I think the S-40B and S-85 are constructed so that the link from
the antenna terminals couples to the two highest bands as well as the
low bands. Redraw the circuit to see how this is done. I find this in a
number of receivers where I think it resulted in lowered manufacturing
cost. The coupling to the high bands is really direct rather than a
transformer.
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On 2/10/2025 5:43 AM, Maynard Wright via groups.io wrote:
Hi, Don,
I did check the S-40A schematic and it shows all the input coils wired
so that on all bands they can function as balanced input circuits unlike
the S-40B and S-85 that leave terminal A2 open on Bands 1 and 2.
Now, is the receiver really wired that way or is the schematic wrong?
Later today (or tomorrow) I'll turn my S-40B around and measure terminal
A2 (DC continuity to A1 and G) with the bandswitch in all 4 positions.
73,
Maynard
W6PAP
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
