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Mike Bosch ZS2FM sadly passed away at the age of 92 on 13 May. Here is his last column he wrote on 11 May. RIP Mike
SILENT KEY: VHF PIONEER ZS2FM
On 13 May 2018 the key of Mike Bosch ZS2FM became silent. He passed way at his home in Port Elizabeth two days after writing his regular VHF column on the SARL Web and his script for Focus on VHF on Amateur Radio Today, his last.
Mike Bosch was born in 1926 and licenced as ZS2FM in 1948. Mike read about the reception of BBC TV in Cape Town by Henry Rieder ZS1P (†) in 1949. Mike built a TV receiver around a VCR-97 war surplus radar cathode ray tube and managed to pick up the TV sound on 41,5 MHz from Alexandra Palace, London. As the solar cycle declined, the receiver was stripped to build an oscilloscope, but fortunately the VHF converter remained intact. In 1956, the MUF rose above 45 MHz again and the oscilloscope was turned back into a TV receiver with the addition of a sawtooth oscillator and a video IF stage connected to the VHF converter. A few weeks later, he picked up his first TV picture from the BBC on this homebrew TV receiver. That event was the spark that started a lifelong love affair with VHF and above, especially the 50 MHz band. He wrote his first article for RadioZS, entitled “See TV on your oscilloscope”, in 1959.
Mike was a prolific author , sharing his experiences and passion with a wide audience. He was passioned about the band above 50 MHz and dedicated most of his amateur radio lives to the promotion of VHF, UHF and Microwave activity. He received several awards for his contribution to Radio ZS and the SARL web and forum. He received the Jack Twine merit award in 2000 and this year was awarded the Willy Wilson Gold badge award for his outstanding achievements in Amateur radio technology and his support of the SARL.
Already in his nineties he wrote a weekly update on VHF activity on the SARL web and for the past few months scripted the amateur radio today programme Focus on VHF.
The South African Amateur Radio Development Trust named Mike the Radio Amateur of the Year in 1987. His research on Sporadic E was cited as a contributing factor. At the time, he had been engaged in this research for three years and was planning to continue for another 8 years. In 1962, Mike was invited by Professor J. A. Gledhill at Rhodes University, Grahamstown, to join Dr Georg Gruber in the exploration of the radio emission from Jupiter. A year later, Georg and Mike were invited by Professor C. H. Barrow of Florida State University, USA, to become part of their worldwide research team that researched those radio emissions. Mike and Georg received honourable mentions in the British journal, Nature.
Through his amateur career Mike kept a list of South African VHF/UHF and Microwave records up to date.
Mike was a giant in Amateur Radio and a dedicated pioneer in many aspects. His legacy will live on as a true inspiration for many in the amateur world of today and the future. Thank you, Mike. Rest in peace.
Focus on VHF 12 May 2018
In today’s tutorial Mike looks at the difference between VHF and HF antennas?
The main difference is wavelength, where HF with its longer wavelengths use wire antennas successfully. The gain and directivity of a HF antenna can be improved with beam types of antennas, such as the Yagi. Where a HF Yagi usually consists of a long boom and limited number of elements, in contrast a VHF Yagi may consist of a long boom with many elements, resulting in very high gain and a narrower beamwidth.
Unlike HF that relies on the ionization of the F, F1 and F2 layers for propagation, VHF is blessed with many modes of propagation, some are seasonal while others appear unexpectedly. Your location will determine how many propagation modes you could benefit . VHF beam antennas, are more challenging to build and require more accurate measurements.
If you are equipped with a very high gain Yagi on the VHF bands, 50 MHz and 144 MHz, then you could expect the best results and distances from Sporadic-E, Meteor Scatter and Tropo Ducting including some other propagation modes.
Next week we will focus on UHF equipment. This what Mike wrote on Friday 11 May. He sadly passed away on 14 May. RIP Mike.
