Re: [amsat-bb] AO-7 DX
Bob W7RLD wrote: Through general consensus would it be possible to establish a unofficial DX watering hole...Essentially, use a given frequency (downlink) only when the satellite is less than 4-5 degrees. Wayne replies: I don't understand. Every satellite is always less than 4 degrees elevation for somebody. It would make sense to have a designated DX calling frequency on linear transponders that are congested with many users. But I don't think that's the case presently. Wayne Estes W9AE Oakland, Oregon, USA, CN83ik ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 07/18/2014 12:08 PM, Joseph Spier wrote: Fox-1C is the third of four Fox-1 series satellites under development, with Fox-1A and RadFXsat/Fox-1B launching through the NASA ELANA program. Fox-1C will carry an FM repeater system for amateur radio for use by radio hams and listeners worldwide. YET ANOTHER analog satellite? I'm not interested. ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
Are FM repeater satellites what we all want in orbit? No. Personally, I'd like a Mode J linear transponder in a sun synchronous circular orbit of about 2,000km (if we can't get anything to HEO). However, the Fox-1A, Fox-1B, Fox-1C, and Fox-1D satellites will eventually lead to the Fox-2 series of satellites. The software designed transponders on board the Fox-2 series will be capable of operating in any number of digital communications modes as well as operating as linear transponders. AO-51's V/U FM repeater was probably the most popular amateur satellite ever launched. Since the loss of AO-51, AMSAT-NA membership has been declining and is at the point where membership dues alone do not sustain the operating costs of the organization. Right now, those who are mildly interested in amateur satellites have one satellite to try with a minimal investment: SO-50, which is a satellite that for about half the days of each month is not convenient for most people who work 9-5 and sleep 10-6 and has a weak downlink that is often very difficult for newcomers to hear. Even experienced satellite operators are at times heard to transmit without being able to hear the satellite. With EO-80 (QB50p2), Fox-1A, and Fox-1C hopefully in orbit and operational next year, there will be three easily heard FM satellites (the 9 dB advantage of the 2m downlinks on these satellites will be quite welcome) - two in sun synchronous orbits with relatively consistent pass times. Having those satellites in orbit will mean that more hams get bitten by the satellite bug, join AMSAT, and progress to improving their stations to operate on the linear transponders and, potentially, on digital satellites. Bottom line - an AMSAT with more satellites in orbit means an AMSAT with more members and that's how we are eventually going to get our ideal satellites in orbit. 73, Paul, N8HM On Sat, Jul 19, 2014 at 2:54 PM, Phil Karn k...@ka9q.net wrote: On 07/18/2014 12:08 PM, Joseph Spier wrote: Fox-1C is the third of four Fox-1 series satellites under development, with Fox-1A and RadFXsat/Fox-1B launching through the NASA ELANA program. Fox-1C will carry an FM repeater system for amateur radio for use by radio hams and listeners worldwide. YET ANOTHER analog satellite? I'm not interested. ___ Sent via AMSAT-BB@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 ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 07/19/2014 12:28 PM, Paul Stoetzer wrote: Are FM repeater satellites what we all want in orbit? No. Personally, I'd like a Mode J linear transponder in a sun synchronous circular orbit of about 2,000km (if we can't get anything to HEO). Getting a launch opportunity is difficult and expensive. Going digital is not. However, the Fox-1A, Fox-1B, Fox-1C, and Fox-1D satellites will eventually lead to the Fox-2 series of satellites. I've been hearing that for years, so please forgive my skepticism. Tony AA2TX himself told me that the analog Fox-1 would be followed by the digital Fox-2. Now we have Fox-1B, Fox-1C, etc, that will also be analog. Forgive me if I feel a little like Achilles racing the tortoise. I originally joined AMSAT as a technical volunteer in mid 1980, shortly after the Phase III-A launch failure. At the time, AMSAT was doing some very impressive things. Many weren't even being done (or were just starting to be done) in the commercial world: the use of digital command and telemetry links, the use of onboard computers, even the use of ground computers to steer antennas. AMSAT had shown how to locate an emergency beacon by measuring its Doppler shift through a LEO transponder -- which eventually became the SARSAT (Search and Rescue Satellite) payload on many US and Russian LEO weather satellites. And AMSAT was showing how to do it all on a low budget, with resourcefulness replacing brute force