[TowerTalk] R7000

Rudy Severns n6lf at arrl.net
Mon Sep 15 22:52:33 EDT 2008

N2EA has it right!

After I ran the test on the R7000 I had an exchange of notes with W1JR who 
was the original designer.  He pointed out that there is no "other half of 
the dipole".  It is loaded in such a way as to be complete.

My test was with the capacitive hat (the short radial rods) at the lower end 
of the antenna about 12" off ground.

While I didn't check it out on all the higher bands, it appears to me that 
it's a pretty good antenna for those with space limitations.

The point of my initial comment was that, with careful design, it is 
possible to get reasonable performance from a vertical which doesn't have a 
large radial system either on the ground or up in the air.  The most extreme 
example would be a simple full size vertical dipole.  As you shorten down 
from the full 1/2-wave dipole there are reasonably efficient loading schemes 
which can be used to approximate the dipole.

73, Rudy N6LF 

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