September 2006 - Eagle (INACTIVE)

Proposed Eagle Antenna Arrays
by Louis McFadin 01 Oct '06

01 Oct '06

Here is a proposal for arranging the Eagle antennas that Stan Wood and I worked out today. By moving the 2M dipoles to the corners we have sufficient room for full sized elements over the ground plane. The 2M antennas should get about 8dB. Three L band patches in cavities should give us greater than 12 dB gain. By putting the S1,S2 and C band patches in hex shaped cups we maximize the available space. The cup arrays can be NC machined out of a solid blank and therefore attain precise control of the spacing. It may also serve as heat a radiating device. Each patch will be circular polarized and fed with a single feed from it's matching amplifier. The 70 CM Circular polarized patch should have around 6 dB gain. We will look at getting more gain on 70 cm. Seven S1 patches will be mounted on top the 70CM patch. They should get about 15dB gain. Tom's S2 interferometric patches are included. Omni antennas similar to that used on P3D will be required on the opposite side of the spacecraft. There should also be room for the Sun Sensors on both sides of the spacecraft. Lou McFadin W5DID w5did(a)mac.com

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Presidents club reception - San Francisco
by R.Haighton 27 Sep '06

27 Sep '06

Hi All, As members of the Board of Directors and members of the Eagle group, You are invited to the "Presidents Club" reception on Friday Evening October 6th 7.00 pm. The object of this reception is to allow the major financial Supporters of AMSAT , our Prominent designers and Builders, and the Board of directors to meet, exchange views, and Gain enlightenment on the various aspects of our organization. I look forward to seeing you there. 73 Robin Haighton VE3FRH

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Eagle 2007 budget input
by Jim Sanford 26 Sep '06

26 Sep '06

All: Attached is my input for the 2007 budget. It is based on a few inputs, some carried over items from 2006 that we didn't (but need to) do, and my best guess on a couple of things. 73, Jim wb4gcs(a)amsat.org

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Antenna Plans
by Dick Jansson-rr 26 Sep '06

26 Sep '06

It is well that the antenna plans are starting to congeal. I do have some comments upon the diagram that John presented, herewith attached. 1) There is an option, whether employed or not, that the U band could be the stacked CP patch design previously shown, with the L band array mounted thereon, also as previously shown. 2) The U band antenna currently shown in John's design could use a modification of the dipole design used for all of the AMSAT-DL P3 satellites. We call that "design adaptation" (not stealing!). 3) The V band antennas are of a great concern as shown in John's design. The P3D V antennas were more than 880mm end-to-end span, and a nominal 144mm spaced off of the spaceframe. Three of these on top of the Eagle seems to me to be of a gargantuan, unwieldy concept. These antennas would greatly impact the spacecraft envelop as mounting in a launcher. John has talked of a bent-end antenna design, is that really practical from an RF sense? I am wondering if some form of dual-feed full-wave V band loop might not serve better in this application. Stan Wood had shown such a full-wave loop design for the Small Eagle that was only about 50mm high. Properly designed, it would not necessarily have to be 144mm high, so I am led to believe. Can some astute antenna designer look at this for us? I feel that we need to look at the options. Dick Jansson --------------------------- <mailto:[email protected]> rjansson(a)cfl.rr.com ---------------------------

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Another New Rocket Fails
by Tom Clark, K3IO 26 Sep '06

26 Sep '06

>From the "It Really Is Rocket Science" department -- this one from New Mexico -- see http://news.bbc.co.uk/2/hi/science/nature/5377958.stm

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Eagle power requirements
by Louis McFadin 25 Sep '06

25 Sep '06

Jim, Do we have any idea how much power Eagle will require in the two different modes 1 In sunlight and 2 during eclipse? Should we design for the 10 hour orbit that Ken used for his studies? In that orbit the worst case eclipse is about two hours and most of the time it is far less. I know we have asked that question before. Maybe it's time to get serious about establishing a power budget. The answers to these questions will drive much of the design of the spacecraft. Lou

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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

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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

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IF switching
by Howard Long 24 Sep '06

24 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

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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

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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

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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 ---------------------------

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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

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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

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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

