----- Original Message ----- From: "Luc Leblanc" lucleblanc6@videotron.ca To: aa5pk@suddenlink.net Cc: amsat-bb@amsat.org; eu-amsat@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:
http://books.google.ca/books?id=J4YcUA-rxJoC&pg=PA128&lpg=PA128&... xial+radiation&source=bl&ots=JtTANyGfs-
"-" Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe DSTAR urcall VE2DWE WAC BASIC CW PHONE SATELLITE
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 radiation.
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