Eagle (INACTIVE) February 2008

8 participants
13 discussions

by Bob McGwier

Phil Karn and I used this series when we were doing some calculation and now Chris Bartram (Mutek front end fame and uwSDR founder) pointed this series out. There appears to have a new section added: SDR in deep space. This is a very very important link for RF communications engineers dealing with space matters. http://descanso.jpl.nasa.gov/Monograph/mono.cfm Bob

14 years, 6 months

Report released on harmful ITAR effects to US space industry

by Daniel Schultz

The Center for Strategic and International Studies has released a report titled "Health of the U.S. Space Industrial Base and the Impact of Export Controls", available at: http://diig-csis.org/calendar/detail.asp?EVENT_ID=261&MONTH_CHOICE=2&DAY_CH… The Aerospace Industries Association states that the report "provides quantifiable evidence that the U.S. space industrial base has been weakened by U.S. export control policy for commercial satellites and their components. Based on a government survey of more than 200 U.S. companies, the report concludes that second- and third-tier suppliers, the source of much innovation, have been hit especially hard since export sales are vital to help offset their significant investments in research and development. The report identifies practical recommendations to improve controls on commercial satellites and components while still ensuring these technologies are protected appropriately." Some particularly relevant passages: Finding 9: Some elements of the export controls laws are in conflict with US National Space Policy. Finding 6: The current export control policy has not prevented the rise of foreign space capabilities and in some cases has encouraged it. Finding 11: The US is the only country that classifies commercial communications satellites as "munitions". Dan Schultz N8FGV

14 years, 7 months

Identify yourself

by Robert McGwier

Please identify yourself directly to me if you have space based experience developing and flying FPGA's. Bob

14 years, 7 months

[Fwd: HFSS Training, Burlington MA, March 6-7]

by Tom Clark, K3IO

14 years, 7 months

Juan Rivera

by Bob McGwier

I regret to inform the Eagle group that at Juan's request, he is no longer in the Eagle project and is not available to work on AMSAT projects and has even gone so far as to resign, not renew, or not get an AMSAT membership. I really do regret this. I tried, almost at the expense of another friendship, to make this work. But in the end Juan had an agenda that was inconsistent with AMSAT's, and he was VERY critical of AMSAT without being proactive in helping with corrective actions. His agenda moved to taking on the entire development of the Intelsat payload by professionals in the Bay area and with a seven figure number as the cost. It moved steadily from volunteers to employment. When I asked for the CV of the people he wanted to involve, it lead to a an explosion and quitting as the request of CV's from people he wanted me to pay millions was an insult. I was supposed to take his word to come to a meeting where they would tell me what we should do. I just could not go down the path he wanted. I want to remind everyone here of an explosion that Juan mounted last year. I suggested that we might need to begin outsourcing some work. He exploded and said that it was inconsistent with AMSAT work. Now, he leaves because he wanted to do exactly that and views all my attempts to get information as some kind of insult or invasion of territory. I hope you all know that we never like to lose volunteers for any reason if it can be helped and if any of you remember my awards at Pittsburgh, you know I singled Juan out for "MVP" for 2007. This was done in conjunction with Jim Sanford. Juan did us a lot of good in 2007 and I wish this could have worked out. My apologies to the group for this disruption and I accept blame and responsibility for this loss but I just could not go forward. I will directly work with John to work out arrangements for finishing the rework of the 70 cm receiver. As a result of our very successful relationship with Juan, I have many questions that Jan King, Karl Meinzer, and many others in this list completely missed in the review. It would be easy to see looking at the group that did the review how one might get complacent. I have a plan to move the RX forward. I will be asking the individual I wish to involve this week. Bob

14 years, 7 months

2 meter digital downlink for geostationary satellite

by John B. Stephensen

I've been thinking about how the use of mode UV might change with a geostationary satellite. It could allow for the use of very simple antennas for mobile operation as was done with AO-16. Since the satellite is stabilized and fairly large, it may be possible for AMSAT to procure space for a broadside array with at least 2 elements on 2 meters with vertical polarization. This would give 8 or 9 dBi of gain and be compatible with 1/4-wavelength whip antennas mounted on automobiles in mid-latitude locations. It would also allow the speed of the currently planned digital uplinks and downlink to be increased. This digital downlink could allow multi-user digital voice operation with fairly low power given that 2400 and 1200 bps MELP vocoders are now available. 50 kHz could allocated for SSB and 50 kHz for a TDM digital downlink. A 24 kBaud QPSK downlink could handle 10-20 users using a rate 1/2 error correcting code. If we assume that the man-made noise level is 6 dB above the thermal noise level, a 1 dB NF LNA, 6 dB SNR and a 32 kHz bandwidth for the downlink signal, -116 dBm is required at the receiver. Path loss is 168 dB, so at least 52 dBm EIRP is required from the satellite which means 20-25 W of transmitter output. This seems feasible for the HELAPS transmiter or there could be a separate transmitter and a high-level power combiner. Both 70-cm analog and digital uplinks could be handled by a common receiver using a short (1 m) yagi antenna or a broadside array. 73, John KD6OZH

14 years, 7 months

Programming help needed

by Bob McGwier

AMSAT Engineering needs experienced help programming MPS-430. This processor will be in a Cubesat. It would be my preference for us to use FreeRTOS on it but this is not a decision I will mandate if adequate reasons for not following this path can be provided. Email me directly. Bob

14 years, 7 months

For Chuck

by Robert McGwier

Apologies for the private email sent publicly: Chuck I have tried to send you several emails. Please respond to me directly with your new email address. Thanks for the bandwidth. 73's Bob

14 years, 7 months

[Fwd: Ansoft Training: HFSS Advanced Antenna, Ansoft Designer]

by Tom Clark, K3IO

14 years, 8 months

Orlando Trip, Airport transportation

by Rick Hambly (W2GPS)

All, I arrive at Orlando airport after 4pm today. The hotel is 22 miles away. I rented a 7 passenger van to help with transportation over the weekend. Anyone who wants transportation this afternoon from the airport should call me on my cell phone (see below). So I know to wait for you. I will be waiting for Tom Clark who arrives an hour later so you can call any time before 5pm. Rick W2GPS AMSAT LM2232 Richard M. Hambly, CNS Systems, Inc. 363 Hawick Court, Severna Park, MD 21146 410-987-7835 phone, 410-987-7836 Fax, 410-299-2147 cell <mailto:[email protected]> rick(a)cnssys.com, <http://www.cnssys.com> www.cnssys.com, <http://www.gpstime.com> www.gpstime.com _____ From: Rick Hambly (W2GPS) [mailto:[email protected]] Sent: Wednesday, January 30, 2008 5:56 PM To: 'John.Klingelhoeffer(a)verizon.net' Cc: Robert McGwier (rwmcgwier(a)gmail.com); 'Tom Clark, K3IO'; 'Martha'; 'Barry A. Baines'; Elaine Hambly (elaine(a)cnssys.com) Subject: Orlando Trip, Flight Itinerary All, Here is my flight itinerary for the Orlando trip. AirTran Airways. February 07, 2008, Flight 472 [Non-Stop] Seat: 22F Departing Baltimore/Washington, MD (BWI) at 02:04 PM Arriving Orlando, FL (MCO) at 04:14 PM February 11, 2008, Flight 470 [Non-Stop] Seat: 22F Departing Orlando, FL (MCO) at 04:51 PM Arriving Baltimore/Washington, MD (BWI) at 06:57 PM Payment Information: Ticket Total 266.00 Rick W2GPS AMSAT LM2232

14 years, 8 months

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Eagle (INACTIVE) February 2008