Topband: Let's try stuff

[Tom Rauch]

> As I am sure you are aware, it's not only the close-in ground system
> that affects the effectiveness of the vertical, but the conditions in
> the Fresnel zone as well.  Most amateurs are not in a position to do
> anything about the latter, as it is outside the boundaries of their
> property.  The soil conductivity in WA is not terribly high, so the
> ground reflection will be very different from that found in an area
> such as yours.

ZL3REX works out much better on an inverted L than on a low 
horizontal. He lives in a valley without particularly good soil 
between high mountains, and has 30 radials on a 70 foot high 
Inverted L. Not a particularly large system, but it is in the clear from 
other antennas, masts and towers.  

VK3ZL (also in a poor soil area) works out about evenly comparing 
a dipole at 100 feet or more and a 40 foot radiator with partial coil 
loading and a whip at top, and the rest of the loading at the bottom, 
when conditions are good. He has about 20 or 30 radials. When 
conditions are poor, the vertical is generally better.

I'm afraid there are far too many variables for us to reach any 
conclusions by looking at even dozens of stations unless they had 
nearly ideal antenna systems in the clear.

The problem is we have no idea what the efficiency and pattern of 
any of the antennas is, unless we compare large full size antennas 
over what we know are efficient  ground systems with more than 50 
1/4 wl radials.

When we stuff a few antennas within a few hundred feet of each 
other on 160 for a comparison, we have little idea what is radiating.  
 
A large part of the results depend on the time of day we operate, 
and the conditions. When conditions are marginal my vertical 
smokes all the other antennas. When conditions are wide open, or 
peaking, and at times during geomagnetic storms, a low dipole can 
come very very close (but never quite as good) as the high dipole 
and vertical.   
 
> reporting his findings after those steps.  We all have to accept that
> a general rule which works for most people, may not be universal.

That is very true, and it is mostly decided by what happens to be 
wrong that we can't for some reason correct. I doubt it is soil or 
propagation, because there are too many good working systems in 
areas of poor soil. 

I think one reason verticals dominate in some locations is the 
users have room for ground systems and space to keep antennas 
apart and away from other vertical structures.
73, Tom W8JI
W8JI@contesting.com