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 philco 1253

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Denver



Join date : 2010-11-25

PostSubject: philco 1253   2010-11-25, 6:56 pm

Well glad you clarified about stupid question& answers . I will fit right in Laughing
Here is a question ? On a philco model 48-1253 , plays great for about 15 minutes then volume starts getting distorted . Would this be a resistor in the audio stage ,or oscillating circuit . It is a tight set to work on , hard to get to some resistors in a space 4" x 15" about 6" deep.
It has a phono also. Sad
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Cliff Jones
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Join date : 2010-11-22

PostSubject: Re: philco 1253   2010-11-28, 1:16 pm

I'm not sure off hand, but it seems to me to be a problem related to heat, resistors may change value or actually open, a capacitor becoming leak or opening, Check your B+ when you first turn on and see if its value changes. If it does then suspects would be filter caps, I don't think the choke would be suspect,unless it is passing too much current, and changing resistance, I would suspect tube sockets need checking and solder joints. To be thorough I would check each tube pin for voltage, write down pin # and readings, then go back and do the same after distortion starts.

The difference between readings should give you a clue. To what stage is affected. There are schematics that list voltages, these could be used for a general guide on what to look for. Hope this helps some.


Last edited by Cliff Jones on 2011-06-03, 11:15 am; edited 1 time in total
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Denver



Join date : 2010-11-25

PostSubject: Re: philco 1253   2010-11-29, 6:26 pm

Have changed all caps . Pretty sure it is a resistor , but was trying too narrow it down a little.
This set is real confined , Just to check some of the resistors i would have too take some of the caps back out. Sad
Thanks Denver.
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Cliff Jones
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Join date : 2010-11-22

PostSubject: Re: philco 1253   2010-11-29, 9:39 pm

Try the grid resistors, just a thought.---> If the bias is not correct it can cut off or distort signals. Tube theory is involved here.
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Denver



Join date : 2010-11-25

PostSubject: Re: philco 1253   2010-12-02, 3:36 pm

Thanks will do. Have a bunch old 78,s like to play them , with out distortion . Very Happy
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Cliff Jones
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PostSubject: Re: philco 1253   2011-06-03, 12:02 pm

Just make sure you clean the needle from dust or you will have distortion, just ask ME! affraid Very Happy

We Have got no stinken distortion!!!!! Laughing

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Cliff Jones
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PostSubject: Re: philco 1253   2011-09-06, 9:07 pm

Did you solve your distortion problem? If so, tell us so we can know. To add to our bank of fixes. Thanks!

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FrankB
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PostSubject: Re: philco 1253   2013-05-20, 6:24 pm

I have seen tubes cause this problem. A bugger to track down at times.
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Cliff Jones
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PostSubject: Re: philco 1253   2013-05-21, 2:42 pm

Sometimes this is where a O'scope helps out! Starting from the final audio stage and working backward.

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copain



Join date : 2011-12-28

PostSubject: Re: philco 1253   2014-01-23, 2:23 pm

Denver: Did you ever solve the problem with your Philco 48-1253?
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