Ocy

Ment thoroughly and to learn how to work efficiently in the field of amateur radio, special care is dedicated to educating future radio amateurs in ham spirit, to ensure that they will ultimately become true ambassadors for peace amongst all the nations of the world. That is one of the reasons that we have on our programme of examinations several questions concerning the international amateur radio movement, its organization, etc. That is, briefly, what I wished to say about the education of...

M Solid State

The basic design for this 28 MHz, one watt, solid state transmitter, was developed on 50 MHz. By the time I had it working, the band had gone dead. So 1 shifted it to 28 MHz. With a tew minor changes, it will work on either band, using the same transistors and suitable inductances. There are three unconventional features about the design, one being the neutralized buffer stage, because on 50 MHz I found if necessary to neutralize both buffer and finai. The neutralization is not to prevent...

Part

As the last part of our FM synthesizer series, this month we cover the actual construction of the unit. Most of the details are pretty well covered by the layout drawings, and so the text itself will cover only some items. When looking at the drawings, make sure to read the fine print in the notes which may explain some questions. The main body of the synthesizer fits on the p.c. board, which is shown in Fig. 13. It is a little smaller than 7 x 9, and is etched on only one side to make it...

In Memorium Wkxm

HATRY ELECTRONICS Hartford, Connecticut transistors must have a high collector The main chassis has to be drilled to mount the tube bases and modulation transformer or a subchassis can be mounted in a suitable place. The transistor circuitry is built on a piece of laminate board. Its construction is not critical as long as care is taken to avoid picking up rf. The leads to the input socket and gain control are made up of shielded cable grounded at one end. The capacitor at the input to the...

Send For Free Fl

Box J CARMICHAEL, CA 95608 (916) 966-2111 DVM adapter for a frequency counter. This circuits consists of a 200 k-ohm volt input low pass active filter stage, a polarity detector and automatic switcher indicator, and a voltage-to-frequency converter. The output frequency is adjusted so that 50 vofts input will give a frequency of 5000 out. The three 25K pots are used for offset balancing. Any counter capable of readout to Hz is fine. Circuit by W0MLD. Light dimmer which will handle up to...

Scanvision

Now unexcelled picture performance with exclusive-feature equipment of highest quality in which the most advanced SSTV techniques are expertly applied SBE Scanvision. Here, carefully considered design has simplified operation to the point where the non-engineer radio amateur can have his SBE Scanvision monitor connected and start enjoying slow scan in just a matter of minutes. Most of the many hundreds of SS TV'ers now active on the air agree that the full excitement and enjoyment of SSTV can...

T

Tl 2 Amidon 15 16 in. diam. toroids. Primary 25T No. 22 Formvar. Four secondaries 5T No. 22 Formvar each. T2 2 airwound windings, 1ST each, No. 14 Formvar, 1 3 16 in. diam. These windings are paralleled and shaped into a doughnut 3'A in. diam. CI 450 pF broadcast variable. C2 through 6 - A (IF, 100V. C7 -450 pF wide spaced variable. C8 - .01 UF, 500V (vary for best coupling). Ql, Q2, Q3 Q4 - TRW PT4526 or similar. Rl, R3, R5 - 7 to 10il, 2 to 5W wirewound R2, R4....

Sig

HA,L provides a complete line of components, semi-conductors, and IC's to fill practically any construction need. Send 24c to cover postage for catalog with info and photos on all HAL products available. *Above prices do not include shipping costs. Please add 75C on parts orders, 2.00 on larger kits. Shipping via UPS whenever possible therefore, street address required. HAL COMMUNICATIONS CORP., Box 365 L . Urbana, Illinois 61801 NEW FROM HAL TOP QUALITY RVD-1002 RTTY VIDEO DISPLAY UNIT....

Kultra

The 4K ULTRA is specifically designed for the most demanding commercial and military operation for SSB, CW, FSK or AM. The amplifier features general coverage operation from 3.0 to 30 MHz. Using the magnificent new Eimac 8877 grounded grid triodes, vacuum tune and load condensers, and a vacuum antenna relay, the 4K ULTRA represents the last word in rugged, reliable, linear high power RF amplification. 100 watts drive delivers 4000 watts PEP input. This amplifier can be supplied modified for...

