[TowerTalk] Wire Antenna Dilemma...Help me decide!

David Gilbert xdavid at cis-broadband.com
Wed Oct 24 16:18:00 EDT 2007



With all due respect, I don't believe that is true.  Higher is almost 
always better, especially on the low bands, at least if you're trying to 
work beyond the adjacent state.  Better takeoff angle, lower ground 
loss, cleaner pattern, less absorption by surrounding buildings and 
trees ...

I used EZNEC to compare a horizontal half-wave 80m dipole at 110 feet 
with one that sloped from 110 feet to 15 feet (I think those were the 
heights given) over average ground.  The horizontal dipole had a peak 
lobe of 6.35 dbi at 36 degrees elevation angle.  The peak  for the 
sloped dipole was straight up, and it had 2.1 dbi at 36 degrees 
elevation.  I'd kill for 4 db additional gain on 80m.

I also checked the average arrival angles for the path from mid-America 
(Kansas) to Europe (as calculated from VOACAP) that are included with 
the ARRL Antenna Book and built into HFTA, the terrain modeling 
program.  Over the course of an entire sunspot cycle, the optimum 
takeoff/arrival angle for that path is less than 25 degrees elevation 98 
percent of the time.  Even within the U.S., the optimum angle is shown 
as being 36 degrees or less roughly 60 percent of the time. 

If it were me, I'd crank that puppy up as high as I could get it.

I certainly agree about the 4-square and beverages, though ... they 
represent a lot more hardware but would give better results.

Dave  AB7E




Bill Turner wrote:
> 2. Higher is not always better. On the low bands especially, even DX
> signals often arrive from high angles. If you really want to improve
> your DXing, go to Beverages and four-squares, etc. The height
> advantage you are talking about will hardly be noticeable. 
>
>
> 73, Bill W6WRT
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