AMSAT-BB November 2011

173 participants
253 discussions

LVB Tracker USB serial port driver for Windows 7 x64?

by Bill Bordy, NJ1H

Has anyone located a driver for the LVB Tracker internal USB to serial port adapter on Windows 7 x64? If not, has anyone reverted to the serial port connection on LVB Tracker and used an external USB to serial port adapter successfully with SatPC32 on Windows 7 x64? I have an Edgeport multiple USB to serial port that has drivers for Windows 7 x64 that I will use if I have to. I would prefer using the LVB Tracker with its USB to serial adapter if someone has another solution. 73, Bill NJ1H

5 years, 9 months

AO-16 telemetry 3 Oct 2010

by Mark L. Hammond

Hi All, Here is a quick AO-16 update. On Sunday I turned AO-16 long enough to get some telemetry packets. The satellite would remain on for less than one minute after being commanded on. A quick test of the "bent pipe" voice mode repeater was successful. . The "hardware watchdog timer problem" is still evident; as expected, spacecraft temperatures are insufficient to keep the transmitter ON (needs to be above 15 deg C). Orbit projections suggest that satellite illumination conditions will not result in increased temperatures for nearly 10 years. Command stations do periodically turn AO-16 "ON" to check on its condition and see if the hardware timer problem has "automagically" fixed itself (which in not anticipated, but who knows...). AO-16 telemetry 3 Oct 2010 1838 utc PACSAT MBL Telemetry Decoder Ver. 1.3 (c) Mike Rupprecht, DK3WN =============================================================================== (average values) +10V Battery Bus : 0.00 V Battery Charge Reg : 0.55 mA Base Temp : 9.07 °C PSK RF Out : 1.90 W +5V RX Bus : 4.87 V +8.5V RX Bus : 8.49 V +10V RX Bus : 11.24 V Here is another teaser :) Several months ago I commanded the AO-16 S-band transmitter ON; it too remains functional (albeit weak), and was received by me, Drew KO4MA, and Alan WA4SCA. 73, -- Mark L. Hammond [N8MH]

6 years, 2 months

Call for Papers--2007 ARRL/TAPR Digital Communications Conference

by Ford, Steve, WB8IMY

Technical papers are solicited for presentation at the 26th Annual ARRL and TAPR Digital Communications Conference to be held September 28-30, 2007 in Hartford, Connecticut. These papers will also be published in the Conference Proceedings (you do NOT need to attend the conference to have your paper included in the Proceedings). The submission deadline is July 31, 2007. Please send papers to: Maty Weinberg ARRL 225 Main St Newington, CT 06111 or you can make your submission via e-mail to: maty(a)arrl.org Papers will be published exactly as submitted and authors will retain all rights. 73 . . . Steve, WB8IMY ARRL

10 years, 2 months

Re: EggBeater

by Bill Dzurilla

Steve, I have both a commercial and a homebrew Eggbeater and am disappointed with both, especially in light of its rather high price. Connected to my IC-7000 via an ARR mast-mounted preamp, performance is far less than with an HT and an Arrow. Guess an omni can't cut it, at least not from my QTH. Maybe if I could get it up higher, clear of all roofs, it would do better. I can make contacts at relatively high sat elevations, but can do just as well with a $10 dual band ground plane. My friend has an Eggbeater and the same preamp at a clearer QTH, and he hears substantially better, down to 10 degrees elevation in some directions. Good luck and 73, Bill NZ5N > > Hi Steve, > > > > It is surprising to read that you are not hearing > anything. I have > > repeatedly used a 2m and 70cm Eggbeater for the sats > and have had no > > problem hearing things. No pre-amp. > > > > I was using a short cable (e.g. less than 10 meters). > The rigs I > > used were a FT-736r (deaf) and a FT-847 (so-so). > > > > 73, > > > > Dave

