[AMRadio] looking for HRO tuning knob

[Donald Chester]

What usually happens with the HRO dials is that the setscrew scores the 
shaft, and the burr keeps the knob from coming off.  I have always managed 
to get them off, but sometimes with great difficulty.  I just recall pulling 
forward on the knob and finally working it loose.  Sometimes it will rotate 
on the shaft, but not come forward.  Avoid rotating the knob on the  loose 
shaft; that will score a ring around the shaft and make it even more 
difficult to come off.

I have never had to actually destroy a dial to get it off the shaft.  I just 
tapped on the front of the knob, then pulled on it, and eventually got them 
to slide off.

Early models had only one setscrew.   Later models had two, located 90 
degrees from each other.

Don k4kyv