March 2012 - AMSAT-BB - mailman.amsat.org

Comparative report between VO-52 Indian Transponder and VO-52 Dutch Transponder
by i8cvs 27 Mar '12

27 Mar '12

Hi All, To make a comparative report for performance of VO-52 Indian Transponder 28 November 2011 and Dutch Transponder 27 March 2012 please find here the internet links for two QSO made between i8CVS and IW6OVD in two similar ascending orbits http://www.hamradio.selfip.com/iw6ovd/VO-52-INDIAN-TRASPONDER.mp3 http://www.hamradio.selfip.com/iw6ovd/Dutch-trasponder-FULL-QSO.mp3 73" de i8CVS Domenico

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Power Plug for a RFC 2-317
by William Liporace - WC2L 27 Mar '12

27 Mar '12

Does anyone have a spare power plug for a RFC 2-317 AMP? TNX Will WC2L

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VO-52 Frequency Drift
by John Papay 27 Mar '12

27 Mar '12

There were three passes of VO-52 here this morning, 27March2012. I was able to copy the beacon on all three passes. Here are the results: 1200utc 145862.6 1335utc 145861.7 1510utc 145861.9 The frequencies are not exact. My CW offset is 850Hz. There is significant frequency drift and temperature is probably the cause. It would be interesting to hear from the control team regarding this. HO-68 provides an excellent check of your doppler compensation in your tracking program. I find that the beacon is always very strong and the frequency is rock solid. You can save the frequency in your program and a month later find that it is right where it was the month before. If you can listen to the beacon with your CW filter on throughout the entire pass, you have everything set right, keps, computer clock etc. The doppler gets quite severe on a high pass and is a great way to make sure you have everything set right. Since HO-68 is on UHF, everything becomes more critical. 73, John K8YSE

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CM2ESP operation today
by Raydel Abreu Espinet (CM2ESP) 27 Mar '12

27 Mar '12

Hi all, I will be at home today, i hope to work AO-27 on today pass at 18:35 UTC aprox. And probable, but not for sure, may be also on SO-50 at 16:30 UTC aprox. If anyone need EL83 just give me a call. 73, CM2ESP, Havana, EL83sc Este mensaje ha sido enviado mediante el servicio de correo electronico que ofrece la Federacion de Radioaficionados de Cuba a sus miembros para respaldar el cumplimiento de los objetivos de la organizacion y su politica informativa. La persona que envia este correo asume el compromiso de usar el servicio a tales fines y cumplir con las regulaciones establecidas.

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WRAL TV News - ARISS Contact
by Trevor . 26 Mar '12

26 Mar '12

Salem Elementary got some good publicity for their ARISS contct, see http://www.uk.amsat.org/6095 73 Trevor M5AKA

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VO-52 Frequency Drift
by John Papay 26 Mar '12

26 Mar '12

VO-52 has been a very loud and easy to work satellite since the recovery and change to the Dutch Transponder. The CW beacon is very loud and you can usually find an image of it elsewhere in the transponder passband. If you are running full doppler control, you have probably noticed that your settings (uplink calibration) have to be changed from pass to pass. The beacon frequency is not constant either so I suspect that the frequency source is not very stable. Stability is usually a function of temperature so it would appear that the temperature inside the satellite is changing due to internal electronics and/or effects from the sun. This would be something that the control team would be aware of. Any feedback from them would be appreciated. I do not recall that the India Transponder had a similar problem but maybe someone else could comment on that. If it did drift, it was only one or two hundred Hz. Initially the difference between the India and Dutch Transponder was about 2KHz. Now it seems to vary plus or minus 500 Hz or so. Maybe some others can comment on this. 73, John K8YSE

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FO-29 QSO Below the Horizon
by John Papay 26 Mar '12

26 Mar '12

Every now and then someone asks about the possibility of making a satellite QSO when the bird is below the horizon. Once in while it happens as it did with Adrian, AA5UK/KH6, on FO-29 this morning at 0849utc. Adrian has been operating from KH6 and trying to give out WAS to the deserving. Many have made their first Hawaii QSO thanks to his efforts. I had a 0.8 degree pass this morning on FO-29 but when Adrian was at 3 degrees, I was at 0.0 degrees. There was a short window of opportunity after that point. As I was waiting for FO-29 to come up over the horizon I started hearing Adrian at -0.9 degrees. At -0.5 I called him and we had a qso that ended about 2 seconds after my AOS. My recorder is configured to start recording at AOS and it only captured a few seconds of my last transmission. Doug KD8CAO had his recorder running so you can hear my qso that took place below the horizon. I have my ground elevation in the setup so the calculations should be accurate. The best opportunity for a below the horizon contact occurs when the satellite is skimming the horizon rather than going away from you. If it is skimming there is much more time at the critical -1.5 to 0.0 degree elevation and that is what happened this morning. Recordings are on my website. http://www.papays.com/sat/general.html A big thank you to Adrian for making the effort to work the difficult passes and stretch the limits. If it were easy, everyone would be doing it. 73, John K8YSE

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KD2AUC-1 in range of Azores
by Lynn W. Deffenbaugh (Mr) 26 Mar '12

26 Mar '12

Just noticed that KD2AUC-1 got a packet through the CU3HY IGate in the Azores! Congratulations to the team! Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

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KH6 Problem solved. Back in business!
by Adrian Engele 26 Mar '12

26 Mar '12

Aloha friends, It came down to a locked IC-7000 and a bad PL259 to BNC adapter. Luckily I had a couple of spare ones with me. Radio Shack is not around the corner here. I just did a check on the 0026Z FO-29 Pass and all was in order. We are back in business. Aloha, Adrian AA5UK/KH6

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KLM CS-2 strip line design
by Darryl Ponder 26 Mar '12

26 Mar '12

I am refurbishing an old KLM 435-18C that has a KLM CS-2 polarization switcher on it. I need help in understanding the design of the 37 ohm impedance strip line transformer that is inside the CS-2. By my calculations the transformer line length is half as long as it should be (1/8 wavelength and not 1/4 wavelength). However, it is folded, and I suspect the answer is in the folding. If anyone on the board is familiar with strip line design and would be willing to trade a few emails (outside the reflector) on the subject I would really appreciate it. I have been unable to track down what I need after many Google and Bing searches, so appeal to a much better source - this group. Regards, Darryl Ponder K0GV

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