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

HO-68 pass NA 6 June 2010 -- 0100-014 UTC -- Just FM carrier no AFSK
by Bruce Semple 22 Jun '10

22 Jun '10

I had my WISP all primed & ready to go -- TNC was ready -- I saw the S meter peak at S9+40 -- but no AFSK heard by me or my TNC ... Did anybody else hear the BBS? Bruce WA3SWJ

1 0

Re: SO-67 back on air!
by Tony Langdon 21 Jun '10

21 Jun '10

At 12:04 AM 6/22/2010, Jan-Albert Koekemoer wrote: >Hello > > > >After much delay we are now in a position to re-activate the SA-AMSAT payload >schedules on a regular basis again! Excellent news! :) 73 de VK3JED / VK3IRL http://vkradio.com

1 0

Re: Batteries for FT 817
by G0MRF＠aol.com 21 Jun '10

21 Jun '10

In a message dated 21/06/2010 17:27:29 GMT Standard Time, tjjapha(a)earthlink.net writes: I use 2 FT817s for portable ops, and have been disappointed in the battery performance. Last year, I bought replacement batteries from Batteries America, the FNB-72xe, rated at 9.6v. at 2000mAh. There's no noticable difference between these new batteries and the originals. The batteries charge to just over 11.0 volts, but quickly drop through 10 volts, as indicated by the voltage reading that appears when the rigs are turned on. Maybe this is just normal behavior for a 9.6 v. battery. Is this what you would expect? Has anyone found a battery with a higher voltage rating and/or one that will maintain a higher voltage for an appreciable period--and fits into the 817? Every bit of power helps! Many tnx and 73, Tony, N2UN LM 183 Hi Tony. Not sure about fitting in the FT817....But there are a lot of people over here participating in "summits on the air" driving / walking / climbing to the top of a peak and making some QSOs. The FT817 is very popular and they all seem to be using 3 series Lithium polymer cells. According to the hype, the lithium polymers weigh nothing hold nearly infinate charge and finally discharge within a few seconds of the natural lifespan of the operators radio. Whatever the reality, they may be worth investigating. Regards David G0MRF

2 1

SO-67 back on air!
by Jan-Albert Koekemoer 21 Jun '10

21 Jun '10

Hello After much delay we are now in a position to re-activate the SA-AMSAT payload schedules on a regular basis again! During the downtime we conducted several experiments in order to investigate possible alternatives for the "cut-off" problem experienced by many at the end of last year / beginning of this year. The cut-off is caused by SW running on piggyback electronics that continues to gate the received audio onto the transmitter for about 3s after a specific ground transmission has ended, whereafter the received audio is cut off. The SW then waits for the next ground transmission with a valid "transponder" tone embedded, before gating the audio onto the transmitter again. So if a second transmission starts within the 3s "tail" period, it will be cut off when the 3s expires. Listen to this mp3 recording as an example: http://tinyurl.com/38vvg3o Unfortunately the piggyback electronics does not have reprogramming functionality, so we are not able to change the SW. We did however manage to implement a mechanism on the satellite transponder (used by the piggyback) that should be of some assistance when using the payload: the PTT of the transmitter now STAYS ON for the duration of the payload activation (i.e. 15 min), regardless of a valid "transponder" tone received. Note that this does not get rid of the "cut-off" problem, nor of the requirement to embed a valid tone when you want to use the payload - see detailed explanation below. The following example depicts the ideal usage scenario of the payload: 1. As the satellite comes over the horizon, an unmodulated carrier ("quieting") will be received by all on UHF 2. Person A starts to transmit on VHF (with valid "transponding" tone embedded in the transmission) and the transmission is relayed on UHF 3. When Person A releases his/her PTT, the satellite will continue to transmit what it is receiving (usually this will be "noise") for a further ±3s. Nobody should start to transmit during this time! 4. At the end of the ±3s period, everybody will again hear the unmodulated carrier. 5. NB: only when this unmodulated carrier is heard should Person B start to transmit. Listen to this mp3 recording as an example of valid usage: http://tinyurl.com/32rjbxm I suppose this will take some getting use to - at least the system has a built-in "punishment" mechanism for the impatient! ;-) Please refer to previous posts on general voice quality optimization when using the SA-AMSAT payload on SO-67. I will request Gladys Magagula at the Satellite Application Centre to obtain regular schedules from the regional coordinators as soon as possible. We will start off with day passes only, transmit on 2.5W and see how things go. Enjoy! Regards Jan-Albert ________________________________________ Jan-Albert Koekemoer, PrEng Sun Space & Information Systems (Pty) Ltd. Stellenbosch, South Africa www.sunspace.co.za <http://www.sunspace.co.za> +27 21 880 8117 (tel) +27 83 461 6643 (cell) +27 21 880 1703 (fax) E-mail Disclaimer http://www.sunspace.co.za/emaildisclaimer.htm

