[Top] [All Lists]

[Towertalk] Matching Individual Antennas in a Stacks

To: <>
Subject: [Towertalk] Matching Individual Antennas in a Stacks
From: (Mike Wetzel)
Date: Thu, 22 Aug 2002 01:49:47 -0500
I am replacing my switchbox and coax in my 4 high, 15 meter system.  The
antennas are 4 element W2PV antennas using a gamma match with a variable
cap.  After attaching new feed lines (odd multiple of a 1/4 wavelength) to
each antenna (and adding in another 1/4 wavelength to make a multiple of a
1/2 wavelength for measurement with a 259B), I discovered that one antenna
was out of whack with the others (higher swr and much lower resonant point).
Now since the bottom 3 antennas are on the same mast and rotate together
from the base of the tower (as opposed to the top one that is on a separate
rotator) I can't turn any of the lower antennas say 90 degrees from the
other 3 (to try an decouple antennas).  The antennas are exactly alike so
should I set all the gamma caps the same or should I try and adjust the
gamma caps individually to get the same resonant point and will I get a lot
of mutual coupling?  Antennas are at 40', 80' 120' and 160'.  Anyone with
any experience along those lines?

Mike W9RE

<Prev in Thread] Current Thread [Next in Thread>