What kind of positioning accuracy can be expected form amateur PC Software and Antenna Rotators? Or, in other words: What kind of S band antenna ( gain or dimensions) is needed to track a S band LEO Sat?
73 Michael
Here you go:
http://www.amsat.it/Amsat-Italia_HamTV.pdf
On Thu, Sep 5, 2013 at 4:59 AM, michael luft milu111@gmail.com wrote:
What kind of positioning accuracy can be expected form amateur PC Software and Antenna Rotators? Or, in other words: What kind of S band antenna ( gain or dimensions) is needed to track a S band LEO Sat?
73 Michael _______________________________________________ Sent via AMSAT-BB@amsat.org. 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
Hi Michael.
Depends on the bandwidth of the modulation and the transmit power
But as a rough guide, I used a 12 turn helix with about 10 degree pointing accuracy with AO-51.
That's not good, but it works.
However, if you take the HAMTV equipment on the ISS, then you need a lot more gain on the ground and pointing accuracy of 2 degrees or better.
Thanks
David G0MRF
-----Original Message----- From: michael luft milu111@gmail.com To: amsat-bb amsat-bb@amsat.org Sent: Thu, Sep 5, 2013 7:42 pm Subject: [amsat-bb] S band LEO Sat tracking
What kind of positioning accuracy can be expected form amateur PC Software and Antenna Rotators? Or, in other words: What kind of S band antenna ( gain or dimensions) is needed to track a S band LEO Sat?
73 Michael _______________________________________________ Sent via AMSAT-BB@amsat.org. 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
When AO-51 used the S band downlink, I used a 18 inch TV dish with a 6 turn helix feed connected to a AIDC 3731 (K5GNA) down converter. I do not know the pointing accuracy as it was not used very much. On AO-40 (sobsob) I used a 4 foot primestar dish (heavy) with the same feed and dc. 73 Bob W7LRD
----- Original Message ----- From: "michael luft" milu111@gmail.com To: amsat-bb@amsat.org Sent: Thursday, September 5, 2013 2:59:29 AM Subject: [amsat-bb] S band LEO Sat tracking
What kind of positioning accuracy can be expected form amateur PC Software and Antenna Rotators? Or, in other words: What kind of S band antenna ( gain or dimensions) is needed to track a S band LEO Sat?
73 Michael _______________________________________________ Sent via AMSAT-BB@amsat.org. 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
Back when I found one like this -
http://www.newegg.com/Product/Product.aspx?Item=N82E16833997212
If I recall it was only about 45 bucks. from a company that I no longer remember their name (input welcomed) who was located in Florida someplace. Never had a problem once I got the VHF and UHF and it all lined up on a 10 feet boom.
Had a downeast microwave pre amp on it.
John, W0JAB
Bob, for comparison, I used a 30" x 24" grill for AO-40. I found that moving the dish +/- one "click" on my controller (10 degrees) would make a just-audible difference in the received signal strength. So, I figure 10 degrees is the 3db beam width, not good enough, apparently, for the ISS TV...
Greg KO6TH
Bob- W7LRD wrote:
When AO-51 used the S band downlink, I used a 18 inch TV dish with a 6 turn helix feed connected to a AIDC 3731 (K5GNA) down converter. I do not know the pointing accuracy as it was not used very much. On AO-40 (sobsob) I used a 4 foot primestar dish (heavy) with the same feed and dc. 73 Bob W7LRD
----- Original Message ----- From: "michael luft"milu111@gmail.com To: amsat-bb@amsat.org Sent: Thursday, September 5, 2013 2:59:29 AM Subject: [amsat-bb] S band LEO Sat tracking
What kind of positioning accuracy can be expected form amateur PC Software and Antenna Rotators? Or, in other words: What kind of S band antenna ( gain or dimensions) is needed to track a S band LEO Sat?
73 Michael _______________________________________________ Sent via AMSAT-BB@amsat.org. 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 AMSAT-BB@amsat.org. 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
On 9/5/2013 9:56 PM, Greg D wrote:
Bob, for comparison, I used a 30" x 24" grill for AO-40. I found that moving the dish +/- one "click" on my controller (10 degrees) would make a just-audible difference in the received signal strength. So, I figure 10 degrees is the 3db beam width, not good enough, apparently, for the ISS TV...
Greg KO6TH
Explain "one click at a time"
A rotor such as the Yeasu G5500 is a must. A "step" rotor (moves X degs at a time) just is not that good for a moving target.
John, W0JAB
participants (6)
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Bob- W7LRD -
g0mrf＠aol.com -
Greg D -
John Becker -
michael luft -
Stefan Wagener