bucks. I was blown away by clever little tricks like spinning a satellite by painting one side of its antennas black and the other side white. This was ham radio at its best. But that was 1980. It's now 34 years later and we're still doing the same old thing. Meanwhile, mobile phones and the Internet have gone from the exotic to the commonplace -- and I don't have to tell you that they're 100% digital. TV broadcasting is also now digital, few cable TV systems still carry analog signals, and FM and shortwave broadcasting are in a digital transition. When AMSAT showed how to use an inexpensive hand-held radio to communicate with a satellite, no one had ever seen such a thing. Now digital satellite broadcasting and GPS are nearly universal in cars, hikers and boaters carry SPOT units, and you can buy handheld Iridium phones that will work anywhere on the globe. All digital, of course. Yet AMSAT continues to fly one analog satellite after another. Why? All these outside developments have rendered FCC Part 97.1, the Basis and Purpose of the Amateur Service, almost completely obsolete with the singular exception of personal technical education and possibly (some) emergency communications. You want to further international goodwill by talking to people in other countries? Get on the Internet. You want to call your wife to see if she needs anything? Pick up your mobile phone. Further the technical art? Go work for a communications RD company, because it isn't happening in ham radio anymore. How are we justifying our spectrum by doing the same thing over and over again, while the world passes us by? Appealing to what the members want doesn't fly with me, because the members are a tiny fraction of our potential audience. AMSAT keeps wondering why it can't seem to grow beyond a tiny niche; it need look no further for the reason. Nor does an appeal to simplicity and cost carry any weight. Mobile phones, GPS units and Sirius/XM receivers may not be simple but that doesn't keep them from being cheap and easy to use. It's their very complexity (if you consider digital to be complex -- which I don't) that makes them cheap and easy to use. But by design they are impossible to take apart and learn from. That's where the amateur service can still play a big role. For those who want to learn communications technology by hands-on experimentation there is still simply nothing like it. But where are the amateur digital voice satellite systems to take apart and study? At least a linear transponder could repeat an efficient digital signal, but with the trend to FM even that is no longer possible. If an amateur satellite carries any digital links at all, they are slow and generally limited to telemetry and command, not user-to-user communications. Many don't even use modern modulation and error-correction methods, making them that much harder to access with the small antennas to which most hams are now limited because of CCRs and other restrictions. Far from being elitist or hard to use, digital represents the *only* way forward. It's time to move into the 21st century. --Phil ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
Getting a launch opportunity is difficult and expensive. Going digital is not. The Fox satellites each have four designated experiment cards. Assemble a team and pitch a proposal for 1D, or 1C if you can do it in a hurry. 73, Drew KO4MA ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 7/19/2014 1:54 PM, it was wrote: YET ANOTHER analog satellite? I'm not interested. I hear yeah ! ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 7/19/2014 3:24 PM, Phil Karn wrote: However, the Fox-1A, Fox-1B, Fox-1C, and Fox-1D satellites will eventually lead to the Fox-2 series of satellites. I've been hearing that for years, so please forgive my skepticism. Tony AA2TX himself told me that the analog Fox-1 would be followed by the digital Fox-2. Now we have Fox-1B, Fox-1C, etc, that will also be analog. Forgive me if I feel a little like Achilles racing the tortoise. Ah, but the plan always was to build four of the Fox-1 series, which is a series of FM analog transponders. Initially, one had a launch and the other three would be ready to fly if other opportunities came up. If you're going to spend the time developing them, why not partner for free launches (ELaNa) for more than one? The opportunities for an FM transponder and educational outreach are good. I still have universities looking to partner. Look at it this way... we are clearing the shelves with 3 out of 4 of the intended Fox-1 going to orbit, that really means that we can pretty much call it a day with Fox-1 and move on to Fox-2 now. We will build them all and be done with them all by next May. There will be more than one flying soon, so that we can learn how well they work and apply those lessons to Fox-2 while we're working out the design. It's only the beginning! Jerry Buxton, NØJY ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
