[regel_1999]

I bought a Philco 42-327 code 121 as a beginner's project. I've replaced all the caps to include the electrolytics and one tube because the heater element was opened. The trouble is this: I assumed the other tubes in the radio were either replaced properly or original to the radio. What I think now is that the tubes were not the original tubes because 1) all but one are not Philco tubes, and 2) the radio still only produces a loud buzzing sound with 170.3 volts dc at the speaker wires. Furthermore, I think the rubes were replaced with incompatible tubes.

My last problem is that the labels on the top of the tubes are rubbed off and I can't identify 4 of the six tubes. Two of them are supposed to be 7B7's and they don't look anything like each other and neither has a label.

My question is this: Could the incorrect tubes produce a steady loud buzz from the speaker and/or the 170vdc at the speaker terminal? If so, should I just break down and replace all the unknown tubes with new tubes, even though they work? Is there a good way to tell which tubes are which?

Thanks for your help in advance!

-Brandon