My 10 tube Zenith (including the eye tube) 'pops' once in a while, sometimes often, but right now not at all. It seems on the weaker stations it pops more, strong stations not much. What can I look for? Thanks

:My 10 tube Zenith (including the eye tube) 'pops' once in a while, sometimes often, but right now not at all. It seems on the weaker stations it pops more, strong stations not much. What can I look for? Thanks

Hi Del,
First try cleaning the tuning cap.

Bill VA

With that description I would initially think of an abrupt / strong spike of AC line inteference. Such as might come from a switch contact or thermal switch action on the AC line or on the other hand,
from within the set with an interelemental tube flashover in the receiver proper, or IF xformer.
As for frequence of occurrence...within minutes...a few times an hour...hourly...every other Thursday
when the wind is out of the South South west...temp is between 58-63 degrees...and a blue '55 Ford pickup passes down the street ?....(bad plug wires !)

Have you tried / thought about this at a time when you could be doing other work adjunct to the set.
Turn on the receiver and tune into a...or the same... station at the same received sig level that you mentioned the trouble before. Get an AM pocket xstr radio and tune into the same station and use its earphone into the ear opposite the one monitoring the big radio. (Or if a headphone...rest the one
on the radio side on the temple just above the ear.)
Now when a big noise burst..."pop" comes along , you can confirm its presence as emanating solely from the subject radio....or BOTH of the units.
There is one deficiency in the respect of the xstr set being isolated from AC line connection, but that potentially lower output might be compensated for, in a manner, by taking the tuning dial and
tuning to a clear spot on the high end of the AM band and cranking the volume to max. That way with this merely being an Am receiver, and not an FM where you would have white noise presence,
you would have a quiet background with only its disruption by static / noise pulses...and that should be more noticable with the volume maxed.
My thoughts.
73's de Edd

The Zenith no longer 'pops'. Did nothing but read the 2 comments. That must have scared it to performing well. And thanks for the information. Best wishes. Del

:The Zenith no longer 'pops'. Did nothing but read the 2 comments. That must have scared it to performing well. And thanks for the information. Best wishes. Del

I had a bad experience with a bandswitch on a Hallicrafters S-40. I cleaned it with Deoxit D5 and turned it on. The radio "popped" intermittently, more and more often, then after only several minutes, the wafer carrying B+ to the mixer plate coils arced over. I had to trade this burned wafer with the antenna coil wafer - which only carries low voltage. I will be more careful to allow a bandswitch to dry out a few days after cleaning it, if it carries B+! Has anyone else had this experience???
Eddie