Need some help repairing the fine tuning knobs on a Deforest Crosley Trirdyn. Wonder if anyone has had one of these apart, can't quit figure out how to get the small fine tuning knob off the larger knob(and don't want to break it) From what I can figure the return spring is broken , but with out getting it apart can't replace spring. Any help would be appreciated..
thanks Martin..........

Can you post closeup photos? If there isn't a visible retainer screw or spring clip the parts are probably just pressed or swaged together, but a good set of photos would infinitely help with that analysis.

https://www.dropbox.com/sh/5pybsekxd9svwmt
Hope this works pictures of Fine tuning knob and chassis
The outer knob is the fine tuning portion which rotates the copper fingers on inside or next to chassis. The fingers push against the chassis with friction fit and in turn move the large knob a small portion either way , i believe clock wise on fine-tuning knob tightens spring and anti clockwise relieves spring. There is a small hole in outer knob but there is no set screw, all you can see is the inner brass hollow tube as you see from rear picture of knob. The spring is broken on this knob but with out getting it apart there is no way to replace it.
I had thought that maybe some one had run across this problem before.The knobs are made by the EZ Toon radio company out of Indianapolis,usa

https://www.dropbox.com/sh/5pybsekxd9svwmt/2r_frhxo_o
:Hope this works pictures of Fine tuning knob and chassis
:The outer knob is the fine tuning portion which rotates the copper fingers on inside or next to chassis. The fingers push against the chassis with friction fit and in turn move the large knob a small portion either way , i believe clock wise on fine-tuning knob tightens spring and anti clockwise relieves spring. There is a small hole in outer knob but there is no set screw, all you can see is the inner brass hollow tube as you see from rear picture of knob. The spring is broken on this knob but with out getting it apart there is no way to replace it.
:I had thought that maybe some one had run across this problem before.The knobs are made by the EZ Toon radio company out of Indianapolis,usa
:
:

Nice pictures. Looks like the small knob was supposed to have a setscrew as does the large knob. Check to see that it is really missing and not just screwed down out of sight in the bore. If the setscrew is missing, the knob is probably seized to the shaft. Most knobs have metal liners (tapped for the setscrew) and these can seize to their shafts over decades of sitting in close contact. You can try soaking the assembly in Liquid Wrench or similar chemical for a few days to weaken the seize bond, then try gently tapping wedges between the two knobs in order to break the top one free. Most "real" hardware stores sell replacement setscrews, although the flatblade-slotted ones may be hard to find (allen-wrench types seeming to be more common these days).

:Nice pictures. Looks like the small knob was supposed to have a setscrew as does the large knob. Check to see that it is really missing and not just screwed down out of sight in the bore. If the setscrew is missing, the knob is probably seized to the shaft. Most knobs have metal liners (tapped for the setscrew) and these can seize to their shafts over decades of sitting in close contact. You can try soaking the assembly in Liquid Wrench or similar chemical for a few days to weaken the seize bond, then try gently tapping wedges between the two knobs in order to break the top one free. Most "real" hardware stores sell replacement setscrews, although the flatblade-slotted ones may be hard to find (allen-wrench types seeming to be more common these days).
:
CV is right about the liquid wrench etc. If you can fit a dish towel under the knob after the L W does its magic. Put the towel around under the knob and you will have an instant handle. Rock it back and forth with tension and it should come right off. Merry Christmas, George T

The small knob is not frozen ,as I should have mentioned, it turns its rotation about 180 degrees,there must be a threaded set up for it to be able to work against the spring action.Looking down the small hole in the small knob you can see what looks like a "c' clip groove on the brass shaft , but no sign of a "C" Clip. But could it be possible there would be a spring loaded pin on opposite side of shaft we can't see?

If there is no setscrew, and a close inspection of the empty hole reveals no release catch, I would try pulling the small knob straight off using wedges or the dishrag method mentioned by George. It is probably retained by a snap spring riding in the groove that you can see, and a sharp pull should disengage it.

Well if I can find the nerve to try it , it's not mine so hate to end up breaking it!