[R-390] The radio machine...

[Nick England]

You can combine both R-390 and precision oscillator interests - several
models of Navy transmitters have a VFO that uses a Collins PTO with a
motor-driven AFC capacitor to lock it to an internal or external frequency
standard. About 3 orders of magnitude better stability than a stock PTO
with the internal standard (Bliley 100kc crystal/oven).
http://www.navy-radio.com/xmtrs/frt5/O91-operation.JPG

No reason you couldn't have a receiver with this scheme but I don't know of
one offhand. Maybe I'll hook up my VFO to an R-390A some day....it'll only
add another 29 tubes.....
http://www.navy-radio.com/xmtrs/frt5/o91-104.jpg

Cheers,
Nick England K4NYW
www.navy-radio.com

On Fri, Apr 15, 2016 at 3:50 PM, Norm n3ykf <normanlizeth at gmail.com> wrote:

> It started with the idea of precision oscillators. Think R-390A.
> Crystal controlled, fully tracking, final IF variable (PTO). What
> makes something like that work? Took 3 blue stripers and made one good
> unit. Still have parts for one more. The WHY of how it worked
> fascinated me.
>
>