196-23 Jamaica Ave., Mollis, NY 11423
Eduardo Noguera M, HKINL, EE. RE, Post Office Box Aereo 774, Barranquilla, Columbia South America, Antennas, transmission lines, past experience in tropical radio communications and maintenance, HF antennas, AM, transmitters and receivers, VHF antennas, test equipment and general amateur problems. Can answer questions in Spanish or English*
D. E. Hausman, VE3BUE, 54 Waiter Street, Kitchener, Ontario, Canada. Would like primarily to help Canadians get their licenses. Would be able to help with Novice transmitters and receivers.
Frank M. Dick WA9JWL, 921 Isabella Dr., Ander* son, fndiana 46013, Will answer queries on RTTYr HF antennas, VHF antennas, VHF converters, semiconductor mobile, general, and microwave.
Gary De Palma, WA2GCV/9, P.O, Box 1205, Evanston, HI., 60204, Help with AMr Novice transmitters and receivers, VHF converters, semiconductors, test equipment, digital techniques and all general ham questions,
Arthur J, Prutiman K3DTL, 31 Maplewood, Dallas, Pennsylvania 18612, All phases of ham radio. Can assist with procurement of parts, diagrams, etc,
William G, Welsh W6DDBt 2814 Empire Ave., Burbank, Calif, 9 T 504, Club licensing classes and Novice problems,
Ralph J- (race, Jr„ WAlGEK, 4 Fox Ridge Lane, Avon, Conn, 0600 L Help with Novice transmitters and receivers and novice theory, lota Tau Kappa Radio Fraternity W7YGT Multnomah College, 1022 S.W, Salmon St., Portland, Oregon 97205. This group of radio amateurs will answer any technical questions in the field of electronics,
Ted Cohen W4UMF, BS, MS, PhD, 6631 Wakefield Drive, Apt, 708,. Alexandria, Va, 22307, Am^ teur TV, both conventional and slow scan.
Howard Pyle W70E, 3434—7th Avenue, S,EM Mercer Island, Washington 98040. Novice help.
Richard Tashner WB2TCC, high school student, 163-34 2\ Road, Whitestone, New York [1357, General,
Roger Taylor K9ALD, BSEE, 2811 West Williams, Champaign, Illinois 61820. Antennas, transistors, general,
Michael Bums Jr. K9KQ1, 700 East Virginia Avenue, Peoria, Illinois 61603. AM, SSB, receivers, transmitters, digital techniques, novice help, general.
Jim Jindrick WA9QYC, 801 Florence Avenue, Racine, Wisconsin 53402. Novice transmitters and receivers, general,
John Perhay WA0DGW/WA0RVE, RR #4 Owatonna, Minnesota 55060, AM, SSB, novice trans* mitters and receivers, HF receivers* VHF converters, semiconductors, mobile, product data, general. Has access to full specifications on almost all standard components presently catalogued by American manufacturers,
Ronald King KSOEY, Box 227, APO New York, New York 09240. AM, SSB, novice transmitters and receivers, HF receivers, RTTYr TV, test equipment, general.
Charlie Marnin W8WEM, 31 12 Latimer Road, RFD I, Rock Creek, Ohio 44084. General technical questions,
Michael Winter DJ4GA/W8, MSEE, 718 Plum Street, Miami urg, Oh io 45342. HF antennas, AM, SSB. novice gear, semiconductors,
Paul Gorrell, high school student, P.O. Box 228, Mashpee, Massachusetts 02649, Novice transmitters and receivers, hf equipments, CB to ham gear conversion, Marine to ham gear conversion, Civil Air Patrol Communications, all aspects.
David D. Felt, .WB6ALF, 79 East Highland Ave., Sierra Madre, California 91024. Semiconductors, IC's, television, test equipment; product data.
Robert Scott, 3147 East RoadT Grand Junction, Colorado 81501. Basic electronics, measurements.
Remote Control Relay
Alco's Remote Control Relay is a remote control component that combines a step-down transformer and a sensitive AC relay in a single laminated core that fits in a compact midget size package. It converts a 95125 VAC power source to 30V that can be run through ordinary surface wiring without shocks and hazards.
Simply plug this relay into any outlet, and it provides the actuating voltage to a 110 VA^1 alarm or remote control accessory. It has a 3-way receptacle to select a Normally Open or Normally Closed circuit. The side jack serves as a plug-in for the remote switch or sensor.
