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

TonyDuell · 5th Dec 2017, 6:21 am

Sounds like a high resistance connection somewhere between the 4V winding on the transformer and the valve socket. With the valve removed, your meter draws a very small current so the high resistance connection doesn't drop much voltage, you measure the 4V. With the valve in place, the current drawn by the filament causes a voltage drop across te bad connection.

With the UU6 removed and the radio unplugged from the mains what resistance do you measure between pins 1 and 8 of the UU6's socket?

5th Dec 2017, 6:21 am	#46
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Murphy A188C repair. Sounds like a high resistance connection somewhere between the 4V winding on the transformer and the valve socket. With the valve removed, your meter draws a very small current so the high resistance connection doesn't drop much voltage, you measure the 4V. With the valve in place, the current drawn by the filament causes a voltage drop across te bad connection. With the UU6 removed and the radio unplugged from the mains what resistance do you measure between pins 1 and 8 of the UU6's socket?