Broken shaft on a Motorola TS-4
 

Hello,

Is this tuner shaft repairable on my TS-4? One half of the aluminum split shaft is broken and the piece is missing -- the set was given to me this way. I'd love to find a way to repair it, if possible, or at least find some way to attach the knob so that I can tune the set.

Thanks.

Dave

:) Hi Dave ,

When I saw your post it brought to mind that there are kits sold to extend a potentiometer's shaft that consist of a coupling to join two shafts , and a piece of shaft to be cut to the desired length . This setup could be used of course to provide a new shaft end to your tuner , the enclosed pic is one such setup I found on Amazon by searching "Oscilloscope control shaft extender" . (I searched oscilloscope because I remember seeing all kinds of shaft extenders in the old vacuum tube scopes)

That's an excellent idea! I searched for your terms on Amazon, however, and couldn't find what you did. Could you double-check?

Dave

This?

https://www.amazon.com/FidgetKute-Ex.../dp/B0812TMJ6R

jr

https://www.amazon.com/FidgetKute-Ex.../dp/B0812TMJ6R

:thmbsp: If this link works , this is what I saw

Wow , we posted it at the exact same time ! :)

Thanks, perfect!

Dave

$25 for that thing? Yikes. Maybe you can cut the end off of an old pot and use a 1/4" coupler.

That's also an excellent idea! :thmbsp:

On a related note, could someone describe the details of the channel knob for this early set? I'm not sure what it looks like. The volume and contrast knobs for the split shafts, which I have, are similar to the reproductions sold at renovatedradios but they're plain without the inscribed gold circles. Since the channel selector shaft is also split, and since there is no fine tuning control on this set, I'm guessing that the knob resembles the volume and contrast knobs but with a simple gold dot to indicate the channel. Is this correct?

Dave

As I recall the tuner knob on the models without fine tuning are identical to the other knobs but with a dot or mark to indicate position. I have one somewhere, I'll take a pic if I find it.

Found it. To think, someone back in 1948 must have had the job of poking a soldering iron in these knobs to make the dot.

http://videokarma.org/attachment.php...1&d=1607306249

I believe that is correct for the early production chassis. The early ones have some of the 6KV caps mounted above chassis, channel 1 and no fine tuning.
Later chassis usually have a smaller center shaft for fine-tuning that rotates a single capacitor plate on the back of the channel water switch.

Thanks. Is it ribbed for a split shaft?

Also, my volume and contrast knobs don't have concentric circles like yours does. Are mine not original? I appended a photo of mine at the bottom of this reply.

Yes, two of the 6KV caps are mounted above the chassis -- they're 0.03 mfd which surprised me. My set also has channel 1 and no fine tuning.

Yes, split shaft. No, those aren't the correct knobs for the Motorola, they had rings, and were red or tan to match the cabinet.

Thanks. I guess I need to find some original knobs, then.

Reproductions are available from this vendor.

http://renovatedradios.com/product.php?product=248