Tdp

TOUCHTONE* DECODER AND CONTROL PACKAGE, ALL FEATURES OF TDP1 EXCEPT YOUR CHOICE OF ANY 6 CARDS, AND 2 TOUCHTONE PADS. THIS UNIT WIRED TO YOUR SPECS ADD RADIOS AND YOU HAVE AN INSTAHT REPEATER 250 ALL OF OUR PRODUCTS UTILIZE THE LATEST STATE-OF-THE-ART DESIGNS, AND AS TECHNOLOGICAL ADVANCES OCCUR THEY WILL 3 INCORPORATED IN ALL NEW DES1GHS, INSURING YOU. OUR CUSTOMER, DF AN UP-TO-DATE DEVICE. NEW ITEMS COMING SOON DIGITAL FREQUENCY SYNTHESIZERS UHF PREAMP 2 METER ) JJO HHz TRANSCEIVERS CRYSTAL...

Wholesale

Will open, close or reverse your garage door. Opens, closes and locks your garage door from inside your car. Light turns on as door opens or closes Individually packed in carton 36 x 10 * 10. Shipping weight 47 lbs. Radio control operates on high frequency over 200 megacycles. Combination of RF and modulation frequencies make available many hundreds of individually coded controls to assure best security. d> -r i nr Transmitter only (with mounting clip) available when additional transmitters...

POWER

For many years there has been a need for increased rf power from transistor amplifiers to replace the output tubes in exciters. Cost, efficiency, distortion, power output, reliability, and stability from temperature changes have prevented the use of transistors in hybrid equipment. The obvious advantages of this design will not be discussed in this article, as the purpose is to disclose a method of generating higher rf power from small transistors. A -though the cost of transistors is greater...

Freck Radio

38 Biltmore Ave Asheville NC 28801 704-254-9551 Crystal Controlled CONVERTERS for DX, FM ATV, Space and other uses. Extremely sensitive and free from spurious responses. With A.C. power supply. Choice of 1-F many in stock. Upgrade your station to JANEL. All postpaid. Write for full details. Also pre-amps. Ask about our OSCAR special 435 MHz converters. P.O. Box 112 was laid out using Rubylith film and rub-on numbers. A negative of this was then made using 3M reversing film. From the negative a...

Navy Tcs Transmitter

Just arrived This collector's item is now available in new condition 1.5 to 12 Mc. CW and AM. 50 watt CW. Ideal for a raft of multi-purpose uses. Designed by Collins Radio. Brand new A Columbia special 75.00 COLUMBIA SLASHES TEST TEST EQUIPMENT PRICES TEK., H.P., G.R. ETC. World's largest storehouse of meters, signal generators, scopes, etc. All popular models. Immediate delivery This compact unit can be used with most Ham Receivers after conversion. Complete with conversion info and schematic....

Using ICS

Just about every kit-type sweep generator on the market starts life out at around 3 or 4 MHz and ends up at 200 MHz or so. This always made analysis or display of 456 kHz i-f amplifier response characteristics a tedious step-by-step plotting procedure or required time out to rig up a temporary gimmick to do the job. No more. The sweep generator to be described here will do the job with ease and precision. Even if you do not intend to duplicate the instrument, you may find parts of it useful for...

Gregory Electronics Corp

J. 07662 BfeSsifcsSSS Phone (201) 489-9000 n nt T sensitive, and will require the two tables to be closer together. Plug the antenna cable into the detector jack No. 1, and the other end into the dipole jack. Tune the detector to 432, and you should then have current showing, if the antennas are only a few feet apart to start. As soon as possible after positioning and tuning up a dipole, reflector, and director, set up at least a three-element beam to use as the...

New Hf Balun

Radiation from the coax it improves antenna radiation pattern, reduces noise on receive, and helps prevent TVI, BCI, and rf feedback within the station. The Balun transformer is wound on a large ferrite toroid core and handles a full kilowatt power from 1.7 to 30 MHz. The transformer is enclosed in a white plastic housing and is completely encapsu lated to prevent moisture from entering. All hardware is stainless steel. Eye bolts on the sides allow the Balun to replace the center insulator of...

