Greetings
Many thanks to the amsat directors for deciding to provide U/V transponder. I noted the website summary mentioned SSB, CW and ETC. Regarding ETC., could beginners use FM in a specific portion of the passband near perigee? I realize it is not as power efficient as SSB and CW but this capability might attract more beginning users. One could assign a voluntary single frequency for this use.
Two further questions; Could someone please explain further the capabilities of the U/V text messaging mode. Would this incude the use of typical packet equipment?
Could some old timers describe a typical AO-13 or AO-40 mode U/V station for my education and to help me build a station.
Thanks for any replies, patrick n2oeq
At 10:23 AM -0400 10/8/06, McGrane wrote:
Could someone please explain further the capabilities of the U/V text messaging mode. Would this incude the use of typical packet equipment?
No. In order to transfer information (even at low data rates) with very small antennas and low power, it's necessary to use every trick in the digital optimization book, so it won't be compatible with existing packet equipment.
By very small, it's meant that the radio might clip onto the back of a handheld PDA, with an antenna system small enough to be manageable handheld. Probably not as small as a rubber duckie, but something that doesn't need pointing. Exact details are still to be designed.
There's not a lot of detail yet about how the system will work from a user standpoint. The work so far has been on making the links work and determining the spacecraft requirements. For higher level architecture, one idea is to use Jabber, which is an open protocol for instant messaging (keyboard chat) used on the internet. It's thought that many of the applications that work on APRS would work great on this system (not just positioning).
Now would be a good time to throw out your ideas for applications for a service like this, so the system designers can try to accommodate them.
(The above info is based on what I heard at the Space Symposium and not to be considered official in any way.)
Could some old timers describe a typical AO-13 or AO-40 mode U/V station for my education and to help me build a station.
The baseline AO-13 Mode B station was a 20-foot-long circularly polarized cross-yagi for 2m, plus a 14-to-20-foot circularly polarized cross-yagi for 70cm, mounted for azimuth and elevation rotation. Rather short low-loss coax feed (e.g., Belden 9913) or a mast-mounted low-noise preamp on the downlink. On the uplink, operators who wanted to work under all conditions had about 100 watts available, but under good conditions much less power was needed. Continuously variable uplink power was considered mandatory since being too loud is bad practice and being too weak meant marginal stations couldn't hear you. SSB and/or CW capability on the radios. Most conveniently, a single-box "satellite" rig would allow the use of a single knob to tune around the transponder, but separate transmit and receive rigs were also common.
Seriously hard-core stations who wanted to hear down to the transponder noise floor even when conditions were poor would phase two or more of the 20-foot cross-yagis. It was good to have a few of those stations around to pick out the very weak uplinks, but it wasn't really necessary for most users to have that much gain.
Computer control of the rotators was convenient but not necessary, since the satellite moves slowly across the sky. Likewise computer control of radio frequency was generally not required, since the Doppler shift changed rather slowly.
73 -Paul kb5mu@amsat.org
Two thoughts on Paul's comments:
1. I was also excited by what I heard about the Text Messaging proposal. Has anybody approached (or future tense, could anyone approach) Kenwood for a re-program of their TH-D7? I suspect that the internal processing capabilities won't be sufficient, but if it worked, that might provide a readily available platform for a new product. If not the D7, maybe the D700?
2. What I thought I heard at the Symposium was that we wouldn't need such a massive station to work Eagle's traditional UV transponder. While I expect there were many such "baseline" stations in existence around the planet, I wonder how many are still operational after years of no HEO UV birds and all the affects of weather? Then there are those of us who cannot put such a station on the air, lacking the space and/or neighborhood setting (cc&r) to do so. I managed a few contacts on AO-10 and one on AO-13 with my 8 footer, under unusually good conditions, but they were an ear strain. I had planned to need to go to LS on Echo until the Symposium convinced me that I'd be fine on UV. Do I need to re-think that?
Thanks to all the presenters at the Symposium. Great event!
Greg KO6TH
----Original Message Follows---- From: Paul Williamson kb5mu@amsat.org To: McGrane tmcgrane@suffolk.lib.ny.us CC: Amsat BB amsat-bb@amsat.org Subject: [amsat-bb] Re: Eagle U/V modes Date: Sun, 8 Oct 2006 09:39:56 -0700
At 10:23 AM -0400 10/8/06, McGrane wrote:
Could someone please explain further the capabilities of the U/V text messaging mode. Would this incude the use of typical packet equipment?
No. In order to transfer information (even at low data rates) with very small antennas and low power, it's necessary to use every trick in the digital optimization book, so it won't be compatible with existing packet equipment.
By very small, it's meant that the radio might clip onto the back of a handheld PDA, with an antenna system small enough to be manageable handheld. Probably not as small as a rubber duckie, but something that doesn't need pointing. Exact details are still to be designed.
