[admin]

No worries.

The entire thread has been about restoration, so it really belongs here.

[Brad Winder]

Dick,
I consulted Ray Bintliff's book "Philco Condensers and More" and I cannot find the part number listed for the substitute tone control that seems to be in your set. But, many of the tone controls had multiple part numbers listed as direct substitutes.

Can you tell me if the wiper in your control contacts each terminal individually? Or does the wiper contact two terminals at once? That information can help deduce what capacitors would be in your control...

[madsowry]

Brad, the wiper on this tone control contacts all the other contacts individually.  Also the 2 caps that were in this control have numbers on them, number 56 and 63.  I don't know if these were manufacturing nos. or what they are.
Thanks

Dick

[Brad Winder]

Based on other controls with three contacts and two capacitors, 0.01 uF and 0.02 uF would be good values to use.

The original "4 point tone control" used one 0.015 uF and two 0.01 uF caps, plus one blank contact.

I believe those numbers on the caps were strictly for the manufacturing process.

[madsowry]

Thanks Brad.  I'm going to use those two values which I also think is correct from what little I have been able to find.  Kind of strange that the pt.# can't be found anywhere.  I thought this chassis had been untouched but it has a mershon electrolytic can and a Philco aluminum electrolytic can.  The aluminum can has a sticker on it with the pt.# 7556.  So I checked the Phorum parts lists and found that can was used in 1936.  So I think that can was changed on this radio at some early time in it's life.  Thanks again

Dick

[Brad Winder]

It's possible that the part number exists somewhere, but either didn't make its way onto a list compiled/published by Philco, or hasn't been added to a "modern" list like the Phorum.

Also possible that the part used was short-lived; with all the part numbers that are listed as "superseded by" under some of the tone controls, it wouldn’t surprise me that the part number on yours was a short-lived replacement variation.

[madsowry]

Well with all the other things in this chassis that aren't on the schematic and parts list, this must have been the one they experimented on and played with and probably a later version.  
I have the tone control rebuilt but I didn't fill up the cap area with anything in case I have to change them.  I have them isolated from each other.  When I know if it is working I'll fill the can with hot glue.
Thanks for all your help Brad.

Dick

[madsowry]

Here's a question for anyone who has or had a model 15.  Does the tone control do much when switched in?  My 15 is a little unique, maybe.  As far as I can make out the tone control and the tone control circuit on this radio is from a model 19 code 128.  It has an extra bakelite block with the caps for bass that go to the 2nd audio tube 37 and the input trans.
Part11-Philco Wiring Diagrams Vol. 1.pdf (philcoradio.com)
It works but very slightly changes the tone.  I clipped in some more capacitance on the caps inside the tone control and got hardly any change in tone.  I'm just wondering if the original tone control and circuit made a bigger difference in tone.
Thanks for any input.

Dick