Re: prog rock ge mastr exec ii


Bob M.
 

I'm working on a similar project, but in my case it's an old Motorola Compa-Station (Motrac-based) on 10m and it uses phase modulation after the crystal, so a ProgRock should be a good substitute for a signal in the 7-10 MHz range. This station uses channel elements. I plan on removing the crystals and feeding the ProgRock into the channel element, using it as a buffer stage. I may need more gain and possibly some filtering to turn the square waves into something more sinusoidal (crystal-like).

I plan on using bank switching by connecting the active-low PTT signal in the station (through a diode) to the Bank Select 0 input. That way I can have just one output active at a time, or at least disable the TX output from the ProgRock.

I initially installed the supplied crystal just to make sure the ProgRock worked. I then installed the Fox 27 MHz TCXO and after adjusting the reference register, I got its 10 MHz output to within 1 Hz. I plan on installing the ProgRock into a small aluminum box and stuffing it with pink fiberglass insulation. In my case, a drift of a few Hz at 10 MHz will only result in a drift of maybe 10 Hz at 30 MHz, and that's definitely close enough for me.

Bob M.

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