There's not a lot of detail yet about how the system will work from a user standpoint. The work so far has been on making the links work and determining the spacecraft requirements. For higher level architecture, one idea is to use Jabber, which is an open protocol for instant messaging (keyboard chat) used on the internet. It's thought that many of the applications that work on APRS would work great on this system (not just positioning).
Now would be a good time to throw out your ideas for applications for a service like this, so the system designers can try to accommodate them.
(The above info is based on what I heard at the Space Symposium and not to be considered official in any way.)
Could some old timers describe a typical AO-13 or AO-40 mode U/V station for my education and to help me build a station.
The baseline AO-13 Mode B station was a 20-foot-long circularly polarized cross-yagi for 2m, plus a 14-to-20-foot circularly polarized cross-yagi for 70cm, mounted for azimuth and elevation rotation. Rather short low-loss coax feed (e.g., Belden 9913) or a mast-mounted low-noise preamp on the downlink. On the uplink, operators who wanted to work under all conditions had about 100 watts available, but under good conditions much less power was needed. Continuously variable uplink power was considered mandatory since being too loud is bad practice and being too weak meant marginal stations couldn't hear you. SSB and/or CW capability on the radios. Most conveniently, a single-box "satellite" rig would allow the use of a single knob to tune around the transponder, but separate transmit and receive rigs were also common.
Seriously hard-core stations who wanted to hear down to the transponder noise floor even when conditions were poor would phase two or more of the 20-foot cross-yagis. It was good to have a few of those stations around to pick out the very weak uplinks, but it wasn't really necessary for most users to have that much gain.
Computer control of the rotators was convenient but not necessary, since the satellite moves slowly across the sky. Likewise computer control of radio frequency was generally not required, since the Doppler shift changed rather slowly.
73 -Paul kb5mu@amsat.org _______________________________________________ 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 used my 8-9 ft U Band M2 crossed Yagi on AO-40 with my S Band dish and downconverter with no problem. I plan to operate my 8-9 ft m2 crossed yagis on P3E and Eagle.
Les W4SCO
- What I thought I heard at the Symposium was that we wouldn't need such a
massive station to work Eagle's traditional UV transponder. While I expect there were many such "baseline" stations in existence around the planet, I wonder how many are still operational after years of no HEO UV birds and all the affects of weather? Then there are those of us who cannot put such a station on the air, lacking the space and/or neighborhood setting (cc&r) to do so. I managed a few contacts on AO-10 and one on AO-13 with my 8 footer, under unusually good conditions, but they were an ear strain. I had planned to need to go to LS on Echo until the Symposium convinced me that I'd be fine on UV. Do I need to re-think that?
Thanks to all the presenters at the Symposium. Great event!
Greg KO6TH
Hi Les,
Same here - I used a 2x8 element crossed yagi for the AO-40 uplink, and a BBQ dish for down. I was figuring on adding an L-band uplink, but don't have the radio or antenna yet. If I can use the 8 element 2m yagi for Eagle, I'm all set.
Greg KO6TH
----Original Message Follows---- From: sco@sco-inc.com To: aMSAT-BB@amsat.org Subject: [amsat-bb] Re: Eagle U/V modes Date: Wed, 11 Oct 2006 00:35:38 -0400
I used my 8-9 ft U Band M2 crossed Yagi on AO-40 with my S Band dish and downconverter with no problem. I plan to operate my 8-9 ft m2 crossed yagis on P3E and Eagle.
Les W4SCO
- What I thought I heard at the Symposium was that we wouldn't need such
a
massive station to work Eagle's traditional UV transponder. While I
expect
there were many such "baseline" stations in existence around the planet, I wonder how many are still operational after years of no HEO UV birds and
all
the affects of weather? Then there are those of us who cannot put such a station on the air, lacking the space and/or neighborhood setting (cc&r)
to
do so. I managed a few contacts on AO-10 and one on AO-13 with my 8
footer,
under unusually good conditions, but they were an ear strain. I had
planned
to need to go to LS on Echo until the Symposium convinced me that I'd be fine on UV. Do I need to re-think that?
Thanks to all the presenters at the Symposium. Great event!
Greg KO6TH
_______________________________________________ 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
Both P3E and Eagle will have 50w class amplifiers on V band. This will be loud. The 50w amplifier for S band with a 4 vacuum dielectric patch array delivering 14 dBi will be loud on Eagle. I am uncertain what the plans are for P3E on the amplifier but the usual antenna is a Helix. The new DL site will have details probably.
Bob N4HY
sco@sco-inc.com wrote:
I used my 8-9 ft U Band M2 crossed Yagi on AO-40 with my S Band dish and downconverter with no problem. I plan to operate my 8-9 ft m2 crossed yagis on P3E and Eagle.
