RE: [amsat-bb] re 10m antenna for downlink

["Reicher, James" <JReicher@xxxxxxxxxxx>]

Anyone remember the formula for calculating a full wave loop?

73 de N8AU, Jim in Raymore, MO

-----Original Message-----
From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org] On
Behalf Of Glen Gardner
Sent: Sunday, June 13, 2004 11:19 PM
To: amsat-bb@AMSAT.Org
Subject: [amsat-bb] re 10m antenna for downlink

I've had very good luck with a full wave horizontal loop antenna for use

with 10M downlink on LEO satellites in the past.
Put a 1:1 balun on it and use a Q section of 75 ohm coax (full wave loop

is around 90 ohms impedance) to get a good radiatin pattern and to get 
the impedance down close to 50 ohms and it works well. It will be 
omnidirectional in the horizontal plane and the height above ground can 
be adjusted to give  nice cardioid pattern upward for high eleivation 
passes.  About 8-10 feet off the ground is fine.

I had one in the rafters of my garage in Michigan, and I was quite 
pleased with the performance.


At present, I'm using a dipole made from helically wound CB trucker 
antennas (which I bought at radio shack a long time ago) and a home made

balun.
It works rather well , but does not have the pickup efficiency of a full

wave loop due to the small surface area ofthe dipole.

-- 
Glen E. Gardner, Jr.
AA8C
AMSAT MEMBER 10593
Glen.Gardner@verizon.net


http://members.bellatlantic.net/~vze24qhw/index.html


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