HAMNET Report 26th November 2023

A tunnel being excavated though a mountain in Uttarakhand, India partly collapsed some two weeks ago, trapping 41 workers behind some 50 metres of rock. Rescue efforts have been underway to reach the men, and supplementary oxygen, water, and simple meals have been conveyed to them via pipelines. A flexible endoscopic camera has been passed through the pipeline too, and the men have been seen and assessed by medical teams, as the work continues to burrow through the collapsed rock and earth to reach them.

As of Thursday, drilling through the fallen rock was still continuing, with hitches due to problems with machinery, including damage to the drill when it struck an iron girder which was in the rubble needing removal. Repairs to the drill were needed, while the girder was cut away to allow further drilling to continue.

News yesterday afternoon is that the drilling machine, known as an augur, broke while being extracted after striking the iron beam, so the last 15 metres or so of earth needing to be removed to rescue the workers will have to be removed by hand. This will delay their rescue even longer.

The NSRI has reported that a catamaran, with two men aboard issued a distress call on Tuesday the 21st, after they suffered engine and rudder failure, while en route to Durban from Mozambique.

A Transnet National Ports Authority helicopter, during a routine flight, had intercepted a VHF marine radio distress call from the yacht skipper reporting to be adrift at sea caught in strong South Westerly winds with motor mechanical failure, limited battery power and rudder failure. The helicopter crew then raised the alarm.

Initially unsure of the safety of the 2 crewmen the NSRI Richards Bay rescue craft Ocean Guardian was swiftly launched. On reaching the general area that they had reported to be in, and following a brief search, the NSRI located the yacht 20 nautical miles from the Port of Richards Bay and 18 nautical miles off-shore of Durnford Point lighthouse.

Communications were assisted by Telkom Maritime Radio Services, NSRI Richards Bay duty controllers and the TNPA Richards Bay Port Control.

The NSRI crew rigged a towline and the sailing Catamaran was towed safely to the Port of Richards Bay where their rescue craft was drafted alongside and they were moored safely at a berth at Tuzi Gazi small craft harbour, where they will render repairs before continuing on their voyage.

Sunmedia from New Zealand issued a report on Friday the 24th, noting that around 40 people from Police, Amateur Radio Emergency Communications (AREC) and Land Search and Rescue were put to the test in the exercise last weekend.

The Operation Extra scenario revolved around three anglers who became separated and lost in the Tukituki River area in the Ruahine Ranges after a day’s fishing. The group had split up, creating two separate search operations.

One operation involved a dementia sufferer (aka “Jon the dummy”) wearing a Wandersearch tracker who was located ‘deceased’ in thick blackberry bushes after succumbing to hypothermia.

A second search was launched for the other two anglers who had walked upriver before getting caught in heavy rain and rising river levels.

After a night in the bush for both searchers and the ‘lost’ fishermen, the pair was found early on Sunday morning.

The Incident Management Team (IMT) was based at the Hawke’s Bay Coastguard HQ in Napier and run by a mix of Police and LandSAR staff.

Senior Constable Andy Walker, who put in months of planning for the exercise, says for some Police staff it was their first exposure to being part of the planning, operational and logistical decision making associated with a search.

He says as with all searches communications played a huge role in its success.

“AREC did a fantastic job keeping communication channels to all teams, including having teams carry the 25kg repeaters to the top of the ranges to provide coverage into the headwaters of the Tukituki,” says Andy.

He says there was a slight hiccup when overnight winds snapped an aerial, necessitating some hasty field repairs.

Andy purposely piled on the pressure on the Incident Controllers, giving them several interjections to contend with.

“These included calls from media wanting information on the search; a large group of family members launching their own search operation; a visit from Inspector Marty James questioning staffing; TOIL, costs and budgets; plus the family liaison aspects due to ‘Jon’ being from Australia and being located deceased”, he noted.

Michael ZS1MJT, the Western Cape’s Regional Director, has written a report about an Emergency Locator Transmitter (ELT) which was activated suddenly on the 17th November.

He says that a request was sent out to HAMNET members to assist with the tracking. Some members started trying to get a direction to the beacon from their homes, but nothing was heard across the Peninsula.

A member went to the top of Tygerberg hill to try to get a direction of the signal from a higher vantage point, but to no avail. Nothing was heard.

