87 USA


Home Up 3035 W/3D USA 3045 3089PH 4019U 5088 5088 w/EM34 87 USA

 

 

This is a table top AM/FM Three tube Hot chassis radio.  And it sounds surprisingly robust.  It is a hot chassis radio that uses an Autotransformer to get the higher B+ of 210 volts to the ECL82 class A output tube.  There is a surprising amount of bass.  Let's take a look.....

 

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I had a strange Dim Bulb test.  It acted as though there was a short...

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...Tapping the chassis cleared, restored and cleared the fault.  The I found.....

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...this red wire.  I think this B+ red wire was intermittently shorting to ground.  The mark is where the wire was stuck to the above bare wire that is ground.  

 

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AM/FM tuner chassis.

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The tone control was frozen.  It would not turn.  A bit of heat and lube  permitted sluggish movement.  But still no good.  

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So it comes out for surgery.  

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OK it is open.  The tone wiper on left.  

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No too bad.  A good cleaning with denatured alcohol.  

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There it is.  Grease that has turned into some terrible baking experiment. 

The control was cleaned with Alcohol.  A dab new grease and then reassembled.  

Works great now! 

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Replacing the selenium with silicon.  A 1N4007 and a 68ohm dropping resistor. 

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As received. 

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As received. 

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As received. 

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First buffed side.   1) Brasso 2) #3 Novus 3) #2 Novus and 4) #1 Novus.

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I started with a test on the bottom in that "inconspicuous" area.

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After a little more than an hour the deep scratches although less noticeable are still there.  

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So as not to remove too much material I stopped here.  

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Shown on the "Burn-in" shelf.  

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