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

Studio263 · 12th Jan 2016, 2:12 pm

The 1612 was a lovely set, the best of the BRC portables. Neat and pretty too, shame that most of them went for export (note the German markings on the PCB silkscreen). The way that the line driver transformer has been wired makes it easy to fit an NPN line output transistor if you want to, the only difficulties are mechanical (e.g. dealing with the transistor body which is no longer grounded). From memory, these used an AU113 as well.

I've never seen a 1590 without the links; I had an Ultra one with red resist that was pretty early, that certainly had them. They used a Ge AD149 for the regulator as well, in the late 1951s (14") I think that that was changed to Si too. A PNP Ge line output transistor could have been considered out of date by 1970, there would have been better choices by then (unless you were Rigonda!). Even the Sony TV9-306UB (late 1965) has a Si NPN transistor here.

12th Jan 2016, 2:12 pm	#30
Studio263 Octode Join Date: Apr 2007 Location: Hampshire, UK. Posts: 1,576	Re: PYE TT1 - First Transistor Portable UK TV The 1612 was a lovely set, the best of the BRC portables. Neat and pretty too, shame that most of them went for export (note the German markings on the PCB silkscreen). The way that the line driver transformer has been wired makes it easy to fit an NPN line output transistor if you want to, the only difficulties are mechanical (e.g. dealing with the transistor body which is no longer grounded). From memory, these used an AU113 as well. I've never seen a 1590 without the links; I had an Ultra one with red resist that was pretty early, that certainly had them. They used a Ge AD149 for the regulator as well, in the late 1951s (14") I think that that was changed to Si too. A PNP Ge line output transistor could have been considered out of date by 1970, there would have been better choices by then (unless you were Rigonda!). Even the Sony TV9-306UB (late 1965) has a Si NPN transistor here.