I have a stack of C31's up - top at 121 then 81'/41'. They work
great on 20 and 15... and I had believed on 10 as well... but
recently I installed a simple D3W warc dipole on the side of the
tower about 10' above the middle C31. The dipole is inline with
the elements of all the antennas (not turned 90 degrees to
them). The C31's drivers are on the opposite side of the tower
(this is a rotating tower so all antennas are mounted to the
tower) which places them not directly under the dipole - and the
dipole is about 11' total distance away... and of course the
dipole is not resonant on 10... however...
I noted today that the difference in signal is much more often
than not just a couple 2 - 3 S units (Orion II). I have seen,
once, with one station and then briefly, a difference of about 7
S units... but I have also seen almost no difference at all (1/2
S unit)... this seems incredibly strange to me. Since I had
nothing to compare it to before putting up the WARC dipole I
don't know if it has changed (the array) due to
mechanical/connection issues, or there is interaction of the
dipole, or it has always been this way due to interaction with
the metal guys (with insulators). But these findings (closeness
of
the dipole to the array in signal strength) just do not seem
right.
I am using an Ameritron switch to switch between them. The
switch is at 60'. There is also a StackMaster box for selecting
the array antennas separately or together.
The SWR has not changed since installing the WARC dipole
that I can see.
Any "modeling experts" have any educated guesses and/or
experience similar to the above?
thanks.
g.
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