[TowerTalk] [SPAM] KT-34 XA Problems

[Jim Walker]

Lee,

You didn't say whether you have EVER checked or changed the capacitor caps.
That antenna was/is notorious for having cracked capacitor caps, thus
allowing water to enter.  That will most certainly cause the symptoms
described.  The other issue with that antenna, especially of that age, is
there are so many aluminum to aluminum surfaces coming together that
oxidation is/can be a problem.  As well, loose connections are also suspect
with that antenna.

Unfortunately, your options are few.  Bring the antenna down for a complete
overhaul or, yes, the obvious other option.  BTW, you may already know that
M2 has a complete kit you can purchase for that antenna.

I've owned the 4-element as well as the big, six element KLM tribander and
they are/were great performing antennas.  But they are also one of the most
troublesome ever built.

Good Luck,

Jim
KB0X 

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of RTTYMAN at aol.com
Sent: Monday, October 16, 2006 1:27 PM
To: towertalk at contesting.com
Subject: [SPAM] [TowerTalk] KT-34 XA Problems

Hello All:
 
I have not been active since the VU4 folks provided the final  country I
needed to "have 'em all worked." Now, there are 2 "new ones" I need.  Having
had some previous problems with obvious higher than normal SWR, I  had
arcing in the Amp. that partially melted the tuning capacitor plates &  some
other components, as well as arcing in my tuner in addition to the tuner
NOT able to tune out the high SWR. The combination of equipment (Amp. &
tuner) has been the same for years. The Coax was replaced about 5-7 years
ago. I  previously melted the original Balun supplied with the XA. A M2
Balun replaced  the original one. I brought the antenna down & re-checked
ALL measurements  before putting it back in the air, long ago. It has served
well enough (thanks  to almost always having to use a tuner) over the years
to have 'em all worked  & confrimed, previously.
 
Recalling the arcing problems I had previously, I checked the XA the other
day with a
MFJ-259 B & discovered the following resonant frequencies where a SWR
reading of 1.1:1 exists except on 10 Meters where the lowest SWR reading
obtainable was 1.6:1.
 
20 Meters resonant at 16.4 MHz.
 
15 Meters resonant at 20.7 MHz.
 
10 Meters resonant (lowest point to resonance) at 28.4
 
The 2:1 SWR range width is as follows:
 
20 M - 335 KHz
 
15 M - 170 KHz
 
10 M - 1.01 MHz (there is also a 3.5 MHz 2:1 SWR curve at 34.5 to 38.0  MHz)
 
The M 2 Balun is about three years old ... and the KT-34 XA itself has been
in the air for the past twenty five (25) years! Despite its age, it has
obviously worked well & is testimony to the original design and  materials
used. 
This is certainly not a complaint about "not getting my monies  worth" over
the purchase. Several matters & personal  limitations prevented bringing the
antenna down sooner. It now appears  it is indeed time for a new tri-bander?
 
If anyone has any ideas as to why the resonance points have shifted so
dramatically, I would appreciate the information. From ground level, using
binoculars, all appears to my eyes to be just like it has been for years  &
years. 
Birds of many species such as Red Tailed Hawks &  Crows have, over the past
25 years, used the antenna as a stopping  point.
 
"Yes" ... I'm certain many of you will simply say "just go buy a new
antenna. You've gotten more than your monies worth from that purchase 25
years ago". 
That sentiment is ever so true & I'm fully aware of that: thank  you.
 
Sarcasm & less than positive comments and/or information are neither
invited, wanted, appreciated, or remotely desired. We can get enough
"contributors" 
IMO in those fields on other, "more than  controversial" matters on a myriad
of subjects rather easily.
 
Thanks in advance to all who may reply & contribute in a positive  manner.
 
73 & Good DX.
 
Les, NN6K  (RTTY Forever)
 
 
 
 
 
_______________________________________________



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