Les W4SCO
- What I thought I heard at the Symposium was that we wouldn't need such a
massive station to work Eagle's traditional UV transponder. While I expect there were many such "baseline" stations in existence around the planet, I wonder how many are still operational after years of no HEO UV birds and all the affects of weather? Then there are those of us who cannot put such a station on the air, lacking the space and/or neighborhood setting (cc&r) to do so. I managed a few contacts on AO-10 and one on AO-13 with my 8 footer, under unusually good conditions, but they were an ear strain. I had planned to need to go to LS on Echo until the Symposium convinced me that I'd be fine on UV. Do I need to re-think that?
Thanks to all the presenters at the Symposium. Great event!
Greg KO6TH
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
We're planing on 1 kW PEP EIRP (25 W into a 14 dBic antenna) U-band uplinks for SSB on Eagle.
73,
John KD6OZH
----- Original Message ----- From: "Greg D." ko6th_greg@hotmail.com To: kb5mu@amsat.org; tmcgrane@suffolk.lib.ny.us Cc: amsat-bb@amsat.org Sent: Wednesday, October 11, 2006 04:08 UTC Subject: [amsat-bb] Re: Eagle U/V modes
Two thoughts on Paul's comments:
- I was also excited by what I heard about the Text Messaging proposal.
Has anybody approached (or future tense, could anyone approach) Kenwood for a re-program of their TH-D7? I suspect that the internal processing capabilities won't be sufficient, but if it worked, that might provide a readily available platform for a new product. If not the D7, maybe the D700?
- What I thought I heard at the Symposium was that we wouldn't need such
a massive station to work Eagle's traditional UV transponder. While I expect there were many such "baseline" stations in existence around the planet, I wonder how many are still operational after years of no HEO UV birds and all the affects of weather? Then there are those of us who cannot put such a station on the air, lacking the space and/or neighborhood setting (cc&r) to do so. I managed a few contacts on AO-10 and one on AO-13 with my 8 footer, under unusually good conditions, but they were an ear strain. I had planned to need to go to LS on Echo until the Symposium convinced me that I'd be fine on UV. Do I need to re-think that?
Thanks to all the presenters at the Symposium. Great event!
Greg KO6TH
----Original Message Follows---- From: Paul Williamson kb5mu@amsat.org To: McGrane tmcgrane@suffolk.lib.ny.us CC: Amsat BB amsat-bb@amsat.org Subject: [amsat-bb] Re: Eagle U/V modes Date: Sun, 8 Oct 2006 09:39:56 -0700
At 10:23 AM -0400 10/8/06, McGrane wrote:
Could someone please explain further the capabilities of the U/V text messaging mode. Would this incude the use of typical packet equipment?
No. In order to transfer information (even at low data rates) with very small antennas and low power, it's necessary to use every trick in the digital optimization book, so it won't be compatible with existing packet equipment.
By very small, it's meant that the radio might clip onto the back of a handheld PDA, with an antenna system small enough to be manageable handheld. Probably not as small as a rubber duckie, but something that doesn't need pointing. Exact details are still to be designed.
There's not a lot of detail yet about how the system will work from a user standpoint. The work so far has been on making the links work and determining the spacecraft requirements. For higher level architecture, one idea is to use Jabber, which is an open protocol for instant messaging (keyboard chat) used on the internet. It's thought that many of the applications that work on APRS would work great on this system (not just positioning).
Now would be a good time to throw out your ideas for applications for a service like this, so the system designers can try to accommodate them.
(The above info is based on what I heard at the Space Symposium and not to be considered official in any way.)
Could some old timers describe a typical AO-13 or AO-40 mode U/V station for my education and to help me build a station.
The baseline AO-13 Mode B station was a 20-foot-long circularly polarized cross-yagi for 2m, plus a 14-to-20-foot circularly polarized cross-yagi for 70cm, mounted for azimuth and elevation rotation. Rather short low-loss coax feed (e.g., Belden 9913) or a mast-mounted low-noise preamp on the downlink. On the uplink, operators who wanted to work under all conditions had about 100 watts available, but under good conditions much less power was needed. Continuously variable uplink power was considered mandatory since being too loud is bad practice and being too weak meant marginal stations couldn't hear you. SSB and/or CW capability on the radios. Most conveniently, a single-box "satellite" rig would allow the use of a single knob to tune around the transponder, but separate transmit and receive rigs were also common.
Seriously hard-core stations who wanted to hear down to the transponder noise floor even when conditions were poor would phase two or more of the 20-foot cross-yagis. It was good to have a few of those stations around to pick out the very weak uplinks, but it wasn't really necessary for most users to have that much gain.
Computer control of the rotators was convenient but not necessary, since the satellite moves slowly across the sky. Likewise computer control of radio frequency was generally not required, since the Doppler shift changed rather slowly.
