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Old 01-12-2017, 11:47 AM
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Electronic M Electronic M is offline
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Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 14,762
If you want to test them before resto work. I recommend using a variac (variable voltage auto transformer), turn the set on with the variac feeding the set to output 10-25V Increase voltage to the set in 5V increments every 5-20min until you hit 120V or the lytics get warm/hot, or smoke or arcing noises occur...Warm lytics, or things like smoke and tubes red-plating are bad signs, and you should stop supplying power to the set if those occur.

Some tube heaters should start to glow around 40-60V, if a set is going to produce a raster (lit screen) it should do so by 85-100V...Sound will likely occur somewhere over 65V.
Rocking the tuner between channels and or playing with the volume knob should produce crackle in the speaker.
Loud hum is a sign of the lytics going open and or shorted.

In my experience ~85% sets from before the ~1958-62 transition from paper caps to film dielectric caps tend to be incapable of producing a raster/nearly dead as found, and about 75% after the transition are still working as found.

Odds of those sets working as is are low. Sets usually don't sit in a store room like that unless they broke and were taken out of service. So in addition to replacing the parts that die with time (capacitors), you will probably also have the problems that took those sets out ~50 years ago to deal with...Unless they originally died of cap problems.
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