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Old July 5th 07, 05:24 PM posted to rec.radio.amateur.antenna
Frank's Frank's is offline
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First recorded activity by RadioBanter: Dec 2006
Posts: 44
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"Richard Fry" wrote in message
...
Apologies, the link in my first post was an analysis
for 25 watts instead of 50 watts.

Here is the correct one:

http://i62.photobucket.com/albums/h8...Radiator-1.gif

RF


The antenna fed with a gamma match appears to be just a very narrow loop,
with very high copper losses.

Eliminating the gamma match, and base feeding the tower
I noticed in my previous analysis that I had read the wrong E-field column.
With
50 W input the peak E-field at 1000 m is 62.9 mV/m (44.5 mV/m RMS). At
24 km the E-field is 2.2 mV/m (1.5 mV/m RMS), at ground level, and 2.0 mV/m
(1.4 mV/m RMS) at 10,000 m elevation. These results appear to be very close
to Richard Fry's analysis, though not sure why there is a 6 dB difference.

Frank

CM 523 kHz NDB Antenna
CE
GW 1 1 0 0 0 0 2 -0.25 0.03125
GW 2 99 0 2 -0.25 0 200 -0.25 0.03125
GR 1 8
GW 12 60 0 0 0 0 0 120 0.03125
ce GW 13 5 0 0 90 0 2 90 0.03125
ce GW 14 45 0 2 90 0 2 2 0.03125
ce GW 15 5 0 2 2 0 0 2 0.03125
GS 0 0 0.304800
GE -1 -1 0
GN 2 0 0 0 4.0000 0.0100
EX 0 12 1 0 5173.59784 0.00000
FR 0 1 0 0 0.53 0.01
LD 5 0 0 0 5.8001E7
RP 1 1001 1 0000 0 90 1 1 1000
NE 0 1 1 11 0 1000 0.0 1.0 1.0 10
NE 0 1 1 11 0 24000 0.0 1.0 1.0 1000
EN