10 years, 3 months

Re: ARISSat-1 (37772) decay

by Fabio Azzarello

Hello Everybody, I totally agree with you James... the process is a continuous evolution. I did my prediction on October 6th for the "Chicken Little Competition" and my date was January 23rd 2012. It surprisingly agrees with your prediction done almost one month later, this make me think that my assumptions were right, up to now at least. 73s Fabio IW8QKU/5 Hi Jim, Thanks for the update on your AMSAT Journal article. There are several people on the bb who are following this topic and are busy plotting data. Any futher thoughts you have, as we move towards January would, I am sure be of interest. 73 John G7HIA ________________________________ From: DeYoung James <deyoung_james(a)yahoo.com> To: amsat-bb <amsat-bb(a)amsat.org> Sent: Tuesday, 15 November, 2011 17:29:31 Subject: [amsat-bb] ARISSat-1 (37772) decay Greetings, First, thank you Mineo for reading the AMSAT Journal and making several of my papers available on your web site. My AMSAT Journal paper published in the March/April 2011 issue is actually still fairly valid for the scenarios shown in the paper. The solar flux has turned out to be somewhat higher than was used/predicted in the paper. This has caused the atmospheric densities to be higher which results in higher decay rates. When I wrote the paper I had this nagging feeling that stopping the release height scenarios at 370-km was not going to be high enough. We are very fortunate that the ISS was boosted to such a height before release of ARISSat-1 and not after release! There is a valuable lesson, I think, to be made with respect to predicting satellite decay dates far into the future. The future state of the atmosphere, i.e. the atmospheric density that the satellite will pass through is poorly predictable in the long-term, say starting greater than a week or two into the future. Predictions of satellite decay dates months in the future should be evaluated with the understanding that your date of prediction errors may be large. The errors are due to the future uncertainties of the orbital path which grow quickly with time in a prediction. The atmospheric density is not the only source of error. Your orbit model, the integrator, and the accounting of the gravitational and drag forces among others will affect your results. Predictions of satellite decay dates are not do-and-forget. The general process is to make a prediction, get new measured observations of the height in the future, and at some point re-do your prediction when the errors become significant to you. With that all said here is my current prediction using the same tools used in the AMSAT J. paper and produced as of 2011 November 13th. The decay of ARISSat-1 (37772) will happen nominally on 2012 January 30th with a 10% rule-of-thumb error allowance of 18 days around this date. The errors may be larger than the rule-of-thumb indicates! Jim, N8OQ _______________________________________________ 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

10 years, 8 months

AO-51 end of mission

by Andrew Glasbrenner

It is with a heavy heart I report that AO-51 has ceased transmission and is not responding to commands. The last telemetry data indicated that the third of six batteries was approaching failure to short, and observations indicate the voltage from three cells is insufficient to power the UHF transmitters. The IHU may continue to be operative. Initial tests with the S band transmitter were also not positive, although more attempts are in order. We have tried leaving the satellite in an expected state where if voltages climb high enough, the 435.150 transmitter may possibly be heard. The command team will regularly attempt communications with the satellite over the coming months (and years). There is always the possibility that a cell will open and we could once again talk to our friend while illuminated. Thanks to all who helped fund, design, build, launch, command, and operate AO-51. It's 7 year mission has been extraordinary. Please support AMSAT's Fox-1 project, and other AMSAT projects worldwide with your time and money. For the AO-51 Command Team, 73, Drew KO4MA AMSAT-NA VP Operations

