Towertalk
[Top] [All Lists]

[TowerTalk] TH11 and Shorty 40, Revisited

To: <towertalk@contesting.com>
Subject: [TowerTalk] TH11 and Shorty 40, Revisited
From: K7LXC@aol.com (K7LXC@aol.com)
Date: Tue, 3 Aug 1999 03:57:00 EDT
In a message dated 99-08-03 00:18:16 EDT, k3gt@pgh.net writes:

> Just got the TH11 up and find out that the VSWR on 17 meters is relatively 
> high, about 1.9.  BTW, rechecked all measurement 4 times while on the 
ground, 
> so there is no chance for a wrong element length. All traps where 
> disassembled and checked for integrity. The Autek analyzer calculates a 1.0 
> VSWR at 17.760 Mhz though. Approximately 10 feet above the TH11 is an old 
Hy-
> Gain 402BA which is as high as the mast will allow. The TT archives say 
that 
> acceptable spacing is anywhere from 8 to 14 feet. IMHO, I think the trouble 
> is the 40 interaction causing the VSWR to rise. 

      I haven't had any experience with this combo but a TH11/402CD was fine 
at about 8 foot spacing and beautiful at 10+ feet. A TH11/XM240 combo with 
about 8+ feet spacing degraded the TH11; turning the 40M 90 degrees made it 
worse. Maybe the TH11 is problematic with a stacked 40M yagi.
>  
>  Any thoughts and possible cures, short of a new mast?

        Roger Cox from Hy-Gain has unsubscribed but may have some answers. 
Let me know if you want his email address. I don't know how much better it'd 
be with more spacing. 

Cheers,   Steve    K7LXC

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


<Prev in Thread] Current Thread [Next in Thread>