73 -Paul kb5mu@amsat.org _______________________________________________ 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
1kw EIRP... I've got about 100w into a 2x8 CP antenna (guessing 8dbi ?), so that's about the same. How does this compare to the uplink requirements for U/S on AO-40? I was able (accidentally) to get Leila's attention with that.
Greg KO6TH
----Original Message Follows---- From: "John B. Stephensen" kd6ozh@comcast.net To: "Greg D." ko6th_greg@hotmail.com,kb5mu@amsat.org,tmcgrane@suffolk.lib.ny.us CC: amsat-bb@amsat.org Subject: Re: [amsat-bb] Re: Eagle U/V modes Date: Wed, 11 Oct 2006 07:14:05 -0000
We're planing on 1 kW PEP EIRP (25 W into a 14 dBic antenna) U-band uplinks for SSB on Eagle.
73,
John KD6OZH
----- Original Message ----- From: "Greg D." ko6th_greg@hotmail.com To: kb5mu@amsat.org; tmcgrane@suffolk.lib.ny.us Cc: amsat-bb@amsat.org Sent: Wednesday, October 11, 2006 04:08 UTC Subject: [amsat-bb] Re: Eagle U/V modes
Two thoughts on Paul's comments:
- I was also excited by what I heard about the Text Messaging proposal.
Has anybody approached (or future tense, could anyone approach) Kenwood for a re-program of their TH-D7? I suspect that the internal processing capabilities won't be sufficient, but if it worked, that might provide a readily available platform for a new product. If not the D7, maybe the D700?
- What I thought I heard at the Symposium was that we wouldn't need such
a massive station to work Eagle's traditional UV transponder. While I expect there were many such "baseline" stations in existence around the planet, I wonder how many are still operational after years of no HEO UV birds and all the affects of weather? Then there are those of us who cannot put such a station on the air, lacking the space and/or neighborhood setting (cc&r) to do so. I managed a few contacts on AO-10 and one on AO-13 with my 8 footer, under unusually good conditions, but they were an ear strain. I had planned to need to go to LS on Echo until the Symposium convinced me that I'd be fine on UV. Do I need to re-think that?
Thanks to all the presenters at the Symposium. Great event!
Greg KO6TH
----Original Message Follows---- From: Paul Williamson kb5mu@amsat.org To: McGrane tmcgrane@suffolk.lib.ny.us CC: Amsat BB amsat-bb@amsat.org Subject: [amsat-bb] Re: Eagle U/V modes Date: Sun, 8 Oct 2006 09:39:56 -0700
At 10:23 AM -0400 10/8/06, McGrane wrote:
Could someone please explain further the capabilities of the U/V text messaging mode. Would this incude the use of typical packet equipment?
No. In order to transfer information (even at low data rates) with very small antennas and low power, it's necessary to use every trick in the digital optimization book, so it won't be compatible with existing packet equipment.
By very small, it's meant that the radio might clip onto the back of a handheld PDA, with an antenna system small enough to be manageable handheld. Probably not as small as a rubber duckie, but something that doesn't need pointing. Exact details are still to be designed.
There's not a lot of detail yet about how the system will work from a user standpoint. The work so far has been on making the links work and determining the spacecraft requirements. For higher level architecture, one idea is to use Jabber, which is an open protocol for instant messaging (keyboard chat) used on the internet. It's thought that many of the applications that work on APRS would work great on this system (not just positioning).
Now would be a good time to throw out your ideas for applications for a service like this, so the system designers can try to accommodate them.
(The above info is based on what I heard at the Space Symposium and not to be considered official in any way.)
Could some old timers describe a typical AO-13 or AO-40 mode U/V station for my education and to help me build a station.
The baseline AO-13 Mode B station was a 20-foot-long circularly polarized cross-yagi for 2m, plus a 14-to-20-foot circularly polarized cross-yagi for 70cm, mounted for azimuth and elevation rotation. Rather short low-loss coax feed (e.g., Belden 9913) or a mast-mounted low-noise preamp on the downlink. On the uplink, operators who wanted to work under all conditions had about 100 watts available, but under good conditions much less power was needed. Continuously variable uplink power was considered mandatory since being too loud is bad practice and being too weak meant marginal stations couldn't hear you. SSB and/or CW capability on the radios. Most conveniently, a single-box "satellite" rig would allow the use of a single knob to tune around the transponder, but separate transmit and receive rigs were also common.
Seriously hard-core stations who wanted to hear down to the transponder noise floor even when conditions were poor would phase two or more of the 20-foot cross-yagis. It was good to have a few of those stations around to pick out the very weak uplinks, but it wasn't really necessary for most users to have that much gain.
Computer control of the rotators was convenient but not necessary, since the satellite moves slowly across the sky. Likewise computer control of radio frequency was generally not required, since the Doppler shift changed rather slowly.
