[amsat-bb] RHP LHP

[Jean Marc Momple]

Rich,

Most of the birds (VHF/UHF) are using dipoles or monopoles which are linear polarisation. The reasons to use circular polarisation is to reduce deep fades and the convention for HAMs is to use RHCP, some also use antennas which can be switch between RHCP & LHCP but the difference is generally quite small except if the satellite has circular polarisation antennas.

To explain a bit more: if you use linear polarisation at your ground station, due to the spinning and/or tumbling of the bird the fades may be up to 30dB but if you use circular the fades will be about 3 dB max.

73


Jean Marc (3B8DU)

> On Sep 24, 2019, at 6:01 AM, RG via AMSAT-BB <amsat-bb at amsat.org> wrote:
> 
> Hi,I was thinking about getting the my eggbeater antenna,One thing I was hesitant about it is that it does just RHP.Is it that most Leo's use RHP?I have no idea what satellites have RHP or LHP,If anyone can tell me where I can find that info that would be helpful.Please excuse my ignorance.ThanksRich
> marzo7088 at yahoo.com
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