Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
Elevation Patterns of Ground Mounted Vertical Monopoles
"Owen Duffy" wrote
On Tue, 26 Sep 2006 16:22:15 -0500, "Richard Fry" wrote: All ground-mounted, vertical monopoles through 5/8-wavelength in height develop maximum radiated relative field in the horizontal plane. If the Richard,is this true in general, or is it restricted to perfect ground (infinite size, perfect conductor, perfectly flat). NEC models would suggest that the major lobe of a monopole up to 5/8 wave over "real" ground is dependent on the ground characteristics, and can be quite high relative to the 0deg to 3deg region that people are focussing upon. __________________ For the shape of the relative field elevation pattern, it is true in general. A poor r-f ground for the monopole (i.e., a ground of high r-f resistance) will change the peak gain of that radiated elevation pattern, but not its shape. NEC evaluations typically don't show 100% relative field in the horizontal plane in the elevation pattern radiated by a vertical monopole except over a perfectly conducting ground plane, which is the root of all this confusion. Once the radiation is launched, then it becomes subject to the propagation losses for the path and frequency. But for verticals up to 5/8-wave tall, peak relative field always lies in the horizontal plane, regardless of the ground conditions on and near the radiator site. This is the basis used by the FCC in determining the coverage capabilities of AM broadcast stations, and has been proven to be a rather accurate approach going back some 60 years. RF |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Gain of Vertical Antenna | Antenna | |||
Cold Water Pipe Ground? | Antenna | |||
HF Vertical - ground mounted or 10-30 feet in air what works best for 20m-80m tx/rx | Antenna | |||
Oddity of ground mounted antenna's. | Antenna | |||
The Apollo Hoax FAQ | General |