- Eagle (INACTIVE) - mailman.amsat.org

Where we're heading for bands and services
by Jim Sanford 25 Sep '06

25 Sep '06

Team: The Eagle Chief Technology Officer (W2GPS), the AMSAT VP Engineering (N4HY) and I met (electronically) to discuss the Eagle payload complement. We have decided the following should be our recommendation to the board of directors of AMSAT for their ratification. This is what will be presented to the BoD: 1. Services to be provided, as defined at the San Diego meeting et seq: Class 0 is linear transponder users Class 1 is SMS text message service users Class 2 is weak signal voice grade digital channel Class 3 is strong signal, large antenna, higher bandwidth signal (think compressed full motion video) 2. Primary class 0 payload: U/V with a design goal that it be usable over 75% of the orbit. 3. Primary class 1 payload: U/V for the reasons discussed at San Diego. 3. Primary Class 2 and 3 ACP payload: S2/C usable over 75% of the orbit. This coverage to be accomplished by using electronically de-spun phased arrays on S2 and C. At San Diego, we discussed S2 vs. S1. S2 was technically superior, but other issues caused us to shy away from it. Upon reflection, the leadership has decided to proceed down the technically superior path, S2 uplink. 4. Secondary Class 0 payload: L/S1 -if and when the power budget and antenna pointing (fixed, nadir-pointing array) can support. We recognize that it may not be usable in many areas due to elevated noise floor resulting from 802.xx devices, as discussed in San Diego and documented in measurements and analysis. NO PERFORMANCE LEVEL IS TO BE PROMISED. 5. Secondary ACP Class 2 uplink: A separate L receiver feeding same DSP and C-band downlink when fixed nadir-pointing antenna array supports. This second receiver will share the L-band LNA and antenna with the L/S1 Class 0 payload. The greater level of service for S2 users should encourage people who can to use S2 rather than L. NO PERFORMANCE LEVEL IS TO BE PROMISED. 6. Use of all secondary payloads will be subject to acceptable costs in power, heat, and/or mass, as assessed by analysis or testing. They are to be turned off if regulatory constraints are imposed post launch. They will not be flown at all if shown to be not feasible through analysis or testing. This is what I will present to the board at Symposium for their concurrence. Please contain this discussion within the Eagle team until the Board makes a decision. I request your comments within the next 48 hours so that I can finish the budget tonight and begin crafting my presentation to the board and my follow-on presentation at Symposium. We need to bring this to closure so that we can present decisions at Symposium, and move out smartly from there. Thanks. Very 73, Jim wb4gcs(a)amsat.org <mailto:[email protected]> UNQUOTE

8 14

New Modus Vivendi for Eagle/Engineering and my analysis of our needs
by Robert McGwier 25 Sep '06

