[Boatanchors] DDS VFO

[Ian Wilson]

Hi Lee,

I used one of the NorCal DDS kits a while ago with some additional
buffering/gain on
the output to drive a 6AG7/1625 MOPA (the 6AG7 could be switched
between operating
as an xtal oscillator or as a buffer stage). Worked nicely except for
"backwave" - fixed
that by using the keying line to turn the DDS on and off.

More recently, I've been experimenting with the Si570 clock chip for a
multiband receiver
LO. This is a much nicer chip than the DDS in some ways: only 8 pins,
easily worked with,
excellent close-in noise. You can find some info on this in the
SoftRock Yahoo group, and
also look at G4OEP's excellent 'Retro' receiver.

I also plan to try Huff-N-Puff stabilization of drifty VFOs (such as
in the 19 Set). But this
is still a 'round tuit'. I think this is a nice combination of old and
slightly newer technology <g>.

73, ian K3IMW