen For The

As a group, amateurs that still operate from anyone else. The one exception seems to be in their loyalty to the old Airplane anchor. Since I joined the ART-13 fraternity only two years ago, I am not as sensitive as some of the members of long standing. Nevertheless, 1 was incensed recently when I heard a well-known ART-13 XYL accused of frequency drift. When the same thing happened to me a few days later, 1 realized that something had to be done. The Collins ART-13 oscillator, as many of you...

Thdxx

6-Element Super Thunderbird DX Superior Performance TriBander Impressive coverage 10-15-20 meters. Separate, improved Hy-Q traps for each band SWR less than 1.5 1 on all bands. Takes maximum legal power, up to 1 kw AM, 2 kw PEP. Exclusive Beta Match. Factory pre-tuned. Feeds with 52 ohm coax. 3-Element Super Thunderbird Popular TriBand Beam Improved Outstanding performance 10-15-20 meters at reasonable cost. Separate, matched Hy-Q traps for each band. Exclusive Beta Match for tapered impedance,...

Write For Brochure

Ready to operate SSTV monitor with built-in cassette tape recorder SBE SCANVISION is conservative reliable-has picture-proved circuitry is all solid slate except for scope tube in monitor and the videocon camera pickup tube. Equipment fully meets all accepted SSTV standards. Now a high quality slow-scan monitor so complete that the non-engineer radio amateur can connect it to his receiver and start enjoying SSTV in minutes The pleasure and excitement potential of SSTV can best be realized when...

Mic

Incoming signal to produce the 455 kHz i-f. There is provision to seLect up to nine receive and transmit crystal frequencies, The transmitter consists of the triode section of a 6AW8 as an overtone crystal oscillator followed by the pentode section as an rf amplifier- The microphone output is amplified by the 12AX7 and modulates the pentode section of the 6AW8 thru the 6AQ5. Note that no antenna relay is used. The antenna is connected to both the receiver rf amplifier and transmitter rf output...

Linear Amplifier

Small but powerful, reliable but inexpensive, this amplifier is another top value from Henry Radio. Using two 8874 grounded grid triodes from Eimac, the Tempo 2001 offers a full 2 KW PEP input for SSB operation in an unbelievably compact package total volume is ,8 cu. ft, . The 2001 has a built-in solid state power supply, a built-in antenna relay, and built-in quality to match much more expensive amplifiers. This equipment is totally compatible with the Tempo One as well as most other amateur...

Frequency Counter

Beginning in he May 1972 issue of 75, K20AW presented a very complete series of articles on the construction of a frequency counter with a low frequency 0 20 MHz input and a divide-by-10 pre-scaler capable of extending the upper frequency limit to 300 MHz, The counter appeared to be just what I needed. In fact I wrote to K20AW and he generously forwarded a copy of the circuit board layout in advance of publication of the next article in 73. The counter was built using mostly surplus ICs and...

Expanded Range Line Voltage Meter

An expanded range meter, as you are no doubt aware, magnifies a selected segment of voltages so that readings may be taken with greater accuracy and fluctuations will cover a greater percentage of the meter arc, making them more easily detectable. On a typical VOM, such as the Simpson model 260, 5V on the 250V range covers one scale division with this adaptor the same 5V is spread over 5 divisions, making the reading of one volt simple and ,1V not impossible. The principle involved is quite...

Cavity

One of the greatest and most positive influences on Amateur Radio to date, as activity and commercial sales prove, is 2 meter FM, Repeaters, au to patches, and solid state transceivers have become commonplace in today's headlines and QSOY As the Fraternity's equipment and knowledge advances, it is also common to be affected by the problems of transmitter noise and spurious, receiver desensitization, am intermodulation interference. The purpose of this article is to discuss the causes and cures...

Rcatd Tunnel Diode

Original packaged, each factory marked, with spec sheet. 1 25 fiach 5 5_00 lt Used, look good, with schematic, receiver or transmitter. Frequency range 1.5 to 12 MC. Three bands, VFO or crystal, voice and CW. These sets Collins design, becoming Postage extra on above. MESHNA PO Bx 62 E. Lynn Mass. 01904

Response

Mitters possibly miles away mix within the receiver and a product falls within the receiver's passband. This type of interference is caused by a deficiency in the receiver, not the transmitter. The common cause of transmitter intermod is a surprise to most. Here again, intermodulation products are generated from the mixing of several signals. However, the mixing takes place within the final amplifier stage and involves one or more external signals that enter the transmitter thru its own antenna...

