Indeed, CP makes sense with a linear tx when you can't tell what the orientation would be. You give up a few dB to avoid deep fades. But I just can't figure out why you need to switch from RHP to LHP in such cases. I've heard a number of people say that it sometimes matters, but I don't understand the physics!
73,
Burns WB1FJ
On Sun, Mar 18, 2018 at 6:06 PM, Eduardo PY2RN py2rn@arrl.net wrote:
Jordan, most of the amateur radio LEOs SATs today have a linear polarized antenna attached, it is not possible to know which position it is in the time of the pass: H, V, moving, spinning... being completely random to the ground station which polarization the signal will be, for this reason I believe CP is more efficient but with RH/LH switching capability. 73 Ed PY2RN From: Jordan Trewitt jmtrewitt@gmail.com To: Eduardo PY2RN py2rn@arrl.net Cc: Brian cqkg8co@yahoo.com; "amsat-bb@amsat.org" amsat-bb@amsat.org Sent: Sunday, March 18, 2018 6:44 PM Subject: Re: [amsat-bb] Antenna Polarization Question
Maybe I'm not understanding it, but why does one need to switch between both, unless a particular satellite has LHCP or RHCP?JordanKF5COQ
On Sun, Mar 18, 2018, 16:34 Eduardo PY2RN py2rn@arrl.net wrote:
Hi Brian, Both. You are going to need to switch between RHCP and LHCP often during a sat pass. The same happens if using linear polarization (V/H) but in this case the switch between V and H will happen much more often than in CP. 73 Ed PY2RN
From: Brian via AMSAT-BB <amsat-bb@amsat.org>To: "amsat-bb@amsat.org" amsat-bb@amsat.org Sent: Sunday, March 18, 2018 6:21 PM Subject: [amsat-bb] Antenna Polarization Question
Should I be using LHCP or RHCP when setting up the 2 meter and 440 yagi's to work the LEO's.
Thank you
Brian, KG8CO
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Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb