SB-101 Low SSB Output Problem (ALC?)

[Jim Simmons]

Forgot this, for low power on all bands, check the finals. If they are RCA,
get/borrow a set of GE tubes (6146 or 6146A) and see if their is a
difference. Sometimes RCA just don't work in the HW's & SB's.

Jim

----- Original Message -----
From: "Randall C. Iliff" <riliff at COMMSPEED.NET>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Sunday, March 16, 2003 11:07 PM
Subject: SB-101 Low SSB Output Problem (ALC?)


> Hi All,
>
> First, many thanks to those kind souls who answered my previous SB-101 /
> D-104 mic compatibility inquiry.  What a terrific resource your experience
> represents!
>
> The original problem was (and, unfortunately, still is) very low output on
> either LSB or USB.  CW and Tune positions are fine into a dummy load, but
I
> now suspect that the ALC circuitry may be the culprit.  I can get an S-4
to
> S-6 needle kick on voice peaks with the Mic Gain full up, but listening to
> the signal (into a dummy load of course!) using another receiver I find
that
> the peaks sound very distorted.  Low level sounds are clearly carried.
> (Indicated power on my Drake MN-4 never exceeds 10 watts on peaks.)  The
> situation is common to all bands, and I see no difference between USB and
> LSB.  Carrier nulls out nicely during adjustment too.
>
> Possibly related is the fact that on receive the S-Meter seems very
stingy.
> It zeroes OK, and seems to hold a setting, but it takes a very strong
signal
> to hit S-6.  Otherwise, the meter seems to operate normally.
>
> (A quick search of the archives turned up a tantalizing reference from '98
> of a person who had just solved an ALC problem on an SB-102, but alas, the
> original posts weren't found.)
>
> If someone has previously slayed a problem that sounds like this, I'd sure
> appreciate hearing about it!
>
> 73's
>
> Randy
>
> (KE0BN)
>
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