25 Sep '06

We have what I consider to be a firm decision on how to proceed. I am proud of where we are a year into my tenure. The details clearly need to be fleshed out but we have a way forward that I suspect technical people and user people can rally behind since it involves compromise and calculation. Rick Hambly has provided some necessary leadership here and I choose to get behind it to implement it. It is not everyone's ideal choice but it is a choice I can support. For your information, we need desperately to get our act together on several different fronts and these are organizational in nature. I need to modify my role significantly now. I believe Jim will be much more comfortable now that we have a reasonably clear direction. He has fixed my greatest concern in that he has demonstrated usable internet connectivity that he can check wherever he is doing his normal daily living which requires travel. I believed he was completely ineffective when he could not communicate in a timely fashion. I saw emails get answered that were clearly "four generations" old in a thread and it aggravated me a lot. That has been completely fixed in my opinion recently. It is clear that with team member scattered over the world and the continent, effective telecommunications are absolutely required to effectively manage this project. I did not view this as fixed until two weeks ago. I now view it as fixed. Since I am a known commodity to many of you, many of you come to me with things that should go directly to Jim. This undermines Jim in his attempt to manage the project. In addition, dealing with you individually actively hinders me doing exactly those things I need to do on an organizational level and slows some technical work that I personally responsible for. Jim and I have repeatedly run into things we thought the other was doing. Jim has fixed his telecom problems and I am now a reflector. Jim works for me since Eagle is engineering but this is going to be an organizational lead where I do composite budgets and make facilities available from the organization but I am not going to do daily management. Direct stuff to Jim. Let me give three examples of those things I am going to be concentrating on in the next 30 days. 1) IHU-3 code since P3E needs a control mechanism to integrate. 2) Finishing a top level mechanical analysis, laying out design principles in spreadsheet form so we can place equipment inside our chosen model, and put the attitude control system in. I will be concentrating on helping the sensor team (welcome back Alan) get the big picture right. 3) SDR things that I am uniquely qualified to do, inextricably committed to doing, or am required to help with in a "hands on" way. It is clear that we have won the battle to get the kinds of transponders we need to make this a new and different spacecraft. It will be technically challenging and that will be the fun part! I am no longer needed to lead the transponder team is my read and it needs someone who can dedicate themselves to that aspect of this. The team I have helped to assemble has an amazing collection of talent in it. Managed correctly, this team simply cannot fail. I need someone to step up and take over the transponder management and Jim should now take charge of finding that person. I do not wish to do more than advise Jim on his selection when he has some choices. For Jim to succeed in implementing these transponders, he needs to find someone he can work with so I bow out of the selection except to give solicited advise. Jim and I discussed this and I agree with his assessment that the team is better off being lead elsewhere. It would be my suggestion to Jim that the person he picks understands that this is really two teams being forced into the same "bucket": linear and ACP and they must be welded into an RF team. I think we are close to announcing a construction, integration, testing facility. We will know in 30-45 days. I need to budget time for doing the planning on taking care of organizational business in the area of getting this lab going and getting our engineering house in order totally, not just for Eagle. This is exciting since I think we can set up a long term facility that is closer to the corporate offices, and can help our organization's educational status, and more. This is going to require a serious effort to complete by the end of the year. I believe this is the best use of my time for AMSAT in general and Eagle in particular outside of those specific technical tasks I have undertaken. HPSDR and GnuRadio are, in my opinion, the most important technical projects outside of AMSAT for OUR future. They will have a large impact on amateur radio in general, and AMSAT in particular. We have engineering management things to get right with our sister organization TAPR. This will heat up in the next few months. After I get the top level mechanical analysis work done with Bob Davis and Dick Jansson, I need to pass off that hat to someone who can live with it day to day. Should we actually make the organizational move on a laboratory that I think we are about to make, I will give my recommendation to Jim but I will need to back out of making this selection and limit my role to computation. The recommendation will be obvious if this falls into place. As V.P. Engineering I will insist on being on all peer review committees and exactly how that will function will be worked out with Jim. Any further advice to the teams will be directed to individuals but will ALL contain CC to Jim. As an organizational matter, we need Jim to succeed and he needs to take the lead. He will have my support (and my friendly cattle prod) to do exactly that. Bob N4HY -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

1 0

IF switching
by Howard Long 23 Sep '06

23 Sep '06

Folks, I believe that I read somewhere recently (although I can't seem to find it now) that the concept of an IF switching matrix has been discounted. I don't know what the reason for this was, however on the basis that it seems clear that no-one is sure what bands may or may not be useable or available over the next few years, is it worth re-addressing this for feasibility? Howard

7 17

Conference Papers
by Robert McGwier 23 Sep '06

23 Sep '06

If you have an outstanding paper, they must be in by tomorrow evening and the earlier the better. Jean and Emily need to go to print on Monday. Bob -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

1 0

Eagle L-band receiver
by Miroslav Kasal 23 Sep '06

23 Sep '06

Hello Eagle Group, According to our e-mail correspondence with Bob McGwier today, I would like to repeat my offer to design and build L-band receiver for Eagle. I am designer of P3E L-band receiver (including command receiver and 5 MHz backup oscillator). At present I solve AGC for both mode - analog/SDX. You can see http://www.urel.feec.vutbr.cz/esl/files/Projects/P3E.htm. Already two years ago I promised to built L-band receiver also for Eagle. All my friends from AMSAT-NA showed pleasure, but project managing people didn't ask me officially. So my offer is still valid. Best regards. Mirek Kasal, OK2AQK AMSAT-NA LM2326

3 7

Welcome
by Dick Jansson-rr 23 Sep '06

23 Sep '06

Hello Mirek: It is good to see that you are now on the Eagle team. I welcome your insights and capabilities. I hope that all is well with you and your family. Best regards from Florida, Dick Jansson --------------------------- <mailto:[email protected]> rjansson(a)cfl.rr.com ---------------------------

