[TowerTalk] KT34A problem

[Dave Hachadorian]

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



_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk at contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk