Topband: DXE Active Receive antenna question

[D Rodman MD]

I should be operating the contest, but spent some of the afternoon
troubleshooting my DXE circular receive array.  One thing led to another and I
decided to bench test one of the receivers.  We pulled out my service monitor (RF
signal source) and played with the jumpers on circuit board while listening to
the receiver and watching the S meter.  To our surprise the compromise position
for the system (160 & 80m) in terms of jumper position does not produce the best
receive signal one can obtain.  It looks more like a monoband system rather than
a duoband.  By changing the jumpers we could obtain at least 10dB signal increase
on each band separately, but also at the expense of an even greater loss of
signal on the complimentary low band.  I wonder if anyone else has experimented
with the active receivers in terms of jumper position on the bench or in the
field and can comment on this finding.  I have been somewhat frustrated by my
lack of ability to hear topband signals from time to time and having the
receivers in a different jumper position might be the trick.  Before I go out and
start taking things apart in the cold, I thought I would ask around first. 
Thanks for the help.  73.,

David J Rodman, MD

Assistant Clinical Professor
Department of Ophthalmology
SUNY/Buffalo

Office 716-857-8654