Let us now look at some VHF, UHF & MICROWAVE NEWS
NASA SAYS SOLAR MINIMUM IS COMING – High up in the clear blue noon sky, the Sun appears to be much the same day-in, day-out, year after year. But astronomers have long known that this is not true. The Sun does change. Properly-filtered telescopes reveal a fiery disk often speckled with dark sunspots. Sunspots are strongly magnetized, and they crackle with solar flares which are magnetic explosions that illuminate Earth with flashes of X-rays and extreme ultraviolet radiation. The Sun is a seething mass of activity.
Every 11 years or so, sunspots fade away, bringing a period of relative calm. “This is called solar minimum,” says Dean Pesnell of NASA's Goddard Space Flight Center in Greenbelt, Maryland. “And it’s a regular part of the sunspot cycle.”The Sun is heading toward solar minimum now. Sunspot counts were relatively high in 2014, and now they are sliding toward a low point expected in 2019-2020. The good news is that they do not expect the Maunder Minimum to follow.
VHF REPORT FROM KLEINZEE – Kobus van der Merwe, ZS3JPY, says: “Good afternoon Mike here is the data that is given via the condition's on the VHF Tropospheric Ducting and it is all done via vertically antennas. We have had up to 15 stasions on the Monday nights 144,500 MHz simplex FM West Coast Radio QSO party from Cape Town to Langebaan, Kleinzee and Port Nolloth. The Cape Town APRS digi repeater’s antenna’s main lobe is trnasmitting away from the West Coast this again shows that the Tropo Ducting conditions are there it just has to be used by the operators. I have asked Pieter V51PJ to switch his beacon to a vertical antenna and immediately the signal improved to S5/8 to S5/9 at my QTH with the Yagi vertical in any direction. At the same time Charles, ZS1CF, received the beacon in Langebaan S5/5 on a vertical antenna.
“We have Cobus ZS3CVB in Port Nolloth in QSO with Eben ZS3EP 140 km in Springbok on 145,500 FM vertical the same time that the QSO’s are happening along the West Coast, Cobus then relayed Eben into the West Coast ducting with crossband repeater and again the experience of experimenting payed off. I have to add we don't hear the band conditions are bad on the VHF FM vertical simplex QSO’s that take place. We have made a video of our QSO’s which shows some interesting information that can help you make similar QSO’s. The video can be found on the facebook pages of Boland and Cape Town Amateur Radio club page's as well as the ZS/V51/PY/ZD7 pages.”
GOOGLE’S PLANNED INTERNET NETWORK – Mobile phone users could receive signals from balloons floating in the stratosphere if a project launched by Google this week succeeds. Google launched 30 test balloons in New Zealand to test the possibility of having a global network of balloons floating about 19 km above Earth to provide internet access and mobile phone signals. Mike Cassidy, head of the project dubbed Project Loon, said in a blogpost: "We believe that it might actually be possible to build a ring of balloons, flying around the globe on the stratospheric winds, that provides internet access to the earth below.
"It's very early days, but we've built a system that uses balloons, carried by the wind at altitudes twice as high as commercial planes, to beam internet access to the ground at speeds similar to today's 3G networks or faster. As a result, we hope balloons could become an option for connecting rural, remote and underserved areas, and for helping with communications after natural disasters. "The balloons are 15 metres wide and 12 metres tall and filled with helium gas. People connect to the balloon network using a special internet antenna attached to their building. The signal bounces from balloon to balloon, then to the global internet back on Earth. Cassidy said: "There are many terrestrial challenges to internet connectivity – jungles, archipelagos and mountains. There are also major cost challenges. Right now, for example, in most of the countries in the southern hemisphere, the cost of an internet connection is more than a month's income."
BOTH CUBESATS ARE ON THEIR WAY TO PLANET MARS – NASA has received radio signals indicating that the first-ever CubeSats headed to deep space are alive and well. The first signal was received at 12:15 Pacific Standard Time and the second at 13:58 Pacific Standard Time on 5 May 2018. Engineers will now be performing a series of checks before both CubeSats enter their cruise to deep space.
Mars Cube One, or MarCO, is a pair of briefcase-sized spacecraft that launched along with NASA's InSight Mars lander at 4:05 Pacific Standard Time on 5 May 2018 from Vandenberg Air Force Base in Central California. InSight is a scientific mission that will probe the Red Planet's deep interior for the first time; the name stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport. The twin MarCO CubeSats are on their own separate mission: rather than collecting science, they will follow the InSight lander on its cruise to Mars, testing out miniature spacecraft technology along the way. Both were programmed to unfold their solar panels soon after launch, followed by several opportunities to radio back their health.