Sunrise Hvwy

Not contribute much selectivity to the receiver or transmitter except at the intended notch. In other words, a band-reject duplexer is a poor choice as a solution for intermod. A circuialor is normally a three port device composed of fcrrite material, magnets, and lengths of transmission line, that functions as a directional rf valve. Referring to Fig. 8a, rf entering port 1 comes out port not port 3. Rf entering port 2 comes out port 3, not port I, etc. An isolator is a circulator with a dummy...

Man

All -segments. MAN lt ail LFJtr und madf by weil-kn.nm West i'-mrtt mfi . Other- h -fleetive H ir type made by OPCOA and LJ-TRO NIX, The Reflective Uar typt1 s nfv low-cost vers lotis i gt t i he MAN'.s except character heiKhil if one Llit blows y01 lose o seftnuent MANV you NOT All reudmir f -to-i numerals, plus letters and decimal. 'Opcoa und Utnmix producTh p n-for-pm replacement- fr gt r MAN-I MAN -i. All V TTL compatible. Hi lew rato op-amp lt TO- Micro power...

Wants To

All types of military electronics equipment and parts, Call collect for cash offer SPACE ELECTRONICS division of MILITARY ELECTRONICS CORP. 76 Br okside Drive, Upper Saddle River New Jersey 07458 201 327-7640 News, The receiver contained thirty lubes on two chassis, had a 40 watt Class A audio amplifier, covered J 5 to 80 MHz in six bands, had two separate amplified age systems, one controlling the two rf amplifiers and the other the four i-f stages, and it had continuously variable selectivity...

Amsat

As of this writing all systems are progressing rapidly on A-O-B construction. The unit is undergoing pre-flight tests and all functions are being checked out. As far as a launch date please listen to the AMSAT netsr especially the one on Mondays at 8 00 EDTon 3855 kHz. There have been a number of visual observations of OSCAR 6, Although the satellite is less than a yard wide it is still possible to see it at certain times as it reflects the sun. Anyone wishing information on how to opti cally...

Meter Radio

Rear panel test jacks for complete Tx and Rx metering and discriminator output for crystal netting input for external tone burst and Touchtone Provision for external speaker. Conservative 10 Watt transmitter with an effective IDC circuit to maintain narrow band deviation 5KHz for today's repeaters Automatic current Control and final protection against high VSWR. Provision for front panel selectable ''Private Channel tone coded squelch CTCSS on both receive and transmit. Triple tuned receiver...

Increase Your Grid Dipper Range

There is general agreement that a grid dip meter is an invaluable piece of amateur test equipment. Why then cofine its use to the usual frequency range of 2 or 3 MHz to perhaps 250 MHz when it is easy to make additional coils to cover the lower ranges. Browsing through the catalogs will quickly convince you that hardly anyone sees fit to supply low frequency coils and when they do it is at additional cost. Why not make your own , All you need is a base that will fit the coil socket of your...

Fm Your G Onset Communicator

Works with Communicator I, II, III, IV and GC-10S FM at a tenth the cost o1 new rig. Frequency adjust for netting uHt In. Built-in tone burst available. Keyed by pustvto-talk switch. 34.50 postpaid U.S.A. Built-in tone burst 10.00. Specify Communicator model and tone-burst frequency. California residents add 5 sales tax, HC-6 U crystal and 9 volt transistor battery not supplied. Send for free descriptive brochure. No modification or rewiring on your Communicator- Just plug Into mike Jack and...

Sawtooth

This simple sawtooth generator could be added to a monitor oscilloscope. These two circuits protect equipment from incorrectly polarized voltage. The single diode keeps the equipment from working when the polarity is, wrong, while the bridge automatically selects the proper polarity. 25 watt modulator uses readily available commercial transformersl Transistors Ql and Q2 are 2N1172, 2N301, 2N1560, SK30Q9, GE-9 or HEP-232 Q3 and Q4 are 2N1 74, 2N278, SK3012, GE-4 or HEP-233,

432 Mhz Amplifier

This is not really a conversion article. There isn't any converting to be done to place this Little gem into operation on any frequency from 400 MHz to 600 MHz. The plug-in unit that we are discussing is the band tuning head from the AN TRC-24 radio transmitter T-302 TRC This plug-in consists of two cavities. The first is a multiplier tripling up from two meters. Output in the 400 MHz to 600 MHz range from the multiplier is fed to the second cavity which is a straight-through power amplifier....

