[TowerTalk] Take off angles, VOACAP, etcf.

[Jim Lux]

----- Original Message -----
From: "Richard (Rick) Karlquist (N6RK)" <richard at karlquist.com>
To: "TowerTalk List" <towertalk at contesting.com>
Sent: Sunday, October 17, 2004 7:40 PM
Subject: RE: [TowerTalk] Take off angles, VOACAP, etcf.


> Has the following experiment been tried?
>
> Suppose you have 2 stations with stacks.
> Skip is long, so that propagation is better
> with both stations on their upper antenna,
> compared to both stations on their lower antenna.
> Now compare propagation with one station
> on the higher antenna and the other on the
> lower antenna.   According to the theory
> that the take off angles at both ends of
> the QSO must be matched, the mismatched
> configuration should be even worse than
> two low antennas.  It would also be interesting
> to see if the mismatched case is reciprocal
> (ie the high station goes to his low antenna
> and vice versa).
>
> I suspect this theory might be true for
> one hop paths, but not hold for multi-hop,
> ducting, etc.

I agree... the takeoff angle from each station will be determined by the
height of the ionosphere on the hop closest, and on a multihop path, it's
almost certainly different.

One might also theorize, though, that since there's a pretty big difference
between the take off for a single hop and a two or more, regardless of the
height, the high angle antenna on the Tx end will favor a multihop path,
which will have a high angle of arrival at the Rx end.

 I used to hear W7RM with
> his stack on 20 talking to OH stations
> with similar stacks, but I am not aware
> of him publishing any results.
>
> Rick N6RK
> ________________