Having the RHCP/LHCP switch is better than not having it since it gives you one more ace in the hole. Sure, it might only provide true value for a few seconds due to all the other variables, but when it occurs, it is nice to have for such high visibility events (especially if someone else is buying the hardware)... but for me personally, I'd probably not bother with the complexity for just a few more seconds of null avoidance...
Just an opinion.
Bob, Wb4aPR
-----Original Message----- From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Daniel Cussen Sent: Wednesday, June 01, 2016 5:00 AM To: AMSAT-BB Subject: Re: [amsat-bb] Polarization (attitude mostly)
I pushed back on that requirement due to cost and availability issues, but went ahead and installed the polarity switch on our CP antennas. With certainty I can tell you that at random times it made a huge difference in downlink signal level.
There was discussion on the ARISS OPs mailing list as to what to recommend to schools and what would give best "bang for buck" I am still not 100% convinced that a RHCP/LHCP switch is indeed necessary for ARISS contacts. The only way to confirm would be one station with both RHCP and LHCP both receiving at the exact same time and logging or recording the results. Most/all stations that have said the switch helped have not compared in real time not switching. Over time the ISS signal can vary wildly, in particular the solar panels can totally block the signal completely from time to time. There is a couple of stations with dual VHF circular systems (mostly ARISS tele-bridge ground stations) and I have asked them to help. Until we have real world comparisons at least in the case of the ISS, I am not sure a switch is needed. Can someone do tests to check? _______________________________________________ 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