Another old time satellite might be waking up from its sleep as it comes out of a period of eclipses. Joanne Maenpaa mentioned that UO-11's telemetry beacon had been heard on 145.825, so I decided to try to give it a listen on its pass to the east. Despite the fact that it was fairly low, I heard the 1200 baud AFSK telemetry quite clearly. I don't have the ability to decode it (couldn't find any Mac programs that would), but I recorded a couple of minutes of it using Audacity on my mac anyway. Because someone might be able to decode it from this data, here's the compressed .wav file:
Here's a screen dump of Audacity, showing the 1200 and 2400 Hz carriers that make up the AFSK signal.
Addendum: Douglas Quagliana, KA2UPW did what I hoped someone would: ran my recording successfully through his own UO-11 decoder. From the email he sent me:
Hi Mark, Thanks for posting the recording! I downloaded your recording and ran it through my DSP soundcard UO-11 demodulator. Most of the data in your recording looks like this, although other sections are quite noisy. UOSAT-2 0711024074656 000000010001020002030003040004050005060006070007080008090009 100001110000120003130002140005150004160007170006180009190008 20000221000322000023000124000625000726000427000528000A29000B 30000331000232000133000034000735000636000537000438000B39000A 40000441000542000643000744000045000146000247000348000C49000D 50000551000452000753000654000155000056000357000258000D59000C 60800E615FC1620004633305644402651E0C662AC467000168000E69000F All of the columns of zeros are telemetry channels that have failed. This agrees with what Clive has previously reported. Earlier Clive reported: >The current status of the satellite, is that all the analogue >telemetry channels, 0 to 59 are zero, ie they have failed. >The status channels 60 to 67 are still working. The real >time clock is showing a large accumulated error [...] Last month the clock was about 74 days slow, but it is now about 81 days off. In the past UO-11 also used to send stored ASCII bulletins as well, but I think that capability of the satellite ended when the spacecraft computer turned off. Anyone know for sure?
Thanks alot Douglas for the decode.
This just came across the amsat-bb mailing list:
Since AO-16 was recovered approximately 6 months ago, the command team has attempted to reload the satellite software almost a dozen times without success. Subsequently a series of memory tests were performed which points towards a hardware failure which prevents restarting the spacecraft software successfully. This team included Bruce Rahn WB9ANQ and Jim White WD0E advising Mark Hammond N8MH as the primary groundstation. Mark put in many early hours during the multiple reloads and test sessions, with Bruce, Jim, and others advising. Thank you to all involved for your hard work. After the conclusion that the spacecraft computer system was damaged and as discussions about decommissioning were taking place, Jim recalled a series of low level commands included in the spacecraft design by Tom Clark, K3IO during construction. One of these commands allows an uplink receiver to be directly tied to a downlink transmitter. The twist is that the uplink is regular FM but the downlink via the BPSK transmitter is DSB (Double Sideband). Mark placed the satellite in this mode early this week and some testing was undertaken. The satellite hears VERY well, and the reduced bandwidth by using either USB or LSB on the groundstation receiver allows for a very robust downlink. Tuning the downlink is just like on a linear transponder, meaning it is tight and with fast Doppler. Uplink tuning is not required, just as with the FM mode V/U satellites. QSOs were made between N8MH, WD4ASW, KO4MA, K5QXJ, and WA6FWF. My personal observations include being able to access and hear the satellite within one degree of the horizon, much lower than any other current bird for my QTH. This should be an easy satellite with omni antennas and a 70cm preamp. With that explanation, I'm happy to open the satellite to general use on voice for a test period. Please submit reports either to the -bb or to firstname.lastname@example.org . The uplink is 145.920 FM, and the downlink is 437.026 SSB ± Doppler shift. Please restrict your uplink power to a reasonable level, and do not transmit without being able to hear the downlink. All the general single-channel guidelines apply. Enjoy this bird's new life! 73, Drew KO4MA AMSAT-NA VP Operations
Whacky! I don't have any UHF SSB equipment, so it really doesn't help me much, but I can imagine that using a cheap 2m handheld for the uplink, and either a TH-F6A or more capable transciever for the downlink would be possible. Neat! I'll have to give this a try sometime.