[Hallicrafters] SX-42 BFO glitch

[zuu6k at juno.com]

Hi Roy et al;

I just went through this. IIRC the 7A4 is the BFO and the FM tuning meter
amplifier. It receives an input from the discriminator and amplifies it
to drive the meter over the FM tuning part of the scale. It does not do
this at the same time. Since you would not use the BFO while listening to
FM and visa-versa there is no conflict.

73, Ed K6UUZ

> 8) It's not clear to me, but the tube used (a 7A4) is supposed to be 
> both 
> the BFO and the S-meter Amplifier. (A cute trick!)  Shorting out the