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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

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

19 Sep '06

Hi all, As discussed with Bob McGwier at this weekend's TAPR conference in Tucson, I believe that the current frequency recommendations for the Eagle digital payload somewhat underestimate the inefficiency and time lags of the international regulatory process, as well as the inconsistency of application from one country to another. While amateurs in some countries may well find themselves unable to use 1.2 GHz uplinks for the reasons stated, that situation may not apply to others. Some countries, such as many in Region II, may continue to permit 1.2 GHz uplinks because their navigation systems will continue to be GPS-based. In some other countries, in and out of Region 2, there is effectively little or no telecommunications regulation at all, or such regulation is ineffective in practice. Similarly, as Robin has pointed out, some countries may well prohibit uplinking on 2.4 GHz for whatever reasons, such as interference with Wi-Fi etc., irrespective of whatever the ITU Radio Regulations might say. So, depending on where he is located and the RF environment in his area, an individual user may find that: 1. He may not use 1.2 GHz but may use 2.4 GHz. 2. He may not use 2.4 GHz but may use 1.2 GHz. 3. He may use both. 4. He may use neither. Since the actual regulatory environment on the ground is unpredictable, Eagle's uplink configuration needs to take all four possibilities into account. The first three may be accommodated by flying BOTH 1.2 and 2.4 GHz uplinks, which I am recommending. Planning for the fourth, however, is a little more complicated. As has been discussed previously, the link budget argues strongly against the use of 10 GHz or higher frequencies, and we cannot realistically fly a 5 GHz uplink since it would be too close in frequency to our 5 GHz downlink. The use of 3.4 GHz is prohibited in Region 1. My suggestion, therefore, is to fly a digital uplink at 70 cm in addition to those at 1.2 and 2.4 GHz, and also in addition to the 70 cm analog SDX uplink already planned. Since the amateur-satellite service allocation there is only 3 MHz wide, the uplink bandwidth would be limited accordingly. My "straw man" suggestion for that would be 435.5-437.5 MHz, with 435.0-435.5 used primarily for SDX and other such systems (e.g., P3E if it is still up and working by then), and 437.5-438.0 used, as now, primarily for human spaceflight applications, i.e., whatever succeeds ISS. A 2 MHz bandwidth would not be as good as the 10 MHz envisioned for L-band and S-band, and the uplink EIRP requirement (and thus ground antenna size) would be higher than I would like, but remember that the 70 cm uplink would be primarily for those who cannot use 1.2 and 2.4 GHz. For them, such an uplink would make the difference between being able to use the Eagle digital payload or not. My 2 cents worth, anyway. 73, Ray P.S. I am speaking here only for myself and not for the IARU Panel, which has not considered this matter.

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Region-1 Countries with S2 Access - REVISED
by Rick Hambly (W2GPS) 18 Sep '06

18 Sep '06

All, The following is a revised list of countries that already have terrestrial Amateur Radio access to S2 in Region 1. This data was collected from Graham Shirville and the official www.efis.dk <http://www.efis.dk/> site. There may be other countries as the sources are focused on Europe. Cyprus 3400-3500 Czech Republic 20 W (info of OK2ZI, 5/2003). Perhaps not. Denmark 3400-3410 Finland 3400-4200? Perhaps upper limit 3408, cw=150,ssb=600W Germany 3400-3475 Great Britain 3400 to 3475, Terrestrial only, 400W at antenna (no EIRP limit). Israel 10 Watt Netherlands 3400-3410 Norway 3400-3500, usage 3400-3410 MHz Poland 3400-3500, Perhaps upper limit 3470? Slovenia 3400-3600. Upper frequency is an assumption. Rick W2GPS AMSAT LM2232

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Region-1 Countries with S2 Access
by Rick Hambly (W2GPS) 18 Sep '06

