Thursday, May 23, 2013

NEE-01 PEGASUS Cubesat

NEE-01 PEGASUS Cubesat


Height: 650km 
Mass: 1266.6 g 
Frequency: Central: 910MHz 
Bandwidth: 25Mhz 
EIRP: 34.1dBm
Carrier: FM
Audio Modulation: AMTV / CW (3 carriers) / SSTV (various modes) 








Monday, May 13, 2013

ESTCube-1 Satellite CubeSat

ESTCube-1 Satellite CubeSat


 It was launched on 7 May 2013
Circular orbit at an altitude of 820 km
CW Beacon 437.250 MHz , call sign (ES5E/S)

  • Output power: 0.1 W
  • CW Bitrate: approximately 9 bps, 18 WPM
  • Sending period: 3 to 4 minutes

AX.25 telemetry 437.505 MHz – 9600 bps , Call sign (ES5E-11)

More details are availbel from http://www.estcube.eu/en/radio-details

Tuesday, May 7, 2013

How to do AFSK, PSK DTMF demodulation on Linux / Raspberry Pi using your RTL dongle

How to do AX25, AFSK, DTMF, POCSAG and PSK demodulation on Linux.

(RTL 2832U  receiver) Where can I get a RTL dongle http://www.giga.co.za


RTL 2832U


Using the programs multimon, sox, mkfifo, rtl_fm, git and RTL 2832U receiver you can demodulate the following modulations.

AX.25 (https://github.com/EliasOenal/multimon-ng/blob/master/README.md)
  • 1200 Baud AFSK
  • 2400 Baud AFSK (2 variants)
  • 4800 Baud HAPN
  • 9600 Baud FSK (G3RUH)
POCSAG
  • 512 Baud
  • 1200 Baud
  • 2400 Baud
Miscellaneous
  • DTMF
  • ZVEI
  • SCOPE

1) Download the following Library by using git
git clone https://github.com/EliasOenal/multimon-ng.git

cd to the multimon directory
cd multimon-ng
run the command make
mkdir build
cd build
qmake ../multimon-ng.pro
make
sudo make install

If you want to get this working on Raspberry pi you need to use the following

qmake --version qmake: could not exec '/usr/lib/x86_64-linux-gnu/qt4/bin/qmake': No such file or directory 
alias qmake="$(find /usr -name qmake | grep qt5)" 
qmake --version QMake version 3.0 Using Qt version 5.3.2 in /usr/lib/x86_64-linux-gnu


Command line options. (here is the help file) multimon-ng [options] [input_file]

sudo sudo multimon-ng -h
multimon-ng  (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
             (C) 2012-2014 by Elias Oenal
available demodulators: POCSAG512 POCSAG1200 POCSAG2400 FLEX EAS UFSK1200 CLIPFSK FMSFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE_CW DUMPCSV SCOPE

Usage: multimon-ng [file] [file] [file] ...
  If no [file] is given, input will be read from your default sound
  hardware. A filename of "-" denotes standard input.
  -t <type>  : Input file type (any other type than raw requires sox)
  -a <demod> : Add demodulator
  -s <demod> : Subtract demodulator
  -c         : Remove all demodulators (must be added with -a <demod>)
  -q         : Quiet
  -v <level> : Level of verbosity (e.g. '-v 3')
               For POCSAG and MORSE_CW '-v1' prints decoding statistics.
  -h         : This help
  -A         : APRS mode (TNC2 text output)
  -m         : Mute SoX warnings
  -r         : Call SoX in repeatable mode (e.g. fixed random seed for dithering)
  -n         : Don't flush stdout, increases performance.
  -e         : POCSAG: Hide empty messages.
  -u         : POCSAG: Heuristically prune unlikely decodes.
  -i         : POCSAG: Inverts the input samples. Try this if decoding fails.
  -p         : POCSAG: Show partially received messages.
  -f <mode>  : POCSAG: Disables auto-detection and forces decoding of data as <mode>
                       (<mode> can be 'numeric', 'alpha' and 'skyper')
  -b <level> : POCSAG: BCH bit error correction level. Set 0 to disable, default is 2.
                       Lower levels increase performance and lower false positives.
  -o         : CW: Set threshold for dit detection (default: 500)
  -d         : CW: Dit length in ms (default: 50)
  -g         : CW: Gap length in ms (default: 50)
  -x         : CW: Disable auto threshold detection
  -y         : CW: Disable auto timing detection
   Raw input requires one channel, 16 bit, signed integer (platform-native)
   samples at the demodulator's input sampling rate, which is
   usually 22050 Hz. Raw input is assumed and required if piped input is used.


