[Elecraft] K3 knob hole threads

[Ken Kopp]

Ron, others ...

If the holes in the knobs were tapped with a "normal"
(tapered) tap, the threaded hole will be of slightly less
diameter near the "bottom" (shaft) end of the hole.  This 
would tend to increase the likelihood of forcing the knob 
to split.  There isn't enough room for a tapered tap to
go far enough through the set-screw hole to produce a
straight thread.  A "bottom" tap produces a straight-sided 
hole even when there's not room for full travel of a tapered 
tap..

Not that any of this would be useful information unless one 
was installing a replacement knob and used a bottom tap 
before installing.

One poster suggested using controls with shafts with flats 
and push-on knobs.  Unless care is used or the depth of 
the hole in the knob and the length of the control shaft is 
carefully controlled, the knob is likely to end up rubbing 
the panel and creating rings of worn-away paint.

73! Ken Kopp - K0PP
      ElecraftCovers at rfwave.net
      http://tinyurl.com/7lm3m5