UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Phil G4SPZ · 11th Jan 2019, 12:51 pm

I have been advising Forum member Trevor (‘Humpty Dumpty’) via several PMs how to repair various faults on his newly-acquired receiver. So far, he has successfully replaced the volume control and the receiver is working, but with constant hum. He has established that the HT at the anode of the output valve is only about 40 volts instead of the normal 200 volts. I have now asked Trevor to measure the valve’s cathode voltage to see whether the low HT is being caused by excessive current draw through the output valve or simply by a faulty reservoir capacitor.

I have suggested starting a new thread here to enable others to contribute and/or benefit as the repair process proceeds.

Phil

11th Jan 2019, 12:51 pm	#1
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Trio 9R59D receiver I have been advising Forum member Trevor (‘Humpty Dumpty’) via several PMs how to repair various faults on his newly-acquired receiver. So far, he has successfully replaced the volume control and the receiver is working, but with constant hum. He has established that the HT at the anode of the output valve is only about 40 volts instead of the normal 200 volts. I have now asked Trevor to measure the valve’s cathode voltage to see whether the low HT is being caused by excessive current draw through the output valve or simply by a faulty reservoir capacitor. I have suggested starting a new thread here to enable others to contribute and/or benefit as the repair process proceeds. Phil __________________ Phil Optimist [n]: One who is not in possession of the full facts