SB-101 transmit audio problems...

[Sandy Gerli]

Hi, folks,

Well, this one has me foxed. My SB-101 puts out tons of rf in Tune, but
is weak as a stone on SSB. All voltages check within tolerances to the
manual. V1 has been changed to a 6CQ8 for more gain per recommedation of
Jim Ray's notes on 'JJL (?)'s website archives. Still weak.

Which brings me to the schematic. Interstage coupling cap C9 from the
plate of V1A to the MIC/CW LEVEL control is a .01uF. Could that be
pumped up to a .05 or perhaps a .1? And, C11, from the wiper of the MIC
control to the grid of the cathode follower V1B is a puny .001uF; could
that be pushed up to .005? Has anyone tried these to increase audio
gain?

This sure puzzles me. Using a mic with known good gain (Heath/E-V stock
mic for the SB-series, so it ain't the mic.

As a postscript, what about the series input resistor R931 from the mic
jack to the grid of V1A; that's a 22K. Has anyone tried to change that
value to let more snort through?

Thanks for the bandwidth. 73,
--
Sandy Gerli, AC1Y
500 Country Club Road
Avon, CT  06001-2406
(860) 675-5566
E-Mail: angerli at esslink.com

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