May 2010 - AMSAT-BB - mailman.amsat.org

AO-51
by Matt 08 May '10

08 May '10

Sorry, it was not heard because it wasnt over Europe ... I miss 1 hour on my computer clock again. SQ7DQX

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AO-51 update
by Andrew Glasbrenner 08 May '10

08 May '10

AO-51 has now reentered a period of eclipses that will reach almost 20 minutes by July. Since we've been in an extended period of continuous illumination and very warm spacecraft temperatures, the next few weeks will be spent determining what the batteries capacities are now. Currently we are running 1.01 watt on 435.300 only, with the new PL mode on. For this summer eclipse season, we are fortunate that the eclipsed periods are while AO-51 is over mostly unoccupied Antarctica and surrounding areas. This means when the batteries alone are supporting the transmitter, there are not likely to be any users. We have a downlink power management routine that we'll be implementing over the next week or so. Downlink power may range from 2 watts in illumination, to maybe as low as 300 milliwatts in eclipse. Using this, combined with the PL, should mean we can protect the batteries from over-discharge, while still providing the strongest possible downlink. I'd like to encourage everyone to use the excellent reporting resource at http://oscar.dcarr.org/ . I check this page at least 4 times a day to check the status of AO-51. If the eclipse periods get too long faster than we can adjust, the repeater may shut off due to a low battery voltage watchdog. If this happens, please email me directly at ko4ma(a)amsat.org, or for those that have my cell phone number already, please feel free to text me a warning that the satellite repeater is off. Additionally, the AO51-modes group would like your input on the desired Field Day mode. We will likely be limited to one transmitter operation. With AO-27, SO-50, and possibly SO-67 and HO-68 on V/U FM, S band or L/U operation is looking very promising to provide some variety. 73, Drew KO4MA AMSAT-NA VP Operations

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thanks
by Larry Gerhardstein 08 May '10

08 May '10

Greetings, I want to thank all of the good folks who helped me get my satellite station on the air. This has been a process since about last fall. We were gone during the winter and restarted the project when I returned home. I'd like to recognize W4AS, K7WIN, PE0SAT, KB7ADL, K0VTY, N6NKF, Scott Hagerman (non ham), AA5PK, K6LCS, G8IFF, certainly others ... and most of all Erich DK1TB, author of SatPC32, who spent much time researching drivers, answering questions, and attempting to duplicate problems I have been having. A few lessons learned... from all this. 1) Don't jump to conclusions. My rotor control spent about 3 months at Yaesu service only to learn nothing wrong with it. The technician at Yaesu never suggested the trouble could be fixed by optical isolation of the RS232 line going to the rotor control box. 2) Do not assume the nature of a RS232 cable. Use an ohm meter and determine if it is good or bad, straight through or cross-over or null-modem. If I had started out using the ohm meter on my cables, that would have saved me much time and frustration. Both GS-232 and CI-17 call for straight through serial cables. I made the mistake of using two null modem cables; unfortunately I did not know they were not straight through until later when I thought to use an ohm meter. 3) Don't assume you can construct a straight through RS232 cable by connecting two null modem cables in series. This may work, and it may not. 4) Before installing optical isolators in the RS232 lines, make certain the devices are compliant with the isolators. I tried optical isolation in both the rotor control and the rig control lines. An isolation device between computer and GS232 rotor interface was needed. However, the CI-17 does not like them. 5) The optical isolators from CF that I used seem to have polarity. Make certain the female end of the isolator is against the computer's male connector. Do not turn the isolator around and use sex-changers between computer and isolator. This was just a random thing I tried.... it did not work. 6) When running into difficulty as I did, document everything. I kept repeating the same trials over and over, wasting time, and about driving myself to madness. 7) In my opinion when using Windows 7 of Vista 64-bit, only install drivers designed for those systems. Drivers for 32-bit are not reliable in 64-bit applications and may cause the computer to crash to blue screen. 8) Before ordering USB to serial conversion devices make certain the drivers that come with those gadgets are compatible with the computer operating system you plan to use. Many days after I received my KeySpan device, I called Tripp Lite. The sales person there told me they do not presently have a 64-bit driver for the USA49WG. Wish I had known that. 9) Make sure the baud rate in the transceiver matches the baud rate being set up in the CAT setup menu. If you can affort it, get a RS232 serial data analyzer. I downloaded the free version of 232Analyzer. Full version is about $140. 232Analyzer helped a lot and allowed me to see both data transmitted and received. This led me to the mismatched baud rates in the ICOM and SatPC32. These are the issued I stumbled on. Different computer hardware, different ham gear, different operating systems may produce different results. Beware of Murphy. 73, Larry W7IN