18 Sep '06

All, The following countries already have terrestrial Amateur Radio access to S2 in Region 1. This data was collected by Graham Shirville and the official www.efis.dk <http://www.efis.dk/> site. There may be other countries as the sources are focused on Europe. Cyprus 3400-3500 Czech Republic 20 W (info of OK2ZI, 5/2003). Perhaps not. Denmark 3400-3410 Finland 3400-4200? Perhaps upper limit 3408, cw=150,ssb=600W Germany 3400-3475 Great Britain Israel 10 Watt Netherlands 3400-3410 Norway 3400-3500, usage 3400-3410 MHz Poland 3400-3500, Perhaps upper limit 3470? Slovenia 3400-3600. Upper frequency is an assumption. Rick W2GPS AMSAT LM2232

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Re: [Advisors] Re: Re: [Fwd: Re: S band and Eagle: an appeal for ahig...
by RaySoifer＠cs.com 17 Sep '06

17 Sep '06

In a message dated 9/17/06 4:17:08 PM Greenwich Standard Time, kd6ozh(a)comcast.net writes: > PAVE PAWS is part of the ballistic missle defense system so it will remain > active. > Perhaps, but I bet if Hillary were elected she would de-fund the system (not that I would vote for her, hi). My point is simply that we cannot predict the future, so must prepare for all reasonable possibilities. 73, Ray

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Re: [Advisors] Re: Re: [Fwd: Re: S band and Eagle: an appeal for ahig...
by RaySoifer＠cs.com 17 Sep '06

17 Sep '06

In a message dated 9/17/06 3:08:03 PM Greenwich Standard Time, kd6ozh(a)comcast.net writes: > Path loss is 15 dB less at 435 MHz than 2400 MHz and antenna gain is 13 dB > less. However, the noise figure is 5 dB higher, so almost twice the EIRP wll > be required on a U uplink than an S uplink. The 70 cm receiver has a 200 kHz > bandwidth so some class 2 (4800 bps) uplinks could be accomodated. Since they > will be BPSK and use FEC, I assume that they will occupy at least 15 kHz > each and will have to be spaced at least 25 kHz apart. This could allow 4 > uplinks. It's not good to increase the receiver bandwidth as it will let in more > PAVE PAWS interference. > > John, I was thinking in terms of an additional 70 cm receiver to accommodate several conference-grade channels, for those users who may be prohibited from using BOTH L-band and S-band uplinks (think Europe). Yes, PAVE PAWS is there, sometimes, but it would still be better than no digital access at all. Also, it's not a certainty that PAVE PAWS will even be there in 2020. 73, Ray

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San Diego Meeting report
by Jim Sanford 15 Sep '06

15 Sep '06

All: It has come to my attention that the San Diego meeting report has format problems. I've ZERO idea how the format got gooned. I have taken it offline for correction. I will advise, tomorrow or Saturday, when I've fixed the format and reloaded. Thanks & 73, Jim wb4gcs(a)asmat.org James A. Sanford, PE Amsat Eagle Project Manager

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Team Speak tomorrow night
by Jim Sanford 14 Sep '06

14 Sep '06

Team: I'm not going to be able to put an agenda on EaglePedia until tomorrow. Things I'd like to discuss: 1. Budget submissions -- I have some, what else is ccoming? What estimates are coming? 2. Status reports -- what should I highlight at Symposium in my BRIEF remarks? Who is making what presentations? 3. Did we write off L-band or not in San Diego? I remember, and my notes and one other attendee confirm, that we wrote off L-band for the digital uplink, but briefly discussed it as ananalog uplink. We never made a decision. Lets discuss and decide. 4. Status reports from those we haven't heard from in a while -- power, sensors, etc. 5. Bob and Rick discussed on the phone, (I was next to Rick) the idea of: Rethinking S2 (3GHz) for the Digital uplink This frees up S1 for any use We offer that anyone willing can develop and submit for testing and qualification a stand-alone L/S transponder to fly in one of the TSFR slots, using fixed antennas. It would be usable at/near Apogee, like the microwave packages on AO-13 and A)-40. What do you think? Les's discuss this. Any other topics? Remember 2100 EDT, 1800 PDT. Thanks & 73, Jim wb4gcs(a)amsat.org

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Analog transponder revisited
by Howard Long 13 Sep '06

