[Elecraft] Sloping Terrain vs Feedline Losses

Jim Brown jim at audiosystemsgroup.com
Fri Jul 15 14:02:51 EDT 2016


On Fri,7/15/2016 10:07 AM, Wes Stewart wrote:
> shows an example where IONCAP says there is no (usable) path between 
> two stations, yet QSOs are made.

Wes,

There are exceptions to every generalization, even when the 
generalization is good most of the time. I recall some well known person 
who had come up poor but was no longer saying "I've been poor and I've 
been rich, and rich is better." :)

Sure, there are times when a higher angle path is better than a low 
angle path (or exists when the low angle path is not present). But 
N6BV's statistical data for paths to various locations shows low angle 
paths to be better far more often than higher angle paths. It also shows 
high angle paths some smaller percentage of the time.

The HUGE problem with using the concept of "takeoff angle," and ONLY the 
takeoff angle to describe and evaluate antenna performance is that by 
looking at only one curve at a time, it fails to compare one antenna or 
mounting height to another. Again, my work looking at the effects of 
antenna height in a "flatland" QTH have all plotted the complete 
vertical pattern ON THE SAME GRAPH, which clearly shows that for the 
range of vertical angles where we can use the ionosphere, higher is 
better! N6BV presents this quite well as a "figure of merit" for the 
plots of his elevation studies in HFTA, while also showing the complete 
vertical data.

73, Jim K9YC



More information about the Elecraft mailing list