# Custom Brass Shaft for Philco Car Radio



## grahamjb (May 3, 2021)

One of my hobbies is converting old car radios to AM/FM/Bluetooth and handsfree phone.
A mate has purchased an imported Plymouth delivery van and asked to me to convert the radio for him and what a challenge this radio has been. This is the first time I have seen a radio style like the Philco and it was in a very sorry state of repair. For starters the volume/tone control was open circuit and these are impossible to buy new necessitating the modification of a modern pot to replace the 73 year old one. I drilled out and turned down some brass rod in the lathe to make the two shafts that were needed and silver soldered them to the shafts of a modern dual shaft potentiometer. Note: you have to use low melting point silver solder such as Commweld 965 to avoid heat damage to the potentiometer carbon tracks. Once the internal shaft has been silver soldered in position wrap a piece of alfoil around the shaft before sliding the external shaft on and soldering into position - (the alfoil stops any stray silver solder from the external shaft soldering to the inner shaft) pull the alfoil out from between the two shafts when finished.
the photos below show the old pot, modified pot and unmodified new pot


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## graham-xrf (May 3, 2021)

Excellent!
I have once taken the other route, and took apart a pot from a classic valve-type Hi-Fi amp (Leak brand). The track was fortunately not worn through, as many are, but the carbon had cracked right on one end next to a "press through" rivet eye, which made the contact on the brown phenolic resin.

The fix was a tiny line of silver-loaded epoxy over the crack. I took it from the very dregs of the little bottle that others had already used up and thrown in the trash. It worked because wiper contact never had to move over the repair.


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## grahamjb (May 3, 2021)

Good repair of a common age related fault Graham.

In this case a section of track had fallen off on the volume pot and the tone pot had a similar issue to the one you describe.
The attached photo shows the missing track on the volume pot

GB


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## Nogoingback (May 3, 2021)

grahamjb said:


> Good repair of a common age related fault Graham.
> 
> In this case a section of track had fallen off on the volume pot and the tone pot had a similar issue to the one you describe.
> The attached photo shows the missing track on the volume pot
> ...


OK, tell us what the motorcycle in the background is...


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## grahamjb (May 3, 2021)

Hi Nogoingback - the bike is a 250cc shaft drive 1958 BMW R26 that I restored a couple of years ago. I can post up a separate thread on the restoration if anyone is interested


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## Nogoingback (May 3, 2021)

Beautiful job. I've always liked the early boxers.  Is that your only one?


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