[Milsurplus] BC-474 versions

[David Stinson]

Re: BC-474 tips
One I forgot, and an important one:
Don't ground the B- of the receiver 90 V supply.
Like many battery sets, the audio output bias is derived from floating B-.
The audio output transformer won't survive a moment with it grounded.
I own two and have worked on half a dozen.
With one exception, someone grounded the B- and blew open
the audio output (they do the same thing to Japanese battery
receivers, and just about every other battery set).
A Command Set output transformer will substitute as
a temporary "fix," with a small reduction in volume.
It will just fit in the case, once you remove the dead tranny.

Oh yes- if you get audio "howling" 
at high volume settings, install a tube shield on the audio output.