May 2015 - AMSAT-BB - mailman.amsat.org

Successful QSO on PSAT1
by David W0DHB 28 May '15

28 May '15

A successful QSO between AA5PK DM91 and W0DHB DN70 this last PSAT-1 pass Also heard was WC7V DN45 . We're starting to get the hang of it

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PSAT
by Red Willoughby 28 May '15

28 May '15

A couple of questions: How much power (to a dipole) is recommended for uplinking on 28.120 PSK31? Also, what is it's altitude? And, how long is its expected lifespan? Thanks in advance. Red KC4LE

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LightSail Data?
by Kelley 28 May '15

28 May '15

I left the rig and packet software running today while I was at work. I was listening to the LightSail beacon on 437.435 MHz. I had one entry on the screen when I got home: 1: Fm V-3 to 70-9 Via uH, , , -6 <RR P/F R5>[07:25:21] No idea what it means, not sure if it was LightSail or not. Posted as an FYI. Curious to know what it might be. -- Kelley - WØRK

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PSAT VHF RX frames
by David 28 May '15

28 May '15

Hi all: I have been able to receive some AX25 frames in the 145.825 Khz downlink frequency. Time showed in the frame is UTC+2 QTH is IN80CP First two corresponding to orbit #117: 1:Fm PSAT-1 To APOFF Via ARISS <UI R Pid=F0 Len=34> [10:46:11R] T#808,856,074,941,644,843,00011100 1:Fm PSAT-1 To APOFF Via ARISS <UI R Pid=F0 Len=34> [10:47:12R] T#809,855,074,938,623,843,00011100 the next to the orbit #119: 1:Fm PSAT-1 To APOFF Via ARISS <UI R Pid=F0 Len=38> [14:08:30R] :BLN2USA :See APRS.FI & 144.39 users 1:Fm PSAT-1 To APOFF Via ARISS <UI R Pid=F0 Len=34> [14:11:14R] T#010,822,357,830,736,832,00011100 Antenna is 9 elements yagi without elevation Software is SoundModem by UZ7HO Best 73s David EA4SG

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ISS digi on?
by Steve Kristoff 28 May '15

28 May '15

Anybody hear anything from the ISS digipeater this morning (between 1019 and 1030 UTC)? This should have been a good pass at my QTH (EM79ji) and I heard nothing. Is the digipeater off or am I "off"? Steve Kristoff AI9IN skristof(a)etczone.com

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Re: [amsat-bb] PSAT- transmission sequence
by Tom Schuessler 28 May '15

28 May '15

The original email from David, reprinted below noted the "Stopping of the 435 downlink carrier and Bob WB4APR came back and said that the transponder is in an "Auto" mode which waits for a PSK signal and then turns on. My experience the other morning was that this was true, but as David says below, he was surprised by it turning off periodically. My surprise was that I was able to repeatedly turn it on when I started transmitting on 28.120 +1Khz, but before my CQ ended, the carier would quit. I repeatedly brought it up and also saw other not so copyable psk carriers on the waterfall but the transponder seemed not to stay on long enough to keep a full QSO going. I know for a fact because I duplicated at least three times turning on the FM carrier about 2-3 seconds after I started to uplink. I personally have yet in my several feeble efforts, been able to make a full QSO although I have been emailed by several to say that they did indeed hear me. This morning, 5-27 1207Z pass I was bad and had my RX radio to the wrong frequency but will give another shot at the 114xZ pass on 5-28 to see if I can make progress on making a Q. Tom Schuessler - - - - - - - - - - - Date: Wed, 27 May 2015 09:54:23 -0400 From: David G0MRF <g0mrf(a)aol.com> To: bruninga(a)usna.edu, amsat-bb(a)amsat.org Subject: [amsat-bb] PSAT- transmission sequence Message-ID: <14d95a711a9-c2e-8cd(a)webprd-m108.mail.aol.com> Content-Type: text/plain; charset=utf-8 Congratulations Bob and USNA on another successful spacecraft. I listened for the first time this morning and could hear the beacon and transponded PSK31 without any trouble. But I was not expecting the 435.350 carrier to stop every now and again. What determines if the carrier is on or off. - Beacon timing.- OK, but is the transmitter also PSK activated in someway? Or is it a timer. Very nice for saving power. Thanks David G0MRF

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9600 baud and IC-9100
by David L Warnberg 27 May '15

27 May '15

Ok, so I'm hearing something I cannot verify. I have be trying to capture 9600 baud packets from BRICSat. Now I discover on the IC-9100 yahoo group someone is saying the IC-9100 does not handle 9600 baud packets over the USB port. I find this hard to believe but can any confirm or deny this claim? I have had issues catching anything with the IC-9100 and 9600 baud packets so was wondering if it was the setup or the radio. All feedback welcome please.. David, KK4QOE