Hey, this sounds like a terrific opportunity. Not only did AMSAT work on securing our new launch opportunities ... but we are in a position to offer a launch opportunity for a mode/radio/experiment for those who can contribute to amateur radio in space instead of complain about it. -- 73 de JoAnne K9JKM k9...@amsat.org -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Andrew Glasbrenner Sent: Saturday, July 19, 2014 15:43 To: 'Phil Karn'; 'Paul Stoetzer' Cc: amsat-bb@amsat.org Subject: Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced Getting a launch opportunity is difficult and expensive. Going digital is not. The Fox satellites each have four designated experiment cards. Assemble a team and pitch a proposal for 1D, or 1C if you can do it in a hurry. 73, Drew KO4MA ___ Sent via AMSAT-BB@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 ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 07/19/2014 01:42 PM, Andrew Glasbrenner wrote: Getting a launch opportunity is difficult and expensive. Going digital is not. The Fox satellites each have four designated experiment cards. Assemble a team and pitch a proposal for 1D, or 1C if you can do it in a hurry. 73, Drew KO4MA I see no reason to consider a digital satellite an experiment. Not in 2014, anyway. Besides, there are several other critical technical hurdles AMSAT must first overcome if we are to do anything interesting with a cubesat. First and foremost among them is ATTITUDE CONTROL! Passive bar magnets (or nothing at all, as on ARISSat-1) no longer cut it. The lack of attitude control forces us to use simple omnidirectional antennas, which in turn keeps us on the crowded and narrow VHF/UHF bands. Worse, there's really no such thing as an omnidirectional antenna so our links are plagued by frequent deep fades of unlimited (or at least unknown) duration. Fading has driven every one of my modulation/coding designs for AMSAT telemetry links -- at the expense of making them much less power-efficient. And power efficient means smaller ground antennas, and that means a cheaper and more accessible ground station for the average ham. And THAT means a much larger potential AMSAT membership. With attitude control, our satellite could use directional antennas on the microwave bands. Directional antennas on higher frequencies mean much better link budgets. You could easily do MEGABITS PER SECOND between LEO and small ground antennas! A lack of attitude control also plagues thermal design. I learned this from Dick Janssen KD1K's talk at the Symposium a few years ago when he said Fox-1 was the most difficult thermal design he'd ever done for AMSAT. And he's done many. The problem is that without attitude control you have to cover every available surface with solar cells to guarantee power in any attitude, and solar cells are excellent thermal radiators. Those not facing the earth or the sun face dark sky, radiating away much of the spacecraft's heat. I think he found the equilibrium temperature of a 1U cubesat to be something like -30 or -40 C! The team had no choice but to add resistance heaters to keep the payload (especially the batteries) warm. I can't think of a more painful use of scarce, hard-earned, expensive DC power in space. Attitude control would completely solve this problem too. In LEO the most common form of attitude control is local vertical/local horizontal, the mode the ISS uses most of the time. You'd designate one face as nadir-pointing; here you would mount antennas and earth observation cameras. With circularly polarized antennas, you'd still have a degree of freedom around the yaw axis, i.e., you could rotate around the local vertical with no effect on the RF links. The opposite (zenith-facing) side would have a solar cell, as would one of the four remaining sides. The remaining three would be covered with thermal blankets to insulate the spacecraft from the dark sky they'd face all the time. (Not being a thermal designer I haven't calculated what the new equilibrium temperature would be. But it would obviously solve Dick's problem. He might even have to leave part of those surfaces exposed to radiate excess heat!) You see how this works? At low beta angles, when the sun is in or near the orbital plane, you point the side with the solar cell forward at local sunrise. At local noon you yaw 180 degrees so the cell faces the sun as it sets behind you. At higher beta angles you simply yaw to track the sun as it passes off to one side; in the limiting case of a beta angle of 90 degrees (continuous sunlight) you'd simply keep the spacecraft yawed at a constant +90 or -90 degrees. And you only need to buy two expensive