That would be under consideration and when you have all of the relevant information, we can go do the link budgets and decide if we can build it and the political and regulatory issues will factor in then.
We would still need to build a phased array because we are informed that for thermal control reasons, the satellite rocks back and forth around one or more axes at a very slow rate to try to keep the power and heat generation down on the solar panels. Both the reality and the amplitude of this rocking needs to be understood. No one more than I would like for us to found out that this is wrong and that we can expect it to be stable. BUT, I wonder if we can even afford to make that decision. It would be horrible indeed, if there were a large disaster, and our comms gear, promised to FEMA/NTIS etc. was found to be unusable because our primary had rocked the satellite for operational reasons and we had decided to put a fixed beam antenna on the platform.
On 10 Ghz: So we would try to get just enough gain to illuminate the earth but Ooooops, that won't quite get it because the path loss at X band is much higher and would not allow for the ground user terminal we would like to support. If you overcome the path loss with gain, you do not illuminate the visible earth. Any phased array we are capable of building I don't think would allow for continent shaping of the beam and if it could, would we really want to be unable to work the DX in the middle of the Pacific Ocean?
There are both technical and political reasons why the decisions made are what they are. I don't believe the reasons have changed that much but I do know we have the opportunity to revisit this and we should.
Our primary satellite owner will respond to our request for 300w and should they say yes, there is little doubt we will find a way to spend it and our job is to optimize that.
Another consideration, is that they are looking for efficiency. I do not believe you can give me the same efficiency at 10 GHz you can give me at 3.4 GHz. I believe the power flux density on 3.4 GHz will be low enough we can claim noninterference but that will have to be tested (with regulatory authorities).
Much to do!
Bob
Bill Ress wrote:
John,
I would second that! That would make it compatible with all the regions.
John B. Stephensen wrote:
If this works out, it will be a big boost for amateur radio. Given the amount of power available, compatibility with their C-band uplink, regulatory issues outside region 2 and the ease of antenna pointing, a C/X transponder may have an advantage over C/S2.
73,
John KD6OZH