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

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 dongle

RTL 2832U

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

AX.25 (
  • 1200 Baud AFSK
  • 2400 Baud AFSK (2 variants)
  • 4800 Baud HAPN
  • 9600 Baud FSK (G3RUH)
  • 512 Baud
  • 1200 Baud
  • 2400 Baud
  • DTMF
  • ZVEI

1) Download the following Library.

Unzip the file tar -xvf multimon.1.gz
cd to the multimon directory
cd mulimon
run the command make
cd to directory cd  bin-i686

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

sudo ./multimon -h
multimod  (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
available demodulators: POCSAG512 POCSAG1200 POCSAG2400 UFSK1200 CLIPFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI SCOPE
Demodulates many different radio transmission formats
(C) 1996 by Thomas Sailer HB9JNX/AE4WA
  -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
  -h         : this help

how to decode a wav file

sudo ./multimon -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 -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.
Hope this help...



Monday, May 6, 2013

CubeBug-1 Cube Satellite

The CubeBug-1 2U CubeSat, also known as Capit├ín 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

Sunday, May 5, 2013



You could listin to my websdr on Sat freq (Egg Beater mark 2 Antenna)

  • 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.

Here is the info regarding this satellite.

Latest Kep's for TURKSAT 3USAT
New TLE info:
Satellite 3USAT number: 2013-018C

Cube Bug-1 Satellite was launched on same rocket.