The CW knob on the S-38 I just bought is missing. ?Is there anything
special about that knob, or is it the same as the others? ?I see that
the shaft has threads unlike the others.
thanks, Fraser, W3UTD

I had to make a couple but had to guess as to how it was configured.
Same knob used on the S-40 and S-40A. fits 1/8" shaft and has some sort
of stop pin to work with the bent out tab on the front panel hole for
the BFO shaft. I made a reducer from a short length of 1/4" tubing that
had the right internal diameter (1/8"). Cut a slot in the tube to clear
the set screw and just cemented a small nut inside the skirt to act as a
stop. You must adjust the BFO for center frequency using its screwdrive
slot. Use the signal generator you use to set up the IF. When its set
put the knob on and tighten the set screw. The depth of the knob has to
be right to make the stop work right. A bit tedious.
I have never been able to find a genuine knob so I don't know if
they were special or a regular knob with a fitting. My knob works and
looks OK but is really rather a makeshift.
The same knob may have been used on other receivers.

On 11/17/2024 12:00 PM, Fraser via groups.io wrote:

The CW knob on the S-38 I just bought is missing. ?Is there anything
special about that knob, or is it the same as the others? ?I see that
the shaft has threads unlike the others.
thanks, Fraser, W3UTD

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Here's the knob from my S-38, probably early as it has a metal bottom
plate.? The inside of the knob is labeled "15-A-058" or "15-A-056,"
although I don't imagine that matters.

It sounds as if your knob is a close substitute, Richard.

73,

Maynard
W6PAP

?

Here's the knob from my S-38, probably early as it has a metal bottom
plate. The inside of the knob is labeled "15-A-058" or "15-A-056,"
although I don't imagine that matters.

It sounds as if your knob is a close substitute, Richard.

73,

Maynard
W6PAP

On 11/17/24 12:59, Richard Knoppow via groups.io wrote:

I had to make a couple but had to guess as to how it was configured.
Same knob used on the S-40 and S-40A. fits 1/8" shaft and has some sort
of stop pin to work with the bent out tab on the front panel hole for
the BFO shaft. I made a reducer from a short length of 1/4" tubing that
had the right internal diameter (1/8"). Cut a slot in the tube to clear
the set screw and just cemented a small nut inside the skirt to act as a
stop. You must adjust the BFO for center frequency using its screwdrive
slot. Use the signal generator you use to set up the IF. When its set
put the knob on and tighten the set screw. The depth of the knob has to
be right to make the stop work right. A bit tedious.
I have never been able to find a genuine knob so I don't know if
they were special or a regular knob with a fitting. My knob works and
looks OK but is really rather a makeshift.
The same knob may have been used on other receivers.

On 11/17/2024 12:00 PM, Fraser via groups.io wrote:

The CW knob on the S-38 I just bought is missing. ?Is there anything
special about that knob, or is it the same as the others? ?I see that
the shaft has threads unlike the others.
thanks, Fraser, W3UTD

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Maynard, Thanks from me too .. so it has a brass insert for fit 1/8” ,
and the knob plastic is the same as others but has that extra stop “辫颈苍”?

*From:*[email protected]
[mailto:[email protected]] *On Behalf Of *Maynard Wright via
groups.io

You can see the stop in his pictures. Just a plastic boss on the rim
inside the little skirt. The brass insert is probably molded into the
knob, can't tell. However, its easy enough to make an adapter.

On 11/17/2024 6:37 PM, don Root wrote:

Maynard, Thanks from me too .. so it has a brass insert for fit 1/8” ,
and the knob plastic is the same as others but has that extra stop
“辫颈苍”?

*From:*[email protected]
[mailto:[email protected]] *On Behalf Of *Maynard Wright
via
groups.io

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

I don't think the stop is necessary but jut to keep you from cranking it
too far off so operation quits.? I just used a regular knob and made an
adapter out of 1/4" aluminum sound stock and drilled and tapped it for
the coil stub...
73,
--
Justin B.
KI5GKD

Its used mainly to prevent the BFO from being set far from its
correct frequency. Simple to glue something like a small nut to the back
of the knob opposite to where the red dot it.
My adapter shaft has a slot cut in it with a file to clear the set
screw, which remains threaded in the larger knob insert. You may need a
longer set screw. It works like the original knob.
I would not tap the insert, there is no point to it. The entire
assembly is held on by the original set screw (or a slightly longer one
if necessary. When its tightened the adapter will not move. Don't make
it more complicated than necessary.

On 11/17/2024 9:56 PM, Justin Bowser - KI5GKD wrote:

I don't think the stop is necessary but jut to keep you from
cranking it
too far off so operation quits.? I just used a regular knob and made an
adapter out of 1/4" aluminum sound stock and drilled and tapped it for
the coil stub...
73,
--
Justin B.
KI5GKD


--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Justin, thanks.? After seeing the replies and Maynard's picture, I have
a good idea of how to modify a normal knob. Your idea is pretty much
where my mind was going.
Thanks to all.
Fraser, W3UTD

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

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

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

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

*From:*[email protected]
[mailto:[email protected]] *On Behalf Of *Richard Knoppow
via groups.io
*Sent:* Wednesday, November 20, 2024 11:50 AM
*To:* [email protected]
*Subject:* Re: [HallicraftersRadios] S-38 CW knob?

I agree, the stop on the knob should be right behind the red dot.
It is possible the stop on the knob is not molded in but stuck on? That
would make sense of the knobs for the BFO are just standard knobs with
an reducing tube. Or else, its a makeshift like the ones I made.
Hallicrafters used these knobs on the S-38 and the S-40/A and maybe B. I
wonder if enough knobs were used to justify molding specials, with
different inserts. Some of this style of knob does not have metal
inserts, just plastic with the set screw just threaded into the plastic.
I am quite sure old Hallicrafters business records that might have
the answers were long ago destroyed.

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998


--
don??? va3drl

…. other S-38s don’t seem to have all knobs listed , but ??for the
*厂-40叠…..*

**


--
don??? va3drl