13 Sep '06

Folks, Under AOB last night I raised a question regarding there apparently being no analog transponder on board as far as I can see in recent documentation. I was of the impression that a parallel analog transponder would be flying as well as the SDX. I am concerned that as this was a hot issue several months ago, I would respectfully request that we clarify the situation at the next meeting prior to the Symposium. 73, Howard G6LVB

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FW: Re: Team Speak tomorrow night
by Howard Long 13 Sep '06

13 Sep '06

Hi Bob > I know from documentation I received from I8CVS that this will > exclude Italy from the digital payload. > I am expecting to hear from several other countries that, excluding > action from a WARC, they will be excluded from the digital > communications package if we use S2. I think it was clear from the meeting last night that there are two options for the wide band DCP that will be proposed for further discussion. Rick will propose a version with both L and S2 uplinks and a C downlink. John will propose a version with C uplink and X downlink (I wasn't sure if an L uplink was also included). In Rick's proposal, as L will still be available so Region 1 with their current allocations, Region 1 will have access to the DCP whether or not S2 is available to us. It seemed clear from last night's discussion that the assessment to drop L band at San Diego wasn't the right decision. There was also some discussion about whether the high bandwidth digital mode would be viable at L band, probably limited by a non-steerable RX antenna on the spacecraft and uplink EIRP, although somehow I doubt Domenico has a problem with with uplink EIRP ;-) As it's being revisited again in the next couple of weeks, we can go over these again in further detail with the benefit of both your's and Tom's input. Cheers, Howard

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N1AL Award
by Tom Clark, K3IO 13 Sep '06

13 Sep '06

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[Fwd: [amsat-bb] Re: S-Band allocation]
by Jim Sanford 11 Sep '06

11 Sep '06

Team: I forward this because the 5MHz bandwidth is news to me. I heard talk in SD about 10MHz BW for the digital signals. This would exclude the JAs. I know we're a long way from nailing this down, just sharing the data. 73, Jim -------- Original Message -------- Subject: [amsat-bb] Re: S-Band allocation Date: Mon, 11 Sep 2006 19:26:43 +0900 From: T.Komatsu <ruruko63(a)po30.lcv.ne.jp> To: AMSAT BB <amsat-bb(a)amsat.org> References: <20060911083016.63490.qmail(a)web25310.mail.ukl.yahoo.com> Hi, Alls, Please do not forget that there are many amateurs who are in big interest in Japan too. And satellite allocation on this band is 2,400 to 2,405, within whole of the allocated band for amateur, 2,400 to 2,450MHz. There is no amateur allocation on 2300MHz band for us. 73s Toyo JA0CQP _______________________________________________ Sent via AMSAT-BB(a)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

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DCP Bands
by Matt Ettus 11 Sep '06

11 Sep '06

In the time since the San Diego meeting, I have come to realize that: 1 - Nothing is ever final. 2 - The decision about bands for the DCP (digital communications payload) is likely to be made in some combination of the following venues, in none of which you are likely to find me: A - AMSAT-BB B - AMSAT Board Meetings C - Meetings with shadowy DoD figures without names D - IARU, ITU, ARRL, QCWA, or Wuoff-Hong Society meetings 3 - Many of the decision makers (especially those speaking the loudest) think that SSB is the way of the future and Shannon's Law means that sex offenders have to register with the police. 4 - It really doesn't matter to me which bands are chosen, as long as they meet certain basic criteria. In that spirit, I decided to distill the major technical constraints which we agreed on at the San Diego meeting, in order to give a basic set of rules which would provide us a workable bandplan for this satellite. The only legal/regulatory constraint I applied to this list is that we are unlikely to GAIN privileges. Someone else can decide how likely we are to lose them. The constraints, and their reasons, as I see the consensus from the SD meeting: 1 - The uplink band must be chosen from the set of { L, S1, S2, C }. The lower bands simply don't have the bandwidth necessary for what we want to do, and would have unwieldy antennas. The higher bands are much more difficult due to the pointing accuracy required for antennas and the difficulty of generating significant power and low noise figures. 2 - The downlink band must be chose from the set of { S1, S2, C }. The same reasons as constraint #1, with the added constraint that L-band is not legal for downlink (which falls under the "we're not likely to GAIN privileges" category). 3 - The uplink and downlink bands must be distinct. This means no C-C or S1-S1. The bands are simply too narrow to allow for practical duplexers in the quantity we are talking about (~36). 4 - The uplink band must not be used by any other payload on Eagle as a downlink. Obvious interference issues. 5 - The downlink band should not be used by any other payload as an uplink. Obvious interference issues. 6 - Sharing of uplink bands or downlink bands MAY be possible, but probably isn't necessary. Taking constraints 1-6 together, the choices are (in the form A/B where A is up, B is down): { L/S1, L/S2, L/C, S1/S2, S1/C, S2/S1, S2/C, C/S1, C/S2 } In addition to the above "hard facts", we can add in the following concerns which were expressed at the meeting: 7 - We would prefer not to use S1 as a downlink because of possible interference from WiFi devices. 8 - Fear of L being taken away 9 - Uncertain legality of S2 in ITU Region 1 This leads to the following matrix, which I believe effectively boils down the decision process from the SD meeting: Bandplan 7 8 9 L/S1 X X L/S2 X X L/C X S1/S2 X S1/C S2/S1 X X S2/C X C/S1 X C/S2 X The only bandplan with no X's is S1/C, which is what we chose at the meeting. Obviously, there are now additional concerns which have been raised: - S1-Uplink being taken away - #8 not being as big a deal as we thought. This would change the matrix. I welcome your thoughts, especially if you feel I have misrepresented the SD meeting consensus. Thanks, Matt, N2MJI

