Amateur Satellites at Skills Night

Steve Hedgecock M0SHQ sending Packet Radio to the ISS

Steve Hedgecock M0SHQ sending Packet Radio to the ISS

The Chelmsford Amateur Radio Society Skills Nights, are hosted by the CARS Training Team and continue to be a popular and appealing event, especially for newcomers to the hobby.

There was an excellent turnout on the evening of Monday, June 15 with 68 people signing in.

A major highlight of this month’s event was a live demonstration of amateur APRS packet data on 145.825 MHz FM from the International Space Station (ISS) as its flew overhead. Steve Hedgecock M0SHQ had clear reception and even managed to get a few of his own packets sent and relayed by the ISS.

Andrew Garratt M0NRD in Newark-on-Trent was one of those who received Steve’s packets and he immediately sent an eQSL.

Steve had received his new Elk 2m/70cms Log Periodic satellite antenna from the AMSAT-UK shop just a few days before and it performed admirably. During the evening Steve explained how to get started with amateur satellites. They can be received on handheld rigs and worked using low power, just 5 or 10 watts. Further information can be found at https://amsat-uk.org/beginners

On May 31 Steve M0SHQ was filmed making contacts via the SO-50 satellite by the team from the TX Factor TV show so you may see him in one of their future videos.

Satellites were just one aspect of great evening, with a wide range of activities from home construction to how to operate portable taking place. Read the report on the evening at http://www.essexham.co.uk/news/skills-night-june-2015-report.html and http://www.g0mwt.org.uk/skills/cars-skills-jun2015.htm

The next CARS Skills Night will be on Monday, July 20. It’s free to attend and all are welcome.

Space Station SSTV and Packet Radio via SUWS WebSDR

ISS SSTV and Packet Radio signals on the SUWS WebSDR

ISS SSTV and Packet Radio signals on the SUWS WebSDR

Martin Ehrenfried G8JNJ reports excellent SSTV and Packet Radio signals from the International Space Station (ISS) using the online SUWS WebSDR.

144 MHz prototype helix antenna

144 MHz prototype helix antenna

The omni-direction helix antennas at the WebSDR were designed with high elevation satellites in mind. Conventional antennas concentrate the radiation pattern towards the horizon resulting in weaker signals when a satellite is above 15 degrees elevation. Comparisons with other WebSDRs show the SUWS antennas provide a 6 to 10dB better signal to noise ratio on similar passes.

Martin says: “I had been experimenting with single turn ‘twisted halo’ design, and decided to try stacking them to see if I could achieve more gain. Modelling suggested that a stretched 3 turn helix with a helix circumference of approx 1/2 wave length and an overall length of 1/2 wave at 70cm, and fed with a gamma match at the centre would offer reasonable gain, an omni-directional pattern and mixed polarisation.”

You can use the free online SUWS Web Software Defined Radio from your PC or Laptop to receive the ISS and the many amateur radio satellites transmitting in the 144-146 MHz or 435-438 MHz bands. It also provides reception of High Altitude Balloons in the 434 MHz band and coverage of the microwave 10368-10370 MHz band.

The SUWS WebSDR is located at Farnham not far from London, 51.3 N 1.15 W, listen to it at http://websdr.suws.org.uk/

Full details of the antennas are available at http://g8jnj.webs.com/currentprojects.htm

Brazilian radio amateur uses SUWS WebSDR to receive ISS SSTV
https://amsat-uk.org/2014/09/06/iss-sstv-on-suws-websdr/

ISS SSTV image 9/12 received by Martin Ehrenfried G8JNJ using the SUWS WebSDR on Dec 18, 2014

ISS SSTV image 9/12 received by Martin Ehrenfried G8JNJ using the SUWS WebSDR on Dec 18, 2014

TNC-Pi Raspberry Pi Packet Radio Board

TNC-Pi kit built by Nick Bown 2E0CGW

TNC-Pi kit built by Nick Bown 2E0CGW

The TNC-Pi is a £22 ($40) KISS TNC board which is designed to connect to the GPIO port of the £25 ($35) Raspberry Pi computer board.

It provides a low cost means of using amateur radio AX.25 Packet Radio and APRS.

Nick Bown 2E0CGW has written a well illustrated review of the board. You can download the PDF from TNC-Pi by Nick Bown 2E0CGW

The TNC-Pi kit is available from http://tnc-x.com/TNCPi.htm

Australia’s own BLUEsat ready for launch

The BLUEsat Team - Image credit UNSW

The BLUEsat Team – Image credit UNSW

The University of New South Wales (UNSW) has declared its undergraduate student amateur radio satellite project BLUEsat is complete and ready to be launched into space.

As the official final green light came it was to have a stratospheric balloon test flight near Wagga Wagga in New South Wales. Talks continue on a space launch date.

BLUEsat satellite - Image credit UNSW

BLUEsat satellite – Image credit UNSW

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 protocol in a “mode J” VHF/UHF configuration.

Magnets will passively stabilise the satellite and align it with the Earth’s magnetic field, and it will be controlled via a dedicated communications groundstation VK2UNS at UNSW is equipped with a Yaesu FT-847 satellite transceiver.

It is hoped BLUEsat will be placed in circular orbit at an altitude of around 750 km that will take it over the poles. At this altitude, the satellite will travel around the Earth at a rate of around once every 90 minutes.

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.

Students from UNSW will continue to be the primary operators of the satellite while it is in orbit and continue the educational focus throughout the full satellite lifecycle.

Through sponsors helping to pay the bills the student-led project has given a space experience that includes VK2UNS the ground control station.

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

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

January 2012 – Australian BLUEsat LEO undergoes tests
https://www.amateurradio.com.au/news/australian-bluesat-leo-undergoes-tests

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/