Vhf Ham Radio Handbook

VUillAUDAnin Explains how to make use kinks, transmitters, anT * tennas, equipment v modifications. receiver and moduiator circuits- t etc. The final section ' describes 25 VHF construction projects, including transmitters, vrrtiMtnc receivers, preamps, filters, RF amplifiers, a fie d strength meter, noise generator, and a VFO for all bands. Other chapters cover VHF propagation phenomena and power supply considerations. Written for the ham who takes pride in contributing to the advancement of...

O

VHF amplifier used to measure gain, noise figure and AGC performance of the Fairchild FT0601 MOSFET. For AGC operation, dual-gate MOSFETs have a fauiit-in advantage owing to their separate gatesf especially in the VHF regionT Amplifiers such as this one eliminate cross-modulation distortion, decrease receiver noise and avoid shifting of the receiver's center frequency. Schematic from Fairchild Semiconductor Application Note APP-189.

Hot Off The Press

Order today ONLY 1,50 postpaid 73 Magazine Peterborough NH 03458 1,50 enclosed for one copy of the ATLAS. 10.00 enclosed for 10 copies of the ATLAS (club special). Heavy wires between the shield and the bandswitch help to maintain a solid ground and also serve to add support to the switch, overcome this, put a 20 pF mica between pin 8 of V7 and ground (Fig. 5 L No more oscillator malfunction If you look at the chassis photo, you will notice the corners are darkened. This is from brazing to...

Light Emitting Diodes

S ,68 2 for 51.45 Jumbo. TO-l.fi, 2 lead* fed l.OO 2 for 1.75 703 RF IF, 14 hookups* TO-5 7 IOC Differential Amp*** . . . ED 7 11C Memory, Sense, Amp*** 723A Voltage Regulator (DIP) TVR 2000 Hi.power 723 (DIP) 74 1 C Freq. Comp. 709-** . , . 748C Freq. Adjustable 741***. ) 7 09-709 Dual 709'i (DIP) 741 741 Dual 741's (DIP) 749-749 Stereo Preamp (DIP J AMATEUR*' 400 MC NPN HI-POWER TRANSISTOR TO-60 case. Similar to 2N3G32 t 400 mc, 3 amps, 0 bvcho, 100 Me 23 watts,...

Cleveland Ohio

2 - Eimac 4010 Air Sockets with 2 - 4X150A's on 5x8x2 chassis unused. Shp. wt. 6 lb. . 25 2 - 6161's in a Tuned Line Circuit, 168 to 360 MHz. Shp. wt. 30 lbs 25 P255A Polar Relay - new 1 Mercury Wetted 275B - new 1 Tuning Units TU47-TU50or TU52 - each 95c Topaz Static inverter. Price includes part 30163 1 and 30163 2. 12V dc in - 115V ac 60 Hz out. 1 KW - new packed. Shp. wt. 266 lbs 295 T464 ALT7 or T465 ALT7 - unused. Shp. wt. 100 lbs packed. Each 35

The Gonset Communicator

The Communicator has been the most popular two meter transmitter-receiver of all time. But it is an AM rig and two meters is now almost exclusively F l, Palo mar Engineers' nev. Frequency Modulator puts rhe Communicator on FM without any modification or rewiring. The microphone plugs into the Frequency Modulator. One of the cables coming out of the Modulator plugs into the Communicator's microphone jack and carries the push-to-talk line. A second cable lias the crystal plug which plugs into any...

Lqh

Figr lr The switches show the mechanical equivalent of a typical and gate. f you have read this far, you are seriously interested in building a button box, so let's review the logic elements that are used as building blocks and dispel the aura of mystery that seems to surround these computer circuits, In the discussion of a specific circuit design, it is necessary to define logic levels in terms of voltage. However, when using logic symbols and describing logicai operations, only two conditions...

ZIP

Circle book wanted A B C D E F G H I II III 1 year 6 choose 1 book Life S73 choose any 3 books Highly popular Editors and Engineers books from Sams give amateurs everything they need to know about radio operation and technology. They're authoritative, clear and easy to follow. You'll want them for your library. Famous E& E RADIO HANDBOOK 18th Edition By William I. Orr, W6SAI The completely updated electronics industry standard for engineers, technicians and advanced amateurs. Shows how to...

Editorial By Wayne Green

How many of you who have read the EA1 proposal prefer it to the hobby class license proposal which would still permit amateurs to use the entire One of the EIA manufacturers has announced a massive CB mobile antenna which is guaranteed noi to burn out in CB installations. We would like lo do some picture stories oil the various aspects of amateur radio and would like to have some good illustrations. We would like to have some good up-to-date illustrations fo...

Help Stamp Out Mental Health

From May 14-21, 1972 the Barry College of Further Education Radio Society will be comme mo rating the 75th anniversary of the Bristol Channel Tests undertaken by Marconi and Kemp in May 1897. They will be establishing stations at Flatolm Island GB3BCT and Lavernoek Point GB3MKT . The 1897 tests were significant in that radio signals were transmitted for the first time across water, radio signals were transmitted for the first time between two countries, and these were the last tests carried out...

