[David Dunlop]

I finally got a chance this afternoon to revisit my COIL, Aerial Tuning No. 2 A which had developed a very stiff tuning knob after its restoration. My thoughts on the problem were that the three mounting screws for the Counter Dial assembly had been overtightened causing the adapter to the main coil drive to bind, or there was no lube left at all between the drive shafts and supporting sleeves in the counter section. I was quite surprised to discover the real problem.

When I removed the tuning knob, I discovered the culprit was too thick a layer of spray paint on the surface of the reinforcing plate welded on the front panel around the opening the tuning shaft passes through. The paint was just thick enough that when the tuning knob was installed and screwed down, the flat, brass bottom of the knob engaged the surface of the paint and dug into it enough to stick.

Fortunately, it popped free and it was relatively easy to buff the surface of the paint down far enough to solve the problem. While the knob was off the shaft, I also took the opportunity to lube the shaft and sleeve assembly. When it all went back together, I now have a firm but smooth rotation of the tuning assembly with just one finger and my thumb.

Though I would mention that potential issue in case somebody else runs across it down the road. Now the next big part of the project is restoration of the Supply Unit.


David