----- Original Message -----
From: "Richard Fry" <rfry@adams.net>
To: <topband@contesting.com>
Sent: Wednesday, October 24, 2012 2:23 PM
Subject: Re: Topband: Monopole Elev Pattern w.r.t. Earth Conductivity
from [Tom W8JI]:
The issue here is one of measurement distance and the assumed flat earth,
and how much the ground wave contributes to low angle radiation. We
obviously know radiation at zero degrees is not zero, as distant models
show.
<As to measured data, below with his permission is a quote from a broadcast
consultant acquaintance of mine who has made helicopter measurements of the
elevation patterns of MW monopoles.>
My point is that does not tell us what happens at the ionosphere.
If I just take a simple program like EZNEC, and use a small sense antenna
out in the distance, the results follow the trend you posted from the
helicopter. I certainly am not disputing that data, because it seems
reasonable.
AFAIK, we do not have measurements of arrival angles useful for long
distances or how lower angles from verticals might apply to that. All we
really know is using simple programs, low angle patterns are misleading.
73 Tom
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Topband reflector - topband@contesting.com
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