[amsat-bb] Re: STRaND1 polarity shift observation

[Ib Christoffersen]

Hi Ken,
You can experience the same effect from SO-50 when using circularly
polarized antennas on ground.
SO-50 also have linear antennas for the FM repeater.
I must change between RHCP and LHCP to get maximum signal during a pass.
Sometimes the difference is from zero to a very good signal.

I think it is interaction between the antennas and the rest of the structure
of the satellite combined with the passive attitude control and the angle
you see the satellite in.

73 OZ1MY/Ib

-----Oprindelig meddelelse-----
Fra: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] På vegne
af Ken Swaggart
Sendt: 04 March 2013 17:03
Til: i8cvs; Amsat - BBs
Emne: [amsat-bb] Re: STRaND1 polarity shift observation

Domenico,

Thanks for sending the K4KJ article.

However my question was why does STRaND1, which only has a whip antenna, 
sometimes appear to exhibit circular polarity characteristics?  I would 
expect a whip antenna transmitting from space to have the same signal 
strength on the ground using either RH or LH polarity on my receiving 
antenna.

73,
Ken, W7KKE

-----Original Message----- 
From: i8cvs
Sent: Monday, March 04, 2013 00:42
To: Ken Swaggart ; Amsat - BBs
Subject: Re: [amsat-bb] STRaND1 polarity shift observation

Hi Ken, W7KKE

The answere to your question is clearly described into the zipped article
"Circular Polarization" by K4KJ, 5 MB long that I have sent to you in
a separate email.

73" de

i8CVS Domenico

----- Original Message -----
From: "Ken Swaggart" <k.swaggart at charter.net>
To: <amsat-bb at amsat.org>
Sent: Monday, March 04, 2013 5:10 AM
Subject: [amsat-bb] STRaND1 polarity shift observation


> During my last pass at 0332Z, max elevation 45 degrees out over the
Pacific,
> I noticed that STRaND1 was stronger when I selected LHCP while approaching
> TCA.  After TCA, RHCP was stronger while it was receding.  I believe this
> cubesat uses a whip, so not sure what is causing this.
>
> Anyone have an idea why?
>
> Tnx,
> Ken, W7KKE
> CN75xa
>
>
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