73 -Paul kb5mu@amsat.org _______________________________________________ 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
800W EIRP should work -- the SNR will just be 2 dB lower. We used 1 kW EIRP as the requirement as it is the power limit in many parts of the U.S. I don't remember any publishedspecification for the AO-40 uplink, so I can't make a numberical comparison.
73,
John KD6OZH
----- Original Message ----- From: "Greg D." ko6th_greg@hotmail.com To: kd6ozh@comcast.net; kb5mu@amsat.org; tmcgrane@suffolk.lib.ny.us Cc: amsat-bb@amsat.org Sent: Thursday, October 12, 2006 04:15 UTC Subject: [amsat-bb] Re: Eagle U/V modes
1kw EIRP... I've got about 100w into a 2x8 CP antenna (guessing 8dbi ?), so that's about the same. How does this compare to the uplink requirements for U/S on AO-40? I was able (accidentally) to get Leila's attention with that.
Greg KO6TH
----Original Message Follows---- From: "John B. Stephensen" kd6ozh@comcast.net To: "Greg D." ko6th_greg@hotmail.com,kb5mu@amsat.org,tmcgrane@suffolk.lib.ny.us CC: amsat-bb@amsat.org Subject: Re: [amsat-bb] Re: Eagle U/V modes Date: Wed, 11 Oct 2006 07:14:05 -0000
We're planing on 1 kW PEP EIRP (25 W into a 14 dBic antenna) U-band uplinks for SSB on Eagle.
73,
John KD6OZH
----- Original Message ----- From: "Greg D." ko6th_greg@hotmail.com To: kb5mu@amsat.org; tmcgrane@suffolk.lib.ny.us Cc: amsat-bb@amsat.org Sent: Wednesday, October 11, 2006 04:08 UTC Subject: [amsat-bb] Re: Eagle U/V modes
Two thoughts on Paul's comments:
- I was also excited by what I heard about the Text Messaging proposal.
Has anybody approached (or future tense, could anyone approach) Kenwood for a re-program of their TH-D7? I suspect that the internal processing capabilities won't be sufficient, but if it worked, that might provide a readily available platform for a new product. If not the D7, maybe the D700?
- What I thought I heard at the Symposium was that we wouldn't need such
a massive station to work Eagle's traditional UV transponder. While I expect there were many such "baseline" stations in existence around the planet, I wonder how many are still operational after years of no HEO UV birds and all the affects of weather? Then there are those of us who cannot put such a station on the air, lacking the space and/or neighborhood setting (cc&r) to do so. I managed a few contacts on AO-10 and one on AO-13 with my 8 footer, under unusually good conditions, but they were an ear strain. I had planned to need to go to LS on Echo until the Symposium convinced me that I'd be fine on UV. Do I need to re-think that?
Thanks to all the presenters at the Symposium. Great event!
Greg KO6TH
----Original Message Follows---- From: Paul Williamson kb5mu@amsat.org To: McGrane tmcgrane@suffolk.lib.ny.us CC: Amsat BB amsat-bb@amsat.org Subject: [amsat-bb] Re: Eagle U/V modes Date: Sun, 8 Oct 2006 09:39:56 -0700
At 10:23 AM -0400 10/8/06, McGrane wrote:
Could someone please explain further the capabilities of the U/V text messaging mode. Would this incude the use of typical packet equipment?
No. In order to transfer information (even at low data rates) with very small antennas and low power, it's necessary to use every trick in the digital optimization book, so it won't be compatible with existing packet equipment.
By very small, it's meant that the radio might clip onto the back of a handheld PDA, with an antenna system small enough to be manageable handheld. Probably not as small as a rubber duckie, but something that doesn't need pointing. Exact details are still to be designed.
There's not a lot of detail yet about how the system will work from a user standpoint. The work so far has been on making the links work and determining the spacecraft requirements. For higher level architecture, one idea is to use Jabber, which is an open protocol for instant messaging (keyboard chat) used on the internet. It's thought that many of the applications that work on APRS would work great on this system (not just positioning).
Now would be a good time to throw out your ideas for applications for a service like this, so the system designers can try to accommodate them.
(The above info is based on what I heard at the Space Symposium and not to be considered official in any way.)
Could some old timers describe a typical AO-13 or AO-40 mode U/V station for my education and to help me build a station.
The baseline AO-13 Mode B station was a 20-foot-long circularly polarized cross-yagi for 2m, plus a 14-to-20-foot circularly polarized cross-yagi for 70cm, mounted for azimuth and elevation rotation. Rather short low-loss coax feed (e.g., Belden 9913) or a mast-mounted low-noise preamp on the downlink. On the uplink, operators who wanted to work under all conditions had about 100 watts available, but under good conditions much less power was needed. Continuously variable uplink power was considered mandatory since being too loud is bad practice and being too weak meant marginal stations couldn't hear you. SSB and/or CW capability on the radios. Most conveniently, a single-box "satellite" rig would allow the use of a single knob to tune around the transponder, but separate transmit and receive rigs were also common.