how to decode a wav file

sudo ./multimon-ng -s SCOPE -t wav /tmp/message.wav (to read wav file) How to convert a wav file to row file using sox sudo sox foo.wav foo.raw
Now we want to take the received signal from rtl_fm and pyp it to the multimon
Create a fifo Pyp 
sudo mkfifo soundfifo.raw 
ls -al 
prw-r--r--  1 anton anton     0 2013-05-07 22:35 soundfifo.raw

You will see its not a normal file its got a prw in front of the file definition when you list the files.
Lets get multimon to start receiving audio from soundfifo.raw pyp.
sudo multimon-ng -a AFSK1200 -a SCOPE -t raw soundfifo.raw
 
And now send the audio from rtl_fm to the soundfifo.raw
Decoding live data from rtl receiver. (Tuning receiver to 144.800 Mhz packet frequency and demodulate that to 22.05kHz audio)
 sudo rtl_fm -f 144800000 -s 22050 ./soundfifo.raw (read my section on rtl if you want to install rtl utilities)


You should then see the scope screen below.
 

Multimon Scope Display
And your afsk1200 decoding will start in console and the scope display will show your audio.
Here is an example of hot to decode directly from rtl dongle sudo rtl_fm -d0 -f 144800000 -s 22050 - | multimon-ng -a AFSK1200 -t raw /dev/stdin

Hope this help...
REF: www.baycom.org/~tom/ham/linux/multimon.html, http://www.youtube.com/watch?v=GBmli8Vflig and http://www.ultratechie.com/2012/10/pigate/
https://github.com/EliasOenal/multimon-ng/blob/master/README.md

Monday, May 6, 2013

CubeBug-1 Cube Satellite

The CubeBug-1 2U CubeSat, also known as Capitán Beto



Beacon 437438 MHz AFSK AX.25, 1200 bps (callsign LU1VZ-11.)

  • 1 watt output
  • After the technology demonstration part of the mission is over, the satellite will enter a mode that will include services to the Amateur radio community, including an AX.25 Packet Radio Digipeater, science data downloads from the payload (including images if possible).


More info here http://1.cubebug.org
and http://www.pe0sat.vgnet.nl/satellite/cube-nano-picosats/cubebug-1/

Sunday, May 5, 2013

TURKSAT 3USAT Satellite

TURKSAT 3USAT Satellite

You could listin to my websdr on Sat freq http://zr6aic.giga.co.za:8902/ (Egg Beater mark 2 Antenna)




Stats:
  • Down-link 435.200 – 435.250 MHz Linear Transponder ("Tracking"mode "inverting")
  • Up-link 145.940 – 145.990 MHz Linear Transponder.
  • Beacon 437.225 MHz CW ( " YM2RTU "call sign)
  • 680 km Low Earth Orbit (LEO)
Reception report submission page.  http://translate.googleusercontent.com/translate_c?depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&u=http://turksat3usat.tamsat.org.tr/info/&usg=ALkJrhgd6DgnRP57nAmSzIGxg5F8v5ufAQ

Here is the info regarding this satellite.
 http://amsat-uk.org/satellites/turksat-3usat/


Latest Kep's for TURKSAT 3USAT
New TLE info:  http://www.celestrak.com/NORAD/elements/tle-new.txt
Satellite 3USAT number: 2013-018C

Cube Bug-1 Satellite was launched on same rocket.