[amsat-bb] Should I "Flip or Not Flip" my m2 Leo_Pack

Douglas Phelps dphelps1 at ameritech.net
Mon Feb 15 17:51:29 UTC 2016

I am sure others will chime in if I am wrong:
Flipping the antenna upside down does not change the circular polarization.
The following example will explain the advantage of allowing the EL to move 180 degrees:
If your Azimuth rotor stops at North, and the satellite will pass from west of north to southeast, at the 360 degree point, the rotor has to stop tracking and move 360 degrees and reacquire the satellite.  If, on the other hand, you allow the rotors to move 180 degrees, then the control program will flip the antennas and then will add 180 degrees to the azimuth.  Now, when the satellite moves from west of North to east of South, the rotor can track the satellite continuously because in reality the rotor is rotating through South and does not have to stop and rotate 90 degrees.

      From: Steve Nordahl via AMSAT-BB <amsat-bb at amsat.org>
 To: "amsat-bb at amsat.org" <amsat-bb at amsat.org> 
 Sent: Monday, February 15, 2016 8:00 AM
 Subject: [amsat-bb] Should I "Flip or Not Flip" my m2 Leo_Pack
I have a lingering question. 
I installed my recently purchased m2 Leo-Pack per spec. Both antennas are RH per the instructions.I'm very pleased with the performance. However...
I have the system installed using a Yaseu G5500 and Green Heron AZ/EL controller. I have the system defaulted and restricted to 90 degrees vertical. I already know this AZ/EL can do the entire flip but have not done so.
Satellite reception limitations are driving me to ask this question.. Right now many of the sats I'm able to work in the current RH configuration and only going 90 degrees then doing a AZ to get back on it are good until they pass by me. Once the AZ rotation is completed then I have trouble getting back in or even hearing them. It appears I've fallen out of the correct orientation.
Would allowing the flip and having the antennas go upside down be OK? I believe this would make them LH at that point. Does anyone else do this? Is the Leo-Pack the exception for the flip rule? (If one exists)
Also, on the Leo-Pack system, I've seen images of others who have angled the antennas x instead of the default + orientation. Take?? What have others observed in performance by changing the angles?
Let me know.
Steve NS3L FN20hq   
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