06-24-2011, 11:28 PM
Hi and Welcome to the Phourm!
Well the Model 87 is a bit different from the '50's table radios. The good thing is electrically it's much simpler. It's a T tuned R radio F frequency set. Basically it amplifies the signal from the antenna through three amplifier stages (the first 3 #26 tubes). The #27 tube turns the amplified rf signal into audio. Next the #26 tube amplifies the audio signal to drive the two #45's in the audio output.
To service this old timer you will need to remove the filters caps and replace them. On this set they are in a metal can full of paper, aluminum foil, and tar. This will require you to remove the can, heat in an oven at 175deg for 20min or so till the tar is soft. Then pull all innards out. Replace with modern film caps. Note the small value like a 1 or 2 mfd. That's the worst of it. The rest is just the small paper caps.
Common problems open rf coils( can be rewound by hand easily) open audio driver transformer(replacement not hard to find). Be careful with the tubes mostly the 45's their expensive!
I had an 87 years ago back in the 70's
Good luck w/it
Terry
Well the Model 87 is a bit different from the '50's table radios. The good thing is electrically it's much simpler. It's a T tuned R radio F frequency set. Basically it amplifies the signal from the antenna through three amplifier stages (the first 3 #26 tubes). The #27 tube turns the amplified rf signal into audio. Next the #26 tube amplifies the audio signal to drive the two #45's in the audio output.
To service this old timer you will need to remove the filters caps and replace them. On this set they are in a metal can full of paper, aluminum foil, and tar. This will require you to remove the can, heat in an oven at 175deg for 20min or so till the tar is soft. Then pull all innards out. Replace with modern film caps. Note the small value like a 1 or 2 mfd. That's the worst of it. The rest is just the small paper caps.
Common problems open rf coils( can be rewound by hand easily) open audio driver transformer(replacement not hard to find). Be careful with the tubes mostly the 45's their expensive!
I had an 87 years ago back in the 70's
Good luck w/it
Terry
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry