[R-390] R390 knob set screw

[Barry]

I wonder if anyone makes #8-36 helicoil thread repair inserts.

Barry - N4BUQ

> Dan,
> my notes say it's 8-36 UNF thread, yet another oddity of the 39x's. If you
> had the tap you could epoxy the hole and drill and retap it but a
> replacement knob can be gotten cheaper.
>
> Sometimes you can smear some JB Weld across just the damaged area, let it
> firm up a bit, and then use the setscrew itself as a tap, then remove it
and
> let the JB cure. If your lucky it can give the setscrew the little extra
> bite it needs to do the job.
>
> That phenolic insulating shaft on the 390 is pretty tough, I wouldn't
worry
> too much about hurting it.
>
> John