A Ham Radio AX.25 Open Source Soundcard Modem

Audio from AX.25 packet radio - Image credit Sivan Toledo 4X6IZ

Audio from AX.25 packet radio – Image credit Sivan Toledo 4X6IZ

AX.25 packet radio is currently the most popular data protocol for use in CubeSats.

Radio amateur Alejandro Santos LU4EXT is developing extmodem an open source APRS compatible AX.25 packet radio modem.

It is currently capable of both sending and receive packets at 1200 bps AFSK. The main feature of the software is that it is currently running three different demodulators in parallel, increasing the quality of reception. The first modem is Thomas Sailer HB9JNX / AE4WA‘s multimon, the other two are described by Sivan Toledo 4X6IZ in an article in the July/August 2012 issue of QEX.

Download extmodem for Windows from
http://extradio.sourceforge.net/extmodem.html

QEX article – A High-Performance Sound-Card AX.25 Modem
http://www.tau.ac.il/~stoledo/Bib/Pubs/QEX-JulAug-2012.pdf

APRS destination address for ham radio satellites
https://amsat-uk.org/2013/08/23/aprs-destination-address-for-ham-radio-satellites/

LU4EXT on Twitter https://twitter.com/alejolp

Good News for CubeBug-1

CubeBug-1

CubeBug-1

The amateur radio satellite CubeBug-1, also known as El Capitán Beto, launched April 26, 2013, is recovering from the power budget issue that caused the transmitter to be turned off for several days.

This was achieved after one of the AMSAT-LU stations in coordination and in conjunction with Satellogic team, send a command to reconfigure onboard software to turn off attitude control circuits feeding magnetorquers this last weekend .

Telemetry text mode command taken before change can be seen at
http://www.amsat.org.ar/images/cubebug130818.txt

CubeBug - command sent shown top and satellite response below

CubeBug – command sent shown top and satellite response below

Operation was with a RTL SDR dongle, connected directly to antenna, using HDSDR recording software as IF mode only, that helped not to record big amount of data from Orbitron connected to DDE, also automatically compensating Doppler.

After reset, Cubebug-1 went to ‘mission state’, batteries showing adequate level of charge.

Good reports were received from several amateurs from different parts of the globe.

This activity is performed as part of the agreement of mutual collaboration that Satellogic and AMSAT-LU signed on July 2013.

The satellite transmits 1200 bps AFSK, on 437.438 MHz, packets are sent every 30 seconds. The signal is at a low level and a directional antenna and preamp are needed for adequate reception.

Cubebug-1 telemetry information at http://1.cubebug.org/coms/telemetry

73, LU7AA, AMSAT-LU
email: info at amsat.org.ar/
http://www.cetra.org.ar/
http://www.amsat.org.ar/
http://facebook.com/AMSAT.LU

CubeBug-1 carries a packet radio digipeater which it is hoped will be activated for amateur radio use when the primary mission has been completed. Further information at https://amsat-uk.org/satellites/cubebug-1/

ANTELSAT a Ham Radio SSTV CubeSat from Uruguay

ANTELSAT CubeSat

ANTELSAT CubeSat

ANTELSAT is a 2U CubeSat class satellite with a 70 cm SSTV downlink and amateur radio AX.25 Digipeater that is planning a Yasny Dnepr launch in November, 2013. It has been developed by ANTEL (the national telecom service provider) and Facultad de Ingeniería de la Universidad de la República (FING), the State Faculty of Engineering.

The purpose is to build and operate the first satellite ever launched into orbit by Uruguay. Its goal is to develop skills in radio and aerospace engineering, to promote enthusiasm in STEM education at all levels, and provide challenging activities for undergraduate students. The spacecraft is planned to transmit colour and infrared images of the surface of the earth, and to provide several services to radio amateurs (AX.25 digipeater, telemetry beacon, uplink signal report, SSTV downlink). The mission is purely experimental and a technology demonstrator of all the satellite subsystems, which have been custom designed locally.

Communications:
– VHF receiver on 2m amateur band, 1200bps AX25 protocol.
– Telecommand uplink.
– Store and forward (digipeater) service uplink.
– UHF transmitter on 70cm amateur band:
– CW beacon.
– Telemetry downlink at 1200 bps AX25 protocol.
– Backup downlink for image data via low resolution SSTV.
– Store and forward service downlink.
– S-band transmitter on 2.4 GHz:
– Downlink for payload image data.
– Telemetry backup link.
– 2 redundant transmitters.

Attitude control:
– Attitude determination via magnetometer and photodetectors.
– Active 3-axis control via magnetorquers.