Our 28 Design Idea Booklet shows circuits on how to build typical remote control circuits of appliances; machine tools; TV commercial killers; fire, smoke and burglar alarms; garage doors; sprinklers—and other apparatus requiring safe, remote control circuits.
For further information, contact Alco Electronic Products, Inc., P.O. Box 1348, Lawrence, Mass. 01843,
ATV Research announces the availability of its new line of SOLID-STATE MODULES for building your own TV camera (vidicon type) or for updating existing cameras. Through the use of these wired, pre-tested, encapsulated modules building a complete camera can be accomplished in a single evening. No previous TV knowledge or special test equipment is required.
Modules include: (!) Video module, (2) Vertical sweep module, (3) Horizontal sweep module, (4) RF modulated oscillator module and (5) DC-DC HV module.
Using the first four modules, experimenters and constructors can build a complete TV camera less power supply). Power requirements include L2V for modules and focus coiL 6V for vidicon filament and 200 volts for the vidicon control circuitry through the use of the (5) module which amplifies and rectifies the horizontal sweep pulses.
These modules are compact, light weight and economically priced from $10 to $20 per module. Each module comes complete with hook-up instructions.
Write ATV Research, Dakota City, NB, 68731.
Sorenson Electronics Co. introduces a com-pleteline of electronic cabinets for the builder. Constructed of high strength H-34 hardened aluminum alloy, these cabinets can be twisted, dropped, drilled, punched, and still stand up with no distortion or misalignment of panels. Chip proof baked enamel finish in contrasting grays (other colors are available on special order) is applied over alodined surface. Available in just about any size any builder could want at modest cost. A catalog is available on request from Kaylor Electronic Products, 1918 Menalto Avenue, Menlo Park, California 94025.
The life of an editor is fraught with many crises. Virtually upon the eve of my wedding day, I received an antenna in the mail. This was for evaluation and review. It comes from Dusina Enterprises of Melbourne, Florida. I have to admit that I asked for it-
In my term as Editor of 73> I have tried to maintain a high degree of integrity in our advertising. If you look back a year or so, you will find many advertisers in the pages of 73 who no longer appear in the magazine. A
few were voluntary "drop-outs." Most of them just didn't meet my rigid standards for honesty in their ads. After receiving complaints from some readers about false and misleading advertising, I began to scrutinize the ads more carefully. We lost a few good old customers in the process.
When an ad came in from Dusina, I was more than skeptical about their claims. 1 came close to not accepting their ad. I made an agreement that we would run the ad for one month, but I wanted to see the antenna. The antenna arrived on Monday. Tuesday morning dawned, cold and rainy. Being partially editor and partially idiot, I often refer to myself as "Idiotor" of 73. Today I really earned the title. At 10 A.M., I was up the tower at 75 feet tying the center of the "Guerilla" to match my existing dipole. Since the dipole is strictly for 75, and the Guerilla is for 40 and 75, I then spent the next hour and a half cutting another dipole for 40, tying it at the 75 foot level, and tossing rocks at tree limbs to tie up the ends of the whole mess.
I am first of all a woman, I'm also a grandmother (albeit a young one) and have a degree of arthritis in my throwing arm.
By noon I was cold, damp, and tired. I had been up and down the tower four times and had thrown innumerable rocks over numberless branches. I took a martini break and, after checking resonant frequencies on all antennas concerned, started making some on the air tests.
What was I trying to prove? Well, the "Guerilla" is essentially a trapped dipole which claims 50% power gain (2 db) over a conventional dipole. My question was, "How can a dipole have gain over a dipole?"
Now, I pride myself on having an efficient antenna system, I am an incurable QRPer. I never run over 100 watts, so if I am going to communicate, I have to do it with the antennas. I consistently get good reports. I do a lot of operating on the top end of 75 meters and compete with kw stations all the timeSo, I know my 75 meter dipole is good- At 3-999 my SWR is 1:1. At 3,999 the Guerilla showed 2:1 SWR. A station in Washington, D.C. gave the Guerilla 10 db over my antenna, A station in New Jersey gave it 1 S unit over my dipole, and a station in Buffalo (not in a favorable direction) said both were the same. On 40 meters, the resonant point of both dipoles were much closer, and the Guerilla topped my dipole on every report.
1 have not answered the question of how a dipole can have gain over a dipole. For the time, i can only say that the Dusina "Guerilla " does have high efficiency to at least 2 db gain over my conventional dipole.
