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Old May 9th 05, 09:01 PM
Netgeek
 
Posts: n/a
Default Suggestions for VHF-AM Transmitter?

Quite a few weeks ago I posted looking for info on VHF-AM receivers and
received a number of pointers to additional resources and study material.
Thanks
to all who responded and, in particular, to Pete-KE9OA who has been a
tremendous help!

Since then, several protos/learning platforms have been built and I'm
pleased
with the results overall - great learning experience (which continues).

Now I'm interested in the transmit side of the equation and have been poring
over the 'net and other materials/articles trying to get a grip on this
part. So far
I have a block diagram (or "blockhead" diagram more accurately 8-) of a two
stage Mosfet widget using some VHF parts from Mitsubishi. Specifically, I'm
thinking:

20 mW LO input - RD00HVS1 Mosfet - .5W - RD06HVF1 Mosfet = ~6W
output. Modulation either transformerless (or transformer) using something
like
an audio amp (e.g. LM384) after suitable compression/limiting. Net result
that
I'm after is approximately 6W output using a 12-18VDC supply. So...........

If anyone here can point out some worthwhile texts, articles, or similar
designs
that might apply I'd be grateful.

BTW, before this sets off a string of cautionary tales and admonishments
about
newbie nitwits playing with transmitters (especially at Airband
frequencies) - I
can tell you this is a "bench only" project intended to feed a well-grounded
10W/50ohm dummy load ONLY... Are you kidding? I live in Arlington, VA -
within walking distance of some of the world's biggest paranoids. I already
worry
about the splatter created by the blender when the wife and I mix up a batch
of Margueritas! (we try not to simulate any "modulation" by hitting the
"pulse"
button 8-).........

Thanks for any help,
Bill