Standard Amateur Fm Equipment

Solid stale, 2 wait, 5 channel, hand held transceiver. Solid stale, 2 wait, 5 channel, hand held transceiver. DIGIPET 160 Frequency Counter v 1000 Hz - 160 MHz 05 microvolt sensitivity 349.95 ppd USA NEW SOLID STATE 2M REPEATER SC-ARPT-1 Complete packaged repeater designed or today's popular 2M FM band, i 2 vdc Idea for new system or emergency portable operation. ALSO IN STOCK REGENCY, CUSHCRAFT, HY-GAIN Modify your Gladding 25 with our Coincidence Detector t t t Complete G-10 epoxy board wired...

Typical Performance Specifications

Transmitter output into 50 ohms 100 MW 8.1 v Frequency Stability 0.0025 -35 C to 55 C , nom. freq. ref. FM Noise 45 dB below 3.3 KHz. deviation 1000 Hz. Audio Response 3dB of 6dB octave pre-emphasis over 300-3000 Hz Crystal Multiplication 18X-trimmer for fine freq. adj. included. Complete receivers for 10, 6, or 2 meters Fantastic performers

Xyr

13130 Yukon, Hawthorne, Ca. 90250 213 679-9022 Wot all the facts on the mysterious Long Island tower were ever known. Some believe that it was intended to transmit at low frequencies, shaking the earth to send signals to distances then believed impossible. Tesla foresaw a complete modern type of service, but never stated how large an area he intended to cover. But, he called it the World Wide Wireless System Wot all the facts on the mysterious Long Island tower were ever known. Some believe...

Tempo I Cl

Frequency Range 146-148 MHz Same general specifications as CL 220 RF Power Output 10 Watts or 3 Watts. Output Impedance 50 ohms unbalanced. Sensitivity 0.5 microvolts nominal for 20 db quieting. Spurious amp Image Attenuation 70 db below desired signal threshold sensitivity. Adjacent Channel Selectivity 15 KHz channels 70 db attenuation of adjacent channels. 1 Type of Receiver Dual conversion superheterodyne. Audio Ouiput 2 Watts minimum w internal speaker at less than 10 distortion destroyed...

The Mark Iii Electronic Keyer

The Mark III electronic keyer Fig. 1 is the end result of a joint cooperative effort by its designer Wes Hay ward W7Z0I, and myself. Design improvements were worked out by W7ZO in response to my requests for improvements in the original keyer circuit' , for fixed station operation. The Mark HI keyer uses two additional transistors Q4 and Q5 , which replace one set of DPST relay contacts formerly required in the original circuit. The addition of three Fairchild 2N3564 NPN-type transistors used...

O

CX7A - Deluxe integrated station 2395 Still top of the Line even greater quality and reliability than ever before CX-10 - Integrated station 1795 Single VFO, P S-10 required, optional built-in Keyer C R-1200 State-of-the-Art Receiver 1095 Single VFO, J.F. Shift, blanker, high sensitivity selectivity CT-1500 State-of-the-Art transmitter 1450 Single VFO, 300 watts, P S-10 required CR-1500 Special Application Receiver 1650 dual VFO's EV-10 - External VFO for CX-10 225 CX-2X Two meter Transverter...

Battery

LI - FVrite Loupstick - Philmore FF15 packaged as wt oi 3 sizes C9 - Sub-mmialure variable capacilor - Philmore 19G3G - 3B5 pF max. T1 - Midget Audio Transformsr. 10M i 8i - Archer 273-1380 RadiD Shack Ins.l SPKR - 2 PM Speaker. 8 . 0.1 watt - Philmore TS28 LI - FVrite Loupstick - Philmore FF15 packaged as wt oi 3 sizes C9 - Sub-mmialure variable capacilor - Philmore 19G3G - 3B5 pF max. T1 - Midget Audio Transformsr. 10M i 8i - Archer 273-1380 RadiD Shack Ins.l SPKR - 2 PM Speaker. 8 . 0.1 watt...

Ssb On

Recently, after a fruitless evening of calling CQ on 43 2, I decided it was time more hams were encouraged to use this interesting band. Most people think that 50 miles on 432 is real DX, That's just not true. Although my best DX this past year was only 415 miles, many hams cover distances as great as 700 miles some claim more. SSB is now starting to come into greater use, and does show its worth on 43 2, so I decided to put together a complete working unit. This unit is a modified version of a...

