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Re: [TenTec] 229B tuner: Slight upward creep of SWR

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] 229B tuner: Slight upward creep of SWR
From: Byron Cordes via TenTec <tentec@contesting.com>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Mon, 23 Jul 2018 12:57:07 -0500
List-post: <mailto:tentec@contesting.com>
I would be surprised if 100watts would be making the caps change!  I think it 
would be a common mode problem. I would try to change ladder line length a 
little and if it a vertical antenna maybe more ground radials .
  I have had that problem before on a inverted L  140 foot long. Went down to 
100 foot total length SWR rock solid running 1500 . 
  Also have changed ladder line length on one antenna doing the SWR creep. 
   And one other time just moving feed line 3 feet farther from steel sheeting 
fixed that problem. 
   There are many variables that could be the cause of SWR creep along with 
those caps. 
 Byron AC9PA.       73 ‘s

Sent from my iPad

> On Jul 23, 2018, at 6:46 AM, Bob McGraw K4TAX <rmcgraw@blomand.net> wrote:
> 
> Your balun is OK.  The ceramic disk capacitors are heating and changing 
> value.  Usually they will return to near the original value when they cool.  
> As to damage, at some temp they will go "bang".  As long as you are satisfied 
> with the performance you should be OK.  
> 
> Bob, K4TAX
> 
> 
> Sent from my iPhone
> 
>> On Jul 23, 2018, at 1:09 AM, Peter Klein <boulanger.croissant@gmail.com> 
>> wrote:
>> 
>> Thanks for all the good info. One thing though. The SWR creep may be a 
>> “clear indication“ that I am using the wrong balun, but that ain’t the case. 
>> I am using a 1:1 Guanella balun, 17 turns RG-58 on whatever torroid Rick, 
>> DJ0IP recommended. The antenna I noticed the “creep“ with is a 40 foot 
>> vertical dipole, which has quite low impedance on 40m and 80m even without 
>> the “help” of a 4:1 balun.
>> 
>> My purpose in asking my question was to ascertain whether it is safe to run 
>> my set up at 100 W despite the creep. I can easily tweak a dial to retune 
>> when running digital. And a creep never rises past 1.4:1, and usually less. 
>> I don’t care about perfection, I just want to make sure I’m not risking 
>> blowing any disc capacitors. My educated guess is that everything is fine, I 
>> simply wanted a reality check here.
>> 
>> Rest assured, if I was going to run higher power, I would be making the 
>> suggested modifications. But that’s not really in the cards right now.
>> 
>> --Peter, KD7MW
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> 
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