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[TowerTalk] KLM KT34A to KT34M2 Upgrade high SWR

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Subject: [TowerTalk] KLM KT34A to KT34M2 Upgrade high SWR
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Date: Wed, 26 Apr 2006 17:16:36 -0500
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Bought a well used KLM KT34A in 1990, fixed a few things on it, put it on my 
tower and it worked great until about 2004, all of the sudden the SWR went up 
on all bands. So last May I took down the antenna, bought the M2 upgrade kit 
and carefully installed all of the new items.
Never did really see what went wrong with the antenna although I tried to 
determine what the problem was. Inconclusive results.  Assumed the balun was 
ok, did not test it and don't know how to test it. Cleaned it all up, put on 
new #12 wire, used a light coat of Penetrox on everything. That M2 upgrade job 
is not for the faint of heart, plan on 40-50 hours work minimum. When 
completed, I did all of the continuity tests on the elements, cleaned the 
shorting bars on the reflector and director, did the resistance measurements on 
the element tips using a Fluke Multimeter which showed .1 ohm or less 
resistance when measuring between the 10m and 15m traps.  Installed antenna 
last week, still shows a poor SWR, like 2.3 and rising on every band.  Before 
it was installed, I triple checked every dimension and am sure everything is 
within 1/16" of where it is supposed to be. Everything is in the proper 
position and what is supposed to conduct is doing so at low resistance, what 
isn't supposed to conduct isn't.  Element-to-Boom measurements are per specs, I 
have an M2 2m12 mounted 59" above the KT34M2, and a 22 element Gulf Alpha 432 
antenna 59" above the 2m12, the manual states the stacking minimum should be 
40" or greater to avoid detuning so that measurement was exceeded by 19 inches. 
Is the Balun bad or did I miss something else?  New 9913F7 cable and Amphenol 
PL-259 connectors were used. I am quite confident that all mechanical 
connections and dimensions as well as parts placement are correct.  I am not 
certain about the Balun and can only hope that is the problem, think it can be 
changed on the antenna without taking the whole thing down. Anyone had a 
similar problem?  Is the Balun bad? 
Thanks and 73
Warren Flearl NØWF

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