Greetings!
We have several projects right now in engineering and I am looking for some volunteers to take on some individual pieces of this after Jan. 1. Please help me recruit talent that can work on these projects for a short intensive period. The goal will be to demonstrate as much as possible at Dayton and even more by October. This means that beginning in January we have to move out smartly. I hope this group will step up and take on either individual pieces or help recruit volunteers to do some of this work.
We are taking on two projects with the Suitsat2 hardware should it ever become available. Suitsat 2 itself, and an on the air demo, to begin with in Florida through the coordination efforts of Drew. The Florida demo is easier than Suitsat2 but still requires work. We have hardware from DEMI (nice, already in Florida!) that will allow us to put an SDX on a tower there at about the 900 foot level which will cover a huge piece of Florida. The other project is the HASP balloon project. This uses the Suitsat 2 hardware, again, assuming availability.
We need to have an SBC to talk to and reload this thing as we update and upgrade code for the Florida experiment. I have not vetted the Suitsat 2 IHU for this purpose because I have never seen it, can't size it, or even tell you if it runs. This will be remedied in January.
In addition, we need to get ready for the pursuit of a working prototype of the full SDX. I talked to Marc Franco a couple of weeks ago. He and his wife have a beautiful new baby and Marc is working again on the amplifier. Marc Franco has made steady progress on the driver and amplifier. He is working through an oscillation problem in the driver in an attempt to NOT have to solve it by gain reduction (lowering the overall efficiency). John Stephenson appears to have solved the critical matching problem for the SAW filter in the 70 cm RX. The goal for this would be to get it ready for on the air testing in time for Dayton and then deploy to the Florida site to take over from the Suitsat hardware. Here we could arrange some torture tests for the Stella.
I have most of the hardware details on Howard Long's version of the SDX. I still need a late version schematic and the latest code but he has shared with me many of his parts selections, reasons, etc. Karl has marked up the P3E transponder in a way that tells Howard how to add SDX to the mix, right down to voltages, current, impedances, etc. I will arrange to get the latest code from Howard.
I have two Lyrtech boards which are XC2V3000 Virtex 2's and TMS320C6713 DSP. These boards are to be used to prototype code for the HELAPS modulator and a small channel version of the ACP.
We need some FPGA work done on the Virtex 2 for SDX and for ACP. The Virtex 2 is overkill for the SDX. We need it to do rectangular to polar conversion, a PWM for the modulus or envelope channel, and a few other minor tasks.
The Virtex 2 is a capable part but it will not support the full ACP. Nevertheless, it will certainly allow us to develop the basic ACP FDM up and TDM down demod, remod cores we need. The difficulty in dealing with this card is that it really does have to have expensive tools. I have them and while Rick has a copy of the Lyrtech, but I am not sure this is optimal if we can find a volunteer with FPGA experience and the time to work. Rick has both real work and institutional difficulties in AMSAT to deal with. Ideally, I would find a different candidate to help with this. This means that I am looking for someone with a) access to Matlab and b) FPGA experience and c) access to TMS320C6713/6726 development tools. This is a tall order but it is the fastest way to a working prototype to "show we can".
There is absolutely no reason we cannot begin the prototype development of an upconverter and a downconverter for the ACP. I can test the ACP at IF with the other Lyrtech board being used for ground terminal development. We need to do work on the modulator, demodulator, FEC, decoder, etc. for this. But we need to come up with some preliminary thinking on devices to be used at 3.4 GHz and 5.7 GHz for the generation and reception of hard limited constant envelope signals and some prototyping needs to be done.
I would like to call for a meeting as early as possible. I don't care if we have multiple meetings but we need to organize our activities around getting some specific tasks and deliverables into our thinking by not later than mid February. We need to set realistic goals for what can be accomplished by a) Dayton and b) the annual meeting.
I will be on TeamSpeak on January 8 for a meeting of anyone who wants to show up and talk about these activities. I hope to report on some definite progress on many things facing us, including a detailed ITAR situation report from Rick. That is moving along but we are at the very hard spot of agreeing on language for the technical assistance agreements. We need to aim for a serious meeting as early as possible in and probably early February. Please think about your availability. This note is an informal heads up to expect a larger and more detailed mailing to come out while I have 5 days at home.
Happy holidays, Bob