2 1

Mini-Circuits
by Emily Clarke 21 Sep '06

21 Sep '06

I was working with Mini-Circuits (they have dontated $3200 worth of components for Symposium prizes) and in the course of gathering information found out that Gerry Edson who was listed as our contact at Mini-Circuits retired last year. Paul Vinsand is the new applications engineer. His contact information is: email: pv(a)mincircuits.com phone: 417-335-5935 X4519 Just thought this was good information to pass along. 73, Emily --------------------------------- N1DID formerly W0EEC - CM87tm Support Project OSCAR - http://www.projectoscar.net

1 0

Steve Cripps
by Howard Long 21 Sep '06

21 Sep '06

Folks I was most impressed to see in the AMSAT journal that Steve Cripps was judging the microwave PA's. Having read two of his books*, I cannot think of anyone more in touch with the state of the art in PA linearity and efficiency. Any chance he might be interested in joining us?! 73, Howard G6LVB * RF Power Amplifiers for Wireless Communications * Advanced Techniques in RF Power Amplifier Design

4 3

Recent arguments and proposals, I am off to Tuscon
by Robert McGwier 20 Sep '06

20 Sep '06

I spent yesterday in a lawyer's office in Washington D.C. for AMSAT and actually enjoyed myself. I followed that with a mad dash back to Trenton to teach the SDR class Frank and I are teaching. Microchip is assisting us beautifully and we have a class full of eager students wanting to take on Suitsat-II and Eagle pieces for their design projects. I apologize for this week being so busy for me that I am unable to jump on to much of the discussions this week on BB and here in Eagle. Let me dash off some quick comments. I do not believe we can successfully build the X band component to the modified DCP system. I believe we will be killed by all sorts of LO problems including, but not limited, to phase noise issues. I am already a week behind in delivering Stephensen an analysis of the phase noise on the Class 1 users in SDX, I will add to this a system analysis of the required oscillator performance to use X band in the DCP. Remember, this is a weak signal mode and we are attempting to operate with only a few dB of margin at best. We cannot shed 1 or 2 more in implementation loss (if we are lucky). I support John's contention that we should choose a band that is currently available world wide for the uplink on which we can feasibly build a system. Pick L or S1 is my recommendation. We chose S1 for all of these reasons. If you choose L, we can put in two L's or share one with SDX. The antenna is the same required area, but the packing of the antenna on the spacecraft becomes more problematic. I understand Rick's motivation to not get hammered at the annual meeting. Welcome to the presidency. It is not a reason to make a bad choice for the uplink which will kill the utility of the package is my current opinion. My current vote: stay with what was decided in San Diego or risk L as the primary uplink. I believe that a serious analysis of the impact of trying to get the dual band L/C antenna packed together will be a very illuminating exercise and I believe we will inevitably be led back to the SD decision based on system analysis rather than emotional analysis. Bob -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

7 19

Re: [Advisors] [Fwd: Re: S band and Eagle: an appeal for ahigher ...
by RaySoifer＠cs.com 19 Sep '06

19 Sep '06

In a message dated 9/19/06 5:46:16 AM Greenwich Standard Time, kd6ozh(a)comcast.net writes: > When we are considering L/S and U/S, we should remember the advantages of > U/V and V/U. The original choice of U/V for phase 3 satellites allowed for an > antenna that would provide 75% orbit coverage. Path loss for L and S is much > higher so AO13 and AO-40 had much narrower beams and covered less of the > orbit in those modes. So, in addition to the fact that S will be unavailable in > many areas due to noise levels that are 20+ dB higher today, the time > available in those areas for this mode is much less than for U/V or V/U. The attached > document provides a graphical comparison of U and L uplink antenna coverage > for the same ground station radiated power level. The V and S downlinks are > very similar. > > Yes, and we should remember also that uplink QRM levels on 2 meters due to illegal high-power cordless phones and the like are much greater than in the past, as OZ1MY has documented. That is why the Surrey Colloquium recommended, a couple of years ago, that U/V be used in preference to V/U. With U/V, the QRM affects only users in immediate proximity to the interference source, not the entire footprint as is the case with uplinks. 73, Ray

1 0