Pocket Calculator

This 1 the kit you haw been waiting tar So compact it actually fits in a shirt pocket 3-13 16 x 4-5 8 x 1-1 4 . It performs every function you would expect in a desk calculator, including constant and chain operation, artd full floating decimal. The unit is powered by self contained batteries, and uses S digit LED displays. The calculations are performed by a single 40 pin integrated circuit, which can truly be called large scale integration LSI . As a stirdent, engineer, salesman, accountant....

An Rtty Selcal With Ttl Logic

The Selcal or automatic character recognizer has become a fairly popular accessory in stations equipped for RTTY operation. Particularly so in the case of people interested in automatic use of their printer while they are not actually in the station. With this equipment installed, a receiver may be left on continuously monitoring a frequency for RTTY signals, and the printer will start up and print a message only after the call letters of the station or other start-up coded sequence are...

In Yugoslavia

Organized by the radio clubs or their branches, and sometimes also by public schools, universities, factories, or other appropriate institutions in which sufficient candidates can be found to justify the preparation of such a course. The SRJ has established a special plan for these courses, laying down a certain minimum knowledge required to become a radio operator within a club or private amateur radio station. Under Yugoslav law, the SRJ has the right and duty to form examination boards, the...

Qq

And the wire winding is 4 turns f gt io. 20 enameled. The tubes for T3 are 1.375 long and the wire winding is 3 turns No. 20 enameled. Large ferrite beads are slipped over the length of each brass tube before final assembly. T2 is mounted between the same end plates as T3 but consists of a twisted pair of No. 18 enameled wire run through both stacks of ferrite beads once no tubing used . The photo graphs give details on the transformer construction. This amplifier is perfect for an...

Um On Tree

Dimensions of a Double Delta antenna which was tested. Coaxial transmission line can also be used as explained in the test. Fig. 3. Dimensions of a Double Delta antenna which was tested. Coaxial transmission line can also be used as explained in the test. 27 ft in order to allow simple erection of the antenna via a rope support around a high tree trunk. The antenna was constructed of ordinary stranded antenna wire with egg insulators attached to wooden stakes, driven in the ground, used...

Poly

BOX. 42A, LYNNFIELD.MASS. 01940 Price 2 per 25 words for non-commercial ads. SJO per 25 words for business ventures. Wo display ads or agency discount. Include your check with order. Price 2 per 25 words for non-commercial ads. SJO per 25 words for business ventures. Wo display ads or agency discount. Include your check with order. Deadline for ads is the 1st of the month two months prior to publication. For example January 1 st is the deadline for The March issue which will be mailed on...

Philco Transistor Am Radio Chassis

Covin 355 Kcs to 1500 Km Broadcast band Originally design tor portable phono systems, and tape cassettes One of the most versatile AM Radio ind muiti-purpose amplifiers we have seen at Poly Paks famous Economy price. Measures only 4 V2 x 3 s 2 high. With tuning capacitor, IF circuitry, loopstick, ant., volume control with switch, AC and. phono-mike jncks, Separate switch for changing Irom AM radio to amplifier. Uses either HOY plug-in. adapter not with unit and...

From the Worlds Number One Manufacturer of Amplifiers

The biggest, broadest, finest line of amateur and The 2K-ULTRA The 2K l TEMPO TPL Ampliliers The TEMPO 2001 The 2K-ULTRA The 2K l TEMPO TPL Ampliliers The TEMPO 2001 2K-4 . . . THE WORKHORSE The 2K-4 linear amplifier offers engineering, construction and features second to none, and at a price that makes it the best amplifier value ever offered to the amateur. Constructed with a ruggedness guaranteed to provide a long life of reliable service, its heavy duty components allow it to loaf along...

Electronics

305 Airport Road Oceansfde, CA 92054 Phone 714 757-7525 2 Meter FM Economy is available with the SWAN FM-2X . . . everything you need for AC or DC operation is included at one low price, just hook up your antenna and you're on the air. Frequency coverage extends from 144 to 148 mHz over 12 channels. Crystals are installed for Channel 1 to transmit and receive on 146.94 mHz Channel 2 to transmit on 146.34 and receive on 146,94 mHz Channel 3 to transmit on 146.34 and receive on 146.76 mHz. 10...

