SB-101 Low SSB Output Problem (ALC?)

[Randall C. Iliff]

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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