SB-301

[Mark Graalman WB8JKR]

 Mine has gone to 40 over quite a few times. The calibrate signal
is about 20 over on 80 meters, gradually dropping to about S2 at
the top end of 10 meters. I'd say put you circuitry back to original
and maybe check the tubes and/or your RF/I.F. alignment.
 I don't have the schematic in front of me, but it seems to me the
S meter measures the voltage drop in the screen of the last I.F. amp
and not the AGC voltage.

73,  Mark  WB8JKR


On Mon, 31 Mar 2003 09:13:20 -0500 "Schichler, Alfred"
<ASchichler at MICROWAVEDATA.COM> writes:
> I was wondering if it is somewhat normal for  the S-meter on the
> SB-301 to
> read very low compared to most modern receivers. I think mine has
> always
> read pretty low, but it seems lower than it used to be. (I have
> owned it for
> about 5 years, but haven't used it for a couple years until
> recently). About
> the highest it ever reads is around S-6, and that is on extremely
> strong
> signals.
> I tried experimenting with changing some resistors in the meter
> circuit with
> almost no improvement, and also tried changing a couple of the
> resistors in
> line with the AGC voltage which did make the meter read a little
> higher, but
> it sounded like it was overloading slightly on very strong signals.
> The
> meter voltage seems to be derived from the second IF tube cathode,
> so I'm
> not exactly sure how it works, not being an expert on tube theory.
> Maybe I'm
> being a little too fussy, but I would just like to know if it is
> working
> pretty much the same as most of the SB-301's out there.
>
> Thanks for any help,
> Al, NE2D
>
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