10 years, 9 months

TS2000 ~436.798 MHz Birdie Solution

by John Papay

As many of you know, my satellite radio is a TS2000X. If you have visited my satellite webpage, you have seen many recordings of AO-27 and SO50 from AOS to LOS. Most of these recordings were made when I was not sitting in front of the radio. At first I used a uhf mobile to hear AO-27 and SO-50. The problem was that those radios were not computer controlled so you had to tune for the doppler. That worked fine when I was in the shack, but it didn't work when I was away. The obvious solution was another radio that didn't have the birdie problem, or a simple UHF to 10M downconverter which wouldn't have the birdie problem. Back in the day, UHF and VHF down- converters were very popular because we didn't have a lot of DC to Light radios out there. Now these converters are sitting in junk boxes and are long forgotten by their owners. One of the more popular manufacturers of these inexpensive downconverters was Hamtronics. They made all kinds of stuff for repeaters etc. At first their products were not that great, but they evolved into some better designs including their UHF to 10m downconverters. Unfortunately most downconverter manufacturers stopped making them when the devices they were using became obsolete and unavailable. The use of current production devices required a redesign of their PC boards and since the demand was no longer there, these products were abandoned. I was fortunate to find a Hamtronics converter on a qrz.com posting from several years back. It never sold back then and the owner still had it. I purchased it and ran some tests on it against the receiver in the TS2000. It turned out that the downconverter had a slightly better sensitivity than the TS2000! The big concern when using a converter or preamp is the fear of transmitting into it and smoking the front end. But the TS2000 has an auxiliary antenna jack which is receive only and perfect for a downconverter output on HF. As Drew mentioned, SatPC32 can compensate for a downconverter and tune the TS2000 for doppler in the 10m band. This allowed me to track AO-27 AO-51 and SO-50 unattended and make all those recordings without any human intervention. A coaxial transfer relay was inserted into the uhf antenna line so that when the converter was in use, the UHF antenna was switched to the downconverter input (which outputs to the aux antenna jack on the TS2000) and the UHF antenna jack on the TS2000 is switched to a dummy load. So if you transmit on UHF, power goes into the dummy load and all equipment is safe. When I want to transmit on UHF (VO-52 and AO-7 mode B), the coax relay switches the UHF antenna back to the UHF antenna port on the TS2000. The downconverter is out of the antenna circuit at this point. I did not use the downconverter when operating on FO-29 so the aux antenna jack had to be switched to normal in the tS2000, menu #18 (FO-29 is a linear bird that outputs on UHF, currently not working). Every owner of a TS2000 that operates satellites needs a UHF to 10M downconverter. Hamtronics is making a VHF to 10M downconverter now. If everyone emailed them to encourage them to make a UHF model, they might just do it. The only other solution is to make one yourself, or find a used downconverter or transverter that is gathering dust on someone's shelf. I now have an IC910H and am doing comparisons against the TS2000. My first impression it that I prefer the TS2000 but that might be because I'm so familiar with it. I use another TS2000 in the mobile sat truck but don't have a downconverter for it. I simply use a uhf mobile for receive on AO-27 and SO-50 since I'm in front of the radio and don't run it unattended. I have a coax switch to switch the UHF antenna from the TS2000 to the UHF mobile. Now that AO-51 is silent, all of the FM operation is on SO-50 and AO-27. If you have a TS2000, you'll want to investigate the use of a downconverter. 73, John K8YSE

10 years, 9 months

ARISSat-1 Orbital Decay

by John Heath

Hi Satelliters, Using Keps from Space-Track for ARISSat-1 (37772) I have been plotting various parameters including Mean Motion. Rrecent results were unexpected. From day 328to 334 the daily change in Mean Motion has been exactly the same. The orbital decay is going at a very steady rate. This is completely different from earlier observations where there is quite a bit of daily variation. My interpretation is that the atmospheric density along the orbital track has been remarkably unchanged over 6 days or so. This is something I have not seen before. 73 John G7HIA

10 years, 9 months

Re: Satellite Satire

by Tony Langdon

At 02:28 AM 12/1/2011, Rick Tejera wrote: >Gordon, > >There are at least two groups that know of that launch High altitude >balloons with amateur payloads. I just joined one: Arizona Near Space >Research. http://www.ansr.org/ High altitude balloons are fun. There's a group here that launches them as well from Adelaide. Had fun when they installed a crossband repeater on one of their balloons. Also had a go at decoding telemetry, but being on the edge of the footprint and with small antennas, I haven't had much luck with telemetry. :( 73 de VK3JED / VK3IRL http://vkradio.com

