[amsat-bb] Re: A432-20T AXIAL RADIATION???

i8cvs domenico.i8cvs at tin.it
Sat Sep 19 13:29:36 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???

> Google give me a lot of return but all related to helical, helix antenna
as this one:

> "-"
> Luc Leblanc VE2DWE
> Skype VE2DWE
> www.qsl.net/ve2dwe
> DSTAR urcall VE2DWE
Hi Luc, VE2DWE

When we refere to helical antennas the radiation is called axial mode of
radiation and can be obtained if the circunference of a turn in ranging from
0.8 to 1.5 wavelenght  with a pitch angle between each turns of 12°
In this case the helix antenna radiates from the reflector in a direction
long the boom.
With different circunferences and pich angles the helix antenna radiates in
a direction perpendicular to the boom and this is called normal mode of

Read ANTENNAS by John Kraus edition 1950 chapter-7 the helical antennas
Sec.7-13 page 206

By the way the above radiation has nothig to do with the axial radiation of
your A432-20T

73" de

i8CVS Domenico

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