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Old September 13th 04, 08:10 PM
Frank
 
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"Roy Lewallen" wrote in message
...
Frank wrote:

Also the series inductor should have a very high Q for 160 m. A Q of

1000
will loose about 30% of your power.


Can you tell us how you calculated this? How much ground loss did you
assume?

Roy Lewallen, W7EL


I have run a number of NEC models (NEC-Win Pro), for ground mounted
verticals with a radial system, using the Sommerfeld/Norton ground models
(usually in the range of: Sigma = 0.02 S/m Er = 17) -- although not for the
specific dimensions indicated. My models would be approximately 0.001
wavelengths above ground (as per Cebik: Basic Antenna Modeling). The input
impedance calculated is of the order of 1.5 - j1500. From these data it is
relatively trivial to estimate the required Q of a series inductor.

I have been very interested in such antennas, but have never actually gotten
around to building -- just modeling! If the original poster is interested,
I would be very happy to model the specific dimensions.

Frank Meredith (VE6CB)