Topband: beverage lobes

[Tom Rauch]

> That's quite interesting.  Bob Brown, NM7M, once told me 
> that for my
> location (southern Arizona near the Mexican border) 
> vertical
> polarization had an 11 (eleven!) db advantage versus 
> horizontal
> polarization for DX paths on 160m.

I get suspicious when I see a number that is obviously too 
precise or "firm". The ionosphere is a constantly changing 
soup. We would have a very difficult time making a stable 
11dB null filter out of stable lumped components, let alone 
in a constantly changing soup of ions.

Another problem is a horizontally polarized antenna like my 
dipole is only perfectly horizontal directly broadside to 
the element. As we move from those points the field tilts 
gradually becoming more and more vertical as we approach the 
ends. There are only two points where a perfect dipole is 
perfectly horizontal in polarization.

As for my tall and short (1/4 wave) verticals, there is 
hardly any difference in radiation at a given angle and gain 
unless we get to really high angles, so I don't think my 
test between verticals actually supports or disproves any 
theories at all about polarization or angle. All I'm saying 
is the verticals with a lower FS at higher angles have more 
signal than a high or low dipole that has higher FS at 
higher angles, and that leads me to believe the wave angle 
is lower than expected most of the time.

What I have been thinking of doing is loading my 318 foot 
tower with a top hat. That would give me an omni directional 
vertically polarized radiator at a high wave angle. 
Comparing that to a regular vertical would prove or disprove 
the wave angle theory.

But the real inhibition is the fact I don't care much. I 
only want to know what antenna works better 95% of the time 
so I can use that antenna, and that antenna is a good 
vertical.

73 Tom