Driving around the area where the GPS points were plotted, was also proving a challenge as the noise levels in the area were causing interference on radio frequencies (RFI).

Following some of the GPS coordinates received from Aeronautical Rescue Coordination Centre (ARCC), our members travelled from Tygerberg to Goodwood, Cape Town International airport, Montague Gardens, and back to Tygerberg Hill.

As nothing was heard, a call was made to stand down that evening and resume the following day.

Through the night, all locations were recorded and plotted on Google Earth. From there, using triangulation of most locations, members were deployed on Saturday to hunt for the elusive signals.

At 11h26, a clear signal was heard, and it was possible to track down the ELT to a business in Elsies River. On closer investigation, those premises proved not to be harbouring the elusive beacon, so the neighboring business was contacted. The owner made arrangements to open up later in the day and finally, at 17h42 on Saturday 18 November, the unit was located and switched off.

It appears that the ELT had been incorrectly disposed of at a dump site, and ended up at an Ewaste facility. The item was in a big crate with other electronic waste, and appears to have been rattled around, unintentionally turning it on. The signals were very scattered due to the nature of the building, the roof, and the material on top of and around it.

Thanks are due to Colin (ZS1RS) and Doug (ZS1DUG) who actively looked for it on Saturday 18 November, Shawn (ZS1LED) who assisted on Friday the 17th and Sybrand (ZS1L), who mapped the locations on both days.

Thank you, Michael, for managing the search while away for the weekend, and for the report.

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

HAMNET Report 19th November 2023

BBC.com reported on Friday that Zimbabwe has declared a state of emergency in the capital Harare over a cholera outbreak. The outbreak has so far killed dozens of people with more than 7,000 suspected cases.

The city authorities say the outbreak, spreading throughout the city, has invoked memories of a deadly outbreak in 2008, in which thousands died. “We have declared a state of emergency because of cholera,” local media quoted Mayor Ian Makone as saying.

The authorities are now asking for help to contain the spread and provide safe water, saying the aid being received is inadequate. Health authorities have been struggling to contain the high number of admissions following the outbreak, according to the International Federation of the Red Cross (IFRC).

It cites a lack of health workers to manage the cases, as well as lack of supplies to stop the transmission. Zimbabwe has been battling the deadly cholera outbreak in recent months amid a lack of access to clean water.

The epicentre of the latest outbreak is Harare’s high-density suburb of Kuwadzana, which accounts for nearly half the reported cases, according to the authorities. On Tuesday, the ministry of health announced that the country had recorded 7,398 suspected cases, 50 confirmed deaths, and 109 people in hospital.

It came as the health minister visited the epicentre, announcing measures to deal with the outbreak – including the removal of street food vendors, and trucking of safe water.

The IFRC says the disease is quickly spreading, affecting multiple geographical areas in 45 out of 62 districts and in all 10 provinces of the country. It says the outbreak can be expected to cross the border.

I do not have to remind you that we share a border with Zimbabwe.

Here’s a clever concept. Hackster.io reports in its news department that Researchers at the Centre Tecnològic de Telecomunicacions de Catalunya (CTTC), the University of Luxembourg, and the Universitat Oberta de Catalunya (UOC) have taken CubeSat technology and blended it with 3D printing to design a nanosatellite which can be held aloft by balloon to deliver broadband connectivity to disaster-hit regions in as little as 90 minutes.

“Our project provides a solution that means that a communications network to provide help in emergency situations can be established quickly,” says Carlos Monzo Sánchez, a professor at the Universitat Oberta de Catalunya. “It uses equipment that offers a communications service quickly, when it would not otherwise be possible. It is especially designed for emergency services, so that they can work in a safer and more coordinated way in complex situations.”

The core of the concept is the CubeSat standard for nanosatellites, low-cost- highly-miniaturized satellites which have been used extensively for experimentation in space. In the team’s approach, though, it doesn’t have quite so far to go: the CubeSats, built on a 3D printer in as little as 90 minutes, are lofted above the disaster zone on a balloon, communicating with the ground over a LoRa low-power long-range radio.

“Our solution enables communication over long distances, as well as providing a scalable system for a large number of users that is reusable anywhere and at any time,” claims Raúl Parada, a researcher at the CTTC and first author of the paper. “We chose [a] CubeSat as for communications in difficult environments due to its speed of deployment and functioning. It operates independently of current communication systems, which may be damaged during a disaster, and enables long-range communication.”