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Arecibo on 432 MHz Moon Bounce (some calculations)
by i8cvs 08 May '10

08 May '10

Hi All, I have received an email from Daniel Esteban LU2DDU informing me that about the Arecibo radiotelescope he was in touch with Victor KP4PQ in order to get from him more details about the feed line running from the operating site up to the feed. Victor says to Daniel that for 432.045 MHz they were using an existing wave guide with the larger side 23" high ( 58 cm ) and 1500 ' long ( about 457 meters long) with a loss of 1 to 1.2 dB i.e. about 1.32 time in power ratio at 432 MHz Please note that the size of the above wave guide can be compared to the air duct of an air conditioning system normally used into a big industrial shed. Considering that the power amplifier was running at best 350 watt it follows that the power reaching the feed was 350 / 1.32 = 265 watt Since the gain of the Arecibo dish is 60 dB or 1000000 time in power ratio it follows that the Arecibo EIRP was 265 MW Tanks to Daniel LU2DDU and Victor KP4PQ for the above information. Best 73" de i8CVS Domenico

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Fw: WC7V/P DN44, Wyoming
by kladuke1144＠msn.com 07 May '10

07 May '10

The satellites I will be working are ao51 starting at about 1400Z and the first ao27 pass at about 1800Z. There are several passes during the day for both birds until I depart at about 2210Z. 73 WC7V Kerry (thanks Bob) From: kladuke1144(a)msn.com Sent: Friday, May 07, 2010 1:44 PM To: amsat-bb(a)amsat.org Subject: WC7V/P DN44, Wyoming All, My plan is to operate portable from Mammoth, Yellowstone Park, Wyoming (DN44) from 1400Z to about 2210Z on Saturday May 8, 2010. I logged 33 contacts on May 5 from this grid and look forward to another successful operation. 73 WC7V Kerry

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WC7V/P DN44, Wyoming
by kladuke1144＠msn.com 07 May '10

07 May '10

All, My plan is to operate portable from Mammoth, Yellowstone Park, Wyoming (DN44) from 1400Z to about 2210Z on Saturday May 8, 2010. I logged 33 contacts on May 5 from this grid and look forward to another successful operation. 73 WC7V Kerry

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Fwd: [Sumbandila: 250] Digest for sumbandila@googlegroups.com - 3 Messages in 1 Topic
by Chris Bloy 07 May '10

