02-14-2008, 10:50 AM
Last summer I recapped and rewired a 41-280, and it has worked well ever since. I've listened to it a few times a week, often several hours at a time.
I had never noticed any hum, but a couple of days ago, I turned it on and heard the broadcast OK, but underneath there was a noticeable 120 Hz hum. The volume control had no effect. The hum was just as loud with the volume turned all the way down as when it was up.
After a few minutes I turned off the radio, waited five or ten seconds, turned it back on again, and there was no hum at all. I have listened to it almost daily since then and there is still no hum. If I turn the volume all the way down and put my ear next to the speaker, there is no audible hum at all.
Anybody have a theory about what could cause an intermittent hum of this sort?
I had never noticed any hum, but a couple of days ago, I turned it on and heard the broadcast OK, but underneath there was a noticeable 120 Hz hum. The volume control had no effect. The hum was just as loud with the volume turned all the way down as when it was up.
After a few minutes I turned off the radio, waited five or ten seconds, turned it back on again, and there was no hum at all. I have listened to it almost daily since then and there is still no hum. If I turn the volume all the way down and put my ear next to the speaker, there is no audible hum at all.
Anybody have a theory about what could cause an intermittent hum of this sort?
John Honeycutt