Engineers

Injection is fed into the cathode through a tapped rf choke resonant between 382 and 432 MHz. Care must be exercised not to resonate this coil at 432 MHz, for if you do, output instability will result. The tap, placement of which is critical, provides an impedance match and expends the rf driving power efficiently for proper loading of the cathode. The vr tube for the 6939 screens is an OA2. The bias is set for 35 mA standing plate current with no drive. The simplest method of obtaining the W...

R

Watt amplifier .01 jlf disc 56 pf dipped mica Unelco 1000 pf .1 fit disc 25 if 35V .Q01 jf disc 1.5 ph molded 56 1 1 2W carbon 1il 1 2 W carbon See Text TRW PT5740 can be as compact as the rest of an SSB rig. Take a look at Fig. 1 and see how simple it is to get 15 watts SSB out of a transistor. With careful placement everything would probably take up less space than an average filament transformer. Figure 2 is a 25 watt amplifier using two PT5740's push-pull class AB. It will operate anywhere...

Info

Grounded base xstr amplifier. applied without a load, the transistor in most cases wilt be destroyed due to the voltages developed in the high Q circuit. Figure 2 can be compared to the grounded grid tube operation. This circuit is quite stable but requires more drive than the first circuit. For this reason, it was not used in the new design. Figure 3 is the grounded collector and has the following advantages First, in the use of non-isolated heatsinks from the case, the collector is in...

Ampere Ac Arc Welder

Vintage Welder Schematic

The welder, although not an essential item in the hamshack, is a welcome addition to the experimenter's supply of tools. It serves such areas as tower construction and general repair. The high cost of an adequate commercial welder and my native curiosity started me on this project which has seen a year and several different transformer designs pass. The present unit is the culmination of my experimentation. It is a continuously variable unit that will weld to 185 ac amperes maximum. The duty...

Ten Meter Cubical Quad

'Just a note to let you know that as a Novice, your 3-E1. 15 Beam got me K.I Section Winner and New England Division Leader in Novice Round-up. See June QST, p. 57 for picture of ant,, below . Tnx for a line working piece of gear. 73s, Jay, WA1JFG-' Compare the performance, value, and price of the following beams and you will see that ' this offer is unprecedented ill radio history Each beam is brand new full size .16' of tubing for each 20 meter element for instance absolutely complete...

Integrated Circuit Trf Receiver

455 Discriminator

An inexpensive Integrated Circuit has been available for some time which contains the complete gain, detection and age functions required in 455 kHz AM i-f strips, Intended for use with ceramic filters and an outboard front-end converter, the LM372 is presently designed into the AM section of several commercial AM FM high fidelity receivers, where it replaces the hand-assembled i-f can type strip formerly used. The LM372 is. in reality, a much broader-band device than its 455 kHz applications...

Tv

TTL Seicai integrated circuit pin connec is present only when the desired character has been entered in SRI. In addition, the second, third and fourth flip-flops in the chain are fed with information containing the state of the previous flip-flop. If it is not at true level, the following flip-flop cannot change state. What this means is that for normal RTTY inputs containing text, the four flip-flops are continuously being reset by the clocks from MSI. However, for example, any time a...

Counters

TUCKER 60 1 KM 60 MHz TRANSISTOR 5 NIX E NEW HP 521A DC to 120KH ,4 DtGIT NEON - - HP 521C DC to 20 KHl. 5 DIGIT NEON HP 52lG DC to gt MHz, 5 DIGIT NEON HP 6220. 10 Hi to 130 KHz. 5 DIGIT NEON HP 623B 10 Hi to 1.2 MHz, 6 Di G IT NEON . HP 624B OC to 10 MHz. 3 D GIT NEOfc HP 624C DC tO 10 MHz. 3 DIGIT NIXIE HP 624D DC TO 10 MHi, 8 DIGIT NEON HP 626A 0 M j to 110MHz CONVERTER UNIT- HP5 5E 110 MMj to 220 MHz CONVERTER UNIT HP 62SC 100 MHz to 510 MHz CONVERTER UNIT HP 540A tO MHz to 5 GHz TRANSFER...

