Topband: Low Dipoles

[Jim Brown]

On 12/11/2020 6:28 PM, donovanf at erols.com wrote:
> While there are always isolated cases when horizontal antennas
> might be the best transmitting antenna, in my experience they're
> isolated cases, usually occurring near sunrise.

Some years ago, I did a disciplined modeling study of horizontal dipoles 
for 40 and 80M at heights incrementing at 5-10 ft from about 30 ft to 
about 130 ft, plotting all vertical patterns on the same graph. It 
clearly showed that a higher antenna produced great field strength at 
all elevations up to about 70 degrees. This disproved universally 
believed fallacy that low antennas are better at high angles, which is 
the result of normalizing all to their maximum field strength, as ARRL 
plots default to. It also disproves the myth that an antenna must be low 
for NVIS. The same physics applied to 160M, scaled by wavelength. The 
fundamental reason is ground losses for the lower antennas.

http://k9yc.com/AntennaPlanning.pdf  (NCJ)
http://k9yc.com/VertOrHorizontal-Slides.pdf

By definition, almost ANY dipole we can rig for 160M is a low dipole as 
a fraction of a wavelength. An exception is one that W8JI rigged at 300 
ft or so. I had one at 120 ft, which I abandoned about ten years ago.

I fully agree with observations that DX can arrive at higher angles.

73, Jim K9YC