Does anyone have any idea what will be in the proposed Eagle Ground Station package that has been proposed to be provided from Amsat?
I assume this is for the digital transponder, correct? Might it be a patch antenna combo for S/C that would attach to a dish antenna? Would it include the upconverter and downconverter required to work S/C digital?
Depending on what is included I might be interested in building such a kit/package for users.
Les W4SCO
The more sources for equipment the better. The ACP design team has a lot of work to do in designing communications protocols and picking coding schemes but there are clearly items that need to be developed that are independent of those design decisions and generally useful. Dual-band feeds for 2 foot and larger diameter dishes are required. There are commercal and surplus power amplifiers for 3.4 GHz available but they can proably be made more inexpensively with MMICs and FETs designed for WiMax.
Beyond that, we know that the uplinks and downlinks will be wideband PSK and that the baseband signals will have to be generated and processed on a PC. Uplink signals will be up to several hundred kHz wide and dowlink signals up to a few Mhz wide. These could be generated and detected at 2 meters to use existing transverters or at other frequencies. There are image-reject mixer ICs available that convert 5.85 GHz directly to a low IF frquency that can be digitized. There are also quadrature modulator ICs that will convert 2-wire baseband signals directly to 3.4 GHz.
73,
John KD6OZH
----- Original Message ----- From: sco@sco-inc.com To: aMSAT-BB@amsat.org Sent: Sunday, October 08, 2006 00:46 UTC Subject: [amsat-bb] Eagle Ground Station Pak
Does anyone have any idea what will be in the proposed Eagle Ground Station package that has been proposed to be provided from Amsat?
I assume this is for the digital transponder, correct? Might it be a patch antenna combo for S/C that would attach to a dish antenna? Would it include the upconverter and downconverter required to work S/C digital?
Depending on what is included I might be interested in building such a kit/package for users.
Les W4SCO
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
At 8:46 PM -0400 10/7/06, sco@sco-inc.com wrote:
Does anyone have any idea what will be in the proposed Eagle Ground Station package that has been proposed to be provided from Amsat?
In short, no, nobody has any concrete idea yet. It's just an intention at this point.
What's completely clear is that a digital solution for accessing the ACP (Advanced Communication Package) would have to be made available to users. It's not something most people would be able to homebrew and there's no off-the-shelf equipment for it. So at least that unique part of the system would have to be made available. There's an explicit goal that this device be made affordable. Beyond that, the details are yet to be designed.
I would hope to see that any other unusual or difficult-to-obtain system component would also be made available. The dual-band feed you mentioned would be a good example.
It might turn out to be feasible to build an antenna that requires no mechanical positioning. A phased array of some sort, presumably. If we come up with a good solution for that, I expect it would also be made available through AMSAT.
73 -Paul kb5mu@amsat.org from the Space Symposium
Les, Paul...
At 07:02 PM 10/7/2006 -0700, Paul Williamson wrote:
At 8:46 PM -0400 10/7/06, sco@sco-inc.com wrote:
Does anyone have any idea what will be in the proposed Eagle Ground Station package that has been proposed to be provided from Amsat?
In short, no, nobody has any concrete idea yet. It's just an intention at this point.
Exactly, Les you are asking to soon for details that have yet to be worked out to specific details, schematics, hdwr... The board just held a meeting to make significant changes to the Eagle band plan. I would guess it will be months/years till those will be determined in any detail.
What's completely clear is that a digital solution for accessing the ACP (Advanced Communication Package) would have to be made available to users. It's not something most people would be able to homebrew and there's no off-the-shelf equipment for it. So at least that unique part of the system would have to be made available. There's an explicit goal that this device be made affordable. Beyond that, the details are yet to be designed.
I would hope to see that any other unusual or difficult-to-obtain system component would also be made available. The dual-band feed you mentioned would be a good example.
I would expect that this item will be designed by the microwave community. Paul Wade, W1GHZ, has made dual-band waveguide feeds for 10/24-GHz. Others have manufactured dual-band mw feedhorns for other bands. I may give it a try for 1268/3400 MHz by scaling Paul' s design. I would assume that the dishes would be centerfed with f/d ~ 0.375. Offset feed dishes would require a feed horn with narrower beamwidth.
It might turn out to be feasible to build an antenna that requires no mechanical positioning. A phased array of some sort, presumably. If we come up with a good solution for that, I expect it would also be made available through AMSAT.
A dual-band design might be a bit tough, but single band phase tracking is acheivable.
73's, Ed - KL7UW =================================== BP40iq, Nikiski, AK http://www.qsl.net/al7eb Amsat #3212 Modes: V - U - L - S ===================================
Lee et al: We would like it to be an easily installed, nearly self-contained system which will work the up and downlinks for the ACP.
Principles of the waveforms and power level have been proposed here at Symposium. However, details are not yet documented, let alone peer reviewed.
There remains much design work to do, then we can look to prototype and test.
Thanks for your interest and support. Stay tuned for further news!
Thanks & 73, Jim wb4gcs@amsat.org
sco@sco-inc.com wrote:
Does anyone have any idea what will be in the proposed Eagle Ground Station package that has been proposed to be provided from Amsat?
I assume this is for the digital transponder, correct? Might it be a patch antenna combo for S/C that would attach to a dish antenna? Would it include the upconverter and downconverter required to work S/C digital?
Depending on what is included I might be interested in building such a kit/package for users.
Les W4SCO
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 (5)
-
Edward R. Cole -
Jim Sanford -
John B. Stephensen -
Paul Williamson -
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