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philco 37-650 low audio issue
#4

Hi Jim, the output transformer is original and riveted to the speaker. Hi Morzh, the plate voltages to the output tubes and rest of the radio are ok and stable only the plate voltage to the 6K5 drops to around 90 volts and when it does the volume gradually drops. I originally replaced the plate load resistor to the 6K5 with a 100K resistor and it is ok so far. The 6K5 is good and I subbed it out with 2 others I have in my tube stock still the same issue. I removed the 6K5 and the voltage at the plate pin on the socket went to 265 volts so there are no shorts around the 6K5 socket. I have checked every connection from the 6K5 to the 6F6 output stage and find no wiring errors. I noticed I can remove one of the 6F6 tubes and have no audio but pull the other one and still have audio but it is lower--is this normal for this oddball output circuit?  Thanks,  Ken


Messages In This Thread
philco 37-650 low audio issue - by Kenradio - 04-30-2017, 06:40 AM
RE: philco 37-650 low audio issue - by morzh - 04-30-2017, 10:18 AM
RE: philco 37-650 low audio issue - by Kenradio - 04-30-2017, 02:12 PM



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