HAMNET Report 3rd April 2022

Riaan Greeff, ZS4PR, Deputy Regional Director for HAMNET in the Free State, has sent me a very interesting summary of events that have taken place in the Vaal Triangle, supported by 3 HAMNET divisions.

He says that members of the Vaal HAMNET team joined forces with the Gauteng HAMNET teams to assist the ARCC,  in partnership with many other SASAR affiliated entities, including SARZA, K9SAR,  Airwing, HAMNET and many more, in a mock exercise dubbed “Exercise Phoenix” on the 12th of Feb 2022.  This simulated an aeroplane crash scenario.

The following weekend the Vaal team joined with Gauteng to support the communications during the Johannesburg 94.7 Ride for Sight on the 20th of February.

Next it was the Northwest province HAMNET members that joined in the fun with Vaal and Gauteng to be the communications and support for the 27th Sasolburg Marathon on 26 March 2022. 

This allowed HAMNET to shine and be at the forefront of communications support for an event that hosts the main national finals of the 10km races, and is one of the last qualifying marathons in preparation for the Comrades marathon in a few weeks.

The organisers, Sasolburg Athletics Club, having made all the necessary arrangements with the Sasolburg traffic department weeks before the event, realised 10 minutes before the starting gun at 6am, that the traffic department was nowhere to be seen.  Without the arranged lead vehicles, the marathon would be called off, and 2000 registered athletes would not run.

HAMNET Vaal was prepared, and within 5 minutes they had their lead vehicles ready to lead the pack, much to the relief of the organisers!

The experience brought by the Gauteng HAMNET members to Sasolburg, and the quick thinking of the Vaal HAMNET leadership, ensured a smooth start on time, and a safe marathon to be enjoyed by all.

The Sasolburg radio club, ZS4SRK have technical members to be very proud of.  The town is now equipped with a DMR repeater, and this allows voice and GPS and messaging to be implemented around the circuit of the Sasolburg Marathon.

Tests done in terms of signal strength were so successful, that the Vaal HAMNET team decided to use DMR radios only at the marathon.  An internal talk group provided localised communication.

In total 20 DMR radios were activated for the event and these provided clear communications.   HAMNET Vaal does recommend the use of DMR in future events – the technology provides several advantages over the use of the normal VHF repeater in Sasolburg.

Initially the plan for the event called for a UHF repeater to be set up to allow a second channel of communications for the day.  However, a serious technical failure prevented the Vaal leadership from using this repeater and as a result DMR was made more active, and really provided excellent service.

This shows that planning beforehand, and having redundancy in the plan, will pay off in the case of serious deviations from the normal event plan.

Riaan further notes that the ideal tracking device used by radio amateurs should be primarily on ham frequencies.  The Vaal Tracker is this type of device.  To prove the capability, a number of these devices were programmed and set up on 144.800 MHz, to be tracking key vehicles during the marathon.

Sasolburg and the greater South Gauteng topography allow for radio trackers to work well.

At the central communications centre of HAMNET Vaal, both GSM and RF tracker signals were received and then SARtrack software was used to map the movements of the vehicles.

In short, the trackers worked well.  The GSM additions made it possible to follow the non-RF devices as well.

A few LORA tracker devices were also activated.  The main problem with these turned out to be the lack of range these devices have on the UHF band used.  When the devices were either out of range of each other or the communications centre, they could not be heard.  This was a disappointment.

Thank you, Riaan, for your report and these useful comments. Clearly HAMNET is alive and well in the Free State and South Vaal areas. Thanks also for allowing me these excerpts from your report.

Now the sun is waking up and we are experiencing the effects on Earth as disruptive radio blackouts and stunning aurora displays. Tereza Pultarova, writing in space.com this week says that the “magnetically complex” sunspot called 2975 has spurted out about 20 solar flares over the past days including an X-class flare that blasted from the sun at 05h37 UTC on Wednesday March the 30th. X-class flares are the most energetic type of solar flares that eject a large amount of charged particles into the surrounding space. These energized clouds travel very fast and can reach Earth within minutes.

Wednesday’s flare was reported to have caused some disruptions to GPS signals and interference with high frequency radio transmissions, which are used by shortwave broadcasting stations, aviators and radio amateurs.

For Thursday (March 31st), the U.S. National Oceanic and Atmospheric Administration (NOAA) forecasted a 50% risk of minor to moderate radio blackouts. On Friday, April 1, the risk was expected to go down to 35%. Both days had a 10% chance of a strong radio blackout, which could cause wide-spread disruption to high frequency radio communications on the sun-facing side of Earth, with a possible hour-long loss of signal.

A strong radio blackout (called R3 on NOAA’s five-point scale) is a relatively common occurrence that can take place up to 2,500 times over the sun’s 11-year cycle of ebbing and flowing activity, according to NOAA.

The more sluggish outbursts called coronal mass ejections, or CME’s, are expulsions of magnetized plasma from the upper layers of the sun’s atmosphere, the corona. When a CME hits Earth, it may temporarily disrupt the planet’s protective magnetic field. When that happens, the plasma particles penetrate deep into Earth’s atmosphere, where they trigger magnetic storms that produce colourful aurora displays.

Two CMEs the sun blasted out on Monday (March 28th) arrived Wednesday evening (March 30th), delivering aurora viewing opportunities all over Canada, and, in the Southern Hemisphere, skywatchers from New Zealand and Tasmania also reporting seeing the Aurora Australis.

In addition to auroras, a geomagnetic storm could cause minor problems to satellites in orbit and power networks on Earth. Solar Cycle 25 has definitely arrived in full force.

Thank you to Tereza and Space.com for these extracts from her article.

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.