[amsat-bb] Re: A432-20T AXIAL RADIATION???
domenico.i8cvs at tin.it
Sat Sep 19 10:30:01 PDT 2009
----- Original Message -----
From: "Luc Leblanc" <lucleblanc6 at videotron.ca>
To: <aa5pk at suddenlink.net>
Cc: <amsat-bb at amsat.org>; <eu-amsat at yahoogroups.com>
Sent: Saturday, September 19, 2009 10:38 AM
Subject: [amsat-bb] A432-20T AXIAL RADIATION???
> I want to thank's Glenn AA5PK who provide me with the antenna manual. When
> reading it i discover something new "axial radiation" the
> matching line can be made for LHCP and RHCP using RG-59 and RG-58
> combination for delay/matching lines
> and two RG-59 for delay/matching lines to produce this "axial radiation"?
Two RG-59 are to produce only the matching between two 50 ohm antennas in
parallel and a 50 ohm feed line but not delay is generated so that the axial
radiation is a linearly polarized wave.
> Is this gives both horizontal and vertical polarization at the same time?
The horizontal and vertical polarizations are both present but they are
two components that combines each the other to generate a resultant wich
is 1.41 greater in amplitude and this combination of two components and one
resultant at the same time is called axial radiation.
If you mount the elements in X configuration the above resultant can be
a vector horizontal or vertical depending on how you have oriented the arms
of the gamma match.
If you mount the elements in a + configuration the above resultant can be
a vector at 45° or 135° depending on how you have oriented the arms of
the gamma match.
Following the schematic diagram in the manual for axial radiation you get
at the same time a vertical and a horizontal components while the resultant
as per Pitagora theorem is oriented at 45°
> If it's the case it's could be a way to counteract the polarization change
> eg; having to manually rotate the antenna. Just note they don't called it
> "polarization" but "axial radiation"
In the axial radiation the maximum radiated power lies in the resultant
vector wich is the amplitude of a componenent vector multiplied by 1.41
In conclusion the axial radiation is a way to get at the same time two
crossed linear polarization components with a resultant linear radiation
in between shifted by 45° or 135° wich amplitude is 1.41 time greater.
> Luc Leblanc VE2DWE
> Skype VE2DWE
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