Have you suspected the shorting stub between your two elements? Pull off the
coax at the bottom of the tower and put an Ohm meter up the line. You should
get a very low DC resistance reading. If it's open, the stub has a problem.
Another possible point of failure is the choke input on the front side of
the antenna.
I'm not familiar with the Cushcraft antenna, but all LPDA's are built to
more or less the same design.
Good luck!
73
dan
k0dan
-----Original Message-----
From: Gary Stone
Sent: February 16, 2012 09:54 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Beam problem
Greetings,
I have a Cushcraft ASL2010, 8 element Log up at 80 feet. All of a sudden
the SWR went up well over 5:1 on all 5 bands the antenna covers (20-10
meters).
I have an Array Solutions RatPak - 6 position antenna switch at the base of
the tower. I have a sloper for 80 meters and a G5RV.
I have completed several trouble shooting steps and still puzzled. The
most significant trouble shooting route was to use an SWR analyzer directly
at the base of the tower and in the shack. At the base of the tower
everything is eliminated except the coax to the beam and the beam itself
(including of course the little Cushcraft match box at the beam).
And here is the interesting thing: The SWR Analyzer can be set to show SWR
and IMPEDANCE. On all 5 bands the IMPEDANCE is around 50 ohms (which would
be correct) HOWEVER, the SWR remains very high.
Any help greatly appreciated.
Gary Stone, N5PHT
****** Gary Stone, N5PHT ******
**** 347 CR 1250 ****
**** Savoy, Texas 75479 ****
UNITED STATES OF AMERICA
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