10-16-2017, 04:07 PM
I'm of two schools of thought on that:
If a radio is AC/DC and not too expensive, I'll just boot it up to see where I'm at. (I'll usually use a dim bulb test at least, or else there's the thrill of wondering if any magic smoke will come out.) A transformer set that's been playing, I'll listen to it before I start, because it'll tell me right away if the transformers and coils are all good if I can get some kind of signal all the way to the speaker, and I'll know how bad the filters are.
In this case, the guy had it plugged in and on display in the living room, so he just switched it on.
If it's a garage find, or clearly one that hasn't had attention in a while, I'll ohm out all the transformers and coils, test all the tubes, and fire it up at 12 volts to see if the transformer outputs are a 10th of what they should be. Still, I'll always try to at least do a listen before I start work. It's risky sometimes, but at least you have an idea what symptoms were present before you started working on it. Had I noticed the B+ issue before I started, that might have saved me some time. But of course it was intermittent, so what can you do?
If I already know the radio's working (or at least trying very hard to work), then I may take some shortcuts, but clearly it burned me this time because of the 3 tubes.
I got into tube radios because intermittent computer problems are not enough aggravation in my daily life, so I need more things to fix in my spare time! ;-)
If a radio is AC/DC and not too expensive, I'll just boot it up to see where I'm at. (I'll usually use a dim bulb test at least, or else there's the thrill of wondering if any magic smoke will come out.) A transformer set that's been playing, I'll listen to it before I start, because it'll tell me right away if the transformers and coils are all good if I can get some kind of signal all the way to the speaker, and I'll know how bad the filters are.
In this case, the guy had it plugged in and on display in the living room, so he just switched it on.
If it's a garage find, or clearly one that hasn't had attention in a while, I'll ohm out all the transformers and coils, test all the tubes, and fire it up at 12 volts to see if the transformer outputs are a 10th of what they should be. Still, I'll always try to at least do a listen before I start work. It's risky sometimes, but at least you have an idea what symptoms were present before you started working on it. Had I noticed the B+ issue before I started, that might have saved me some time. But of course it was intermittent, so what can you do?
If I already know the radio's working (or at least trying very hard to work), then I may take some shortcuts, but clearly it burned me this time because of the 3 tubes.
I got into tube radios because intermittent computer problems are not enough aggravation in my daily life, so I need more things to fix in my spare time! ;-)
"Why, the tubes alone are worth more than that!" (Heard at every swap meet. Gets me every time!)
Philcos: 90, 70, 71B, 610, 37-61 40-81, 46-420 Code 121 to name a few.
Plus enough Zeniths, Atwater Kents and others to trip over!
