07-05-2015, 11:47 AM
I've been working, off and on, for a couple years on Grand Mom's old 41-280. Replaced all the paper caps; discovered that the speaker winding for the power front end was open and replaced the speaker with a matching one purchased from a forum member here; discovered that the audio output transformer was bad and replaced that, but still couldn't get sound.
A friend with more tube electronics experience than I (my EE schooling had moved on to transistor theory when I got there) recently checked all the tubes, and discovered that the radio can be manually tuned in the push button mode, but the oscillator doesn't output in the other three band selection positions.
So currently I have a few AM stations programmed to the push buttons and it's working fine for that. It's producing wonderfully rich sound for a single-speaker AM radio! But without dial-tuning I can't repeat the joy I experienced as a kid, scanning across the shortwave bands and picking up who-knows-what overseas stations.
It's frustrating to have the radio so close to restored (electronically... still some cabinetry work to do) and I am stuck for ideas. Any suggestions from the forum on what to test, or to probe for, or even what to shotgun replace, to remedy this problem?
Mark Lipford.
A friend with more tube electronics experience than I (my EE schooling had moved on to transistor theory when I got there) recently checked all the tubes, and discovered that the radio can be manually tuned in the push button mode, but the oscillator doesn't output in the other three band selection positions.
So currently I have a few AM stations programmed to the push buttons and it's working fine for that. It's producing wonderfully rich sound for a single-speaker AM radio! But without dial-tuning I can't repeat the joy I experienced as a kid, scanning across the shortwave bands and picking up who-knows-what overseas stations.
It's frustrating to have the radio so close to restored (electronically... still some cabinetry work to do) and I am stuck for ideas. Any suggestions from the forum on what to test, or to probe for, or even what to shotgun replace, to remedy this problem?
Mark Lipford.