solar cells instead of (nearly) six. Attitude control systems for cubesats already exist. You can buy one for $200,000 from suppliers serving the burgeoning cubesat community (most of which considers ham radio completely irrelevant except as a source of free spectrum). But that's not the AMSAT way. I am sure that if we brought enough clever minds together (along with some good mechanical engineers and craftsmen) we could design and build our own attitude control system for far less. But to attract all those people to do all these new (in AMSAT) things, you have to stop doing the same old thing over and over. You have to make a conscious choice to stand back and actually innovate at the systems level instead of relegating digital to the status of an experiment on the same old primitive spacecraft bus. Look at all the attention and excitement generated by the ISEE-3 Reboot project. That's because they're actually doing something new and challenging. They say they've gotten donations from many people far outside the usual space groupie segment of the population. It's also caught the imagination of at least a few hams, including the AMSAT-DL gang which has been using their 20m Bochum dish to
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 07/19/2014 02:04 PM, Jerry Buxton wrote: other three would be ready to fly if other opportunities came up. If you're going to spend the time developing them, why not partner for free launches (ELaNa) for more than one? The opportunities for an FM transponder and educational outreach are good. I still have universities looking to partner. Ah, because launches are scarce and expensive, and (re)developing even the same old thing consumes much of AMSAT's limited resources. And they're limited because we have yet to interest more than a tiny niche in what we're doing. It's great to have universities looking to partner, but what do they bring to the table, really? Are we sure they're not just looking for free spectrum? one flying soon, so that we can learn how well they work and apply those lessons to Fox-2 while we're working out the design. We already know how well they'll work because we've done the same thing many times before. I hate to say it, but this is no longer rocket science. The physics is well understood, and those same physics tell us how we could accomplish so much more with our (currently) limited resources. --Phil ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 7/19/2014 4:50 PM, Phil Karn wrote: Ah, because launches are scarce and expensive, and (re)developing even the same old thing consumes much of AMSAT's limited resources. And they're limited because we have yet to interest more than a tiny niche in what we're doing. But you arguing about something that has already happened. That makes no sense. Arguing for doing something different, as you also did just a bit ago today, makes sense. Why did the U.S. go back to the moon so many times? I don't know. But we did, and that is done. You could argue now that it had been done before, why did we do it over and over, it was the same old thing. That doesn't change the facts. There is an audience for these FM satellites. It's great to have universities looking to partner, but what do they bring to the table, really? Are we sure they're not just looking for free spectrum? Both universities that I am working with are building amateur radio ground stations and interesting the students in becoming hams. We all benefit from that. And some other universities want to fly an ADAC system. We may benefit from that on Fox-2. one flying soon, so that we can learn how well they work and apply those lessons to Fox-2 while we're working out the design. We already know how well they'll work because we've done the same thing many times before. I hate to say it, but this is no longer rocket science. The physics is well understood, and those same physics tell us how we could accomplish so much more with our (currently) limited resources. We have already learned a great deal from an engineering process perspective, as well as about cramming a lot into a little cubesat. Not rocket science, but certainly for a large all volunteer group a valuable step toward what it will take to build something more complex. I think you over estimate the ability of an all-volunteer workforce, in terms of churning out satellites akin to how a business does it. Amateur radio is a hobby! You see lemons. I see lemonade. But by all means, let's go for pink lemonade and keep on talking about Fox-2 opportunities while people enjoy what we have already done with the Fox-1 series! Jerry Buxton, NØJY ___ Sent via AMSAT-BB@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
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
