Alexander,
how much topload on your vertical?
Mine is 22m high with 300pF top. R at feedpoint is 24 Ohm. After some tests
(compared with DCF39) and calculations the radiating restistance seems to be
abt. 45 mOhm. Realistic?
73 es gl de Peter, dj9dw
----- Original Message -----
From: "Alexander S. Yurkov" <[email protected]>
To: <[email protected]>
Sent: Sunday, January 09, 2005 2:39 AM
Subject: Re: LF: Antenna plans de J.
Dear J,
On Fri, 7 Jan 2005, J. Allen wrote:
>
> Elnec shows the radiation resistance of the antenna with all resistances
set
> to zero, to be about 0.02053 Ohms.
It seems to be very strange. Simple formula for top
loaded vertical R=1600(H/lambda)^2 yelds about 0.16 Ohms if H=20m. Though
it is more resonable then 0.02 Ohms. Are You sure there is no mistake in
elnec modeling? Number of computer experiments with NEC done by me
for different antennas on 136 kHz yelds results very close to this simple
formula.
73 de RA9MB/Alex
http://www.qsl.net/ra9mb
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