UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - PYE TT1

FERNSEH · 6th Jan 2016, 4:40 pm

I thought it would be a good idea to have another look at this set. Well it seems because the voltage regulator was missing, the DC supply to the receiver was too high. The set was designed to operate from 10 volts. Something like 15 volts was being supplied to the receiver. You'll recall the NiCad battery serves as the voltage regulator.
The first casualty seems to be one of the 2G221 line output transistors, it has a emitter to collector leak, the meter reading is 75 ohms.
The set is full of OC171 transistors so there could be a likelihood that many of them will have the metal whisker fault.
This not going to be an easy restoration. What's more it's a difficult chassis to work on.

DFWB.

6th Jan 2016, 4:40 pm	#19
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: PYE TT1 - First Transistor Portable UK TV I thought it would be a good idea to have another look at this set. Well it seems because the voltage regulator was missing, the DC supply to the receiver was too high. The set was designed to operate from 10 volts. Something like 15 volts was being supplied to the receiver. You'll recall the NiCad battery serves as the voltage regulator. The first casualty seems to be one of the 2G221 line output transistors, it has a emitter to collector leak, the meter reading is 75 ohms. The set is full of OC171 transistors so there could be a likelihood that many of them will have the metal whisker fault. This not going to be an easy restoration. What's more it's a difficult chassis to work on. DFWB.