On 07/19/2014 03:32 PM, Jerry Buxton wrote: But you arguing about something that has already happened. That makes no sense. None of the Fox satellites have yet flown, so they haven't already happened. Why did the U.S. go back to the moon so many times? I don't know. But we did, and that is done. You could argue now that it had been done before, why did we do it over and over, it was the same old thing. That doesn't change the facts. Good analogy, actually. They returned to the moon six times (succeeding on five) because they had excess hardware originally built in the expectation that the first attempts would fail. And when they did return, they began to do some serious scientific exploration that made it worthwhile. Unfortunately, the public *did* see this as the same old thing and Congress quickly withdrew support. As everyone knows, NASA canceled the last three Apollo lunar missions and humans haven't left earth orbit since Apollo 17. (Strictly speaking, even Apollo never left earth orbit, since the moon orbits the earth.) Yet NASA has always managed to find support for new and interesting things in space even without a human presence. The two keys to public interest have always been 1) exploration and 2) photography. Apollo certainly did that in its time. More recently, stunning pictures from the surface of Mars and of the moons and backlit rings of Saturn have done much to keep NASA going even as it flails aimlessly in its human program. Sure, the ISS returns some pretty good pictures of earth but so do many robotic spacecraft. And the ISS certainly isn't exploring much of space from only 400 km up. That's why most people don't find it very exciting. Both universities that I am working with are building amateur radio ground stations and interesting the students in becoming hams. We all benefit from that. And some other universities want to fly an ADAC system. We may benefit from that on Fox-2. I'm hearing privately that many university groups really are after us for only our spectrum. Or our spectrum plus a ready-made telecommunications system they can use for their purposes without having to worry about the details. I actually don't oppose this categorically as some do, but I insist on *some* benefit back to the amateur service, such as an interesting new communications system to experiment with and to learn from. Some aren't even willing to go that far. --Phil ___ Sent via AMSAT-BB@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
[amsat-bb] ANS-201 AMSAT News Service Weekly Bulletins
AMSAT NEWS SERVICE ANS-201 The AMSAT News Service bulletins are a free, weekly news and infor- mation service of AMSAT North America, The Radio Amateur Satellite Corporation. ANS publishes news related to Amateur Radio in Space including reports on the activities of a worldwide group of Amateur Radio operators who share an active interest in designing, building, launching and communicating through analog and digital Amateur Radio satellites. The news feed on http://www.amsat.org publishes news of Amateur Radio in Space as soon as our volunteers can post it. Please send any amateur satellite news or reports to: ans-editor at amsat.org. In this edition: * AMSAT-NA Board of Directors Ballots in the Mail * AMSAT-UK International Space Colloquium Coming Soon * Upcoming Potential Satellite DX Operations * AMSAT Presentations from the 2014 ARRL Centennial Celebration Available * Orbital Sciences Cygnus Cargo Ship Launched to ISS * Louisiana Tech University Online Course -- Steps to STEM SB SAT @ AMSAT $ANS-201.01 ANS-201 AMSAT News Service Weekly Bulletins AMSAT News Service Bulletin 201.01 From AMSAT HQ SILVER SPRING, MD. July 20, 2014 To All RADIO AMATEURS BID: $ANS-201.01 AMSAT-NA Board of Directors Ballots in the Mail Ballots have been mailed to the AMSAT-NA membership in good standing and must be returned to the AMSAT-NA office by 15 SEP 2014 in order to be counted. Those sent outside North America were sent by air mail. If you have not received your ballot package in a reasonable time for your QTH, please contact the AMSAT-NA office. Your returned ballot should be sent as promptly as possible, and those from outside North American preferably by air mail or other expedited means. Normally there would be 3 full Board seats open this year, plus 2 alternates. However, with the passing of Tony Monteiro, AA2TX (SK), there will be an additional full Board seat open to fill the remainder of his term. This means that the top three recipients of votes will have two-year terms, the fourth most vote recipient will serve as full member for one year. The fifth and sixth highest vote recipients will serve as first and second Alternate, respectively. You may vote for up to 4 individuals. Election of board members is both an obligation as well as an opportunity by our membership to help shape the future direction of