[Elecraft] K3 & S9 43' Vertical

[Paul Christensen]

> If you do modeling, please be aware that the pro's know that all modeling
> programs on the planet terribly underestimate ground losses.

Another trap to avoid is thinking that (all other things being equal), more 
radials on a vertical will somehow result in better low-angle radiation. 
Well, it does, but only to the extent that the radials are also improving 
the entire vertical field strength profile through a minimization of ground 
loss.  The radials are not improving low angle radiation independently 
without improving overall radiation efficiency.

Medium and far-field ground conductivity rules when wanting efficient 
low-angle radiation from a vertical (or vertical dipole) at angles lower 
than about ten degrees above the horizon.  The mid to far field conductivity 
and geography also applies to horizontal antennas atop a tower, for example. 
The best real-world example I've ever seen of this is W4ZV's study of the 
W3CRA site.  A few pictures and graphs are worth ten thousand words.

Same general rules apply to 160m/80m four-square arrays.  It's just that to 
get directivity and low-angles from a horizontal antenna up in the air on 
those bands requires some pretty darn tall mounting structures (especially 
160m) that are beyond the capabilities of most station owners.  So, 
four-squares on the lower bands offer a good compromise.

I've lived with verticals for the last fifteen years and it's only been the 
last two years that I've had a horizontal wire antenna up for operation on 
80m-10m.  Unless there's no way of getting wire up in the air -- or unless I 
were immediately adjacent to salt water, an all-band vertical would be an 
antenna of last choice for me (perhaps small loops would be dead last!). 
I've also come to this conclusion for my own operating if I've got just one 
all-band (80m-10m) antenna:  (1) Flat top dipole at 0.15 - 0.20 wavelength 
high on 80m; (2) Open feeders; (3) and Remote ATU.  Justification:  On 80M, 
I'm mostly interested in regional 75m contacts and DX to a much lesser 
extent.  On 40m-10m, my interest in lower angles increases as frequency 
increases.  On 40m and above this is pretty much satisfied.  Open feeder 
length chosen so that the ATU sees a reasonable (under 1K Z, but more than 
25 ohms on all bands, all operating frequencies), high-quality open feeder 
spacers to minimize ATU changes and line loss with precipitation.

Paul, W9AC