Towertalk
[Top] [All Lists]

Re: [TowerTalk] TH7-DX 15M problem

To: k1ttt@arrl.net, towertalk@contesting.com
Subject: Re: [TowerTalk] TH7-DX 15M problem
From: Pete Smith N4ZR <n4zr@contesting.com>
Date: Thu, 27 Aug 2015 15:12:32 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Or a feedline connector that happens to be at a current or voltage node on 15?

73, Pete N4ZR
Download the new N1MM Logger+ at
<http://N1MM.hamdocs.com>. Check
out the Reverse Beacon Network at
<http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.

On 8/26/2015 3:43 PM, David Robbins wrote:
a problem with the amp?


Aug 26, 2015 03:28:05 PM, kzerohb@gmail.com wrote:

I have an odd issue with a TH7-DXS.

A while back I started to see a higher-than normal SWR, just on 15M, and just 
when running some smoke.

While barefoot the problem never arises.

The problem never happens on 20M or 10M under any circumstances. I can put a 
brick on the key at full legal limit on those bands, and the SWR is 1:1 forever.

If I key down full power (actually any power over about 500W) the SWR will be fine for about 
20-30 seconds, then will rise (not instantly, but “ramps” up) to about 2.5:1 
across the 15M band. If I unkey, kill the amp, then key up barefoot the SWR drops back to 1:1 
and stays there forever.

It is as if something heats up under power, then changes value. BUT ONLY ON 15M.

I suspected one of the 15 traps, and hunted down a full new set for a very nice 
price.

This morning I replaced all of the 15M traps, and freshened up all the slip 
joints in the antenna. It looks like new!

The problem persists.

Suggestions?

73, de Hans, K0HB
--
"Just a boy and his radio"™
--
Proud Member of:
. ARRL - http://www.arrl.org
. RSGB - http://www.rsgb.org
. A1 Operators - http://www.arrl.org/a-1-op
. Minnesota Wireless contesters - http://www.W0AA.org
. Arizona Outlaws contesters - http://www.arizonaoutlaws.net
. Twin City DX Assn - http://www.tcdxa.org
. Minnesota Amateur Radio Technical Society - http://www.mn-arts.org/
. Lake Vermilion DX Assn - http://www.lvdxa.org
. Royal Naval Amateur Radio Society - http://www.rnars.org.uk/
. SOC - http://www.qsl.net/soc
. CW Operators Club – http://www.cwops.org
. SKCC - http://www.skccgroup.com/
--
_______________________________________________



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



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

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
<Prev in Thread] Current Thread [Next in Thread>