Seriously hard-core stations who wanted to hear down to the transponder noise floor even when conditions were poor would phase two or more of the 20-foot cross-yagis. It was good to have a few of those stations around to pick out the very weak uplinks, but it wasn't really necessary for most users to have that much gain.
Computer control of the rotators was convenient but not necessary, since the satellite moves slowly across the sky. Likewise computer control of radio frequency was generally not required, since the Doppler shift changed rather slowly.
73 -Paul kb5mu@amsat.org _______________________________________________ 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
My best recollection is that there never was one published and though this could have been easily derived once on orbit, the propulsion incident ended any hope of that.
Bob N4HY
John B. Stephensen wrote:
800W EIRP should work -- the SNR will just be 2 dB lower. We used 1 kW EIRP as the requirement as it is the power limit in many parts of the U.S. I don't remember any publishedspecification for the AO-40 uplink, so I can't make a numberical comparison.
73,
John KD6OZH
----- Original Message ----- From: "Greg D." ko6th_greg@hotmail.com To: kd6ozh@comcast.net; kb5mu@amsat.org; tmcgrane@suffolk.lib.ny.us Cc: amsat-bb@amsat.org Sent: Thursday, October 12, 2006 04:15 UTC Subject: [amsat-bb] Re: Eagle U/V modes
1kw EIRP... I've got about 100w into a 2x8 CP antenna (guessing 8dbi ?), so that's about the same. How does this compare to the uplink requirements for U/S on AO-40? I was able (accidentally) to get Leila's attention with that.
Greg KO6TH
At 9:08 PM -0700 10/10/06, Greg D. wrote:
- I was also excited by what I heard about the Text Messaging
proposal. Has anybody approached (or future tense, could anyone approach) Kenwood for a re-program of their TH-D7?
It will take a lot more than reprogramming. The Kenwood radios contain the wrong kind of modem, and it's implemented in hardware (the same on both the HT and the mobile). It will take a rather complete redesign of the unit to work on Eagle's text messaging mode.
In any case, it would be premature to approach manufacturers. The parameters aren't fixed yet, and need to be subjected to peer review, implementation, and testing before they can be.
I would not expect big commercial manufacturers like Kenwood to be involved in the first round of hardware, any more than they were involved in making packet TNC's before TAPR productized and popularized them. And a fully-integrated radio/TNC like the TH-D7 and TM-D700 was still longer in coming. So, don't hold your breath.
- What I thought I heard at the Symposium was that we wouldn't
need such a massive station to work Eagle's traditional UV transponder.
The U/V transponder isn't all that different from the ones we've flown before on high orbits. The size of the spacecraft constrains the antenna designs that are possible at VHF and UHF. The antenna systems haven't really been designed yet for the new spaceframe, but the example drawing showed three dipoles on VHF and a few patches for UHF. Those are not killer antennas, and there are no magical modulation or coding tricks available for SSB and CW users.
It might be possible to allocate more power to the downlink than before. Or maybe not; we do want to run the analog and digital payloads simultaneously (all the time) and the power budget hasn't been finalized. I believe the current plan is to run more power than before, but not spectacularly so.
This not being Star Trek, we can't improve the uplink by shunting warp power to the receivers. The SDX implementation technology will help on the uplink by solving the alligator problem once and for all, but it will still be necessary to use enough power+gain on the ground to close the link to the distant spacecraft with its compromise antennas.
I'll leave the forecasting of exact ground station requirements to those who have studied the link budgets. And then I will take the results with a grain of salt. I hope it will be better than before. But what's really better than before is the ACP (Advanced Communication Package, that is, the digital stuff), and people who don't want to put up large antennas should really be looking forward to that rather than the U/V transponder.
In my opinion.
73 -Paul kb5mu@amsat.org
At 9:08 PM -0700 10/10/06, Greg D. wrote:
- I was also excited by what I heard about the Text Messaging
proposal.
Are any of the details of the Text Messaging system published yet? I looked on Eaglepedia, but didn't find any details. Will the SDK regenerate the bits at the satellite, or will it just send the ground station's digital signal back through the SDR bent pipe?
Is this going to be a heavy coded downlink like the AO-40 telemetry (Reed Solomon plus Viterbi r=1/2 k=7)? Coding? Baud rate? Message format? Modulation scheme?
kb5mu@amsat.org wrote:
This not being Star Trek, we can't improve the uplink by shunting warp power to the receivers.
Hmmmm... What would be the RF equivalent of a Heisenberg compensator? :-)
Douglas KA2UPW/5
Are any of the details of the Text Messaging system published yet?