Quick Crystal Checker

What does one do with an unmarked or questionable crystal You could try it in several different types of oscillators to determine if it would oscillate. An all band receiver would tell you the approximate frequency of oscillation if you don't mind tuning carefully and bandswitching a few times. A simpler way is to make the crystal think it is a filter which it is and sweep the spectrum until you find a frequency which the crystal will pass. The usual shop type signal generator and a vtvm or...

He Likes Us

The free and easy style of your magazine is in sharp contrast to some other amateur periodicals which tend to be a little too formal and a bit stuffy. 73 makes for enjoyable reading and since this is still a free country in spite of some recent FCC rulings the readers can disagree with portions of the editorial comments without the possibility of facing a firing squad. I suppose editorials with which all read ers agree would make for very dull reading. Keep blazing away - most of us like it....

Sentry Manufacturing Company

Mp4bjo Qsl

Crystal Park, Chickasha, Oklahoma 73018 By Gus M. Browning, W4BPD Drawer DX Cordova, SC 29039 Two days after I had written about SY5MA being active and handing out Mount Athos contacts I find that he had to all of a sudden flee the country he was actually living in Greece, near the Mount Athos border . It was reaffy a shame too, because he was just about to get rolling over there and i am sure that if things had not went wrong he would have had Mount Athos off the rare country'1 list in a short...

J J

BOX 112r SUCCASUNNA, NJ 07876 Telephone 201-584-6521_ proaching the proportions of a craze. Almost all broadcast receivers covered a portion of the shortwave bands. Indeed, the all wave broadcast receivers were ahead of communications receivers in many areas. Bandswitch-ing, direct calibration, avc and rf amplification were all in common use before then-adopt ion by communications receivers. Several broadcast receivers used double conversion in the early 1930 s, fifteen years before it was...

Uqf

Fere is a SPECIAL DEAL for 6 and 10 meter fans 50 watts output, transistorized receiver. Standby drain is only 2,2 amps. this month only 100.00, with accessories. We stilf have a few 30 watt TPLs left for only 155.00. These are for use in the two meter band. TERMS All items sold as is. Accessories do not include antennas or crystals. If equipment is not as represented, return for exchange within five days of receipt, shipping charges prepaid. Illinois residents add 5 sales tax. DuPage FM, Inc....

List Price

Offset Side Mount Radiation Pattern Reference Dipole 191 VARNEY STREET MANCHESTER NH 03102 TEL. 603 627-1010 LED READOUTS OPCOA SLA 1 Similar to MAN-1. .33 high. 20 rnA per segment. With decimal point. Every one checked - all segments operating. Red - S2.65 each, 6 S15.00 Green - 3,50 Big Readouts, .7 high. Red , , . S5.55 each CLOCK I.C., National MM5314, for 1 2 or 24 hours, 50 or 60 Hz, 4 or 6 digits. Only 11,95 each LED - molded plastic dome shape with leads. .312 inches in diameter. Red -...

S S

GYX-200 slightly modified 200.00 Heath 1 B-101 counter with Vanguard scaler 250.00 DIG I rAL frequency display for your receiver and transmitter. Also works as conventional counter, Detailed plans S3, Communications Electronics Specialties, 814 Orwell Ave., Orlando FL 32809. FA PAPER For Desk-Fax, new not surplus , precut not rolls , 15 per thousand sheets, postpaid worldwide, Bill Johnston, 1808 Pomona, Las Cruces, New Mexico 88001, MOULTRIE AMATEUR RADIO KLlJIi, 13th Annual Hamfest, Wyman...

Jh

IdeaJ for reference oscillator and clock applications, the new crystal oscillator features a choice of complementary sine wave, single-ended MTTL, and complementary MECL outputs from a single IC chip. Designated the MC12060 12560 for operation from 100 kHz to 2.0 MHz, and the MC12061 12561 for the 2.0 to 20.0 MHz range, these devices operate with a fundamental series mode crystal. Stability is excellent, averaging -0.08 parts per million degree centigrade ppm C for the MC12060 12560 -0.16 ppm C...

Self Starting Astable Mv

In the design, R is selected to ensure saturation of the NOR gates used as inverters. I used Motorola MC717P quad two-input NOR gates, although a HEP 573 could be used, C was selected to be 15 xF measured to be 40-60 juF at 6V dc, R was calculated to be dash - R 27K letter space R 47K While NOR gate 2 is at the logic I level, C3 is charging up to approximately VCC VBE When gate 2 goes from the n level to the level, C3 causes NOR gate 3 to go from the 0 level to the level This process of...