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Philco 20A - Electronic Restoration Questions
#16

Got it. Thank you.

- Eric

Philco 20A
Zenith T825
#17

I have no idea what the circular strip of frequency numbers is called nor what it's made out of.

What is the best way to straighten it out and clean it up without damaging the printing?

[Image: https://www.dropbox.com/s/3rfr8p8idtht5p...8.jpg?dl=1]

[Image: https://www.dropbox.com/s/41wlrrebxpkq91...0.jpg?dl=1]

- Eric

Philco 20A
Zenith T825
#18

...actually the 20-A was also sold in the USA as there were some areas (parts of NY state as an example) that still had 25 cycle AC in 1930.

It seems a majority of Canada was on 25 cycle AC early on, but they had areas with 60 cycle AC as well. A Canadian-made Philco will have a metal tag instead of a paper sticker and will plainly state "PHILCO PRODUCTS LTD. TORONTO, CANADA" on it.

--
Ron Ramirez
Ferdinand IN
#19

>I have no idea what the circular strip of frequency numbers is called
It's commonly known as the dial.
Good choice for cleaning is oms (odorless mineral spirits) gently rubbing w/a Qtip. Most Philco dials use water soluble ink so water or soap destroys the printing.
Yours is pretty flat as things go. Remove from set and use a heat gun on low to soften press between two flat objects.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!

Terry
#20

http://www.wjoe.com/

Is a great source and very nice man, a good supporter of the radio hobby.
Paul

Tubetalk1
#21

What was the color of the original power cords for the units?

- Eric

Philco 20A
Zenith T825
#22

Brown cloth covered. 1937 and later have rubber molded cords.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!

Terry
#23

I found a tear in the paper speaker cone and I saw a "how-to" repair online using Elmer's glue & coffee filter paper.

http://www.instructables.com/id/How-to-R...aker-Cone/

And I gave it a shot. It seems to be working well, the sound is coming through just fine. I can paint the repairs if I wanted, but the dried result actually looks less conspicuous than the picture shows:

Fresh repair front
[Image: https://www.dropbox.com/s/iftmpj3ktf0bj0...4.jpg?dl=1]

Fresh repair back
[Image: https://www.dropbox.com/s/bk6rutgc78dbxu...2.jpg?dl=1]

Dried repair front
[Image: https://www.dropbox.com/s/re1xanj25azjz1...9.jpg?dl=1]

Dried repair back
[Image: https://www.dropbox.com/s/hiehq1ever2k9i...7.jpg?dl=1]

- Eric

Philco 20A
Zenith T825
#24

I thought about a little upgrade for the model 20 and found a spot to attach a female audio jack with future plans to drill a hole into the rear of the chassis to mount the female AUX input. I soldered ground to ground and the left & right audio inputs together on the low side of capacitor #19.

Volume for the AUX input isn't controlled by the radio itself, but instead from the input device (my cell phone for example). What's nice is that when the AUX is unplugged the radio audio then returns to whatever it was tuned to. If the radio does cut in while the AUX is plugged in, then the radio volume can just be turned down.

I've been running AUX audio through the radio for several hours with no issue. Here's the circuit diagram with the left & right connection point (marked with a red arrow), some pics and a video. I was pretty excited that it worked, so there's a bit of giggling on the video...

[Video: https://youtu.be/57Ugih6a4DY]

[Image: https://www.dropbox.com/s/4r345m39ffuymn...t.gif?dl=1]

[Image: https://www.dropbox.com/s/j3ygbmuo6a9ez4...n.jpg?dl=1]

- Eric

Philco 20A
Zenith T825
#25

So what happened to the spider (the thingy in the center that looked like one of those old 45rpm record inserts)??? That part needs the be really flexible.[Image: https://encrypted-tbn0.gstatic.com/image...1kLAHSAhEG]

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!

Terry
#26

(08-14-2017, 07:48 AM)Radioroslyn Wrote:  So what happened to the spider

When I tore it down there was no spider, only a screw, washers and paper. :/

- Eric

Philco 20A
Zenith T825
#27

Terry, remember, it's a 20 , they have the solid spider.

Steve

M R Radios   C M Tubes
#28

Terry

It is 70&90 that have it, 20 has the solid one. Also the repairs of these are difficult as the paper becomes extremely brittle. I opt for recone.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#29

I've merged all of the MrGrnEgz Philco 20A electronic restoration threads into this one thread. Its generally easier to follow and easier to find by someone in the future if the questions on one radio are all in one thread. The rules ask not to have multiple threads on the same subject. Subject can be defined in many ways but we prefer to keep the electronic questions for the same radio together. Thanks!
#30

(08-14-2017, 07:44 PM)klondike98 Wrote:  I've merged all of the MrGrnEgz Philco 20A electronic restoration threads into this one thread.

Thanks for doing this klondike98 Icon_smile I'll post any future questions I have about the 20A project into this thread.

- Eric

Philco 20A
Zenith T825




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