[TenTec] ladder line

jerome schatten romers at shaw.ca
Sun Jul 10 12:59:08 EDT 2005


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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