[TowerTalk] KT34A problem

[n8de at thepoint.net]

Remove the balun from the feedline and connect the coax directly to  
the feedpoint.
I KNOW the balun is 4:1 ... that's not the point here.

If the balun is the problem, you should see a difference in 'resonant'  
frequency, even though the SWR will be way high.

If that occurs .. replace the balun.  If not, reinstall the balun and  
check the matching section further.

Don
N8DE

Quoting Dave Hachadorian <K6LL at ARRL.net>:

> 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 at yahoo.com>
> To: "TowerTalk" <towertalk at 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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