----- Original Message -----
From: "Tom Rauch" <w8ji@contesting.com>
To: <zl1aih@ihug.co.nz>; <towertalk@contesting.com>
Sent: Monday, October 18, 2004 4:29 AM
Subject: Re: [TowerTalk] Re: Take off angles
> > I wonder if Guy's observation begs the question, if both
> ends have antennas
> > with different vertical apertures (or horizontal patterns)
> which is more often
> > the case, then different take off angles versus arrival
> angles might go some
> > way to explaining the apparent paradox of 'one-way-skip'.
>
> If my antenna has a deep null at the favored angle, it is
> there on both transmitting and receiving.
>
> I think most cases of "one-way skip" are really other easily
> explained very common effects, like high noise or poor
> antennas.
It could also be a polarization fading thing. The timescale of fades (or,
if you will, the distribution of multipath) has a pretty wide range.
How deep (and narrow) are the nulls in the vertical plane on a real antenna,
anyway? 10 dB? 20dB? And a corollary question, how wide a variation in
takeoff angle is there on a given path at a given time?
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|