AM RF Signal Generation

Jun 28, 2006 22 Replies

OK, thanks very much. The pdf was cramped but quite a bit easier to follow.

There seems to be only two crystals, with inductors in series. Other bandswitched sections seem to be a straight LC oscillator.

Also, there seems to be a varactor in a pi connection with what looks like a variable tuning cap. The varactor lead goes way off to the right - maybe part of a PLL?

So that helped me understand it a bit better. Thanks. Nice to know the schematics are still available. Regards,

Mike Monett

Hello Mike,

Not two, there are four positions. You can pick four 200kHz segments of the 144-148MHz ham band which is usually plenty for SSB plus satellite. Two are shipped as standard and two others you'd have to order if you want them.

AFAIR this radio does not have any PLL. I don't remember what the varicap was for, usually they are there to provide the necessary 1kHz offset between xmit and receive during morse code (CW) transmissions.

From a spectral and phase noise point of view the IC202 was one of the cleanest radios in its time. Probably still is. You could follow it with a big amp and a high gain yagi and not run into trouble with any other hams.

Regards, Joerg http://www.analogconsultants.com

So that's why those positions are empty. Makes sense.

Regards,

Mike Monett

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