First Bermuda Repeater

The first two meter repeater on Bermuda is going on 34 94. This will be VP90DA and, after getting checked out, will be set up on the lighthouse. It will cover the entire island. Remember to bring your handy-talkies when you go to Bermuda. Geting a license is simplicity you get in touch with VP9EP, the Wireless Inspector in the phone book and he will get you set up. You'll get your own call portabfe VP9. A visit to Bermuda is about 800 more fun when you get to meet and talk with the local...

Ic Socket Panel

INTERDYNE Wire-wrap Panels Wired 19.SO Has 198 Wire-wrap 14 Pin IC sockets. Has pin 7 connected to ground and pin 14 to power p one. May be used as-is or sockets removed for breadboard nq. THAT'S 10y a SOCKET_____ 1. Micro Switch 163W3-8 Hal Effect Solid State Keyboard. Has 16 individual dual outputs 12, s0 Z. Controls Research 11 Key Reed Switch Keyboard 6.00 3. ControLs Research i5 Key Reed Switch Keyboard 7.QQ A. NEW Toueh-Fene Pad Keysets 24.S5

Tester

.1 portable impedance bridge, crystal calibrator, field strength meter, etc. When was the last time you hung on the tower or in a tree trying to couple your dip-meter with one hand to the bridge which was in the other hand while hanging on with the third hand - not to mention the problem of how to turn the Fig. la. Circuit board layout. iJleter 0-50jUA from maii order listed as light meter movement 365 pF variable - from old transistor radio socket amp coil form allied radio D1S99 454...

New Leader Digital Multiplier

The LDM-850, a digital readout ac dc multimeter that measures voltage, current and resistance in 25 ranges, is now being offered by Leader instruments Corp., Long Island City NY 11101. It offers a dual slope operating mode and has a maximum input voltage of 1,000V dc and 350V ac with 10MS2 input impedance. Sensitivity ranges from 100 V to IV with current from 0.2 mA to '1,000 mA, ac or dc. The Model LDM-850 measures 10 x 7 x 3'A and weighs 10 lbs priced at 299.50.

Kvh

A high power linear amplifier capable of covering any specified 20 MHz segment in the 130 to 170 MHz range. Delivers 2000 watts continuous duty . . . trouble free performance. Please write for price and full specifications. HENRY ELECTRONICS' PGB INDUSTRIAL POWER GENERATORS FOR PLASMA GENERATION RF power generators, with buiit-in exciters, used to supply high power radio frequency for commercial, industrial and scientific uses. Frequency 13.56 MHz Frequency stability 2KHz Continuous Duty Power...

The Double Delta Antenna

Double Delta Antenna

The Double Delta antenna is basically a combination of a vertical half rhombic design A , frequently called a delta antenna, and a turnstile antenna B made from folded dipole antennas. Fig. 1. The Double Delta antenna is basically a combination of a vertical half rhombic design A , frequently called a delta antenna, and a turnstile antenna B made from folded dipole antennas. Double Delta, was not simply pulled out of the hat but is based upon two well established and proven antenna...

Repeat It The Long

Iet me be quick to say that this is not ijust another of the many fine articles on . FM or repeaters, as the title may suggest. The availability and low cost of used commercial FM equipment in recent years has brought many hams into the use of channel-type and repeater communications. I would like to introduce you to what I feel might produce results far beyond the present dream of linking the four corners of the U.S. via FM repeaters. Moonbounce is the name of our game, via a system of...

Antennas

FROM THE WORLD'S LEADING MANUFACTURER OF VHF UHF COMMUNICATION ANTENNAS A FM RINGO 3.75 db GAIN The most popular high performance, half-wave FM antenna. Gives peak gain, and efficiency, instant assembly and installation. AR-2 100 walls 135-175 MHz 12.50 AR-25 500 waits 135-175 MHz 17.50 AR-6 100 waits 50-54 MHz 18.50 B 4 POLE A four dipol array with mounting booms and coax harness 52 ohm feed up to 9 db gain. AFM-4D 1000 watts 146-148 MHz 42.50 AFM-24D 1000 watts 220-225 MHz 40.50 AFM-44D 1000...