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Eagle S-Band & L-Band decisions
by Larry Brown 10 Sep '06

10 Sep '06

I have been following this discussion for a number of months now both on the Eagle discussion group and on AMSAT-bb. I don't want to add to the noise on amsat-bb but do have an opinion. I want to hear the satellite as well as possible so if that means abandoning 2.4 Ghz as a downlink, I can live with the decision. I am not happy with the prospect but I realize that you can't fight physics. I do plan to borrow a spectrum analyzer and examine how bad the situation is around my house in Tucson. Before we lost the L1 transmitter and the dish antenna on AO-40 I was hearing the bird very well with a minimal antenna and poor noise figure down-converter. The AO-40 S-band downlink took a huge hit when all we had was the S2 transmitter and the helix antenna. I have spent the best part of 15 years selling S-band as the satellite downlink of choice to satellite users so it is very hard to now have to start selling another answer, but so be it. My BIG concern is giving up the L-band uplink without a fight based on the assumption that at some time in the future we may lose the band due to a system that has not even been fielded yet. While the Galileo system will probably be fielded, let's not give them the benefit of the doubt. Even if it is fielded we do not automatically lose the allocation. It looks to me like our potential for interference is relatively minor compared to the real issues that they face on the E5 links in the radiolocation band where there are aircraft transponders, DME transponders, DME interrogation links, Link-16 Data Links and numerous other radio navigation emitters and radars. I personally don't think that they will even notice us. I have seen one or two places where they are selling the Safety of Life services as being jam resistant and these capabilities are spread out among all of the downlinks. Since L-band only involves a receiver on the satellite and antenna space that could also be shared with other receivers if necessary (with well designed stacked patch antennas or feeds), I think that an L-band receiver should be flown (unless we lose the allocation prior to launch). In making this statement I am assuming that the cost of adding an L-band uplink is not excessive. I think we should plan on using the band and then turn off the receiver if we lose the allocation. It is part of our responsibility to use and defend our bands to the best of our ability and the L-band uplink is very valuable to us. Many of us have existing equipment and are L-band terrestrial or EME users and we need L-band on the satellite to help defend our rights to the band. Have a back-up or alternate uplink in case we do lose L-band at but plan to fly and use it as long as possible. We can inform our members that the band is at risk and then it is their choice if they invest in new L-band equipment. We should make it be the government (not AMSAT) that takes away our access to this band. There are my thoughts. I will happily adapt to whatever decision that AMSAT's management and the Eagle design team make. I am looking forward to seeing many of you at the TAPR/DCC conference next weekend. Larry Brown, W7LB

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Netherlands, S band problems
by Robert McGwier 10 Sep '06

