Topband: Topband resource

[Jim Brown]

On 1/15/2020 9:55 AM, Roger Parsons via Topband wrote:
> There is very little pattern difference between a purely horizontal dipole and an inverted V provided that the angle of the V is not too acute. A horizontal dipole 5/8 wavelength high has predominantly low angle  radiation.

But there IS a difference in efficiency that looking ONLY at the pattern 
misses. To understand this, take a look at

http://k9yc.com/VertOrHorizontal-Slides.pdf

starting around slide #18, which plots the pattern of an 80M dipole as 
it's height is varied ON THE SAME AXES, and the following slide, which 
picks points off of those curves to show gain vs height at vertical 
angles of 5, 10, 15, 20, and 70 degrees. Slide #19 clearly shows that 
gain at low angles increases with mounting height. To apply these data 
to 160M, simply multiply height by 2.

There is, of course, also the matter of how horizontally and vertically 
polarized waves propagate, and how they are affected by nearby earth. 
Vertically polarized waves encounter a very strong loss component from 
poor soil conductivity, while horizontally polarized waves are almost 
unaffected.

73, Jim K9YC