[amsat-bb] Re: eggbeater II antenna performance oscar 50-52
Fhaighton at cogeco.ca
Fri Aug 17 10:03:10 PDT 2007
Hi Pat, Just a couple of thoughts,
You need a preamp to strengthen the signal from the satellite to
1) overcome any change of Polarity which may occur during reception.
2) to strengthen the signal to be stronger than any noise picked up in the
transmission line - which could compete with a week signal.
3) to overcome any losses in the transmission line and it's connectors which
can be significant.
Personally I use a high quality, low Loss, well shielded transmission line,
and a Pre-amp (capable of switching when RF is applied) and with a gain of
at least 25 db and a very low noise factor < 0.9db
I do get good results.
Robin Haighton VE3FRH
Immediate Past President AMSAT
Canadian Representative to ARISS
Past President BARC
Member ARRL, RAC, RSGB, AMSAT-NA, AMSAT-UK.
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of Patrick Green
Sent: Friday, August 17, 2007 9:15 AM
To: Amsat BB
Subject: [amsat-bb] Re: eggbeater II antenna performance oscar 50-52
What kind of feedline are you using for the UHF antenna? This is meant as
an open question to all related to this. Do you *really* need a preamp
because you are using something lossy and noisy like most braided shield
73 de Pat --- KA9SCF.
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