|
Funny you mention this. I have several Zenith AM/FM radios from around 1950. Among the more expensive sets, I have a couple that are rock solid, needing no re-tuning as they warm up. The others seem to need a touch up once they are warm.
I did notice that there is a capacitor with a negative TC listed in the Sams. I suspect this is not working quite as it should(or the 50 year old tubes are drifting to much) in the ones that need a touchup.
Another thing to remember is that at this time, there were no solid state components(other than selenium rectifiers), so it would have been fairly costly to add AFC to a table radio.
|