Basically, the Guerilla is a twin lead folded dipole, fed with twin lead feeders with a built in balun at the transmitter end. The overall length is 120 feet. The feedline is 50 feet- I found it necessary to go to RG58/U coax to reach the shack, but this still looked like 50 ohms at the transmitter. I can only assume the 2 db gain comes from the low loss in the twin lead over a coax feedline of over 100 ft.
The Guerilla comes with green nylon cord, built-in eyelets at the ends of the dipole, and lead weights for throwing over tree limbs. (The rocks were for my 40 meter dipole.) It is lightweight, easy to erect? and works! It is rated to take two kw PEP, The SWR curve is very flat on 40 meters, but has a more pronounced dip at resonance on 75. It is cut for
TOROtD POWER TRANSFORM■ RS THESE ARE NEW AND UNUSED
£ T-2—Thfi lorold waa designed for use In a hybrid F.M+ mobil* unit, u&ing a single ££47 tube in the KP amp. for 30 waits output. Schematic included. 12 VDC prl, uitng 2N1554's or e<iuiFatenir Sec. 500 *olla DC out at 70 watts. Sec. —65 volts DC bias. Sec* «3 1.2 volts AC for filament of 8H47 lube. .Sec "4 C/T feed back windln* for 2N155I S IV thick, 2%* dla 2 fer $5,00 £ T-3—Has a powikted iron core and U built tike a TV fly back transformer, Operates tit about SOO 12VDC FM. using or equivalent* DC output of V/DBLR 475 volts DO watts, C/T feed back winding for 2NH2 s. $2.95 ti 2 for $5.00
Sf P4—105-113'125 V SO cy t>rL @ IIA. 2Q5v @ HA,
P-5 Prl. 117 VAC/12 DC. Sec. 295 VDC fV, DRLHi 85 ma. Sec. Z2 12,G VAC 2,0 A. Ac C-T. winding for Vibrator. Double Half Shell. Wt. lbs. $2.25—2 for UM P*6 Prl. 117 VAC/12 VDC. Sec. 'I 275 VDC (V, I>BLR) ft 150 ma Sec 12.6 VAC C-T. for Vibrator winding wv lbs 12.95 M.
P-7 117 VAC Prl. f^ec, #1 1*5 VAC @ 120 ma Sec, #2 6.3 VAC (5 4A, Double Hair Shell Mail Box Type. SX
P*ft 117 VAC Prl- Sec. * 1 470 (\T. DC out of Brid«e f)60 V 300 ma, Max. Sec. =2 100 VAC 10 ma Bias S«. f!) 12.6 VAC & .75 A, to 6.3 VAC & 6At Half Shell HT 46
P-9 117 VAC Prl Sec. * 1 900 VAC ffi 300 ma. Sec. 10Ö VAC <& 10 ma. Bias. Sec, 12.6 VAC (ffl 2 AMP.
P-J0 117 VAC Prl. Sec. tf 1 000 VAC C.T. & lfiO ma. S*e+ - 2 425 VAC C.T and lap at JOG VAC 10 ma liUs. Sec, 12.6 VAC & 4.5A, Double Shell Mail Box type. Wt.
Output transformers, ail types .59 ee^ts or 9 fer ¡1.50 OT-i translator TO-3 Power Diamond.. Imp. 1j ohms to 3.2 ohms DC Her Tri. .0 ohm. Sec. ,3 ohm. 07-2 Pri imp. 7000 ohm. Sec 1*2 and 5ftfi ohm r^r Phones or 70 To't tire 3 watts, full fhield-d Double Ha'f Rhill, OT-3 Prl, Imp. 5500 ohms Sec, 3.2 ohms. SX1C2 type.
RG-196AU SO ohm Teflon coaxial cable 080 outside diameter silver shielding &. conductor use for Internat wiring, on antenna coupling between stapes, general purpose RF to 400 tiu-piicycles colors brown blue, grey, while blj«Jk. orange S3.00 per 100 ft or per ft
All prices FO B, All weights listed are net, Plra*e allow for packaalnii Please allow enough for postage We will return any extra.
924 Elm St.. Racine, Wis. 53403
LARGEST SELECTION in United States AT LOWEST PRICES—48 hr, delivery
Thousands of frequencies In stock.
Types include HC6/U, HCI3/U. FT-241, FT-243, FT-171, ate.
SEND 10* for catalog with oscillator circuits. Refunded on first order.
2400B Crystal DrtJ Ft. Myers, Fla, 83901
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