At the AMSAT conference I was reminded that AO16 is still alive and well and digipeating. And Doug's UPW sound card software allows for the uplink and there are other programs for doing the PSK downlink, so we have everthing we need to use this venerable satellite for things like Field Day QSO's.
I wonder if there is published a plug-and-play guide to operating AO16 in Keyboard CHAT or QSO mode? In fact, with soundcard downlink software, then we could add it to the global APRS Satellite gateways system too. The uplink uses AX.25 1200 baud packet through an FM transmitter (though manchester encoded). But again, this is trivial to generate in APRS trackers and/or UPW's uplink software.
Bob
Hi Bob,
you can see - APRS works very well with AO-16...
2006-Okt-11 19:31:19 PACSAT-1>LSTAT,DK3WN-1,I:I P:0x1D00 o:0 l:6654 f:7171, d:1 st:1 2006-Okt-11 19:31:36 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:31:44 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:31:45 PACSAT-1>TIME-1,DK3WN-1,I:PHT: uptime is 2432/13:08:49. Time is Wed Oct 11 16:59:55 2006 2006-Okt-11 19:31:49 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:31:49 PACSAT-1>LSTAT,DK3WN-1,I:I P:0x1D00 o:0 l:6654 f:7171, d:1 st:1 2006-Okt-11 19:31:53 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:31:57 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:32:15 PACSAT-1>TIME-1,DK3WN-1,I:PHT: uptime is 2432/13:09:19. Time is Wed Oct 11 17:00:25 2006 2006-Okt-11 19:32:16 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:32:19 PACSAT-1>AMSAT,DK3WN-1,I:1616Z 02/18/2003 2006-Okt-11 19:32:28 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:32:43 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:32:45 PACSAT-1>TIME-1,DK3WN-1,I:PHT: uptime is 2432/13:09:49. Time is Wed Oct 11 17:00:55 2006 2006-Okt-11 19:32:49 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:33:04 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:33:19 PACSAT-1>LSTAT,DK3WN-1,I:I P:0x1D00 o:0 l:6654 f:7171, d:1 st:1 2006-Okt-11 19:33:31 DK3WN-1>APU25N,PACSAT-1*,DK3WN-1,I:=4943.90N/00857.30E-APRS TEST via AO-16 - 73, Mike 2006-Okt-11 19:34:19 PACSAT-1>LSTAT,DK3WN-1,I:I P:0x1D00 o:0 l:6654 f:7171, d:1 st:1
73, Mike DK3WN
-----Ursprüngliche Nachricht----- Von: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] Im Auftrag von Robert Bruninga Gesendet: Mittwoch, 11. Oktober 2006 14:41 An: 'Douglas Quagliana'; kb5mu@amsat.org Cc: amsat-bb@amsat.org Betreff: [amsat-bb] Re: Eagle U/V modes
Are any of the details of the Text Messaging system published yet?
At the AMSAT conference I was reminded that AO16 is still alive and well and digipeating. And Doug's UPW sound card software allows for the uplink and there are other programs for doing the PSK downlink, so we have everthing we need to use this venerable satellite for things like Field Day QSO's.
I wonder if there is published a plug-and-play guide to operating AO16 in Keyboard CHAT or QSO mode? In fact, with soundcard downlink software, then we could add it to the global APRS Satellite gateways system too. The uplink uses AX.25 1200 baud packet through an FM transmitter (though manchester encoded). But again, this is trivial to generate in APRS trackers and/or UPW's uplink software.
Bob
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Doug:
In Eaglepedia there are the San Diego Meeting notes, the excel spreadsheet (adapted from KA9Q by N4HY), and in the annual meeting procedings there is an article by Frank Brickle, AB2KT on the technical approach to the messaging itself but there is not yet a coherent presentation of the entire system. We are making sure the receiver design on 70cm, a fantastic job by KD6OZH of this thread, has the correct design for the LO's. After that design is in final revision, which will enable us to compute a theoretical performance, we can sign antennas, transmitters, etc.
In the interim, AB2KT and I will be attempting to get the job done on the design of the device up to prototype stage using HP donations in the form of IPAQ's, the HPSDR Odyssey (http://hpsdr.org), and we will be testing through AO-7.
We are going to set up a jabber service on the web using AMSAT or other facilities so we can perfect the protocol. The protocol doesn't care if the medium is the internet or the satellite!
There is a lot to do to make this work and finalize the design. I SUSPECT that it will have a great deal more coding than you have presented here and will use residual carrier to help acquistion and tracking. The plan is indeed to have the spacecraft do acquisition, tracking, demod/decode of the uplink and then remod on the downlink. This service is so fantastic in potential, but it might require additional horsepower to accomplish, and this has to be weighed in the balance of power/complexity . . .
