PHILCO 38-15 Mod notes? - Printable Version

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+--- Thread: PHILCO 38-15 Mod notes? (/showthread.php?tid=8027)

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RE: PHILCO 38-15 Mod notes? - Bradley Rush - 12-02-2013

Thx all

So putting a 78 tube in and I will replace the 1M's and the 250K.
Can always put it back. If I have any issue's. I want to see the difference with the schematic and this Mod any way.

I will let the Phorum know.

Just want to confirm what I am reading.

Thx

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RE: PHILCO 38-15 Mod notes? - Mondial - 12-02-2013

Take a look at this schematic:

http://www.nostalgiaair.org/PagesByModel/233/M0013233.pdf

It appears that the AVC circuit of this 38-10 model is wired the same way as what you now have (with 6Q7G instead of the 75, but same function). You can see the two 1 Meg resistors connected to the diode plate, with the mica cap connected to the IF coil.

The 250K triode plate load resistor should really not make any difference in operation.

Check the operation of the AVC, because if you remove the 1 Meg resistors, you may disable the AVC function.

Let us know what you find.

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RE: PHILCO 38-15 Mod notes? - Bradley Rush - 12-07-2013

Yes

I was just going to rewire per schematic.

I see that whom ever did this mod might of had some problems in the circuit.

So went to this to clean up his AVC.

I have ordered all the resistors.

I will just replace the ones there first see what I get on the radio.

Thank you Very much Mondial this does very clearly show what was done to the 38-15 I have.

Any issues I'll be back

Brad

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