----- Original Message ----- From: "Andrew Rich" vk4tec@people.net.au To: "OZ1MY" oz1my@privat.dk; "Amsat-Bb@Amsat. Org" amsat-bb@amsat.org Sent: Tuesday, January 01, 2008 4:54 PM Subject: [amsat-bb] Re: 70cm Yagi and AO-51
If I have this correct.
- LHCP recieved on a RHCP can knock your signal down by some 20dB
- LHCP matched with LHCP will result in a good signal.
So how does a linear antenna equate when receiving a circular signal ?
And the other way around, a circular receiving a linear signal ?
Andrew Rich VK4TEC
Hi Andrew, VK4TEC
Read please my article "Switching four Polarizations on a 70 cm Crossed Yagi"
Part-1 in AMSAT-Journal March/April 2007 Part-2 in AMSAT-Journal May/June 2007
Switching from Horizontal to Vertical and from RHCP to LHCP from the shak using 4 small coax relays antenna mounted you will get the better polarization match between the signal actually received from the satellite and your antenna system. In addition mounting the elements in X configuration over the boom you get Horizontal and Vertical polarizations for best performance in tropo communications.
If you cannot find the above articles please let me know.
73" de
i8CVS Domenico