10 years, 9 months

Re: Satellite Satire

by Lowell White

OK.. a LARGE "punkin' chunker" or two really tall and flexible trees for a slingshot... More seriously, it seems that for anything of reasonable size to be launched, particularly into an orbit that we rapidly enter not only the perview of costly specialization but also of military / government permissions, etc., probably much more delicate than ITAR considerations. Please enlighten me if indeed there might be a way to get something up (and to stay up) more economically. Would there be any feasiblity to an initial "launch" by using high-altitude weather ballons and THEN firing a small booster with appropriate guidance and CCC (command, control, and communications) to steer it into an orbital insertion? If the bird and booster weights were small enough, could a wx balloon lift them adequately? Just wondering... Lowell K9LDW EM12sr ------ Original Message ------ Received: Tue, 29 Nov 2011 04:38:33 PM CST From: Bob- W7LRD <w7lrd(a)comcast.net> To: George Henry <ka3hsw(a)att.net>Cc: AMSAT <amsat-bb(a)amsat.org> Subject: [amsat-bb] Re: Satellite Satire > > > Cool George! it's not the building and concepts that's difficult. It's getting the damn things up there. We should have a division of AMSAT that does rockets, and launch our own. Like my Dad told me, "the difficult we do immediately, the impossible takes a little longer". > > 73 Bob W7LRD > > > ----- Original Message ----- > From: "George Henry" <ka3hsw(a)att.net> > To: "AMSAT" <amsat-bb(a)amsat.org> > Sent: Tuesday, November 29, 2011 10:06:39 AM > Subject: [amsat-bb] Re: Satellite Satire > > Better yet, take the 10.8 MHz IF output from one of their old Bearcat scanners, > > programmed for a 2-meter uplink, add an appropriate local oscillator and high > pass filter, feed the resulting signal to the final stage from one of their old > > sideband CB's, and you've got a mode A *LINEAR* satellite!! > > We could call it OSCAR 10-4! > > > George, KA3HSW > > > > > > ----- Original Message ---- > > > From: K4FEG <K4FEG(a)K4FEG.COM> > > > To: amsat-bb(a)amsat.org > > > Sent: Tue, November 29, 2011 8:49:31 AM > > > Subject: [amsat-bb] Satellite Satire > > > > > > OK I have a suggestion: a new inexpensive satellite, It will be designated: > > > > >*ReNe-Sat-3, *that will be an abbreviation for: *Red Neck Satellite #3 ( > >Dale > > > > >Ernharts Sr. NASCAR #). > > > > > > *We will take 2 Woxun HT's, 2 Larsen Mag-mounts, 2**1/4 wave antennas, a > >solar > > > > >panel with charger from Northern Hydraulics and last but not least about 100 > > > > >feet of NASCAR 200mph duct tape. > > > > > > We take the 2 radios set them up for our frequencies, duct tape them > >together > > > > >mount the antennas on the solar panel hook the solar panel up to the HT > > >batteries and last but not least we send two of the south's finest: > >*Astronaut > > > > >"Bubba & Cooter"* up with the new bird to deploy it. We will tell Bubba & > > >Cooter that they can have free passes to all the NASCAR races for 2012 when > > > >they get this satellite working and in orbit. > > > > > > I promise they will have that thing (or should i say "thang") up and > >running > > > > >in HEO and be back before the first race in February 2012. > > > > > > For those that are not sure, YES I AM MAKING A JOKE! > > > > > > /*It is difficult work to keep these satellites working and the control > > >operators deserve a round of applause from us for all that they have done to > > > > >extend the life of AO51 and all of the other birds. > > > > > > THANK YOU ONE AND ALL! A JOB WELL DONE! > > > */ > > > Frank > > > K4FEG > > > _______________________________________________ > 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 > > > _______________________________________________ > 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

10 years, 9 months

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AMSAT-BB November 2011