Re: a cheap LEO tracker for single op
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other)
Bill,
YES
Dave-KB1PVH
Sent from my Verizon Wireless Droid RAZR On May 28, 2013 1:14 PM, "Bill (W1PA)" w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
With practice, yes. Broad beamwidth antennas tilted up just a bit, and point just in azimuth.
73, Drew KO4MA
Sent from my iPhone
On May 28, 2013, at 12:57 PM, "Bill (W1PA)" w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
Bill,
You should find something in the reflector archives from 3 or 4 weeks ago where there was a discussion of what percentage of passes were overhead. It is an extremely low percentage. If I recall, most are at a an elevation of 33 degrees or less.
Because of the wide beam width of my antenna, tilting the antenna at an angle of 20 to 25 degrees works well for me. I can copy the satellite beacons down to the horizon. And only on the high angle passes do I have a any drop out
And because of the beam width of the antenna I don't need to keep a hand on the rotor control all the time. But it takes some practice to remember to look at the azimuth reading on the computer and to adjust the rotor accordingly every couple of minutes.
The problem comes on the more overhead passes. Because the bird is closest to my location at that time it seems to accelerate as it gets overhead. On those, though, it doesn't seem to be as critical that the rotor be adjusted anywhere close to the indicated azimuth. I can hear the signal starting to fade and it is a reminder to check the azimuth.
I would definitely run a number of passes with the setup before Field Day to make sure that everything works and that you can remember to do all the things that your three hands need to do during a pass!
73 from another newbie,
Rolf NR0T
On Tue, May 28, 2013 at 11:57 AM, Bill (W1PA) w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
I found my old web page with graphics that shows the exact geometry of passes and elevations. See http://aprs.org/LEO-tracking.html 70% of all pass times are below 22 degrees.
After the discussion a few weeks ago, I sat down today to begin building a web page on the topic and when I went to save it, there was a page already there that I had made years ago! So there it is.
Bob, Wb4aPR
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Rolf Krogstad Sent: Tuesday, May 28, 2013 4:17 PM To: Bill (W1PA) Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: a cheap LEO tracker for single op
Bill,
You should find something in the reflector archives from 3 or 4 weeks ago where there was a discussion of what percentage of passes were overhead. It is an extremely low percentage. If I recall, most are at a an elevation of 33 degrees or less.
Because of the wide beam width of my antenna, tilting the antenna at an angle of 20 to 25 degrees works well for me. I can copy the satellite beacons down to the horizon. And only on the high angle passes do I have a any drop out
And because of the beam width of the antenna I don't need to keep a hand on the rotor control all the time. But it takes some practice to remember to look at the azimuth reading on the computer and to adjust the rotor accordingly every couple of minutes.
The problem comes on the more overhead passes. Because the bird is closest to my location at that time it seems to accelerate as it gets overhead. On those, though, it doesn't seem to be as critical that the rotor be adjusted anywhere close to the indicated azimuth. I can hear the signal starting to fade and it is a reminder to check the azimuth.
I would definitely run a number of passes with the setup before Field Day to make sure that everything works and that you can remember to do all the things that your three hands need to do during a pass!
73 from another newbie,
Rolf NR0T
On Tue, May 28, 2013 at 11:57 AM, Bill (W1PA) w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
Good reading material Bob! Everyone should bookmark this page. Back when I had a sat station I had my antennas fixed at 45 degrees. The reason why is first I didn't know any better and second I built my mast out of PVC and 2" 45 degree elbows were all I could find locally. It worked well enough for me to make contacts. Then I had to move my antennas and never got around to putting everything back up again. If I ever do it again, I will cut off the 45 degree elbows and do it right.
73 Matt W5LL EM23
On 5/28/2013 3:48 PM, Robert Bruninga wrote:
I found my old web page with graphics that shows the exact geometry of passes and elevations. See http://aprs.org/LEO-tracking.html 70% of all pass times are below 22 degrees.
After the discussion a few weeks ago, I sat down today to begin building a web page on the topic and when I went to save it, there was a page already there that I had made years ago! So there it is.
Bob, Wb4aPR
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Rolf Krogstad Sent: Tuesday, May 28, 2013 4:17 PM To: Bill (W1PA) Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: a cheap LEO tracker for single op
Bill,
You should find something in the reflector archives from 3 or 4 weeks ago where there was a discussion of what percentage of passes were overhead. It is an extremely low percentage. If I recall, most are at a an elevation of 33 degrees or less.
Because of the wide beam width of my antenna, tilting the antenna at an angle of 20 to 25 degrees works well for me. I can copy the satellite beacons down to the horizon. And only on the high angle passes do I have a any drop out
And because of the beam width of the antenna I don't need to keep a hand on the rotor control all the time. But it takes some practice to remember to look at the azimuth reading on the computer and to adjust the rotor accordingly every couple of minutes.
The problem comes on the more overhead passes. Because the bird is closest to my location at that time it seems to accelerate as it gets overhead. On those, though, it doesn't seem to be as critical that the rotor be adjusted anywhere close to the indicated azimuth. I can hear the signal starting to fade and it is a reminder to check the azimuth.
I would definitely run a number of passes with the setup before Field Day to make sure that everything works and that you can remember to do all the things that your three hands need to do during a pass!
73 from another newbie,
Rolf NR0T
On Tue, May 28, 2013 at 11:57 AM, Bill (W1PA)w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
I'm not sure why a rotor or PC is needed. I have made many contacts in the past two years with an Arrow antenna (hand driven) and an IC-910 (manual Doppler correction.) With a little practice, it's really not difficult. The trick is to practice, practice, practice. Y
Over the weekend I made contacts on all the active satellites with no PC, no rotor, and no big arrays. Sure, Field Day will be a little more difficult. Be prepared. Pick your passes wisely. If you're on the East Coast don't pick a pass centered over North America. Choose one out over the Atlantic so that less stations will be in the footprint.
