04-08-2020, 07:18 PM
I've never tested or replaced transistors for noise. But I've only repaired a few HiFis and usually dried out caps. I'd not have thought of checking a portable radio unless it seemed unusually noisy. Most of my commercial service work was on AV monitors / Multistandard TVs, Industrial / Medical / security and budget studio camera as well as various VTRs/VCRs such as Umatic, EIAJ, N1500, N1700 and early Betamax and VHS. Then it was Apple, RM, BBC, Pet, IBM etc in my own company, though mostly the ex Chubb guy did servicing and I was designing Z80 controllers and analogue controllers; it was the last time I did hand layout. From the next job it was all CAD, from 1983.
