[AMRadio] Sentnel Radio Co. Musicair Console, Help Needed

[Jim Wilhite]

I don't know what type of tube tester you have Ron, but if you have one 
that you can lock in the "test" position, do that.  Your symptoms are of 
a tube that is warming to a point then quitting.  You really need a 
tester that is transconductance rather than emission, but if you can 
lock it in test you may be able to find it.  The reading will test high 
then fade out.

If you don't have one that does that, then replace your tubes one at a 
time in the set until you find the one(s) that maybe be the problem. 
Use an oven glove to remove the hot tubes, one at a time, until you see. 
The problem may be underneath the chassis, but lets start with the easy 
part first.

73

Jim/W5JO


----- Original Message ----- 

>I am in the process of restoring a Musicair Console Radio. Replaed 
>several defective capacitors.
> The radio plays now, but after warming up for 2-3 minutes, it fades 
> out, no audio.
>
> Turn it off, let it rest a few minutes and turn it on. It plays and 
> then does the same thing again.
>
> Anyone have some advice on what to check? Can a coupling capacitor do 
> this? AGC tube?
> Or, is it a tube? All the tubes check out fine on a tube tester. 
> Something warms up and changes.
> Any help will be appreciated. Thanks, Ron 100% DisAmerVet
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