HAMNET Report 8th May 2022

In reports on the Ukrainian conflict, the European Commission says that they are coordinating the delivery of assistance via the EU Civil Protection Mechanism to Ukraine, from all 27 Member States and two participating states. Over 26,500 tonnes of non-military assistance from these countries and items from the rescEU medical stockpile have been delivered to Ukrainian civilians via the UCPM logistic hubs in Poland, Romania and Slovakia.

And for the war-ravaged country of Afghanistan, the horror continues. Flooding and storms in 12 provinces have resulted in 22 deaths and 40 injured citizens, according to Hassibullah Shekhani, head of communications and information at Afghanistan’s National Disaster Management Authority.

The Taliban government, struggling to cope with the disaster that has affected more than a third of its provinces, will approach international relief organisations for help, officials said.

The rain and flooding was particularly severe in the western provinces of Badghis and Faryab and the northern province of Baghlan. Afghanistan has been suffering from drought in recent years, made worse by climate change, with low crop yields raising fears of serious food shortages.

Shekhani said 500 houses were destroyed, 2,000 damaged, 300 head of livestock killed and some 3,000 acres of crops damaged. He said the International Committee of the Red Cross was helping and officials would approach other international organisations for help.

Thank you to dawn.com for this insert.

Danie, ZS1OSS, has added another feather to the bow (if you’ll pardon the mixed metaphor) of relays of Western Cape repeaters outside the Western Cape, by installing an OpenWebRx receiver at his home, with links to 4 possible VHF and UHF spectra on the internet. You can choose VHF digital channels, VHF analogue audio channels, UHF digital channels or UHF analogue audio channels. You will then be presented with a waterfall on your browser, showing the relevant segment of the spectrum with frequencies marked, and favourites highlighted. This will allow you to click on a frequency in the waterfall, and receive the signal on that frequency.

He also notes that, by watching this reception on the internet, while you are transmitting on RF, you can easily gauge the quality of your signal and audio.

This is available 24 hours a day, and can be accessed by entering https://openwebrx.gadgeteerza.co.za/ in your browser. All the HAMNET and club bulletins are available via this portal. Thank you to Danie, ZS1OSS, and his knowledge of matters digital, for making this available to us all.

The ITU Radiocommunication Bureau’s Nick Sinanis SV3SJ/F5VIH/HB9DSR writes about amateur radio and notes that basic equipment like a handheld radio is affordable and sufficient to make local contacts, while more expensive, larger antennas enable more distant communications. Still, tinkering with a rooftop long wire connected to a software-defined radio module can deliver the joy of a long-distance call at a reasonable cost

Another hallmark of amateur radio is its unique combination of knowledge in telecommunications, electronic engineering, physics and tinkering of all sorts. This magic mix can help one recognize a radio ham even in a data centre! Moreover, radio science plays an important role in scientific and technological innovation.

Above all, amateur radio is a social hobby that still attracts the interest of the young, through social networking apps, or challenges, like copying high-speed Morse code.

The passion of radio amateurs and their community have also provided crucial assistance in the form of emergency communications.

Thanks to Southgate Amateur Radio News for highlighting that passion for us.

With nothing in common with the thriller movie of almost the same name directed by Alfred Hitchcock, the spacecraft PSYCHE has arrived at Kennedy Space Centre, to be prepared over the next three months for a launch on 1st August this year.

SciTechDaily tells us that it will use solar-electric propulsion to travel approximately 2.4 billion kilometres to rendezvous with its namesake asteroid PSYCHE in 2026. This will make it the first spacecraft to use Hall-effect thrusters beyond the orbit of the Moon. This thruster technology traps electrons in a magnetic field and uses them to ionize on-board propellant, expending much less propellant than equivalent chemical rockets. PSYCHE also carries three scientific instruments: an imager, a magnetometer, and a gamma ray and neutron spectrometer

The unique, metal-rich PSYCHE asteroid may be part of the core of a planetesimal, a building block of rocky planets in our solar system. Learning more about the asteroid could tell us more about how our own planet formed and help answer fundamental questions about Earth’s own metal core and the formation of our solar system.

Techxplore.com reports this week on a spiralling helical compressible antenna that looks like two strands of DNA, developed by a group of mechanical engineering students at the University of Colorado at Boulder.

As the space industry evolves its focus from large satellites to smaller ones with the same functionality, there is a growing need for the hardware on board to shrink as well. Current satellite antenna hardware is fully deployed upon launch. Those systems can be large and not aligned with the industry’s goal for smaller hardware.

The team’s prototype is a deployable helical antenna that starts as a compressed coiled spring.

The students designed their antenna to deploy once it is in space—activated by an on-board computer. This would trigger the device’s antenna component to extend four times its compressed height from 6cm to nearly 50cm for full functionality.

The team accomplished this by designing the antenna with the properties of a mechanical spring, which is an idea the industry has rarely attempted to build before. The students explained that optimizing the prototype to be both a spring and an antenna was difficult to do.

They had to take geometry, material and frequency bandwidth all into consideration. The students used spring calculators and high frequency structure simulator software to build an antenna that could stow and deploy with the properties of a mechanical spring.

The students have completed antenna functionality, deployment, and mechanical shock and vibration tests on their prototype. The radiofrequency testing was done at First RF, a company specializing in antennas and radiofrequency systems, while the vibration testing happened at Lockheed Martin. The antenna size is scalable to be resonant on a variety of frequencies.

Finally, may I take the opportunity to wish all our Mothers out there a very meaningful Mother’s Day. And if you aren’t a Mother, you definitely do have one. If she is still with you, tell her how much you appreciate all she ever did for you, and, if she isn’t, remember her on this day with fondness.

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