Next Project Horus Launch – Horus 63 – 1st December 2024 – Cross-band Repeater – Mt Barker Launch!

AREG’s High-Altitude Ballooning sub-group, Project Horus, is planning their next launch for Sunday the 1st of December, with a planned launch time of 10 AM ACDST. If we have to scrub due to poor weather, the backup launch date will be the 8th of December.

UPDATE 27th Nov: This launch is currently planned to be performed from the Mt Barker High School Oval with the launch team arriving on site from around 9:15 AM. Note that access to the oval is via Stephenson street, and parking near the oval is extremely limited. 

TRACKING LINKS

This flight will feature a new cross-band repeater payload, enabling amateur radio operators around the state to communicate via the balloon! Along with this will be a newly built Wenet Imagery payload, using a PiCam v3 in autofocus mode.

  • FM Crossband Repeater: 145.075 MHz Input (91.5 Hz CTCSS), 438.975 MHz output.
  • Wenet Imagery on 443.5 MHz.
  • Primary Horus Binary telemetry on 434.200 MHz
  • Backup Horus Binary payload, on 434.210 MHz
  • TheThingsNetwork tracking payload, using the AU915 band-plan.

During the flight, all the payloads can be tracked lived on the SondeHub-Amateur tracker here!

FM Cross-band Repeater Payload

This is the first test flight of a new experimental FM cross band voice repeater based around a Yaesu FT-530 handheld transceiver.The balloon repeater should be heard on:

  • INPUT: 145.075MHz with 91.5Hz CTCSS
  • OUTPUT: 438.975MHz  – 0.5W into 1/2-wave omni

Please note that this repeater is experimental, and may have performance issues or even fail completely during the flight!

To transmit to the balloon at the maximum range of 800km (once the balloon reaches 100,000ft ++) you should only need approximately 10-20W and an 2-4dB gain antenna.

Receiving the balloon at 400km range in a handheld environment should be achievable, but to hear the repeater at the maximum range of 800km you should expect to need a 10dB gain Yagi for a 0.4uV capable receiver and 2dB feeder loss

This setup is much the same as the LEO satellites but without the doppler shift.

PLEASE MAKE SURE YOU CAN HEAR IT BEFORE YOU TRANSMIT!

This repeater will be operated as a controlled net, with the net control callsign VK5ARG – please listen out for net control before calling!

We will be offering QSL cards to stations that make a contact with net control during the flight, so get your stations setup and give it a go!

Primary Telemetry – Horus Binary 434.200 MHz – HORUS-V2

Reprogrammed RS41The primary tracking telemetry will be transmitted on 434.200 MHz using the Horus Binary 4FSK data mode. Amateurs in the Adelaide and Central SA region are also encouraged to get involved with the flight through receiving and uploading flight telemetry from our 70cm band tracking beacons. Every piece of telemetry data is valuable to the flight tracking and recovery teams so if you can help join the distributed receiver network to collect that data you will be making an important contribution to the project!

If you try receiving the telemetry from this flight, you’ll need a SSB-capable 70cm receiver (or a SDR), and the Horus-GUI telemetry decoder software. A brief guide on setting this up is available here: https://github.com/projecthorus/horusdemodlib/wiki/1.1-Horus-GUI-Reception-Guide-(Windows-Linux-OSX)

Listeners that already have Horus-GUI installed are encouraged to update to the latest version, which is available at this link.

Note that you will need to use a USB ‘dial’ frequency of 434.199 MHz for the 4FSK signal to be centred in your receiver passband and hence be decodable.

Backup Telemetry – Horus Binary 434.210 MHz – VK5ARG

A backup tracking payload will be transmitting on 434.210 MHz using the Horus Binary 4FSK data mode, and can be received in the same way as the primary tracking payload, with information above. For this payload you will need to use a USB ‘dial’ frequency of 434.209 MHz.

Wenet Imagery – 443.500 MHz

Imagery on this flight will be transmitted via the Wenet downlink system, which uses 115kbit/s Frequency-Shift-Keying to send HD snapshots. Reception of the Wenet imagery requires a Linux computer, a RTLSDR, and a 70cm antenna with some gain (a 5-element Yagi is usually enough).

This payload will be experimenting with a PiCam v, which we previously flew with only partial success on Horus 59. This time around many software updates have been written, hopefully allowing the PiCam v3’s autofocus to work on a balloon launch. This flight aims to test out these software changes, and gather data to help improve performance on future launches.

Wenet imagery from Horus 62

A guide on how to get set up to receive the Wenet signal is available here: https://github.com/projecthorus/wenet/wiki/Wenet-RX-Instructions-(Linux-using-Docker)

Please note the transmit frequency of 443.5 MHz, which may require listeners to re-configure their Wenet setup. 

