UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Trio 9R-59D receiver problems.

Phil G4SPZ · 11th Jan 2019, 2:03 pm

I’ve been communicating with Trevor via PMs, which are a bit unwieldy.

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 (pin 5) 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.

Trev, can you now please let us know what make and model of multimeter you are using?

11th Jan 2019, 2:03 pm	#10
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Re: Trio 9R-59D receiver problems. I’ve been communicating with Trevor via PMs, which are a bit unwieldy. 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 (pin 5) 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. Trev, can you now please let us know what make and model of multimeter you are using? __________________ Phil Optimist [n]: One who is not in possession of the full facts Last edited by Phil G4SPZ; 11th Jan 2019 at 2:05 pm. Reason: Update