AMSAT-NA. Please take the time to review the candidate statements that accompany the ballot and determine who you wish to see on the Board. [ANS thanks Alan, WA4SCA, for the above information] - AMSAT-UK International Space Colloquium Coming Soon The AMSAT-UK International Space Colloquium takes place July 25-27, 2014 at the Holiday Inn, Guildford, GU2 7XZ, United Kingdom. The presentations will cover a number of amateur satellites which carry transponders including LituanicaSAT-1 (LO-78), KLETSkous, Fox-1 and FUNcubes 1 (AO-73), 2, 3 (EO-79) and 4. The return of the NASA spacecraft ISEE-3 (ICE) has caught the attention of the media recently with the attempts by volunteers to receive and command the spacecraft. There will be ISEE-3 presentations by two members of the AMSAT-DL Bochum team. [ANS thanks Trevor, M5AKA, for the above information] - Upcoming Potential Satellite DX Operations Editor Tedd Mirgliotta, KB8NW, Editor of the Ohio/Penn DX Bulletin reported the following possible satellite opportunities in the July 14, 2014 Ohio/Penn DX Bulletin No. 1171: TF, ICELAND. Operators Jaime/EA4TV and Montse/EA4GCA will be active as TF/EA4TV and TF/EA4GCA during their holiday between July 20-31st. Activity will be holiday style using a FT-817nd into a Buddistick for HF and an arrow antenna for satellites, if possible. QSL via their home callsign (see info on QRZ.com). XR0, EASTER ISLAND (Update). Operators Cristian/CE2WTF and Manuel/CE2NTT will be active from Isla de Pascua (SA-001) starting z, August 2nd, ending z, August 4th. Manuel informs OPDX that their special callsigns could be one of the following: CE2NTT - XR0YNTT / 3G0YNTT / CB0YNTT / CE2WTF - XR0YWTF / 3G0YWTF / CB0YWTF Activity will be on 40/20/15/10/6 meters using SSB. They will also use Echolink and Hamshere, and possibly QRP LEO satellites. Look for details and updates on: http://www.ce2ntt.blogspot.com [ANS thanks the Ohio/Penn DX Bulletin for the above information] - AMSAT Presentations from the 2014 ARRL Centennial Celebration Available Five presentations were made by AMSAT at the All Day Thursday Training Tracks during the ARRL Centennial Celebration and National Convention in Hartford Connecticut July 17, 2014. PowerPoints from AMSAT's training track presentations on Working Satellites have been made available. http://www.amsat.org/?page_id=2914 [ANS thanks AMSAT
Re: [amsat-bb] ANS-199 AMSAT News Service Special Bulletin - AMSAT Fox-1C Launch Opportunity Announced
The lack of attitude control forces us to use simple omnidirectional antennas, which in turn keeps us on the crowded and narrow VHF/UHF bands. Worse, there's really no such thing as an omnidirectional antenna so our links are plagued by frequent deep fades of unlimited (or at least unknown) duration. Fading has driven every one of my modulation/coding designs for AMSAT telemetry links -- at the expense of making them much less power-efficient. And power efficient means smaller ground antennas, and that means a cheaper and more accessible ground station for the average ham. And THAT means a much larger potential AMSAT membership. With attitude control, our satellite could use directional antennas on the microwave bands. Directional antennas on higher frequencies mean much better link budgets. Yes, but with who? 95% of everyone in view is more than 45 degrees OUT of the main beam. Directional antennas have zero value on LEO birds that need to serve everyone in view at the same time. And if you only serve those in the main beam, then the duration is under 1 minute. A lack of attitude control also plagues thermal design I think he found the equilibrium temperature of a 1U cubesat to be something like -30 or -40 C! I cannot believe that. The equilibrium of a nominally black (solar panels on all sides) spacecraft is something like about 0 to 30 C (32F to 90F) a very benign operational range. The only time you DO have thermal issues is when you DO have attitude control and have things that are not equally over time seeing the sun and dark sky. PCSAT is now 13 years in orbit and the above range is what it sees. And that range is over a 2 month period. THe orbit-by-orbit temperature changes are less than +/- 10 degrees C. The extremes are due to the seasons of the orbit. When it is seeing eclipses it averages to about 10C and when it is in full sun for weeks at a time, it gets up to 30 C (90F) I do agree that attitude control is nice to have, but my point is that it only makes the thermal problem much worse and that gain is of no value for a LEO where it must see everyone in a footprint at the same time. (Remmebr you cannot have wide beamwidth and gain at the same time). Gain for HEO's of course is another matter! (think AO-10, AO-13 and AO-40) Bob, WB4APR ___ Sent via AMSAT-BB@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