The team’s prototypes are based on the Semtech SX1278 LoRa transceiver, which can be connected to an antenna as simple as a length of metal ruler. The 1U CubeSat in which the transceiver is installed was 3D printed and fitted with a sensor package including a Bosch Sensortec BME280 environmental sensor, a TDK InvenSense MPU-9250 inertial measurement unit (IMU), a Hanwei MQ-135 air quality sensor, and a Roithner LaserTechnik GUVA-S12SD ultraviolet light sensor, all linked to an Arduino Nano microcontroller — with a GPS receiver added at a later date to make it easier to recover downed satellites.

“Our solution is designed to provide a rapid service in complex scenarios, and as such we have prioritized its ease of deployment over its use as a telecommunications solution in normal situations, where other infrastructures would be more suitable,” Monzo concludes. “The next step is to work on the services that could be included in this type of infrastructure, minimizing deployment times and ensuring it can be used in a wide range of situations.”

The team’s work has been published in the journal Aerospace under open-access terms.

Now Hackaday’s Dan Maloney reports on a Ham who used a can of “ham” to make a pretty effective 70cm “cantenna”. If you’d have asked us for odds on whether you could successfully turn a canned ham into an amateur radio antenna, we’d have declined the offer. Now, having seen [Ben Eadie (VE6SFX)]’s “hamtenna” project, we’d look at just about any “Will it antenna?” project with a lot less scepticism than before.

To be painfully and somewhat unnecessarily clear about [Ben]’s antenna, the meat-like product itself is not included in the build, although he did use it as sustenance. Rather, it was the emptied and cleaned metal can that was the chief component of the build, along with a few 3D printed standoffs and the usual feedline and connectors. This is a slot antenna; a design [Ben] recently experimented with by applying copper foil tape to his car’s sunroof. This time around, the slot was formed by separating the top and bottom of the can using the standoffs and electrically connecting them with a strip of copper tape.

Connected to a stub of coax and a BNC connector, a quick scan with a NanoVNA showed a fantastic 1.26:1 SWR in the centre of the 70-cm ham band, and a nearly flat response all the way across the band. Results may vary depending on the size of canned ham you sacrifice for this project; [Ben]’s can measured just about 35 cm around, a happy half-wavelength coincidence. And it actually worked in field tests — he was able to hit a local repeater and got good signal reports. All that and a ham sandwich? Not too shabby.

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

HAMNET Report 12th November 2023

At the beginning of this report, and it being Remembrance Sunday, I should pause to reflect on those special people, both Radio Amateurs and signalers all across the world, who have lost their lives in the course of their duties. I hope and trust that their endeavours were never in vain, and that they shall not be forgotten.

An earthquake that struck Nepal last weekend, with magnitude 6.4, affecting the Karnali Province in southern Nepal, has turned out to have resulted in 157 fatalities, of which 82 were children. Another 349 people were injured, and 10000 displaced. 17740 houses were destroyed, and another 17127 partly damaged.

The Nepal Humanitarian Country Team estimate that 1.3 million were exposed to the shaking, and that 250000 people are still in need of assistance. Will it come before the next humanitarian disaster strikes that part of the world, I wonder.

HAMNET Western Cape is busy renovating and repurposing a horsebox-like trailer, acquired from a source in Division Six, with a view to equipping it with the necessary power infrastructure, coaxial cables, working surfaces, radios, antennas, solar panels,  computers and screens, to become a fully operational mobile Emergency Operations Centre, which can be moved to wherever it is needed.

It is tall enough to stand up in, and can host at least three operators comfortably in chairs at desks built in. Its side wall flaps up like an awning to provide shelter to anyone standing next to it during bad weather, but a door has been cut into that awning, so that it doesn’t always have to be flapped up if not needed. It has been repainted with very weatherproof paint in a white colour, and will have suitable logos and identification from above, so that it will stand out at an event, and for helicopters from above.

A work party was held yesterday, to lay out the wiring from battery, mains, solar and generator sources, as well as reconnecting the trailer’s backlights to the 7 pin socket on the towing vehicle. A small group of HAMNET members has formed the trailer working group, under the command of Sybrand Cillie, ZS1L, the Deputy Regional Director of HWC.