Bob
Douglas Quagliana wrote:
At 9:08 PM -0700 10/10/06, Greg D. wrote:
- I was also excited by what I heard about the Text Messaging
proposal.
Are any of the details of the Text Messaging system published yet? I looked on Eaglepedia, but didn't find any details. Will the SDK regenerate the bits at the satellite, or will it just send the ground station's digital signal back through the SDR bent pipe?
Is this going to be a heavy coded downlink like the AO-40 telemetry (Reed Solomon plus Viterbi r=1/2 k=7)? Coding? Baud rate? Message format? Modulation scheme?
kb5mu@amsat.org wrote:
This not being Star Trek, we can't improve the uplink by shunting warp power to the receivers.
Hmmmm... What would be the RF equivalent of a Heisenberg compensator? :-)
Douglas KA2UPW/5
Hi Paul,
Thanks for your thoughts. I kind of figured the Kenwood would be out, but it was worth asking.
As for the link budget on UV, I think the uplink side isn't the problem - a bigger amp can offset a smaller antenna, within reason. But the downlink is my worry; I may only have half the antenna that would otherwise be expected. Sounds like we just don't know yet, so I'll keep monitoring the progress. No panic.
Thanks again,
Greg KO6TH
----Original Message Follows---- From: Paul Williamson kb5mu@amsat.org To: "Greg D." ko6th_greg@hotmail.com CC: amsat-bb@amsat.org Subject: RE: [amsat-bb] Re: Eagle U/V modes Date: Wed, 11 Oct 2006 00:33:07 -0700
At 9:08 PM -0700 10/10/06, Greg D. wrote:
- I was also excited by what I heard about the Text Messaging proposal.
Has anybody approached (or future tense, could anyone approach) Kenwood for a re-program of their TH-D7?
It will take a lot more than reprogramming. The Kenwood radios contain the wrong kind of modem, and it's implemented in hardware (the same on both the HT and the mobile). It will take a rather complete redesign of the unit to work on Eagle's text messaging mode.
In any case, it would be premature to approach manufacturers. The parameters aren't fixed yet, and need to be subjected to peer review, implementation, and testing before they can be.
I would not expect big commercial manufacturers like Kenwood to be involved in the first round of hardware, any more than they were involved in making packet TNC's before TAPR productized and popularized them. And a fully-integrated radio/TNC like the TH-D7 and TM-D700 was still longer in coming. So, don't hold your breath.
- What I thought I heard at the Symposium was that we wouldn't need such
a massive station to work Eagle's traditional UV transponder.
The U/V transponder isn't all that different from the ones we've flown before on high orbits. The size of the spacecraft constrains the antenna designs that are possible at VHF and UHF. The antenna systems haven't really been designed yet for the new spaceframe, but the example drawing showed three dipoles on VHF and a few patches for UHF. Those are not killer antennas, and there are no magical modulation or coding tricks available for SSB and CW users.
It might be possible to allocate more power to the downlink than before. Or maybe not; we do want to run the analog and digital payloads simultaneously (all the time) and the power budget hasn't been finalized. I believe the current plan is to run more power than before, but not spectacularly so.
This not being Star Trek, we can't improve the uplink by shunting warp power to the receivers. The SDX implementation technology will help on the uplink by solving the alligator problem once and for all, but it will still be necessary to use enough power+gain on the ground to close the link to the distant spacecraft with its compromise antennas.
I'll leave the forecasting of exact ground station requirements to those who have studied the link budgets. And then I will take the results with a grain of salt. I hope it will be better than before. But what's really better than before is the ACP (Advanced Communication Package, that is, the digital stuff), and people who don't want to put up large antennas should really be looking forward to that rather than the U/V transponder.
In my opinion.
73 -Paul kb5mu@amsat.org
Hello Patrick
Regarding ETC., could beginners use FM in a specific portion of the passband near perigee?
Power and bandwidth issues aside, technically there is no reason why FM would not work through the transponder, although the equalizing effects of STELLA in the SDX may distort the signal somewhat because it's designed to deal with SSB/CW signals.
Regarding perigee: firstly, of course at perigee the footprint is a lot smaller, so coverage would be a lot smaller. Plus, the spacecraft will be off-pointing at perigee.
I realize it is not as power efficient as SSB and CW
It is also much less frequency efficient - currently, we are designing for a 100kHz passband. An FM signal might take 15kHz of that whereas an SSB signal would only be 3kHz.
The inefficiency from the power aspect that you mention could be mitigated by converting the FM uplink into an SSB downlink, although of course this rather cancels your suggestion that FM might encourage more beginning users!
73, Howard W6/G6LVB
participants (10)
-
Douglas Quagliana -
Greg D. -
Howard Long -
John B. Stephensen -
McGrane -
Mike Rupprecht -
Paul Williamson -
Robert Bruninga -
Robert McGwier -
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