Ti^NS NO. 30 EHAM ON L/4" FORM <03 REMOVE TURNS FTOM i SO}
, RftPER /^TUBULAR
Fig. 1. Schematic of the Poor Man's 220 MHz transmitter. Output is 500 mW with 5 W input. This isn't exactly overpowering efficiency, but the transmitter modulates upward and gives excellent local coverage.
able. If a final grid current meter is desired, a 100 pA or 200 \xA meter would be suitable. Those values don't come in the low cost variety, however. Grid current runs near 75 pA.
All components are mounted on an 8 x 12 x 3 aluminum chassis which is later housed in a Bud "Shadow Box. Chassis layout is shown in Fig* 2. A nut is placed between the chassis and front panel on the two switches and the microphone jack to accommodate lite mounting flange. W hen the chassis was installed in the shadow box, spacers had to be used to raise the whole chassis for alignment with the recessed frame. Shields were used on the 12AX7 and the 6GH8, but should not be used on the other tubes.
The layout of the KF section is the only critical part. Keep RF Heads as short as possible and avoid unnecessary kinks in the wire. The parts layout of the RF section lias been used on three transmitters with some small variations. All units produced the same results. One of the units is on a 17 x 5 x 2 chassis which was rack mounted. The original construction (only the RF section) was made on a 5 x 7 x 2 chassis, Such an idea may appeal to anyone with separate power supply and modulator.
There is sufficient room on the chassis to add a receiver, if desired. The modulator could be switched for receiver audio. First thoughts on a receiver are to build a superregenerative type with a broad grounded grid RF stage. A converter, used with a super-het is the best path to take, but a bit large for
5 models to choose from.
By any standard of measurement, the Hy Tower is unquestionably the finest allband vertical antenna system on the market today. Delivers outstanding omnidirectional performance on DX as well as short haul contacts. Takes maximum legal power. Feeds with 52 ohm coax, SWR less than 2:1 on all bands, Posrtive action automatic band sefection ts prodded by unique stub decoupling system that effectively isolates various sections of the antenna so that an electrical Vz wavelength (or odd multiple of a wavelength) exists on all bands. Structurally, the self-sup porting Hy-Tower is built to last a lifetime...withstands 100 MPH gales. If you want the finest, you'll want a Hy Tower Model 18HT $1 39.50 Net
The New Model 18AVQ. A high-performance all-band vertical for under $50.00
You asked for it ,,Hy-Gaiin built it, A high-performance automatic band switching all^band vertical at a modest price. Features individually tuned Hy-Q traps that provide peaked performance on each band. Takes maximum legal power. Feeds with 52 ohm coax. SWR less than 2:1 on all bands. Simple to install on ground or rooftop-■vithstands 100 MPH winds vhen properly guyed. The biggest value all hand vertical available. Model 18AVQ $49.95 Net
Improved successor to Hy-Gain's Model I4AVS...the world's most popular automatic band switching vertical for 10 thru 40 meters. Outstanding omni-directional performance on DX as well as short haul contacts. Features individually tuned Hy-Q traps that provide peaked performance on each band Takes maximum legal power. Feeds <vith 52 ohm coax SWR less than 2:1 on all bands, Easy to install on ground ot rooftop-withstands 100 MPH winds when properly guyed. Terrific for portable as well as permanent applications. Model 14AVQ $29,95 Net
Roof Mounting Kit lor Model I4AVQ -Includes adjustable roof saddle, guy wires, hardware and complete instructions tor installing Model 14RMG $ f 1.95 Net
The New Model 12AVQ for 10, 15, 20 Meters
A new companion antenna to the Model 14AVQ. Outstanding omni directional performance on 10, 15 and 20 meters. Individually tuned Hy-Q tr.ips provide peaked performance on each band, Takes maximum legal power. Feeds with 52 ohm coax. SWR less than 2:) on all bands. Easy to install on ground or rooftop withstands 100 MPH winds when properly guyed. Model 12AVQ _ _ , $21,95 Net
Roof Mounting KM for Model 12AVQ Adjustable root saddle, guy wires, hardware and complete instructions for installing. Model 12RMQ , $9.50 Net
A high performance trapiess vertical for 10 thru 80 meters Junes to any band by simple adjustment ot feed point on base matching inductor I eeds with 52 ohm coax Heavy gauge aluminum construction - mounts on ground, roof or tower. Exceptional portability, Model 18V $1G.95 Net
Available from your Hy-Gain Distributor or Write
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