Here’s some interesting technology described by TechXplore.com. Most anyone who’s used noise-cancelling headphones knows that hearing the right noise at the right time can be vital. Someone might want to erase car horns when working indoors, but not when walking along busy streets. Yet people can’t choose what sounds their headphones cancel.

Now, a team led by researchers at the University of Washington has developed deep-learning algorithms that let users pick which sounds filter through their headphones in real time. The team is calling the system “semantic hearing.” Headphones stream captured audio to a connected smartphone, which cancels all environmental sounds.

Either through voice commands or a smartphone app, headphone wearers can select which sounds they want to include from 20 classes, such as sirens, baby cries, speech, vacuum cleaners and bird chirps. Only the selected sounds will be played through the headphones.

The team presented its findings on 1st November at UIST ’23 in San Francisco. In the future, the researchers plan to release a commercial version of the system.

“Understanding what a bird sounds like and extracting it from all other sounds in an environment requires real-time intelligence that today’s noise-cancelling headphones haven’t achieved,” said senior author Shyam Gollakota, a UW professor in the Paul G. Allen School of Computer Science & Engineering.

“The challenge is that the sounds headphone wearers hear need to sync with their visual senses. You can’t be hearing someone’s voice two seconds after they talk to you. This means the neural algorithms must process sounds in under a hundredth of a second.”

Because of this time crunch, the semantic hearing system must process sounds on a device such as a connected smartphone, instead of on more robust cloud servers. Additionally, because sounds from different directions arrive in people’s ears at different times, the system must preserve these delays and other spatial cues so people can still meaningfully perceive sounds in their environment.

Tested in environments such as offices, streets and parks, the system was able to extract sirens, bird chirps, alarms and other target sounds, while removing all other real-world noise. When 22 participants rated the system’s audio output for the target sound, they said that on average, the quality improved compared to the original recording.

In some cases, the system struggled to distinguish between sounds that share many properties, such as vocal music and human speech. The researchers note that training the models on more real-world data might improve these outcomes.

Thank you to Phys.org for bringing that post to our attention.

I was going to start the bulletin off by warning you of the rogue white dwarf star WD 0810-353 which is due to hit our solar system. This latest scare came about in 2022 when astronomers Vadim Bobylev and Anisa Bajkova analysed the data sent back by ESA’s Gaia space observatory, which was launched in 2023. By studying the shift in the spectrum of the white dwarf star WD 0810-353 in the constellation of Puppis 36 light-years away, they calculated that the star was on a collision course with our solar system.

Since the rogue star will only pass within 31,000 AU (4.6 trillion km) of the Sun, this doesn’t seem much to lose sleep over, but that distance means it will pass through the Oort cloud, which is home to icy objects only kept in position by the tenuous grip of the distant Sun. When something like a rogue star passes through it, it can dislodge these objects and send them into the inner solar system.

Long story short: it could cause a rain of comets and asteroids, like the one that may have killed off the dinosaurs.

Taking new spectra of the rogue star confirmed that the first calculations hadn’t taken into account the powerful magnetic field of the star. Such fields can distort a spectrogram, spreading out the spectral lines and shifting them into new wavelengths. In the case of WD 0810-353, it made it look as if it was coming our way. By correcting the spectrum using a polarizing filter, a more accurate calculation was possible, which showed that the first estimate was more than a little bit off.

“We found that the approach speed measured by the Gaia project is incorrect, and the close encounter predicted between WD 0810-353 and the Sun is actually not going to happen,” says Stefano Bagnulo, an astronomer at Armagh and co-author of the study.

So I moved this item to the bottom of the bulletin instead. Oh, and by the way, it was only due to affect our solar system in 29000 years, so there is still time to take in the washing and bath the baby.

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

HAMNET Report 5th November 2023

The ARRL letter of this Thursday says that Radio Amateurs are still providing communication services to and from the affected areas in and around Acapulco, Mexico.

On the morning of Wednesday, October 25, 270km/h winds from Hurricane Otis knocked out all communications and unleashed a nightmare scenario in Acapulco. The area is home to roughly 800,000 people.

Radio Club Queretaro member Ruben Navarrete Galvan, XE1EC, told ARRL News that amateur radio operators are still active with multiple operations, and they are receiving citizen requests to obtain information on the whereabouts of their relatives.

