static
 

I have a 1928 Eveready console radio. It has been fully recapped and has strong tubes in it. I noticed that there is a continuous crackling static all the time at low volume. If I turn the set up the static can be covered up by the music. If I turn on another tube radio the second radio will not have the static.What do I check ? Thanks, Doug.

I had a radio of similar vintage do that and it was caused by an arcing field coil on the loudspeaker. My coil had an odor to it and the voltage coming out of the power supply would vary as the coil arced. That problem could be caused by almost anything: loose connections, noisy resistors, arcing power transformer, etc.

Could be one of the above causes. But any defective plate resistor in an audio stage can cause the complaint as well. If the volume control has no effect on the volume level of the static then your search can be narrowed to what comes after the volume pot in the circuit path.

When I recap a tube-type anything I also examine all power handling resistors...plate, screen,...whatever, and consider replacing them--especially if they are of the carbon composition type. When they go sour they can produce noise that sounds like an AM radio off station with a bunch of thunderstorms in the vicinity...or noise that sounds like roaring surf at beachside...

Also to be regarded with suspicion are any of the bakelite wafer tube sockets that were in common use in the day. If the tubes involved generated a lot of heat, and darkened the wafers to any degree, the socket became leaky, and such could be determined by wiggling the tubes until a change in the static was heard. Particularly susceptible are output tubes.

I did notice that all I need inorder to get static is the rectifier and one output tube in the set. That would make the resistor thought make a lot of sense. I also wonder if it was the speaker field arcing, would it not eventually quit working altogether? I have played this radio alot.