If the swr is totally non-responsive like that, it is likely
either an instrument problem, or a problem in the driven
elements and feeding system. Try this:
1. Try a real swr bridge, instead of an analyzer. Sometimes
those analyzers get confused by broadcast station rf.
2. Verify that your feedline in the shack shows a short
circuit. The balun presents a dc short.
3. Up on the tower, verify that the phasing straps are not
touching each other or the boom. Then, reach out and measure
the dc resistance between the two halves of the rear driven
element. It should show a dc short, verifying the
connections through the straps, the front driven element,
the matching section, and balun. The balun should be a dc
short on this side too.
Dave Hachadorian, K6LL
Yuma, AZ
----- Original Message -----
From: "Gary Slagel" <gdslagel@yahoo.com>
To: "TowerTalk" <towertalk@contesting.com>
Sent: Sunday, February 15, 2009 11:12 PM
Subject: [TowerTalk] KT34A problem
Hi all,
I'd appreciate a little more tech help if anyone can give
it!
I just got a KT34A up on my tower. I had tested it on the
ground, sitting on top of a couple sawhorses, and SWR seemed
fine on all 3 bands according to my mfj antenna analyzer.
Got it up on the tower and I can't get even the slightest
dip in SWR from 7mhz to 40mhz... let alone on 14.025, 21.050
and 28.050 where I expect it! I've looked at connections and
all looks well except I'm a little suspicious of the
connection between the matching section and the driven
element. The aluminum strap which tightens around the
matching section and driven element seems loose. This is a
new/used antenna so I'm not sure if that was the case when
it was new.
I've put a different coax on it to make sure the coax isn't
the problem. Checked the antenna analyzer on another antenna
and all seems well there. Tried continuity testing between
the coax and different elements and basically, there was
continuity everywhere... coax braid to both elements,
etc.... I suppose I was seeing that because the balun was
still in line?
My best idea is to take the balun off the antenna and then
do some more continuity testing. I'm also wondering if the
old balun (15 years) didn't make it through the trip from
the ground to the tower. Of course, the next step after that
will be to take the antenna back off the tower... ugh!!!
Any advice on what to look at? Thanks for any input.
Gary Slagel/N0SXX
Hot Springs, SD
http://marina.fortunecity.com/sanpedro/351
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