Kit Amp 200 Watt Sanken

SANKEN HYBRID AUDIO AMPLIFIER MODULES We have made a fortunate purchase of Sanken Audio Amplifier Hybrid Modules, I With these you can build I your own audio amplifiers at less than the price of diserete components. Just add a power supply, and a i to act as a heat sink. Brand new units, in original boxea, guaranteed by B and F, Sanken and die Sanken U.S. distributor, Available in three sizes -10 watts RMS watts music power . 25 watts RMS 50 watts M.P. and 50 watts RMS LOO watts M.P. per...

Allband Verticals

Twenty meters is murder these days. Let's see you make a contact on twenty meter phone with low power So K4KXR switched to twenty, using a V80 antenna and 35 watts AM. Here is a small portion of the stations he worked VE3FAZ, T12FGS, W5K.YJ, W1WOZ, W20DH, WA3DJT, WB2-FCB, W2YHH, VE3F013, WA8CZE, K1SYB, K.2RDJ, K1MVV, K8HGY, K.3UTL, W8QJC, WA2LVE, YS1-MAM, WA8ATS, K2PGS, W2QJP, W4JWJ, K2PSK, WA8CGA, WB2-KWY, W2IWJ, VE3KT. Moral It's the antenna that counts...

Transistor Regenerative Receivers

Transistor Regen Receivers

From time to time, various amateur magazines have had notes on using transistors in regenerative detector circuits. Some time ago, I made a two-transistor receiver, and immediately ran into trouble with the regeneration. The problem was that as the regeneration control was advanced to the point of oscillation, the received frequency was pulled, and stations disappeared as I tried to tune them in. Also, the start of oscillation was very violent, and when the control was backed off. the dropout...

Generators

HP 2O0BR AUDIO OSCILLATOR 20 Mi TO 20 KHE 35.00 HP 200 JR INTERPOLATION OSCILLATOR 6 h w 6 KHz 95.00 HP 200TH TELEMF.TRY OSCILLATOR B0 Hi lo 100 KHz 40.00 HP 202CH AUDIO OSCILLATOR 1 Hi 50 1 00 KHi 75.00 HP 205AG AUDIO OSCILLATOR 20 Hi to 20 KH HP 206 AR AUDIO OSC lt LLATOR 20 Hi to 20 KKjr 250.00 HP 211A SQUARE WAVE GENERATOR 1 Hz to 1 MHz SO.OO HP 2t2AR PULSE GENERATOR 60 Hz TO 5 KHz 25.00 HP 233A CARRIER TEST OSCILLATOR 50 Hi TO 500 KHz 75X0 HP 608D SIGNAL GENERATOR tO MHz to 4.20 MHz...

Capacitive Discharge Ignition System

C-D SYSTEMS has announced a totally new CD ignition system, the MACH II COMPU-SPARK. The unit is designed to permit the length of the spark to be regulated with engine rpm. A very long spark at low rpm aids starting and idle smoothness. A built-in three-position switch permits C-D operation, standard ignition usage or off as an anti-theft feature. The ignition system utilizes only silicon semi-conductor components for reliable operation under extreme temperature conditions. The unit will...

Drafting

Wildman W6MOG Bill Morello Wayne Peeler K4MVW T. M. Graham W8FKW The League.is showing an increased if belated interest in FM and was represented at the recent FM Symposium hosted by 73 by W11CP, who was most helpful with suggestions and . ideas. More on the symposium on page 281 . Mike Frye WB8LBP 640 DauviUe Dr. Dayton OH 45429 From ail the reports I have been receiving, A-O-C is progressing at a good rate. Launch preparations are progressing smoothly and to my knowledge the launch is...

Wjji

1 A Simple Electronic Key, Wes Havward WA6UVR, QSTVec. 1965. For Antenna R.F. Type Coax Switches insist on Barker amp Williamson B. amp W. PROTAX Model 375 Switch up to 6 antennas Single Pole 5 position switch with automatic grounding to give you that added protection from lighting damage. Rear mounted connectors. B. amp W. PROTAX Model 376 Smtch up to 5 antennas Single Pole 5 position switch with the same protection features as above but with side mounted connectors. B. amp W. 595G Switch up...

