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Re: [TowerTalk] KT-34A Tuning Problems

To: towertalk@contesting.com
Subject: Re: [TowerTalk] KT-34A Tuning Problems
From: Karl Bullock <karl@dixie-net.com>
Date: Tue, 09 Aug 2005 13:52:00 -0500
List-post: <mailto:towertalk@contesting.com>
Well, therein lies part of the problem.  The balun does not check good 
on the analyzer, and I don't have another 4:1 balun to try on it.  The 
beam's on a 50' fold-over tower, and it's a chore to crank it down, then 
back up again.

When I checked with just the coax (no balun), I didn't notice the 
impedance, only the resonance points (should have in retrospect), and 
the antenna was about 25' off the ground at a 45 degree angle at the 
time (cranked half-way up)

Would your (collective) advice be to wait until I have a 4:1, then 
install and check it? 

Thanks also to K6II for his reply.

Karl, WA5TMC

Marc Wullaert wrote:

>Karl,
>
>you can not use a 1:1 balun on this antenna!!
>You need a 4:1 balun.To check swr on the old balun
>just put a 200 ohm resister on the terminals and check with your
>analyzer ..shoud gave from 10mhz a good value !
>I shoud leave the antenne on the tower and first install the 4:1 balun!
>
>marc on4ma
>
>
>
>----- Original Message -----
>From: "Karl Bullock" <karl@dixie-net.com>
>To: <towertalk@contesting.com>
>Sent: Tuesday, August 09, 2005 6:03 PM
>Subject: Re: [TowerTalk] KT-34A Tuning Problems
>
>
>  
>
>>OK, thanks!  I'll pull her down and try that (obviously I missed this in
>>the archives).
>>
>>On the analyzer issue, I wasn't as much looking at the impedance as I was
>>the SWR.  Also, on the 10M band (since 29.35 MHz is the only resonant
>>point still in the ham bands), the SWR on both my TS-440's internal
>>meter, and on the tuner I've been using, show a 1.6:1 match with my
>>homemade coax balun (a 1:1 balun).  While that'd be close enought for me,
>>once tuned correctly, I'm assuming I'll need the 4:1 balun at that point.
>>
>>I'm also not sure the original balun is good at this point.
>>
>>Thanks for the hint.  I'll get back to 'yall....
>>
>>Karl, WA5TMC
>>
>>On Tue, 9 Aug 2005, David O Hachadorian wrote:
>>
>>    
>>
>>>Connect a dc ohmmeter between the 10 meter and 15
>>>meter trap capacitor outer tubes on each element half.
>>>After correcting for ohmmeter lead resistance, the
>>>total resistance should be less than 0.5 ohm. This
>>>one measurement tests all of the critical connections
>>>on each element half.
>>>
>>>Then connect the ohmmeter across the two halves of
>>>the rear driven element. Once again, it should read
>>>less than 0.5 ohm. This one measurement tests all
>>>the connections through the phasing straps, matching
>>>assembly and balun.
>>>-------------------
>>>That's a 4:1 balun on there, so when you fed the antenna directly with
>>>coax, the swr went very high, right? Try using a real swr bridge instead
>>>of the analyzer. Make sure the antenna is high enough during these test
>>>measurements.
>>>
>>>
>>>
>>>Dave Hachadorian, K6LL
>>>Big Bear Lake, CA
>>>_______________________________________________
>>>
>>>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
>>>      
>>>
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>  
>
>>>_______________________________________________
>>>TowerTalk mailing list
>>>TowerTalk@contesting.com
>>>http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>>
>>>      
>>>
>>_______________________________________________
>>
>>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
>>    
>>
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>  
>
>>_______________________________________________
>>TowerTalk mailing list
>>TowerTalk@contesting.com
>>http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>>
>>--
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>>
>>
>>    
>>
>
>_______________________________________________
>
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any 
>questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>.
>
>  
>
_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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