[Eddie Z]

I recently got a Philco 38-116 code 125 which has the tuning firmly stuck to the bandswitch, and have never worked on a large Philco.  It takes too much force to try to tune it.  You can change bands - but very stiffly, and the dial moves locked to the bandswitch.  At first I figured everything was just too gummed up with old grease - but now I think the problem is that the "mask" is stuck to the hub.  Using SB273 on this site - I removed the dial (which already had 10% of the markings wiped off, and is cracked - anyone want to part with a good original dial?  I'm just hoping the repro's will look just like the original).  I tried to remove the "spacer - item 13", after finally convincing myself it is indeed a separate piece even on the 1938's, but it is firmly stuck - even after "vibrating" it with a buzzing tool.  

My best guess is that the mask (item 11 - which makes the light beam window for each band) is firmly stuck to the auto-tuning hub (item 7), and apparently is supposed to smoothly rotate separately from the hub, right?  I figure I need to remove the mask and sand its inner diameter so it will rotate smoothly - is that right?  So I want to get that apart without damaging the mask OR exposing it to pen-oil or anything.  The mask already has a crack started - and I presume the mask has shrunken a little, explaining why it is locked to the hub.  (The dial was also shrunk tight around the hub, and finished cracked as I gently removed it.)  What is the best way to get that "spacer" off the hub so I can get to the mask?  Has anyone had this trouble before?  

Thanks guys,
Eddie Z

[rfeenstra]

I recently did a 37-116, have another one and a 38-116 in the que. You are correct. The mask needs to rotate freely on the hub else when changing the band switch, the tuner dial will want to turn as well. I did not have the problem of binding or shrinkage that you seem to be having. I checked the 2 in line and I can see that there is a bit of friction between the mask and the hub on both radios. Not enough for the band switch to actually turn the dial but you can see that it is trying. So, I assume I'll have to sand the inside of the mask to eliminate the friction.

I had no trouble removing the spacer on my 37-116. Don't know what I'll run into on the other 2. I'm not sure of the composition of the metal, but if it is something akin to pot metal, it could be expanding a bit.

[Eddie Z]

Thank you for your suggestion - now I'm worried that the hub indeed may have expanded so much that the dial and mask were both stuck to it, as well as the spacer.  That might explain why both the dial and the mask had a crack started from the hub, and when I gently pried the dial off, it cracked the rest of the way up.  If might also explain why the mask "pops" slightly back and forth if you flex it forward and backward - all suggestive that the hub is wider than it is supposed to be.  

I have tried heating the spacer at 12 points around its circumference, first with 20W, then with a 200W Weller gun applied for 15 seconds per point until it was pretty warm - but not at all hot enough to damage the mask, then buzzing it stoutly with a "Multitool" through a firm stick of wood, and it still did not loosen at all.  After that, I applied a few drops of Superlube Syncopen "synthetic penetrating oil" (hoping that kind would be the least threatening to the mask), then buzzing it again afterward, and again 12 hours later, and again tonight - with no effect at all - except I'm convinced that the inside of the spacer must be fully coated with the pen-oil now because the mask now has a slight but obvious "oily" look to it for about 1/2" to 1" away from the hub - so the pen-oil must have made it all the way through the spacer, all the way around - and buzzing it again still has no effect - it's just stuck hard and won't come off.  

Anyone see any way of saving the situation without hurting the phenolic mask?  Thanks, Eddie Z.

[rfeenstra]

I just started a thread on my 38-116. The hub and associated pieces came right apart but I can see where the the dial and both masks have shrunk. both are quite brittle. I can see where someone had enlarged the holes that go around the hub so I think there was a problem with this in the past. The mask with the slit in tt over the focusing rod shrunk enough to crack one end at the slit. Radio Daze does not seem to sell this part so I'm going to ask them if they can supply a sheet of the mask material to make my own. Not sure what you are running into with your unit.

In addition, I've discovered that the contact that shorts out the audio when the auto tuner is engaged is missing. So, I know that someone was in there! Good luck!

Rob

[Eddie Z]

Thanks for the extra input Rob - sounds like it's possible that on mine, the dial and mask both shrunk (which was my initial impression), and like you suggested, and in addition the hub may also have expanded a little - making the fit even worse, and holding the spacer tight.  I do hope I can get them apart.  The spacer is so tight against the hub that I initially thought it was one piece.  I had to look REALLY close to finally see that they were indeed 2 pieces - made the same way as in the SB273 document.  

By the way - I figure if my mask splits the rest of the way - I can probably just glue the split together with a little splice plate behind it - my crack is near the narrowest part where it won't interfere with the light slots.  That is, assuming I get the spacer off!  

Eddie Z

[tbone]

I don’t know if this will help. It is a link to the service bulletin that covers the tuning assembly. Wish I had it when working on mine.

Bulletin 273

[rfeenstra]

Thanks Tony! I haven't seen that either. Good to have.