Brochure: http://iie.fing.edu.uy/investigacion/grupos/lai/files/ANTELSAT_brochure_2012W01.pdf

It is reported that ANTEL contributed nearly $700,000 towards the project
http://tinyurl.com/ANTELSAT-2013

ANTELSAT in Google English http://tinyurl.com/ANTELSAT

IARU Amateur Satellite Frequency Coordination Status http://www.amsat.org.uk/iaru

Amateur Radio CubeBug-2 hopes for November 2013 Yasny Dnepr launch

CubeBug-1

CubeBug-1

CubeBug-2 is the second technology demonstration mission for a new 2U CubeSat platform design (mechanics, hardware and software) intended to be released as Open Source and Open Hardware for its use in Amateur projects, University projects and Research labs.

This project is sponsored by the Argentinian Ministry of Science, Technology and Productive Innovation. As payload on this second mission, some custom designed components will be tested: an antenna, solar panels, and an on-board computer, a camera, a GPS transceiver and a software defined radio based on COTS components.

CubeBug-2 is expected to be launched as part of a group of CubeSats in a DNEPR rocket launch planned for November 2013 from Yasny.

The satellite will be periodically transmitting AX.25 packets for the Amateur radio community to receive, and after the technology demonstration part of the mission is over, the satellite will enter a mode that will include a Digipeater, science data downloads from the payload (including images and recordings from the SDR, if possible).

Proposing to use 1k2/9k6 FSK/GMSK AX25 on UHF with an AstroDev L1 transceiver.

Its predecessor CubeBug-1 launched on a CZ-2D rocket from the Jiuquan Space Center on April 26, 2013 at 0413 UT.

CubeBug website http://1.cubebug.org/

IARU Amateur Satellite Frequency Coordination Status http://www.amsat.org.uk/iaru

CubeBug-1 with ham radio digipeater to launch Friday

CubeBug-1

CubeBug-1

CubeBug-1 is the first technology demonstration mission for a new CubeSat platform design (mechanics, hardware and software) intended to be released as Open Source and Open Hardware for its use in Amateur projects, University projects and research labs.

A CZ-2D rocket launch

A CZ-2D rocket launch

The project is sponsored by the Argentinian Ministry of Science, Technology and Productive Innovation.

Payloads on this first mission include:
• an ARM based on-board computer
• a nano-reaction wheel with its driver circuit
• a low resolution camera
all based on COTS components

CubeBug-1 is a 2U CubeSat and uses a 1 watt output AstroDev Lithium Li-1 on 437.445 MHz using 1200 bps AX.25 AFSK FM packet radio, callsign LU1VZ-11. Depending on the mode of the satellite the beacons will be transmitted every 10 to 30 seconds. Telemetry information is at http://1.cubebug.org/coms/telemetry

The team say “Please, if you hear the satellite, lets as know by email to cubebug1@satellogic.com. If you decode a beacon or save its audio, please please please, share it with us!”.

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).

CubeBug-1 is expected to launch on a Long March CZ-2D rocket from the Jiuquan Space Center on April 26, 2013 at 0413 UT. After 816.5 seconds the CubeBug-1 will be deployed from the rocket. Orbital data including TLE is at http://1.cubebug.org/orbit

Other satellites on the same launch include NEE-01 Pegasus (910 MHz) and TURKSAT-3USAT (145/435 MHz linear transponder).

Watch a CubeBug-1 video at http://vimeo.com/56055215

CubeBug-1 website http://1.cubebug.org/

Follow #CubeBug1  on Twitter @CubeBug1 https://twitter.com/CubeBug1

Keplerian Two Line Elements (TLEs) ‘Keps’ for CubeSats are at
http://celestrak.com/NORAD/elements/cubesat.txt

TLEs / ‘Keps’ for new satellites launched in past 30 days
http://celestrak.com/NORAD/elements/tle-new.txt

Free satellite tracking software:
• SimpleSat Look Down http://www.tomdoyle.org/SimpleSatLookDown/
• Gpredict http://gpredict.oz9aec.net/
• Orbitron http://www.uk.amsat.org/?p=9051

PhoneSat team thank Radio Amateurs

Phonesat ConstructionThe Team behind the three PhoneSats, deployed April 21, have thanked radio amateurs for their response so far and they request further telemetry reports.

They say:

Since the successful deployment of our three PhoneSats on Sunday, we have already received over 200 packets from Amateur Radio operators around the world! We are sincerely grateful for all of your support and would like to thank you for your key contributions in making this technology demonstration a success. The received packets are being processed right now and will be published soon. Please keep sending packets so we can follow the status of the satellites for the complete duration of the technology demonstration.

The three PhoneSats carry amateur radio payloads on 437.425 MHz. The callsign of all three satellites is KJ6KRW and they transmit using AFSK (1200 bps) modulation, AX.25 packet radio. The two PhoneSat 1.0 satellites, Graham and Bell, transmit with a periodicity of respectively 28 seconds and 30 seconds. The PhoneSat 2.0 beta satellite, Alexandre, transmits with a periodicity of 25 seconds.

Register your amateur radio satellite station on the PhoneSat Dashboard at
http://www.phonesat.org/dashboard.php

PhoneSat CubeSats with Ham Radio Payloads Launched
https://amsat-uk.org/2013/04/22/phonesat-cubesats-launched/