And my S-40A schematic is from Sam's Photofacts (via the Web) and it
doesn't have C62 as in your schematic nor does it use independent
designation of each component, but labels them with numbers referred to
the table of components. So more than one component can have the same
number.
So I suspect that your schematic excerpt is from the S-40A Hallicrafters
manual, which looks (in your excerpt) more like the S-40B and S-85
schematics I have from Hallicrafters manuals. But I don't have that manual.
Since those two schematics don't agree, I wonder whether there was a
revision during production of the S-40A.
73,
Maynard
W6PAP
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On 2/27/25 12:38, Maynard Wright wrote:
Hi, Don,
When I said that there is no C62 equivalent in the S-40A, I meant that
there is no capacitor like C62 that is connected around the switching
and resonant circuits so that it is completely independent of the
setting of the bandswitch.
73,
Maynard
W6PAP
On 2/27/25 11:49, don Root wrote:
Maynard on the S-40A,? C62 is ??in use on band 2 only but connects V1
and V2?? like in the B version …I think.
We need somebody to LRC a sample switch.
*From:*[email protected]
[mailto:[email protected]] *On Behalf Of *Maynard Wright
via groups.io
*Sent:* Thursday, February 27, 2025 11:16 AM
*To:* [email protected]
*Subject:* Re: [HallicraftersRadios] S-85: how are the RF amplifier
tube (v1) and the MIX/OSC tube (v2) coupled in band1?
Note that the S-40A uses an entirely different arrangement of coils and
capacitors and has no equivalent to C62 in the S-40B.
So why is the S-40B equipped with C62? Maybe switch S1B in the S-85
exhibits a higher capacitance between the two rotary segments than does
S1B in the S-40B, making C62 unnecessary to achieve the desired coupling
capacitance in the S-85.
Although the parts numbers are the same, maybe Hallicrafters used a
different switch vendor for the S-85.
Knowing this would matter only if someone were restoring a receiver and
expected a part number for one type to represent the same exact part for
another type. And maybe that's the case. But I haven't thought about
that until now.
73,
Maynard
W6PAP
--
don??? va3drl
