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Old March 9th 15, 01:45 PM posted to uk.radio.amateur,rec.radio.amateur.antenna
Richard Fry[_3_] Richard Fry[_3_] is offline
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First recorded activity by RadioBanter: Dec 2010
Posts: 18
Default E/M radiation from a short vertical aerial

"Spike" wrote in message
...

Imagine a short rod vertical aerial not connected to ground, for the (say)
160/80/60/40m bands, as might be found in a typical /M set-up, fed with RF
energy and operating over ground of average conductivity. (etc)

__________

Below is a link to a NEC study showing the 1.9 MHz fields radiated by a
3-meter vertical monopole driven against 4 x 2-meter horizontal radials,
where the entire assembly is elevated 9" above earth of average
conductivity. This might approximate a mobile installation of a whip
antenna mounted on a vehicle, except for the pattern distortions produced by
the body of the vehicle.

Radiation from this system at elevation angles other than near zero degrees
could act as direct waves, space waves or skywaves, depending on propagation
paths, propagation conditions, and the physical locations of receive
antennas.

http://s20.postimg.org/ipzwlc9kd/Fie...t_Vertical.jpg

R. Fry