[amsat-bb] Re: S band LEO Sat tracking
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 ___ 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
[amsat-bb] Re: S band LEO Sat tracking
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 milu...@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 ___ 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
[amsat-bb] Re: S band LEO Sat tracking
Here you go: http://www.amsat.it/Amsat-Italia_HamTV.pdf On Thu, Sep 5, 2013 at 4:59 AM, michael luft milu...@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 ___ 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
[amsat-bb] Re: S band LEO Sat tracking
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 milu...@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
[amsat-bb] Re: S band LEO Sat tracking
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 luftmilu...@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 ___ 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
[amsat-bb] Re: S band LEO Sat tracking
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 ___ 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
