Posted by
John Hoaglun-2 on
Jan 23, 2011; 2:20pm
URL: http://elecraft.85.s1.nabble.com/NG0R-KSB2-low-audio-level-tp5930478p5952782.html
I need some help troubleshooting an issue.
K2+KSB2+K160RX+KIO2+KAT2+K60XV+XV144+XV222+XV432+IMA rework module
I have not spent much time using this rig on SSB but I plan to use it to
drive some transverters. So as part of the setup & checkout of the
system
I am noticing that my SSB power level seems pretty low compared to my CW
power level. Specifically when I test my transverters I am getting my
expected power on all of them with CW. (The transverter power level on
each unit is setup for driving the input power level for the brick for
that band.)
144: 25w CW --expected
222: 10w CW --expected
432: 10w CW --expected
When I change over to SSB the power level is almost nothing (even with
modulated CW)
144: 1-2w SSB --lower than expected
222: less than 1w SSB --lower than expected
432: less than 1w SSB --lower than expected
Following Don's suggestion I tested the K2 independent of the
tranverters & interfaces. (K2+20dB dir coupler+20dB pad)
On 40m my Booton microwatt meter and oscope show that on SSB at peak I
am only making about 50-60% of the power that I am on CW. (About 3 dB
down)
I have tried a couple of different bias approaches with the IMA rework
module and the results are the same. (The recommend config is 10k which
is where I started.)
I am using an (older) Icom HM-36 mic (and have tested with two Heil
headsets
with similar results). The menu is set to SSBA=3 and SSBC=4-1
There are are probably some other folks using a similar mic
configuration and I am curious what their experience has been. Maybe
there is some guidance from the group based upon their experience.
73 de NG0R
--
John Hoaglun
NG0R - EN25
http://www.hoaglun.com______________________________________________________________
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