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Philcol 71 code 125 schematic - Printable Version

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Philcol 71 code 125 schematic - HooiserScootrer - 01-11-2020

Hello.

I searched many sites and chased many threads but have yet to find a schematic for this radio. Does anyone out there know of a source for it?

This radio is very close to a 71 but has a shadow meter (which is open of course). Someone worked on it back in the day and made some mods, it would be helpful to have a schematic to put it back in order.  I fear though that a schematic does not exist, but might as well ask.

Cheers.

Scott

RE: Philcol 71 code 125 schematic - Bill Bacco - 01-11-2020

Not sure if you already saw this or not, but here is an old post that discusses someone else looking for that schematic. Not sure if they ever found one, but maybe you could try to contact them.

https://philcoradio.com/phorum/showthread.php?tid=866

Bill

RE: Philcol 71 code 125 schematic - HooiserScootrer - 01-11-2020

Bill,

I did see that thread but didn't think of contacting the creator, worth a try.

Thanks for chiming in. If I ever find one I'll ensure it's made available on the Phorum.

Scott

RE: Philcol 71 code 125 schematic - Radioroslyn - 01-11-2020

Hi Scott and welcome to the Phorum,

I would roll w/what I've got. You didn't mention if it's a 71B or two spkr console. You can find the shadow meter installation here:  http://www.nostalgiaair.org/pagesbymodel/836/M0013836.pdf  Just redraw the schematic w/it added in. All the other stuff would use the 121 or 221 schematic depending on the # of spkrs. Would verify the IF frequency. Philco used a couple different one around that time period just to be sure.
The worst part of redoing the sm is getting apart and all the wire off the bobbin. Winding isn't hard you just have to be careful.

RE: Philcol 71 code 125 schematic - HooiserScootrer - 01-11-2020

Terry,

Thanks for the link, that's exactly what I needed.  

This is the one speaker version.  The onlyother issues I've found besides the SM being open are open circuits in the primary of the antenna coil and the oscillator cathode coil. Rewinding fun for me.

Cheers,
Scott

RE: Philcol 71 code 125 schematic - Radioroslyn - 01-11-2020

Stock up on 38g wire and 5.00 readers  [Image: https://philcoradio.com/phorum/images/smilies/icon_lol.gif]

RE: Philcol 71 code 125 schematic - HooiserScootrer - 01-15-2020

I was able to repair the antenna primary and rewound the oscillator primary.  On to the SM.  

I see threads calling for 40 AWG magnet wire for the SM.  I have a big roll of 38 AWG. Would the fewer turns from using 38 AWG wire have much effect on the sensitivity of he SM?

Cheers,

Scott

RE: Philcol 71 code 125 schematic - Radioroslyn - 01-15-2020

I used 40 cuz that's what I had on hand. The 40 works out to 1ohm per foot 38 is a little less but who's gonna know once it's rewound??