Tag Archives: Digipeater

Dec 30 2016

Making contacts through the ISS APRS UHF Digipeater

International Space Station - Image Credit NASA

International Space Station – Image Credit NASA

John Brier KG4AKV has released a video showing his contact through the International Space Station packet radio digipeater on 437.550 MHz FM (+/-10 kHz Doppler shift).

This was my second contact through the ISS digipeater. I actually contacted the same station I contacted in this video, W8LR, three days before, but I wasn’t recording any video.

For this video I recorded the audio from my Kenwood TH-D72a and later played it back to Soundmodem+UISS. Soundmodem decodes many more packets than my radio does. I made a screen capture of UISS and its map so you can see the complete details of every received packet.

Another thing this video shows is how hard it can be to track a near overhead pass (close to 90 degrees elevation). When I was beginning in satellites I only tried to work overhead passes because I knew the signal would be strongest when the satellite was closest to me. While that is true, the closer the satellite is to you the faster its relative speed is. When it passes overhead it switches from coming towards you to going away from you very fast, and drops 10s of degrees in seconds. That makes the satellite very easy to lose track of.

In this video I got distracted while changing settings on my radio and lost the ISS after it went overhead. It didn’t help that I was using a tripod for the first time. I prefer to hold the antenna in my hand precisely because I find it’s easier to track, as I can make quick adjustments and listen for the signal going up and down. To control the radio for packet, it helps to have two hands.

Watch I made CONTACT! UHF ISS Digipeater

You can subscribe to John’s Space Comms YouTube Channel at
https://www.youtube.com/SpaceComms1?sub_confirmation=1

Sep 19 2013

Australian ham radio BLUEsat satellite in the press

BLUEsat with some of the team members. From left to right are Chun-kan Leung, Anne Gwynne-Robson, John Aiden Rohde, Thieñ Ñguyeñ, Daniel Jedrychowski and Varun Nayyar - Image credit UNSW

BLUEsat with some of the team members. From left to right are Chun-kan Leung, Anne Gwynne-Robson, John Aiden Rohde, Thieñ Ñguyeñ, Daniel Jedrychowski and Varun Nayyar – Image credit UNSW

The Daily Advertiser newspaper reports the University of New South Wales (UNSW) undergraduate amateur radio satellite project has been given the tick of approval to have a stratospheric balloon test flight in Wagga.

BLUEsat - Image credit UNSW

BLUEsat – Image credit UNSW

The Basic Low Earth Orbit UNSW Experimental Satellite, better known as BLUEsat, will undergo a test flight in April ahead of its launch into space.

BLUEsat, a 260mm cube weighing around 13 kilograms, will carry a flight computer with transmissions to include a beacon and amateur packet radio using the AX.25 packet radio protocol in a “mode J” VHF/UHF configuration.

Once in orbit BLUEsat will be a digital amateur radio satellite, which means that voice and data files can be uploaded to it by any amateur radio operator in the world over which the satellite passes.

Read the Daily Advertiser article – Satellite project to reach new heights
http://www.dailyadvertiser.com.au/story/1781014/satellite-project-to-reach-new-heights/

Australia’s own BLUEsat ready for launch
https://amsat-uk.org/2013/09/13/australias-bluesat-ready-for-launch/

BLUEsat on Facebook https://www.facebook.com/bluesat.unsw

Basic Low Earth Orbit UNSW Experimental Satellite (BLUEsat) project http://www.bluesat.unsw.edu.au/

Aug 24 2013

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/

May 30 2013

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

May 30 2013

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

Apr 25 2013

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