10 Sep '06

All of this hoopla about S band in the AMSAT bulletin board, which thankfully is blocked to me because comcast has chosen to blackball amsat.org (oh drat, the block just got removed ;-) ) caused me to do some talking, searching, thinking. We are definitely NOT at the end of this story. I believe the Netherlands has lost 2400-2540. I am investigating with some help how universal this is. What I believe we are seeing is that like here, the licensed operators are supposed to be protected but what actually happens is that when the licensed operators interfere severely with the 802.11 use, the amateurs are summarily dismissed. It is my opinion that we got bloody lazy. We took the ITU/IARU tables as found on the web and took them as gospel. We need to understand the actual reality as found on the ground. If we cede L band as an uplink, and we see a definite trend towards loss of 2400-2540 because of 802.11 across Europe, we are close to being between a rock and a hard place. Thanks to Lee, a study that was pointed out called ARIA. This, commissioned by Paul Rinaldo at the League was EXACTLY what we are after. It is a study of the rise in noise floor at 2400 due to 802.11. Paul is a) helping me get the results and b) attending our symposium and giving a talk on frequencies. Rick and I spent an hour in discussions with a very high ranking general officer at the Pentagon in a position to have an opinion worth listening to. His opinion is that our band at L band is NOT in danger from Galileo. I will not go into greater detail here and I will never put his remarks in a public record. But suffice it to say, his remarks have indeed caused me to go investigate this. We did our TECHNICAL job in San Diego. We have NOT done our regulatory job and our political job and it has caused many to write me in private about existing situations. I am afraid we are about to be made to look as if we are knuckling under to pressure and it will have nothing to do with the pressure. It will have everything to do with this story getting out before we were ready to tell and had done all of our home work. If the serious impact of 802.11 resulting in loss of 2400 MHz uplink privileges in region 1 and 2 and 3 can be substantiated, then that is a fait d'accompli we must take into account. The loss of privilege, in every case I know of, results from BLOODY ATV users blocking 802.11 users. If we transmit and block, we can cause the same kind of problem. We need to understand how widespread this phenomenon is. We now can document it has happened in LU. I am given to understand by a European who should know that it is true also in the Netherlands. We must find out how widespread. Given loss of 2400 as a fact (should we find this widespread and growing), I would risk using L band and 3400 instead rather than lose the ability to use our satellite altogether within a very short period following launch. Should we find this to be necessary, then we have a tough job to decide how, or whether to do 23cm, 9cm, or both and if we do both, can we put credible antennas on the spacecraft. I believe Rinaldo is coming to tell us the cold hard facts of life. Be prepared to listen. I am also going to ask questions in the amsat-bb to try to elicit first hand knowledge of loss of this band from lurkers there. 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

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[Fwd: [amsat-bb] Re: S band downlink on P3E]
by Jim Sanford 09 Sep '06