6 5

Electronics parts in space?
by Andy Brian 21 Jun '10

21 Jun '10

what happen with electronics parts in space like quartz and electrolytic capacitor in vacuum. I have never heard about how quartz works in space is there any limitations? I know that some plastic outgasing and are not suitable for use in space, but if using COTS technology like hamradio station yaesu vx-series on cubesats, I believe that there are many electronics parts which are crytical for use on the cubesats? thanks for comments, best regards Andy

1 0

Batteries for FT 817
by ANTHONY JAPHA 21 Jun '10

21 Jun '10

I use 2 FT817s for portable ops, and have been disappointed in the battery performance. Last year, I bought replacement batteries from Batteries America, the FNB-72xe, rated at 9.6v. at 2000mAh. There's no noticable difference between these new batteries and the originals. The batteries charge to just over 11.0 volts, but quickly drop through 10 volts, as indicated by the voltage reading that appears when the rigs are turned on. Maybe this is just normal behavior for a 9.6 v. battery. Is this what you would expect? Has anyone found a battery with a higher voltage rating and/or one that will maintain a higher voltage for an appreciable period--and fits into the 817? Every bit of power helps! Many tnx and 73, Tony, N2UN LM 183

2 1

AO-51 Mode V/S schedule should start 10:45Z 21Jun10
by Andrew Glasbrenner 21 Jun '10

21 Jun '10

Please submit any reports to -bb or the website at http://oscar.dcarr.org/ . Of particular interest are reports between 10:45 and 11:29 today. We may need a few passes to get the scheduling working right, so please send those reports, and bear with us. 73, Drew KO4MA

1 0

States needed for WAS on satellite
by Daniel "Nick" Kucij 21 Jun '10

21 Jun '10

Hi Larry, I'm over in Maine on vacation this week, near Acadia National Park. I've got my HT and small yagi with me. I'd be glad to try for a QSO with you. Just send me an email. 73 Nick KB1RVT/P FN54

1 0

States needed for WAS on satellite
by Larry Teran 21 Jun '10

21 Jun '10

I need the following States to complete the WAS award from ARRL, I will appreciate if they are any stations from these states or information of a station to contact to sked a QSO. thanks for your time. 73"s Larry KI6YAA Connecticut Maine Massachusetts Mississippi North Carolina Rhode Island West Virginia Wisconsin

3 2

AMSAT Assistance from Morocco, Norway
by Clint Bradford 21 Jun '10

21 Jun '10

I had a speaking engagement at the Orange County (CA) Amateur Radio Club scheduled for last night. They know of my involvement with AMSAT so, when they received an inquiry earlier in the week from the University of Southern California ham station regarding equipment setup, they forwarded the inquiry to me. I have no experience with the transceivers mentioned, so I immediately re-post the inquiry here earlier this week. Within 24 hours, USC received assistance from Norway and Morocco. The USC contactperson re-wrote me, thanking me for getting him assistance. I told him that it was AMSAT-Worldwide that was really to be thanked. And in my "signature file," I mentioned that I was speaking in Orange County ... Well, USC's Omair didn't receive my reply until 8:30am Friday morning - the date of my talk. But as we completed the 5:40PM PDT pass of AO-51 (speaking to US contacts as well as Canadian contacts), this gentleman walks up to me and introduces himself. "Hi, Clint. I am Omair Rahman from USC ... " I was floored. Not only did Omair show up for the demo, but stayed for my sat presentation. OF COURSE I introduced him to the 40+ in attendance, and had him explain his station and plans for their upcoming two satellites. It was a special night - THANK YOU to Omair for showing up and presenting your satellite plans. And THANK YOU to the fellow AMSAT members here who IMMEDIATELY sent info to Omair to assist him with his station's setup. Clint Bradford, K6LCS 909-241-7666

2 1