Sensitivity

Ham Wattmeter

Center strip of vector board is soldered to center post oi SO-239. Other components are mounted at each end of board as shown only one end shoi here . flow between the strip. Each outer strip acts as a pickup element for the SWR meter circuit shown in Fig. 1 . The terminating resistor and diode are soldered to each end of the outer strip as shown in the photo and with minimum excess lead length to the strip. The use of a heat sink on the diode is necessary to prevent damage during...

New Tempo

While several of the manufacturers have been firming up their 220 MHz transceiver designs, Henry Radio has been spurring their Japanese supplier to provide a unit, t looks as if Henry will be the first one to be able to supply the 220 rigs in quantity. Two samples of the New Tempo 220 were checked out at 73 and run through their paces. We must say congratulations to Ted Henry for getting these designed, manufactured and imported. The rig is similar to the two meter FM rigs, but is deluxe all...

New Products

It looks ike solid state has finally hurdled the last barrier toward its conquest of the vacuum tube. TRW has announced that it is manufacturing a new line of RF power transistors designed for HF linear applications. Designated PT5740, PT5741 and PT5742, they will deliver 15, 30 and 60 watts output respectively when powered by a 12 volt source. They are brutes In typical linear installations they will withstand a wide range of bias and temperature conditions. They are impervious to ioad...

MHz Front End Using Fets

Mosfet 3n200

This article describes the design, circuit, and practical working model for the home brewer. One rf, mixer, and channel-crystal L.O. are used. A second similar rf stage may be used as desired. Today's FET The protected and insulated dual gate metallic oxide semiconductor field effect transistor, to spell out just what is inside one of those little tin cans, is shown in symbol form in Fig. 1. This device is good for rf amplification up to 500 MHz, which makes it fine for 146, 220 and 432 MHz....

Buffer

Lumped-line oscillator with tuning provisic MHz oscillator. proximity of conducting surfaces, and mechanical vibration. In the Clapp circuit in particular, the juncture of the inductor and the resonating capacitor is at a very high impedance level and displays very high sensitivity to stray capacitance. Awareness of these matters leads to defensive measures such as rugged construction, shielding, short leads, etc. But would we not have a more desirable situation if built-in immunity...

Scopes

T AI RCHILO 70t DC to 500 KHz ..................................... ..... 195.00 F Al RCHILD 766H 76 08 74-13A DC to 50 MHz DUAL TRACE TRANSISTOR ......... 795.00 HI5 1 152B DC to 10 MHz DUALTRACE . .5195 00 HP 16D USM105 DC 10 15 MHz DUAL TRACE 00 HP 175 A C to 50 MHz DUAL TRACE 696.00 HP 185B BR DC to 1 GHz SAMPLING SCOPE ............................ 295 00 TEK 512 DC lo 2 MHz SINGLE TRACE . .................. 95 00 TEK 51 4AD DC to 10 MHz SINGLE TRACE .......... ....................... 125...

Motorola Tuning Diodes

Silicon voltage variable capacitance diodes in TO-92 plastic case like plastic transistors. Both standard Motorola and HEP numbers are listed devices are same. Capacitance value is typical at 4Vdc. Tuning ratio is approx. 3 1. MV2101 R2500 6.8 pF ............ 1.10 MV2103 R2501 10 pF ............ 1.10 MV2105 R2502 15 pF ............ 1.10 MV2109 R2503 33 pF ............ 1.10 MV2112 R2504 56 pF ............ 1.10 MV2115 R2505 100 pF ............ 1.10 UL900 Buffer .........................80 UL914...

Meters

HPiOOCn VTVW lOH to4MHi1MV 3 OV ..................... 5 00 HP 4O0C VTVM. 10 Mi To 4 MHz 1 MV to 300V...........................S 25-00 HP 400D VTVM 10 Mi lo 4 MM 1 MV lO 3QOV ..........................S t IS. 00 HP dOOH VTVM 10 Hi to 4 MHi 1 MV to 300V HP 405AR AUTOMATIC DC DVM 3 DiGlT 1 MV to t KV ..................... 126.00 HP 4106 OLD STYLE VTVM- AC-DC AND OHMS ................ ........... 75,00 HP AUA RP MILLO VOLTMETER 10 MV-10V HMS ..................... - S 2 96-00 HP412A OC VTVM 1 MV io...