Last year, I snuck onto SO-50 in the middle of the night with nothing but an Arrow and ten watts. I'm not sure it'll be so easy this year considering that the recently published QST article will draw some fresh blood.
I'm glad this is getting discussed now. Maybe more stations will decide to dust off the gear and try contacts now rather than "wing it" for their 100 bonus points.
I am a firm believer in the KISS principle and also "Train for how you will operate; operate how you train."
73 Clayton W5PFG
On Tue, May 28, 2013 at 11:57 AM, Bill (W1PA) w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
Clayton, good stuff. You are certainly right, a rotor, PC and computer based doppler correction are all optional. There is a certain thrill in working SO 50 with a 10 W HT and a hand held arrow antenna, and pretty rewarding to. But honestly, when you work AO-7 on SSB with your fully automated ground station - happily correcting your RX/TX frequencies in 10 Hz. intervals controlled from one laptop, and your fully automated homebrew tracking AZ / EL rotors clicking away controlled from another laptop, your full duplex 'Earth Station' FT 847 producing a crystal clear signal from a 40 year old bird limping along on ancient solar panels and all you have to do is press the PTT button - that puts a smile on your face, too :) Anderas - VK4TH
________________________________ From: Clayton Coleman kayakfishtx@gmail.com To: Bill (W1PA) w1pa@hotmail.com Cc: AMSAT-BB amsat-bb@amsat.org Sent: Wednesday, 29 May 2013 9:33 AM Subject: [amsat-bb] Re: a cheap LEO tracker for single op
I'm not sure why a rotor or PC is needed. I have made many contacts in the past two years with an Arrow antenna (hand driven) and an IC-910 (manual Doppler correction.) With a little practice, it's really not difficult. The trick is to practice, practice, practice. Y
Over the weekend I made contacts on all the active satellites with no PC, no rotor, and no big arrays. Sure, Field Day will be a little more difficult. Be prepared. Pick your passes wisely. If you're on the East Coast don't pick a pass centered over North America. Choose one out over the Atlantic so that less stations will be in the footprint.
Last year, I snuck onto SO-50 in the middle of the night with nothing but an Arrow and ten watts. I'm not sure it'll be so easy this year considering that the recently published QST article will draw some fresh blood.
I'm glad this is getting discussed now. Maybe more stations will decide to dust off the gear and try contacts now rather than "wing it" for their 100 bonus points.
I am a firm believer in the KISS principle and also "Train for how you will operate; operate how you train."
73 Clayton W5PFG
On Tue, May 28, 2013 at 11:57 AM, Bill (W1PA) w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a single rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
Anderas,
I don't dispute the merits of a fully automated station. Your point was made very eloquently! AO-7 is only a couple of years older than me and I love using it.
In the spirit of "Field Day" I do think simple is better. That's just my opinion...
73 Clayton W5PFG On May 28, 2013 7:37 PM, "Andy Kellner" hawat1@yahoo.com wrote:
Clayton,
good stuff. You are certainly right, a rotor, PC and computer based doppler correction are all optional. There is a certain thrill in working SO 50 with a 10 W HT and a hand held arrow antenna, and pretty rewarding to.
But honestly, when you work AO-7 on SSB with your fully automated ground station - happily correcting your RX/TX frequencies in 10 Hz. intervals controlled from one laptop, and your fully automated homebrew tracking AZ / EL rotors clicking away controlled from another laptop, your full duplex 'Earth Station' FT 847 producing a crystal clear signal from a 40 year old bird limping along on ancient solar panels and all you have to do is press the PTT button - that puts a smile on your face, too :)
Anderas - VK4TH
From: Clayton Coleman kayakfishtx@gmail.com To: Bill (W1PA) w1pa@hotmail.com Cc: AMSAT-BB amsat-bb@amsat.org Sent: Wednesday, 29 May 2013 9:33 AM Subject: [amsat-bb] Re: a cheap LEO tracker for single op
I'm not sure why a rotor or PC is needed. I have made many contacts in the past two years with an Arrow antenna (hand driven) and an IC-910 (manual Doppler correction.) With a little practice, it's really not difficult. The trick is to practice, practice, practice. Y
Over the weekend I made contacts on all the active satellites with no PC, no rotor, and no big arrays. Sure, Field Day will be a little more difficult. Be prepared. Pick your passes wisely. If you're on the East Coast don't pick a pass centered over North America. Choose one out over the Atlantic so that less stations will be in the footprint.
Last year, I snuck onto SO-50 in the middle of the night with nothing but an Arrow and ten watts. I'm not sure it'll be so easy this year considering that the recently published QST article will draw some fresh blood.
I'm glad this is getting discussed now. Maybe more stations will decide to dust off the gear and try contacts now rather than "wing it" for their 100 bonus points.
I am a firm believer in the KISS principle and also "Train for how you will operate; operate how you train."
73 Clayton W5PFG
On Tue, May 28, 2013 at 11:57 AM, Bill (W1PA) w1pa@hotmail.com wrote:
Let me ask this another way...
Assuming minimal setup prior to each pass, can I track a LEO with a
single
rotor well enough for QSO’s? (single rotor control in one hand, VFO/Doppler on my other) _______________________________________________ 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
participants (8)
-
Andrew Glasbrenner -
Andy Kellner -
Bill (W1PA) -
Clayton Coleman -
Dave Webb KB1PVH -
Matt Patterson -
Robert Bruninga -
Rolf Krogstad