09 Sep '06

Team: The kind of rational technical argument we should be prepared to answer. . . . 73, Jim -------- Original Message -------- Subject: [amsat-bb] Re: S band downlink on P3E Date: Thu, 7 Sep 2006 17:40:39 -0400 From: Jeff Griffin <kb2m(a)comcast.net> Reply-To: Jeff Griffin <kb2m(a)comcast.net> To: <amsat-bb(a)amsat.org> References: <01b401c6d28f$cc51d870$1001a8c0@RAFPavillion> <050e01c6d2ac$e29ff720$6401a8c0@KO4MA> Ok guy's, how about a test ? Why not everyone who is mode L/S capable get on AO-51 between September 11, and September 18th and post all results here? Or have another mode V/S session for the L band challenged? All we need is degree(s) of elevation worked, type of antenna, and rx environment, and quality of rx signal received. This should tell us what we want to know. I don't think there is a problem, as I worked up to 10 stations a pass last mode V/S session , and didn't hear anyone complain.... 73 Jeff kb2m ----- Original Message ----- From: "Andrew Glasbrenner" <glasbrenner(a)mindspring.com> To: "Rick Fletcher" <rfletcher(a)plumdragon.com>; "'AMSAT'" <amsat-bb(a)amsat.org> Sent: Thursday, September 07, 2006 2:38 PM Subject: [amsat-bb] Re: S band downlink on P3E > Rick, > > I am in _TOTAL_ agreement. I live in the suburbs of Tampa/St. Pete and > never > had an interference problem on my 3 foot dish. I have used the same dish > to > log well over a dozen WiFi access points in that immediate neighborhood. > With properly designed equipment, all that trash on 2.4 ghz goes away with > some elevation. What won't work is helixes with multiple sidelobes, and > surplus dishes that let one whole polarity of noise right thru the back. > > Everyone knows I'm a big supporter of AMSAT, but I gotta call it as I see > it. It makes me think of "bait and switch" to collect money for a project > featuring such a popular mode and then drop it. > > The loss of Mode B on AO-40 caused a lot of the hardcore AO-10/AO-13 types > to walk away, and that was tough to overcome. Now that we have, and we > have > people wanting S band, we leave them behind too. Even if it's a sound > engineering decision (and that hasn't been proven to me) it's a horrid > marketing decision. Bad mojo for a organization that lives on the > donations > of it's members. > > Sorry if this causes any pain to those involved with Eagle, but I needed > to > get it off my chest. > > 73, Drew KO4MA > AMSAT LM 2332 > > >>While AO-40 was still alive and I was working it from deep within "Silicon >>Valley", an area blanketed by WiFi, 2.4GHz cordless phones, etc., I >>discovered that a parabolic dish with a properly positioned and designed >>patch feed (slightly under-illuminating the dish and having no significant >>side-lobes) would bring in AO-40's S-band downlink very nicely and >>cleanly. > >>Of course, other feed or antenna types such as helical antennas/feeds were >>useless in that environment. > >>I have to admit that I don't buy the "too noisy" argument. > >>73, > >>Rick >>KG6IAL _______________________________________________ Sent via AMSAT-BB(a)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

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[Fwd: Re: S band and Eagle: an appeal for a higher level discussion]
by Tom Clark, K3IO 08 Sep '06

08 Sep '06

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Last call for papers - Deadline Approaching
by Emily Clarke 01 Sep '06

01 Sep '06

2006 AMSAT North America Space Symposium 6-8 October 2006, Foster City, California Call for Papers: Final Call http://www.amsat.org/amsat-new/symposium/2006CallForPapers.php Invitation: Speakers are invited to submit and present papers dealing with the science of Amateur Radio Satellites and associated technologies for the AMSAT 2006 Space Symposium. The Symposium will be held at the Crowne Plaza Hotel in Foster City, California approximately 10km south of San Francisco International Airport. This is an annual Symposium, however the 2005 Symposium was cancelled due to hurricane damage caused by hurricanes Katrina and Rita. Speakers originally scheduled for the 2005 Symposium are invited to re-submit papers for the 2006 Symposium. Topics: Recommended topics include but are not limited to the following categories: · AMSAT P3E · AMSAT Eagle · Microsatellite Projects · Cubesat and Nanosatellite Projects · ARISS · Attitude Determination and Control · Propulsion · Communications · Mechanical · Antennas · Groundstations · Digital Modes · Education and Outreach · Launch Opportunities · Status Reports Other Activities: · The AMSAT Board of Directors will meet on 5-6 October. · The AMSAT Annual General Meeting (AGM) will be held on 6 October. · AMSAT International will meet 8 October · The IARU Satellite Committee will meet during the Symposium and will hold a public round table discussion on frequency coordination on 8 October · The ARISS International Delegates Meeting will be held on 9-10 October · "Birds of a Feather" sessions (BOFS) will be available on request Deadline: Applications for papers must be received ASAP. Papers must be submitted no later than 12 September 2006. Procedure: The planning committee has created an online registration system where you can submit your abstract and track it. Using this system you will allow you to submit your paper and any subsequent changes online. Visit the 2006 Symposium Paper Registration webpage for instructions: http://www.amsat.org/amsat-new/symposium/2006PapersProcedure.php Contact Emily Clarke, N1DID for additional information or Jean Fletcher KG6IAK for additional information Venue: See the 2006 Space Symposium web page for additional information about the venue.

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