Author Archives: PE0SAT

AO-27 update 07-07-2015

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AO-27 active update.

Update: It isn’t active yet!

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 boot-loader 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).

Please do not transmit unless you hear the FM repeater functioning. Any interference while the command team is attempting to upload new code will significantly prolong the recovery process.

Source: N8HM (07-07-2015 12:48 UTC)

Amrad Oscar AO-27 PreFlightAfter I had read the news on the Amsat-BB about AO-27 being active again, I visited the AO-27 website and found the following information.

June 28, 2015:
AO-27 Turned on today. Seems good on the bootloader. If anyone has contacts into CelesTrak to get AO-27 back into the amateur.txt file it would help some of the control operators stations. Our e-mails have gone unanswered.

  • Michael, N3UC
  • Dan, KM4HZJ
  • James, N3UCC

April 18, 2015:
AO-27 Turned on today. Uploaded Secondary boot loader

  • Michael, N3UC

April 12, 2015:
Turned on High power to check power output. Looks good.

  • Michael, N3UC

Lets listen for the satellite, decode some telemetry and pass it on to the operators so they have a clear idea about the health of AO-27 (EYESAT-1). Don’t transmit unless you hear the FM repeater functioning.

Current Space-Track TLE:

AO-27
1 22825U 93061C   15186.11965546  .00000058  00000-0  40075-4 0  9999
2 22825 098.7096 136.2347 0007264 255.0254 170.5745 14.29889618135507

AO-27-Orbit

Modes

Analogue Low  = 145.850MHz Up <==> 10mW 436.797MHz Down
Analogue Med  = 145.850MHz Up <==> 500mW 436.797MHz Down
Analogue High = 145.850MHz Up <==> 4W 436.797MHz Down

Digital Low   = NO Up          ==> 10mW 436.797MHz AFSK 1200bps Down
Digital Med   = NO Up          ==> 500mW 436.797MHz AFSK 1200bps Down
Digital High  = NO Up          ==> 4W 436.797MHz AFSK 1200bps Down

UWE-3 update 03-07-2015

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UWE-3 Status report

UWE-3 redundant UHF SubSystem

After the communication anomaly and the autonomous recovery of UWE-3 two weeks ago we uploaded an extended software to the OBC to analyze the event in detail. As we already have known the EPS, OBC and ADCS were not affected, so the secondary radio.

During the tests made possible by the new software we temporarily switched back to the primary radio to check its electrical characteristics and communication performance. As the values were promisingly normal we performed extensive communication tests without seeing any existing anomaly. Therefore we will continue normal operation.

UZ7HO Sound-Modem 0.83b

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UZ7HO has updated his Sound-Modem software. The current version is 0.83b. Below a part of the latest changes.

SoundModem v0.83b changes:
- Added 12 dB PreEmphasis filter.
- Added 3 parallel decoders with NONE, 6 and 12 dB preemphasised signal.
  By default this option is ENABLED ("PreEmphasis filters - All" in "Modems"
  menu). On both (http://wa8lmf.net/TNCtest/) WA8LMF's Track1 and Track2 records
  1021 frames are decoded.
- Fixed some minor bugs.

Pre-emphasis

In processing electronic audio signals, pre-emphasis refers to a system process designed to increase (within a frequency band) the magnitude of some (usually higher) frequencies with respect to the magnitude of other (usually lower) frequencies in order to improve the overall signal-to-noise ratio by minimizing the adverse effects of such phenomena as attenuation distortion or saturation of recording media in subsequent parts of the system. The mirror operation is called de-emphasis, and the system as a whole is called emphasis.

Pre -De -Emphasis

Pre-emphasis is achieved with a pre-emphasis network which is essentially a calibrated filter. The frequency response is decided by special time constants. The cutoff frequency can be calculated from that value.

In high speed digital transmission, pre-emphasis is used to improve signal quality at the output of a data transmission. In transmitting signals at high data rates, the transmission medium may introduce distortions, so pre-emphasis is used to distort the transmitted signal to correct for this distortion. When done properly this produces a received signal which more closely resembles the original or desired signal, allowing the use of higher frequencies or producing fewer bit errors.

Source: Wikipedia

SDRSharp 1347 released

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SDRSharp LogoTo my surprise I saw today (11-06-2015), that there was a new SDR# version released on there website. Below all the changes that have been done on the code since version 1337.

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r1347 | prog | 2015-06-09 18:22:46 +0200 (Tue, 09 Jun 2015) | 1 line

Added sticky tuning mode.
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r1346 | prog | 2015-06-09 17:27:06 +0200 (Tue, 09 Jun 2015) | 1 line

Fixed click to tune on non-tunable sources
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r1345 | prog | 2015-06-09 17:12:10 +0200 (Tue, 09 Jun 2015) | 1 line

Added additional modes: Center and Free tuning.
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r1344 | prog | 2015-06-09 00:35:23 +0200 (Tue, 09 Jun 2015) | 1 line

Fixed multi-device support
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r1343 | prog | 2015-06-08 23:52:56 +0200 (Mon, 08 Jun 2015) | 1 line

Added more checks for RTLSDR source.
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r1342 | prog | 2015-06-08 23:27:17 +0200 (Mon, 08 Jun 2015) | 3 lines

Revamped the RTLSDR controller to use the new API:
 - Added USB Enum;
 - Added Auto stop when the device is unplugged.
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r1341 | prog | 2015-06-08 19:46:11 +0200 (Mon, 08 Jun 2015) | 1 line

Ported Airspy plugin enhancements to RTLSDR plugin
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r1340 | prog | 2015-06-07 23:33:39 +0200 (Sun, 07 Jun 2015) | 3 lines

Enhanced the Airspy plugin;
Added a button center the current frequency on the spectrum;
A few GUI tweaks.
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r1339 | prog | 2015-06-07 21:07:08 +0200 (Sun, 07 Jun 2015) | 1 line

Enhanced the init behavior
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r1338 | prog | 2015-06-07 16:09:17 +0200 (Sun, 07 Jun 2015) | 5 lines

Added support for RFSPACE CloudIQ and CloudSDR sample rates;
Added new API to control the program from front-end plugins;
Changed the streaming from non-blocking to blocking I/O's.

PSAT Telemetry

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PSAT Telemetry 03-06-2015 10:53 UTC

1:Fm PSAT To APRSON Via ARISS [12:52:23R] T#444,871,032,130,129,412,00000000
1:Fm PSAT To APRSON Via ARISS [12:52:56R] s#013306,0z200,FGeFGeEGeDGeBGd0GdaGdbGddGddGddGedFe
1:Fm PSAT To APRSON Via ARISS [12:53:24R] T#445,829,357,129,129,411,00000000
1:Fm PSAT To APRSON Via ARISS [12:54:24R] T#446,819,371,129,128,411,00000000
1:Fm PSAT To APRSON Via ARISS [12:59:08R] s#013310,0z200,IbEIaDI0CIABICAID0HE0HFaHFaGFaGF0FF0

PSAT Telemetry