The last bastion of VHF-AM is aircraft, both civilian and military. The
civilian aircraft com band goes from 118-137 MHz. and the military from
somewhere around 225 to 400. Those of us who have spent our lives in this
little corner of the design world are few and far between.
As to those who say that AM is so simple that anybody could do it, I
respectfully disagree. I even DISrespectfully disagree. Trying to
amplitude modulate a synthesized AM radio without having as much FM in the
output as AM is no mean feat. In the old vacuum tube days with crystals for
the synthesizer it isn't all that difficult. However, with digital
synthesis and VCOs that will FM at the drop of a hat, it is far from
trivial. Shielding to the center of the earth and power supplies bypassed
from DC to daylight are the order of the day.
Jim
"Netgeek" wrote in message
...
Still looking for some pointers and/or advice on current AM
transmitter design. There doesn't seem to be much out there
apart from the "pirates" who are building SW transmitters
around 5W or so...(e.g. the "Grenade" QRP transmitters and
similar designs)...
Is AM ("Ancient Modulation") considered dead and therefore
there are no links/publications worth reading?
Bill
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