[AMRadio] FSK mods for Valiant


Byron Lichtenwalner w3wkr at verizon.net
Mon Jul 4 14:09:43 EDT 2005


John
I has been a while since I used a loop and keyed a tube trqnsmitter, but
here is whaqt I remember.
VFO keyers in typical CW/AM rigs are single band devices since the shift
multiplies as the VFO output multiples to the next up band.
Since the keyer is adding (or subtracting) capacitnce to the VFO circuit ,
any change if VFO frequency will also change the shift frequency.

I am not a fan of AFSK.  But if you can generate a carrier with the SSB
adapter, think about keying the BFO  in that section.  Then a single keyer
will give you shift over the entire range, and side band selection will give
you the choice of mark/space signalling.

Byron, W3WKR




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