SB-301

[Stu Lyon]

Al,
Your SB-301 S-meter reads way too low. Using the calibrator as a signal
source my SB-301 reads as follows:

3.7 MHz    S9+40
7.2 MHz    S9+40
14.2 MHz  S9+30
21.2 MHZ  S9+20
28.2 MHz   S7

I think you have a bad tube (or tubes) in the RF/IF stages or your set is
badly out-of-tune. If you plan to retube, try a 6GM6 in place of the 6BZ6 at
V1. Really makes a difference.


73, Stu W6CUX
Winnetka, CA
slyon at pacificnet.net


----- Original Message -----
From: "Schichler, Alfred" <ASchichler at MICROWAVEDATA.COM>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Monday, March 31, 2003 6:13 AM
Subject: SB-301


> 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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