[ARC5] Programmable Oscillators - Redux

[David Stinson]

Good info, Peter and thank you!
Going to have to try that AD9851.

The step-attenuator in my service monitor is on the blink,
so I measured the sensitivity of my BC-942 (R-28)
with the simple programmable oscillator / UNUN
http://home.netcom.com/~arc5/ItWorks2.jpg
on 122.8 MC by comparing it to a modern scanner.
Very surprised to report only 2-3 dB of difference.
Impressive for a 70-year-old tube front end.

I have two oscillators coming that, rather than set
for the "regular" Fxtal = (Fop - 6.9) / 24 
are set for the fourth harmonic: Fosc = (Fop-6.9) / 6

18.608 (118.55 MC)
22.887 (144.22 MC)

For those of you with a lot of misc. xtals,
Fxtal = (Fop - 6.9) /12 also works in the R-28,
But there don't seem to be a lot of  9 MC xtals 
around.  The high 7 MC and 8 MC ones 
will get you the local FM stations.  Actually don't 
sound too bad if you happen to have a xtal on 
the "right" part of the FM signal's slope.
I've got a handful of crystals for local stations.
I may have the only "FM Tuner" in the country 
that runs off a dynamotor!

73 DE Dave AB5S