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.
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@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 feedlines?
73 de Pat --- KA9SCF. Amsat #35741
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