[TenTec] ladder line

[denton]

Some months ago I picked up a used Gap Titan that had some wind damage....
Hauled it home, repaired the damage and installed it in the backyard.
SWR was as specified and indeed it was very quiet on recieve.
But comparing it to my 80 meter ladder line fed doublet also indicated that 
the Gap was several s units down on performance.
Since I paid very little for it, I pulled out the center coaxal matching 
network and the stubbs and with minor other modifications, now use it as a 
center fed vertical dipole, fed with 450 ohm twin lead with a Johnson 
Matchbox on 20 thru 10 meters..Whole different antenna.
----- Original Message ----- 
From: "jerome schatten" <romers at shaw.ca>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Sunday, July 10, 2005 9:59 AM
Subject: Re: [TenTec] ladder line


> NJ0IP wrote:
>> Hey guys, comparing a Gap Titan to a flat-top or a horizontal loop is
>> already an apples to oranges comparison.  The vertical is vertically
>> polarized and the two others are horizontally polarized.
>>
>> For short haul (NVIS), both horizontal antennas are going to work better
>> anyway.
>>
>> For long haul (transatlantic) you might just find that the GAP works 
>> better.
>> I've never had a GAP but I can assure you that my vertical dipole with 
>> just
>> 6m (19 ft.) per side works 10dB better than my horizontal full size 
>> dipole
>> up 13m (40 ft.) for transatlantic work.  Both are fed with ladderline.
>>
>> When I work local German hams, the vertical is about 3 S-Units weaker.
>>
>
> [...]
>
> What about the fact that the lower element of Rick's vertical dipole fed
> with ladder line is, of course, closer to the ground?  Does this
> constitute an unbalanced load?  Would we then assume that Rick's
> feedline radiates?
>
> I use a 30 ft rod on a tower fed with ladder line, the tower (30 ft.) as
> the other leg, with the same results as Rick describes.  One would think
> (at least this one) that if feedline radiation was significant, the long
> haul gain of the vertical (take off angle?) would be impaired. But I see
> as Rick does, better than 10db over a cf Zepp to Europe/Asia and even
> the east coast on 20/30/40.
>
> So, does it make any noticeable difference if the ladder line feeding
> these verticals radiates?  Can this be modeled easily?  Enqiring minds
> need to know.
>
> Jerome - VA7VV
> Vancouver
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