Hi John!

Does anyone know the polarization of the 2.4 GHz transmissions from AO-51. Are they circular?  If so which polarity, RHCP or LHCP?  Are they linear? If so is there a preferred receiving polarization?  I have examined the AMSAT web site and many references on the Internet, but cannot seem to find the answer.

It's linear. Page 7 in the PDF at:

http://www.amsat.org/amsat-new/echo/OSCAR-E_Status_Report_5.pdf

has a brief description and a picture of the L/S antenna on AO-51.

73!

Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/

John,

It is linear. You are right that the information exists, but is sometimes not readily available. A good place to look is the Weekly Satellite Report which AMSAT distributes. For many, but not all satellites, that information is just below the frequency information. For AO-51 we find:

Mode and Antenna Polarization:

V: Linear U: TX A (usually digital)LHCP TX B (usually analog) RHCP L: Linear S: Linear

Alan WA4SCA

-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of jmfranke Sent: Tuesday, December 21, 2010 1:57 PM To: [email protected] Subject: [amsat-bb] AO-51 S-Band antenna polarization

Does anyone know the polarization of the 2.4 GHz transmissions from AO-51. Are they circular? If so which polarity, RHCP or LHCP? Are they linear? If so is there a preferred receiving polarization? I have examined the AMSAT web site and many references on the Internet, but cannot seem to find the answer.

Thanks,

John WA4WDL AMSAT member 10211

_______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

Timely info, as I am going to rebuild my directional satellite array this week using: 144: M2 2M7 12.4-dBi (vert-pol) 432: M2 436CP24 14-dBic (est.) RHCP (rear half of 436CP42) 2401: L-com Patch 8-dBic RHCP No L-band http://www.kl7uw.com/MODSATTWR.jpg

I may add pol switch to the 432 x-yagi later on.

This is my minimized array to lower wind resistance and get a tracking array back up in mid-winter. I can consider restoring the fully antenna array next summer when able to lower the tower on hinge-over base using my pickup truck.

At 11:10 AM 12/21/2010, Alan P. Biddle wrote:

John,

It is linear. You are right that the information exists, but is sometimes not readily available. A good place to look is the Weekly Satellite Report which AMSAT distributes. For many, but not all satellites, that information is just below the frequency information. For AO-51 we find:

Mode and Antenna Polarization:

V: Linear U: TX A (usually digital)LHCP TX B (usually analog) RHCP L: Linear S: Linear

Alan WA4SCA

-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of jmfranke Sent: Tuesday, December 21, 2010 1:57 PM To: [email protected] Subject: [amsat-bb] AO-51 S-Band antenna polarization

Does anyone know the polarization of the 2.4 GHz transmissions from AO-51. Are they circular? If so which polarity, RHCP or LHCP? Are they linear? If so is there a preferred receiving polarization? I have examined the AMSAT web site and many references on the Internet, but cannot seem to find the answer.

Thanks,

John WA4WDL AMSAT member 10211

---

Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

---

Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-1.4kw*, 432-100w*, 1296-testing*, 3400-winter? DUBUS Magazine USA Rep [email protected] ====================================== *temp not in service

jmfranke wrote:

Does anyone know the polarization of the 2.4 GHz transmissions from AO-51. Are they circular? If so which polarity, RHCP or LHCP? Are they linear?

Last Sunday I tried to receive the 2.4GHz downlink with a linear polarized wifi patch and signals seem to be linear polarized. I was all the pass rotating the antenna to get the better signal. Most of time signal was almost horizontally polarized.

73 de EA4EOZ

John,

From the information of the time I researched it soon after AO-51 was

launched, I recall it was linear but polarity was pointing angle dependent. I used a patch LH rotation feed on a 20" MDS dish with great results using a KG5NA down converter. Being circular there was one less variable to contend with during the short duration passes of AO-51. The gain of the dish with the low noise figure of the down converter more than made up for the 3 dB loss from linear to circular.

Art, KC6UQH

-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of jmfranke Sent: Tuesday, December 21, 2010 11:57 AM To: [email protected] Subject: [amsat-bb] AO-51 S-Band antenna polarization

Does anyone know the polarization of the 2.4 GHz transmissions from AO-51. Are they circular? If so which polarity, RHCP or LHCP? Are they linear? If so is there a preferred receiving polarization? I have examined the AMSAT web site and many references on the Internet, but cannot seem to find the answer.

Thanks,

John WA4WDL AMSAT member 10211

_______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

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