In article , "HeavyMetal"
writes:

I acquired a BC-348 receiver. The receiver did play. But stopped. It has a
110 volt mod.
I replaced the caps but the rectifier tube is shorted. The tube is a
Raytheon glass tube with shoulders. Ther is no tube mumber on it except
'280' and 026' on thebottom next tot he name.
Anyone have an idea of what tube they used for the mod?
Thanks..

Sounds like an '80.

If you replace the four-pin socket with an octal, or make an adapter, you can
use the much more common 5Y3GT in place of the "280". They're electrically the
same, but 5Y3s are smaller and much less expensive.

TWO IMPORTANT CAUTIONS ON THE BC-348!!

1) The BC-348 uses a rather unique circuit in the last audio, which functions
as both an audio power amplifier and a shunt regulator. Under no circumstances
should the B+ exceed 220 volts! The ideal B+ supply is between 190 and 220
volts.

2) The BC-348 B- (negative high voltage) is *NOT* grounded! It must be kept
isolated from ground in the power supply, unless major modifications are done
to the receiver. The receiver will work, sort of, with B- grounded, but it is
not recommended.

Complete manuals for the various models of the BC-348 are available free for
the download on KG7BZ's excellent website.

73 de Jim, N2EY