“We keep an online database with these requests that we share with the different hams participating in the operation. Read-only access to this database is provided to the authorities who might need it, too. We also transmit this information to hams deployed in the Acapulco area via HF,” Galvan said.

Additionally, hams in the Acapulco area are trying to locate civilians using their own resources. Some of these hams are operating their equipment on battery power, while others have access to generators. Accessing many areas in the region has been a challenge due to the amount of debris blocking travel

Amateur radio operators have also been receiving requests from Acapulco residents to call their relatives and let them know they are fine. Those requests are transmitted via HF to the Emergency Net Operator, and then the call is made to the family members.

Galvan also reported that hams have been providing communication between state agencies and their field personnel deployed in the Acapulco area. “At least three state agencies have hams on their teams. This is the case for the states of Durango, Morelos, and Santiago de Querétaro. We have been communicating their messages to their central coordination via HF relays. Requests for specific requirements have been escalated to the support teams. Air medical services have been directed to areas that were not being attended,” he said.

Just too late for inclusion in last Sunday’s bulletin, Keith Lowes, ZS5WFD, of HAMNET KZN sent me a report of the radio comms during the Amashova Durban Classic cycle race of 22nd October.

He notes that eleven Hamnet KZN members were deployed in very challenging weather conditions to provide communications for the Amashova Durban Classic cycle race held that Sunday..

Thunderstorms, heavy rain, strong winds and misty conditions prevailed throughout the day to keep [them] on [their] toes.  This also had a major impact on participants as 1893 did not start the race although they had registered.  This was likely due to family members not prepared to take unnecessary risks with potholes hidden underwater and slippery road conditions.

The 38Km race from Hillcrest and 65Km race from Cato Ridge started at 05H00 whilst the 106Km from Pietermaritzburg started at 06H00.

Communications were via the 145.7625 Highway and 145.750 Midlands Club repeaters with the Joint Operations Centre (JOC) at Suncoast Casino in Durban manned by Keith ZS5WFD.

Operators were situated at five Water Points along the route with one Roving Patrol crewed by Deon ZS5DD and Troy ZS5TWJ that had full route access.

Apart from a number of private vehicles entering the closed route, no other serious issues were reported.  One cyclist was admitted to hospital suffering from a dislocated shoulder. Three other cases involved cuts and abrasions but they were treated and discharged.

An initial report of a serious accident on the N3 freeway at Cato Ridge caused some concern in the Durban JOC as this could have resulted in traffic having to be diverted onto the alternate route which would have required possible stoppage of the race. Fortunately, the incident had been cleared prior to the arrival of the Emergency Services and no further action was required.  This was an important lesson, as if action had been taken without first verifying the initial report it would have had a major negative impact on the event. [The message is] “Verification before Action”.

Thank you to the team that braved the miserable weather to ensure the successful outcome of the event, on behalf of the organizers and Keith himself.

He regrets to have to bid farewell to Hamnet KZN members Peter ZS5HF and Hettie ZS5BH as they are emigrating to Australia at the end of November. This was their last sporting event with HAMNET KZN, so he expresses his sincere appreciation for their loyal support of HAMNET over the past years and wishes them every success in their new ventures in VK land.

Thanks for the report, Keith. I’m glad the weather didn’t make matters too difficult for your group.

Talking about reporting about things, Grant ZS6GS, our National HAMNET Director, has sent an email to HAMNET Members who are involved with the dissemination of information of the public relations type.

He correctly feels that we need to put more effort in to informing both radio amateurs and the public of what HAMNET is there for, what it can do, and what it has done, in the way of service to the community.

Anette ZR6D is tasked with posting any and every news item she hears about on Facebook, Grant ZS6GS will manage Instagram and Twitter (or X) feeds, Brian ZS6YZ will manage the reporting of the very busy time which HAMNET Gauteng South seems to experience, and I will continue providing a bulletin on the website and both Facebook pages.

This may succeed in bringing to the attention of all, the many endeavours we do get up to, but which seem to slide under the radar, and are never reported on.

In this connection, I appeal to everyone who involves him or herself in activities involving radio, to remember to write a short report of a paragraph or two, and send it to me for distribution amongst the PRO group just mentioned.

You can reach me at zs1dfr@gmail.com

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