On my knob, the red indicator dot is across the knob from one edge of
the plastic stop, not centered on the stop as I would think would be right.
73,
Maynard
W6PAP
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On 11/20/24 07:54, Richard Knoppow via groups.io wrote:
About what I imagined. While the plastic stop could be cemented in
it makes more sense to cast it in. If the bushing for the shaft is in
two layers then perhaps an added reducer was added to the usual 1/4"
bushing. The one I made has a slot cut in it (with a file) to clear the
set screw. I used the original set screw but a somewhat longer one might
be necessary since the threaded part of the hole would be only the
original bushing. This arrangement works fine. There is little torque
needed to turn the BFO shaft. If making a knob one could even leave the
stop off, just adjust the BFO shaft for zero beat at the IF frequency
and put the knob with shaft adapter on with the red indicator dot in the
correct position.
On 11/20/2024 7:27 AM, Maynard Wright, P. E., W6PAP via groups.io wrote:
Visual inspection of my knob leads me to believe that the plastic knob
was originally cast around a 1/4 inch brass insert with the added
plastic stop cast integrally and then a 1/8 inch sleeve with a larger
section with a shoulder as a stop was pressed in later.
Not sure about that and I don't want to try to pry my knob apart to test
that theory, but there appears to be a joint between the shoulder of the
1/8 inch insert (if that's what it is) and the flat brass surface of the
1/4 inch insert that adjoins the plastic knob. The insert would have to
have a hole for the set screw but only one of the two holes, which would
have to be aligned, would have to be threaded.
73,
Maynard
W6PAP
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