07 May '10

BODY { font-family:Arial, Helvetica, sans-serif;font-size:12px; } Hi All, Please see news posted by Sumbandila :- ----- Original Message ----- From: sumbandila+noreply(a)googlegroups.com To: Digest Recipients sumbandila+digest(a)googlegroups.com Sent: Fri 07/05/10 19:39 Subject: Fwd: [Sumbandila: 250] Digest for sumbandila(a)googlegroups.com - 3 Messages in 1 Topic Today's Topic Summary Group: http://groups.google.com/group/sumbandila/topics [1] *[Sumbandila: 247] Sumbandila amateur radio schedules [2] [3 Updates] Topic: [Sumbandila: 247] Sumbandila amateur radio schedules [3] Eddie ZS6BNE May 07 03:49AM -0700 ^ [4] Hi guys, What’s happening amateur radio wise on Sumbandilasat lately? It would be really great to see some amateur radio activity schedules again! I’m in the process of writing the “Amateur Radio in Space’ [ARiS] column for Radio ZS and I’d really like to write of some good news. 73 Eddie ZS6BNE "Jan-Albert Koekemoer" May 07 01:34PM +0200 ^ [5] Hello We've indeed have a long "radio silence" now. Some good news is that we're reprogramming the command transceiver on the satellite used by the SA-AMSAT payload (CTR-VU2) tonight. This will hopefully sidestep the issue we've had with the cut-off at the PTT tail. The idea is to keep the PTT active for the 15 minute duration that the SA-AMSAT payload will be active at a time, i.e. uncouple the PTT functionality from the rest of the SA-AMSAT payload functions. We will then make sure it works as expected (hopefully first half of next week) and if all goes well, aim to have the payload fully operational and in service again by the end of the week. With some unexpected hiccups on the satellite, the commissioning took longer than expected. We've already completed the initial transfer of operations to SAC (March) and will be completing the training of their Mission Specialists this coming Mon - Wed. We should then be in a position to have >95% of mission operations in place at SAC. SunSpace will continue to provide expert support for the duration of the satellite lifetime. Thank you for your patience! Regards JA -----Original Message----- From: sumbandila(a)googlegroups.com [mailto:sumbandila@googlegroups.com] On Behalf Of Eddie ZS6BNE Sent: 07 May 2010 12:49 PM To: Sumbandila satellite Subject: [Sumbandila: 247] Sumbandila amateur radio schedules Hi guys, What's happening amateur radio wise on Sumbandilasat lately? It would be really great to see some amateur radio activity schedules again! I'm in the process of writing the "Amateur Radio in Space' [ARiS] column for Radio ZS and I'd really like to write of some good news. 73 Eddie ZS6BNE E-mail Disclaimer http://www.sunspace.co.za/emaildisclaimer.htm [6] May 07 01:39PM +0200 ^ [7] Eddie see SARLNEWS for last Sunday SUMBANDILASAT SOON BACK IN AMATEUR RADIO MODE SA AMSAT announced that SumbandilaSat will soon be back in the Amateur Radio Mode. Currently Sunspace will re-program CR2 with a fix for the SA AMSAT PTT problem . This is expected to be completed by mid May. Programming of the Amateur Radio Payload will in future be carried out by the CSIR Satellite Application Centre at Hartebeeshoek. SA AMSAT will work with SAC to coordinate operational requests. More details on how to request operation will be announced in the next two weeks and published on www.amsatsa.org.za. We will not be using googlegroups. Eddie I am in the process of updating www.amsatsa.org.za. the request for areas to be included in the schedule, special events etc will have to be sent to saamsat(a)intekom.co.za by Mondays . SA AMSAT will coordinate with SAC and publish a schedule for the following week during Friday. Currently Jan-Albert is testing the PTT software change. Hans. Hans van de Groenendaal Features Editor EngineerIT 012 991 4662 082 781 4631 ----- Original Message ----- From: "Eddie ZS6BNE" To: "Sumbandila satellite" Sent: Friday, May 07, 2010 12:49 PM Subject: [Sumbandila: 247] Sumbandila amateur radio schedules Hi guys, What’s happening amateur radio wise on Sumbandilasat lately? It would be really great to see some amateur radio activity schedules again! I’m in the process of writing the “Amateur Radio in Space’ [ARiS] column for Radio ZS and I’d really like to write of some good news. 73 Eddie ZS6BNE Links: ------ [1] http://groups.google.com/group/sumbandila/topics [2] http://webmail.photofuture.co.uk/#group_thread_0 [3] http://groups.google.com/group/sumbandila/t/23e786bb1df9e220 [4] http://webmail.photofuture.co.uk/#digest_top [5] http://webmail.photofuture.co.uk/#digest_top [6] http://www.sunspace.co.za/emaildisclaimer.htm [7] http://webmail.photofuture.co.uk/#digest_top

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Re: 70cm yagi
by Clint Bradford 07 May '10

07 May '10

>> ... homebrew equipment. Some can even be better than commercial! I would not live in a community where my public service departments were depending upon homebrew comms equipment for critical emergency communications. This is not demeaning to the amateur radio community at all. Amateur radio should DEMAND such respect and recognition in the emergency plans of their communities. Clint Bradford, K6LCS 909-241-7666 ---------------------------------- Clint Bradford, K6LCS http://www.clintbradford.com

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SO-50 Frequency Jump
by John Papay 07 May '10

07 May '10

Over the past week or two I have noticed that SO-50 is changing frequency during the pass. Today at 2308z I made some transmissions and then noticed that my downlink was distorted as well as the station I was working. A change from 436.790 to 436.795 for the center frequency (not the doppler corrected frequency) made the audio clear again. This has happened to me a few times now and seems to occur once the transmitter has been on for a minute or two. Has anyone else noticed this? 73, John K8YSE

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SO50 FRQ JUMP
by paul robinson 07 May '10

07 May '10

Hi John ,yes this problem with so50 has been abt for a while....de paul 2E1EUB

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