Quote:
Originally Posted by zeno
A few notes:
1) dampers were a big problem on these so double check it. Original
was a single diode, first update was two diodes in // newest was
a kind of squarish one.
2) double breaker has a resistor in the cathode. If it gets hot it pops. The breaker has to have its case soldered to the chassis to work. Just
jump it out for now.
3) Never had a bad FBT in one. The big problems were the 5GH8's & other
low level tubes. Also the tube sockets suck.
4) check the hoz hold pot for tin whiskers.
73 Zeno 
LFOD ! |
I did not think about the tin whisker possibility, but with that damn metal can around the pots, it can happen it guess.
But I still and very curious as to why he got 140v on the plate cap at one point, then 258v later on, something strange going on there.
But I do agree, ground the cathode for now, get that out of the picture.