Note: Stations that are already ready to receive Wenet are advised to update to the latest testing version for this flight. See here for instructions: https://gist.github.com/darksidelemm/cdc36a90ca96b87d148fdd7d68d5d5fe

During the flight, the live imagery will be available at this link: http://ssdv.habhub.org/

TheThingsNetwork Payload – 915 MHz LIPD Band

This flight will also fly a LoRaWAN payload built by Liam VK5ALG, relaying positions via TheThingsNetwork (TTN), a global Internet-of-Things network with hundreds of receiver gateways across Australia. You can find out more about how TheThingsNetwork works here.

The aim of this payload is to test a new antenna, and try and beat our previous range records on the 915 MHz band.

AREG’s HF Spectrograph shows the effects of Solar Flares

An X-class Solar Flare imaged by the Solar Dynamics Observatory in 2012.

An X-class Solar Flare imaged by the Solar Dynamics Observatory in 2012.

Solar flares from the sun can result in many different effects on High Frequency (HF) propagation. The most immediate and noticeable is when the increased solar X-Ray flux resulting from a flare interacts with the ionosphere. These X-Rays charge the ionosphere’s D-layer (responsible of the absorption of the lower HF band during the daytime), and results in higher levels of absorption extending right up to the top of the band. This has the effect of reducing signal strengths right across the band, resulting in what is known as a ‘HF fadeout’.

X-Ray Flux data from the GOES satellites, provided by NOAA

Solar flares are categorised based on the peak X-ray flux they emit, with the different levels given letters A, B and C for relatively weak flares, and M and X for stronger flares, with X-class flares being the strongest. HF fadeouts are generally caused by M and X-class flares. A live plot of X-Ray flux data as observed by the Geostationary Operational Environment Satellites (GOES) is available here: https://www.swpc.noaa.gov/products/goes-x-ray-flux

Short Wave Frequency Coverage Prediction

HF Fadeout Coverage area for a M1.2 class flare, from the Space Weather Service website.

The Australian Space Weather Service provides a HF fadeout warning service via email, and you can also see reports of the most recent HF fadeout on their website.

AREG’s HF Spectrograph Service

AREG hosts many services at its remote HF receive site located near Tarlee, including multiple KiwiSDRs, skimmers for WSPR, FT8 and SSTV, and other higher performing receivers reserved for club members. We thank Swoop Internet for providing us with the internet service at this site, for free!

The HF receiver antenna (a broadband monopole) at AREG’s remote HF receive site.

Using software written by Mark VK5QI, AREG also generates a Spectrograph showing the state of the HF band over the last 3 days. A spectrograph is similar to the waterfall display you might have seen on other SDR receiver software, though in this case covering the entire HF band (0 – 30 MHz), and looking over a much longer timescale. Warmer colours (reds and yellows) represent stronger signals, and cooler colours (blues and greens) represent weaker ones. The spectrograph updates approximately every 30 minutes, and is available at the bottom of the Remote HF Receiver site page, or directly here.

A typical HF Spectrograph, with some features annotated.

The spectrograph gives us a ‘quick look’ at the state of the HF band. The strongest signals (red) are the bands of shortwave stations around 6, 7, 9 and 11 MHz, mostly propagating in from south-east Asia. The most obvious time-varying effect is the change in propagation conditions from day (propagation mainly at the higher end of the band), to night (propagation mainly at the lower end of the band), but we can also see other effects such as solar radio bursts, local noise issues, and of course HF fadeouts.

In the above figure, a number of HF fadeout events over the 18th through 20th May 2023 period have been marked, showing the X-Ray flux event they correspond to. The HF fadeouts can be seen as a sudden reduction in signal strength right across the HF band, followed by a slow return to normal. Note that we don’t see the effects of X-ray flux events occurring during our local night, due to the Earth sheltering us from those X-rays.

So, next time you think the HF band seems a bit dead, maybe go take a look at the AREG HF Spectrograph to see if there’s a HF fadeout in progress!

73 Mark VK5QI

Medium Wave Digital Radio Mondiale Broadcasting Trial: AREG Members Listening

There is a very un-publicised Digital Radio Mondiale (DRM) trial on air in Australia at the moment. The trial is on 747kHz from a transmitter site in Wangaratta, Victoria and the program is ABC Radio National.

Youtube video from “digitalmediafan” 

The signal does become decodable at times during the early evening however; there is co-channel interference coming in from MW AM transmitters on 747kHz in Toowoomba, Hobart and Esperance to contend with along with selective fading in the pass-band.

More information on the DRM format can be found here: https://www.drm.org/

Steve VK5SFA has been experimenting with decoding the signal and has had some success using the following information and links:

  • How to install the decoding software. (HERE)
  • Source of the required Dream V2.2.x software (HERE)
  • And the missing dll file here:  (HERE)

He also suggests a directional antenna such as a magnetic loop might be of some benefit. Steve has used his Flex Radio as well as an Airspy HF+ Discovery SDR receiver with some success. Experimenters should also remember to use a digital USB mode (no audio EQ) and make the RX filter wide enough to fit the whole digital spectrum when trying to decode the signal.  (Note the centre carrier frequency is 747kHz +/- the signal BW)

Have FUN experimenting!