12-30-2015, 02:20 PM
I just finished recapping & replacing some out of tolorance resistors. E caps also replaced. I need help with how to verify if the 5Y4 rectifier tube is working. When powered up all I get is a very low hum out of speaker that has no change with volume control, basically nothing. Buy the way it played before I worked on it 
with tube in socket I get 262v. ac and 261v. ac on each plate to chassis ground. But the filament I only get .oo5 dc to chassis ground. From center tap of transformer to rectifier filament I get 183v/dc neg.
I'm asking this because I have no plate voltage on any of the tubes
I ohmed out the power trans. and got 580/ohms plate to plate
276/ohms & 302 ohms on each side to center tap.
The 5Y4 tube filament of power tranny ohms out at .003.
All the tubes light and have been tested. I changed 5Y4 with another known good one.
Speaker feild coil ohms out at 1800 ohms and output transformer at 450 ohms.
I have been over the wiring at least 10 times and find nothing in error. Here is a schematic of the radio.
http://www.nostalgiaair.org/pagesbymodel...024982.pdf
Any help with this would be greatly appreciated.
with tube in socket I get 262v. ac and 261v. ac on each plate to chassis ground. But the filament I only get .oo5 dc to chassis ground. From center tap of transformer to rectifier filament I get 183v/dc neg.
I'm asking this because I have no plate voltage on any of the tubes
I ohmed out the power trans. and got 580/ohms plate to plate
276/ohms & 302 ohms on each side to center tap.
The 5Y4 tube filament of power tranny ohms out at .003.
All the tubes light and have been tested. I changed 5Y4 with another known good one.
Speaker feild coil ohms out at 1800 ohms and output transformer at 450 ohms.
I have been over the wiring at least 10 times and find nothing in error. Here is a schematic of the radio.
http://www.nostalgiaair.org/pagesbymodel...024982.pdf
Any help with this would be greatly appreciated.
