[TenTec] Re: Opinions on vertical

[Rob Atkinson, K5UJ]

<<As L. B. Cebik has modeled, vertical dipoles like the Gap do not benefit
from earth radials to any significant degree, and I do not have auxiliary
radials.  Just like a horizontal half wave dipole; a Vertical half wave
dipole is a complete antenna unto itself.>>

Lobe plots for vertical dipoles over perfect ground and average (typical) 
ground such as that found here in Illinois (See the Kraus W8JK Antenna books 
for example) show that while they differ in gain and angle, there would 
probably not be noticable difference i.e. the plots are similar enough that 
any improvement over average ground by the addition of a screen would 
probably not help that much, especially for a full sized vertical 1/2 w. 
center fed dipole.  My point was that a screen always offers an improvement 
over extremely poor ground such as sand and the type found in arid desert 
where the gentleman with the vertical antenna question resides.  This is why 
for example, the WWVH dipoles are on screens -- they are sited on poor sandy 
ground.
Further I would not be so quick to apply data, plots and calculations for 
test range full sized 1/2 w. center fed vertical dipoles at standard heights 
to the Gap, which is asymmetric, and physically small with a 40 meter loop, 
linear loading, stubs and capacitors (all depending on the band being 
operated), particularly on 80 meters.  : )

Rob Atkinson
K5UJ

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