AO-27’s on/off times run open-loop and have drifted a bit so that the information on ao27.net is out of date. We’re trying to collect current telemetry before attempting to upload new settings.
AO-27 sends 20 seconds of AFSK telemetry followed by 240 seconds of FM repeater operation during descending nodes (North to South passes). As best we can determine from Satnogs observations, the satellite currently turns on when near the equator and shuts off at about 12-14 deg South latitude. Stations with UHF receive capability should be able to receive the telemetry and detect/use the FM repeater operation.
We think the ascending node on time begins when AO-27 is at about 75 deg N latitude and ends around 85 deg N as the satellite begins the descending part of the orbit. Stations probably have to be fairly far north with good northern horizons to hear anything. No telemetry is sent on ascending node passes.
The AO-27 command team would greatly appreciate reception reports, especially with the time(s) telemetry or repeater operation started/ended. Please provide station location, 6 character grid square is sufficient.
If you have AFSK reception/decode capability, any telemetry successfully decoded.
Reports from northern stations able to copy the start or end of the ascending node on time are also sought.
Please send reports to firstname.lastname@example.org
Thanks in advance from the AO-27 command team.
Turned on low power during first pass. Had good tone, received a few TLM frames but then lost commanding of it as it came over the US. Seems to have major interference on uplink while over the US.
It faded mid pass and was not heard from for the rest of the pass. Sent off commands in the blind. Don’t know if the TX turned off or not.
The good news is it was at least heard from after last weekend’s problems.
– Michael, N3UC
It has not yet been recovered. The command team turned the transmitter on to test it out on June 28th, but they still need to upload the secondary bootloader and then the high level code necessary to operate the satellite.
The issue in the past has been that the satellite crashes when they try to run high level code. We will see if they’ve managed to work around that problem (probably radiation damage to a section of the satellite’s memory).
AO-27 Turned on today. Uploaded Secondary boot loader
April 12, 2015
Turned on High power to check power output. Looks good.
We tried to do a restart of the high level code today which did not work out. We left the transmitter on to drain the batteries in hopes of clearing any latch ups.
On the next pass, we could turn the bird back on so it survived the battery draining. The modem problem was back and we got that cleared.
Its back up on the secondary bootloader.
We have cleared the AFSK Modem problem again and are up on the secondary bootloader.
AO-27 has crashed again. Its back in bootloader mode.
The command team has finished uploading the high level code to AO-27. EOS is now running and we are checking out the bird. The TOPR schedule will be on digital for the entire pass until we collect enough telmetry and finish the on-orbit checkout.