[Hallicrafters] Tuning Knob Set Secrews

[Rich Evans]

I am faced with a similar problem on three, maybe more, boatanchors, 
concerning the main tuning knob set screws.
Previous owners were apparently not aware of the applied-heat trick to break 
loose the set screws, whether Bristol
or Allen or straight.

These frustrated guys drilled out the screw, thus destroying the thread. The 
only solution I can see is to tap the
holes for a #10. I guess it will be 32 tpi; I can't find anything finer. In 
fact I can't find any #10 set screws. I could
make my own carefully in a vice, I suppose.

So, what have any of you done to solve this problem?  Specifically, a 75A4, 
SX-101, R-390A  (maybe 2).
Thanks as always.

Rich Evans  W3FYD  Sellersville, Pa.