[StephenB]

Greetings!  I'm in the midst of restoring a very dusty but beautiful 37-650b (tombstone).  Only two bakelite caps left to go.  So far, working like a champ!  The issue I'm facing is with the fine tuning innards.  I'm not sure whether I just can't figure it out, or if there's a missing or broken part.  I've seen two different diagrams of how they're supposed to work, but neither appear to be a match for the parts I've extracted from the unit.  I've attached a photo of the parts laid out in the order I believe they fit.  There are six ball bearings.  One small, two medium, and three large.  I think the two medium-sized ones are supposed to be on each end of the spring, which fits into the coarse tuning shaft.  The three large bearings fit in the three holes of the coarse tuning shaft.  It's what's left that puzzles me.  If the small ball-bearing were somehow fused to the tip of the fine tuning shaft, I could see this working.  As it stands, the fine tuning shaft just spins, does nothing, and can be simply pulled out of the coarse tuning shaft.  Given the way it's shaped, it's really no surprise - there isn't anything to keep it in place.  Maybe it's simple, but clearly not simple enough for me.  I'm hoping to tap into the wisdom that I've seen answer so many other questions on this board (which have been invaluable in getting me to this point).  Any help would be greatly appreciated.  At this point, I'm desperate and looking to pick up another 37-650 chassis just to dissect it!

Stephen

   

[klondike98]

Hi Stephen, Welcome to the Phorum!!
I can't answer your question but I'm sure someone will jump in soon.

[Chuck Schwark]

All is made clear with re-building this vernier shaft assembly in my Service Tip #39.
It does show the 1938 version, but I believe they are the same assy. or very close
so you can use the info and diagram.

Here: http://philcorepairbench.com/tips/svctip39.htm

Chuck

[StephenB]

All is made clear with re-building this vernier shaft assembly in my Service Tip #39.
It does show the 1938 version, but I believe they are the same assy. or very close
so you can use the info and diagram.

Here: http://philcorepairbench.com/tips/svctip39.htm

Chuck

Hi Chuck - thanks for the reply.  I did see the Service Tip previously.  Looking at the assembly shown in in the Service Tip, I don't understand how the fine tuning shaft stays in place.  I used the diagram to assemble the parts, but it doesn't yield a working fine tuning control.  Desperate and looking to satisfy my own curiosity, I super-glued the small ball bearing to the end of the fine tuning shaft.  When I assembled as such, it seemed to work and the fine tuning shaft was held in place nicely.  Within minutes, the super glue failed and left me where I started.  I know... the experiment sounds like heresy.  I removed all traces of the glue and I'm back to square one... clueless.

[Radioroslyn]

I think the small shaft should have the ball as part of the shaft. It's been a long time since I've had one apart. Does it look as though it's broken??
Terry

[StephenB]

I think the small shaft should have the ball as part of the shaft. It's been a long time since I've had one apart. Does it look as though it's broken??
Terry

That makes perfect sense.  Although it doesn't appear broken, I think you're right.  I've been searching high and low and just came across a photo of a disassembled 38-10 shaft that confirms your assertion.  Even though I am now nearly certain I've got a broken part on my hands, I do feel a whole lot better!  Thanks so much for your reply.  I'll make an attempt at affixing the ball to the shaft, but will be on the lookout for a parts chassis for a more permanent replacement.  At least I'm feeling confident that I won't find the same parts I have now.

Thanks again!

https://www.flickr.com/photos/70039806@N...0383644064

Stephen.

[StephenB]

Working like a charm!  I took out the blow torch and some silver solder to fuse the ball bearing to the end of the fine tuning shaft that puzzled me so.  Once reassembled, the shaft is holding strong and now the radio is working like new...  just in time for opening day baseball games.

[Radioroslyn]

Nice lookin' set!!!
Terry

[Eliot Ness]

That is a beautiful radio!  Glad you were able to fix that shaft and get her back on-line.

[StephenB]

Thanks! I'd be lying if I didn't say I was thrilled with how it came out. Inside the radio was a service ticket dated March of 1941 and it doesn't appear to have been touched since. This is my first Philco, and I don't think I could have found a better specimen! It certainly is a well built unit.

[StephenB]

Nice lookin' set!!!
Terry

Thanks!  And, thank you for helping to confirm that the ball-bearing should be affixed to the shaft - very helpful.

[klondike98]

This may muddy the waters a little but I just took apart the vernier on the 610 I'm working on. Its similar if not identical to Stephen's. It had the ball loose from the shaft just as Stephen's appears in the first photo. After getting all the old grease off and packing with new, I put it back together without affixing the ball to the shaft just to see what would happen and all seems to be working well. Can't explain it but ....

[StephenB]

This may muddy the waters a little but I just took apart the vernier on the 610 I'm working on.  Its similar if not identical to Stephen's. It had the ball loose from the shaft just as Stephen's appears in the first photo.  After getting all the old grease off and packing with new, I put it back together without affixing the ball to the shaft just to see what would happen and all seems to be working well.  Can't explain it but ....

KHHHHAAANN!! 

What keeps the fine-tuning shaft from sliding out?  From what I can tell, the attached small ball-bearing held on the radio side of three large ball bearings by the three large ball-bearings is what keeps the shaft in place.  Also, I was thinking that it was the friction between the end of the fine tuning shaft/small ball bearing with the three large ball-bearings and the coarse tuning shaft that allows it to turn.  This blows that theory!

On the other hand, there's no arguing that it didn't work before and that now it does.  I'm not sure what I'm doing differently.

Stephen.