Marco

Jerome Hurwitz W3EZT, was in iiis Silver Spring shack on Novembei 1-when he heard a distress call from Venezuela The South American was in dire need of a special medicine l or a two-month-old hoy in Caracas. Jerome, an engineer by profession, served as a relay between the State and Defense Departments, Panama, and Caracas. Within 24 hours, the medicine was safely on Lis way to Venezuela from New York. Although this is not the usual substance of ham radio, emergencies such as this do occur and...

Sweep Generator Frequency Vs Varicap Sias

Find some way to vary the dc potential across the varicap repetitively. The schematic diagram is shown in Fig- 3. Q1 is a unijunction transistor relaxation oscillator that generates a sawtooth waveform. I his sawtooth is used to provide the voltage variation across the varicap to provide the sweep function. The potentiometer R1 sets the sweep speed and can adjust the sweep rate from under one sweep per second up to about 50 sweeps per second. The sawtooth from the unijunction is coupled into Q2...

North Tucker Shawnee Ok

Range switch is used, it will be necessary to calibrate for each switch position. Also, if multi-band use is expected, the graphs must be made for each band. Use of the wattmeter now requires only the connection to the transmitter, setting of range switch to the proper level, and reading the graph. The uses of this dummy load-wattmeter are as varied as the amateur mind can devise. One very important use is determining the losses of 50 ohm coax. Measure the output of the transmitter at the...

General Notes On Schematic

ALL FIXED RESISTORS ARE 1 4 WATT COMPOSITION .001 AND 01 CAPACITORS ARE DISC CERAMIC CAPACITORS MARKED SM ARE SILVER MICA Rl AND R2 STANDARD CARBON ELEMENT POTENTIOMETERS C2,C3, AND C4 ARE ELECTROLYTICS-25WVDC OR MORE Inward the front near the center frequency capacitor. The board is supported on I pacers from the top of the minibox. The plug-in coils are wound on plastic coil forms I used pill hollies 7 8 inch in diameter. Winding data is given in the table-After the turns have been adjusted...

Standard Src-146 Transceiver

Standard Src146

Crystal Park, Cfricfcosha, Oklahoma 7301S PHONE 405-224-6780 TWX 910 830-6925 tern is omnidirectional. Radiation from this antenna is vertically polarized. Finally, the quarter-wave antenna is the shortest conductor which can he used as a resonant antenna any shorter structures must he loaded to an electrical quarter-wave in order to achieve resonance. General course, part XI 2Z What is TV 19 J low can it be remedied if the amateur station is at fault If the TV receiver is at fault TVI stands...

Cw

W6TYP 40 and 20 CW, 80, 10 2 fone WA8MCQ - 80, 40, 20, 15, 10 CW, plus one for receivingon 40 CW Current official record holder When trying for this award, remember that the distance in miles one must work is equal to one thousand times the watts input, or one mile per milliwatt input eg,. 2 watts need 2000 miles 5 watts needs 5000 miles, and 250 milliwatts needs 250 miles, I tie QRP C lub also has another award. It is the QRPP-WAS Award, for working stales in steps of 10, 20, 30, 40, 45, and...

Caveat Emptor

Price 2 per 25 words for non commercial ads M per 2 5 words for business ventures. No display ads or ii encydiiiCQunU Include your chtek with order. Deadline for uds is the 1st of the month two months prior to publication, For example January ,1st is ihe deadline for the March issue which will be mailed on the 10th of February. Type copy Phrase and punctuate exactly as you wish it to appear. No all-capital ads. We will be the judge of suitability of ads. Our responsibility for errou extends onI...

Vhf Dummy Load Wattmeter

Wattmeter Parts

The active vhf amateur often has need of some type of dummy load for transmitter checkouts. The units found in amateur applications range from the Bird Termaline units costing around S350, downward through the Waters units, through the Heathkit Can-tenna. to the inexpensive units described in the various amateur publications.1 The Bird and Waters units have the advantage of a direct readout wattmeter movement, whereas the cheaper units are dummy loads only. A dummy ioad serves as a constant...

International Crystal

International Crystal Oscillator

Since I have been building some kind of solid-stale unit such as an i-f amplifier, an rf power stage, a solid-state X-band oscillator, etc., at an average of about one a week, I appreciate an organization that is marketing kits for us amateurs in a sensible fashion. Frankly the prices don't appear sensible, being much, much too low For 2,95 you get a complete crystal oscillator kit 3 60 MHz . You doni get the crystal at that price, but you do get the transistor, and the oscillator works right...

T Gv

POWER SUPPLY USE EITHER TWO 6V BATTERIES Oft A WELL ALTERED AC SUPPLY OF PLUS AND MINUS 6Y WITH MIDPOINT GROUNDED. Fig, 1. A simple diode switch circuit using 6 diodest Suddenly the answer came - simple the diode switch Before I get deluged with a chorus of WhatinhelTs a diode switch , let me explain, A diode switch is a half-dozen diodes such as the IN415 I wired as shown in Fig. 1. Easy, eh Here's what happens J carries the switched output. One side is already grounded and the action of I lie...