[R-390] Cap Confessions

[Tisha Hayes]

I encountered the "you can never have too much capacitor" on a '600 where
those two metal can caps had failed on the power supply. I had gone in and
replaced them with 450 volt electrolytics on the bottom of the radio and
left the old cans in place. That got me poking around with how much B+
ripple there was on the supply of the radio. Using modern replacements I
was able to reduce the B+ ripple to down around 20 mV.
The risk you run is that it is a choke fed supply so on power-up those
capacitors appear like a dead short on the B+. I had left the tube based
rectifiers alone so that kept things from getting too "thunky" (power
transformer noise). If I had solid stated the rectifiers that might be a
really bad thing to do to those chokes.
Just about everything else you can find a replacement for in the '600,
except for the transformer and the chokes and those little fingers in the
turret deck.

-- 
Ms. Tisha Hayes. AA4HA

*""It is not because things are difficult that we dare not venture. It is
because we dare not venture that they are difficult." -Seneca"*