[R-390] BFO Drift?

[Barry]

> You can take a look at the heater/filament voltages to see if you can spot 
> any variation over time.  Another thought along the same lines is to 
> operate the BFO heater on a separate supply.  This is a complicated test 
> though since I seem to recall that the BFO and PTO heaters are in series 
> along with the 3TF7.  Try to isolate which oscillator is doing the dance 
> before getting into his kind of thing.
>
> Regards,
> Jon WA3MVM

Wouldn't it take considerable fluctuation in the AC supply to cause a 
significant shift in these oscillator frequencies?  I ran one from the 12.6V 
supply from the power transformer and bypassed the 3TF7 altogether.  I never 
noticed any drift, etc.

Barry - N4BUQ