On Wed, 17 May 2006 20:15:24 +0100, "Reg Edwards"
wrote:


How does Eznec know the number of hops? How does Eznec know which
angle is correct? How does Eznec know the height of the reflecting
layers? How does Eznec know the distances at which the radio wave
returns to Earth to be re-reflected?

Eznec doesn't know. And neither does the radio operator unless he
estimates everything AFTER the event.

Radio waves follow paths dictated by trigonometry and geometry and are
entirely independent of the idiosyncrasies of radio antennas.
----
Reg.


Reg, what were you drinking when you wrote this? EZNEC doesn't deal
at all with the atmosphere, it deals with the antenna. If the antenna
has a stronger lobe at 10 degrees in some given direction, EZNEC plots
it, but that doesn't mean the signal will come from that direction.

I have done only a little modeling with the ARRL version and the newer
free one. EZNEC plots the angles of the antenna from a horizontal and
vertical standpoint. Some antennas create single or double, primary
lobes, and others have more primary (highest gain) lobes. However,
when you change the elevation angle that you are watching, those
primary lobes may change to a different angle.

--
73 for now
Buck
N4PGW