Quote:
Originally Posted by Tubejunke
I would say the biggest thing that was going on there was that I had the transformer wired wrong in that I had the entire heater network including rectifier wired on a single tap. I couldn't understand why heater voltage measurements were a bit over 7 volts. That number may be skewed as I was using a slightly reduced voltage.
Later I noticed a pair of wires that had heat shrink on them with no label and for giggles put my VOM on them and found that it was a 6v tap with small conductors. So I decided that they would naturally be for the single heater of the 6X5. As far as the other pair I was using goes, I just moved the large conductor that was marked 6.3 or something like that to the "input" of the heater network and bam, I had 6.3 everywhere that I should.
As far as caps go, there was only one 47mfd as I think a 40 is what the schematic calls for, but the rectifier is of different specs, so all of that is likely different. Seems like my Silvertone with a 6X5 has a 16 and an 8mfd (maybe). EVERY paper cap was a resistor. Not on the verge or any variation of a bad cap. They were petrified. I added a 10mfd cap to the filter network and pulled all but a tiny bit of hum out. So far, so good. It runs cool and strong. Some heat after say 30 min, but that's normal. Thanks so much for the great help. I'm glad you came in to say hi!
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That transformer configuration wasn't shown on the schematic, but it was listed on the parts list as an alternate. The chassis, I removed it from has the first audio tube, a 7X7 heater was using this center tapped winding, probably to minimize hum. I sealed it off because it seemed to only be good for one 300ma tube.
It's always a little harder to subsitute an important part like a power transformer and it does require a little trial and error.