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PSAT Status (day 4)
by Robert Bruninga 27 May '15

27 May '15

PSAT PSK31 435.350 MHz FM downlink is full quieting with 6 bars using a decent UHF Yagi. But we have not seen any users other than those using the 28.120 PSK channel on HF normally. We welcome people to experiment with it. Everyone within the 28.120 to 28.123 MHz ten meter passband will be uplinked and heard on the 435.350 MHz downlink. The Naval Academy's PSAT seems healthy with plenty of power (we are keeping the APRS digipeater off to allow max power for PSK31). PSAT 's radio and packet system are a simple $250 APRS tracker http://www.byonics.com/mtt4b sent to space. The PSK31 transponder is a single 3.4" square circuit board made by Brno Universtiy in the Czech Republic. The CPU for controlling bulletins and timing is a simple Parallax Basic Stamp. PSAT is actually only about a 1U cubesat but in a 1.5U package since the flight was available and it gave us more power for our NON-SPACE solar cells. We are using standard silicon that are only half as efficient as multi-junction cells, but only cost 1% as much. PSAT has a single 21" VHF and 72" long HF whip. It has two UHF 6" orthogonal monopoles, all of very thin Nitinol wire. More details will eventually follow as the page will be updated over the coming weeks. http://aprs.org/psat.html * PSAT packet telemetry is OK, Digipeater will be off (secondary mission) * PSAT PSK31 transponder is ON with 28.120 MHz uplink! (primary mission) * WOD data fixed. Spin data now available. Right now it is at 3 RPM with +Z pointing 45 deg off Sun * Launch TLE elements (below) are still very good * http://PCSAT.APRS.ORG web page is now capturing PSAT telelmetry that users inject into the APRS-IS * BRICSAT telemetry has been heard but is cycling OFF due to low power * BRICSAT PSK31 downlink (also FM) has also been heard barely (when ON) * USS Langley not heard FREQUENCIES: PSAT: 145.825 - 1200 baud AX.25 telemetry - digi off PSAT PSK31-5: 435.350 FM down, 28.120 SSB PK31 uplink - Brno University Xponder BRICsat: 437.975 - 9600 baud telemetry evry 20s BRICsat PSK31-6 - same as PSAT but PSK TLM on 375 Hz (PSAT on 315 Hz) USS Langley - 437.475 9600 baud telemetry <== CORRECTION ULTRASat3 <these are still tracking well> 1 99993U 15140.67013889 .00040043 00000-0 10235-2 0 00009 2 99993 055.0004 339.9238 0251027 182.3314 074.3075 15.12517086000014 Bob, WB4APR

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ISS Digipeater QSOs
by Steve Kristoff 27 May '15

27 May '15

I'm still looking for QSOs through the ISS digipeater. There's a pass in a couple of minutes, but I'm open to making a sked in the future. Thanks! Steve AI9IN Oldenburg IN EM79ji

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Listen for LightSail - transmissions stopped
by JoAnne Maenpaa 27 May '15

27 May '15

Just read on-line at http://planet.ly/0gVop (Planetary Society) that the LightSail satellite stopped transmitting. The team is attempting a reboot. The telemetry data is sent on a downlink of 437.435 MHz, AX.25, 9600 bps FSK. Excerpt from their page ... As of late Friday afternoon, LightSail was continuing to operate normally. The spacecraft's ground stations at Cal Poly San Luis Obispo and Georgia Tech were receiving data on each pass. Power and temperature readings were trending stably, and the spacecraft was in good health. But inside the spacecraft's Linux-based flight software, a problem was brewing. Every 15 seconds, LightSail transmits a telemetry beacon packet. The software controlling the main system board writes corresponding information to a file called beacon.csv. If you're not familiar with CSV files, you can think of them as simplified spreadsheets-in fact, most can be opened with Microsoft Excel. As more beacons are transmitted, the file grows in size. When it reaches 32 megabytes-roughly the size of ten compressed music files-it can crash the flight system. The manufacturer of the avionics board corrected this glitch in later software revisions. But alas, LightSail's software version doesn't include the update. Late Friday, the LightSail team received a heads-up warning them of the vulnerability. A fix was quickly devised to prevent the spacecraft from crashing, and it was scheduled to be uploaded during the next ground station pass. But before that happened, LightSail's automated chirps fell silent. The last data packet received from the spacecraft was May 22 at 21:31 UTC (5:31 p.m. EDT). A LightSail map tracking application is at: http://sail.planetary.org/missioncontrol -- 73 de JoAnne K9JKM k9jkm(a)amsat.org AMSAT VP User Services

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