"Both MarCO-A and B say 'Polo!' It's a sign that the little sats are alive and well," said Andy Klesh, chief engineer for the MarCO mission at NASA's Jet Propulsion Laboratory in Pasadena, California, which built the twin spacecraft. The computers inside each MarCO CubeSat haven't been turned on since being tested at California Polytechnic State University, San Luis Obispo, in mid-March, where they were prepared for launch by Tyvak Nano-Satellite Systems of Irvine, California. What was needed in order to prove successful should not be underestimated for the pair of CubeSats. The batteries had to retain enough charge to ensure the solar panels deploy, stabilise their attitude, turn towards the Sun and finally turn their radio systems on.
A couple of weeks will be spent assessing how the MarCO CubeSats are performing. If they survive the radiation of space and function as planned, they'll fly over the Red Planet during InSight's entry, descent and landing in November. They each have a special antenna to relay InSight's vital signs during the infamous "Seven Minutes of Terror," the crucial phase which has claimed the majority of humanity's probes sent to land on the Red Planet. CubeSats were invented to teach engineering students how to build spacecraft. Today, they offer access to space for private companies and research institutions. They're just one kind of "SmallSat," which includes a broad range organized by weight class. CubeSats are generally under 15 kilograms, and can even weigh as little as 2.5 kilograms. Their distinctively modular design makes it easier to buy "plug-in" parts rather than custom-design every part of the spacecraft.
NASA is taking the opportunity to test several experimental systems with MarCO. Their radios, folding high-gain antennas, attitude control and propulsion systems are all included to prove new technologies in deep space. "We're nervous but excited," said Joel Krajewski of JPL, MarCO's project manager. "A lot of work went into designing and testing these components so that they could survive the trip to Mars and relay data during InSight's landing. But our broader goal is to learn more about how to adapt CubeSat technologies for future deep-space missions. "When InSight arrives on Mars in November, it won't rely on MarCO for sending landing data back to Earth. That job will go to NASA's Mars Reconnaissance Orbiter, as well as several Earth-based astronomy telescopes. But the MarCO mission could help prove the potential for CubeSats as a kind of bring-your-own "black box" for future NASA missions. MarCO was built by the Jet Propulsion Laboratory, which manages InSight and MarCO for NASA.
Apologies for not posting last weekend. This was due to a technical problem.
Tutorial 13 – VHF transmitting and receiving equipment
In the early days most radio amateurs built their own AM transmitters and some even tried their hand at building communication receivers. When the solid-state era arrived the Japanese shrunk all mode transmitters and receivers into a single unit and called it transceivers, based on transistors and chips, which makes it difficult for amateur to emulate having to look for spares etc. so it was far easier to purchase the finished professional job.
Many HF transceivers in the African States already include the 50 MHz band, so this has solved half of their VHF problem. It is not known how many commercial repeater systems are in use and are some allocated for amateur use on 145 MHz. If so then they are already equipped with FM transceivers, which must be reprogrammed with the new frequencies. Later they can try to replace the FM transceivers with all mode, which will open up a new VHF world for them.
Once you can listen to distant VHF signals on 50 MHz and 144 MHz these two VHF bands will provide the best between them, such as Super Sporadic-E season, Meteor Scatter and Tropo Ducting across the land. Then keep an eye on Tropo Ducting developing along the African West Coast on 144 MHz Tropo Ducting, also watch out for ZD7VC in St, Helena Island.
Next week we will discuss VHF antennas.
VHF, UHF & MICROWAVE NEWS
A FOREIGN STATE IS GETTING INTERESTED IN VHF – We have a ZS ham working in EXO country and he is pushing VHF. Then the good news came hot off the Press, EX0 country will get its 2m and 70cm licences soon. He informed V51PJ yesterday that the government is busy finalising the licencing of the hams there. With the enthusiasm of us on VHF and above he got interested in VHF and UHF too. In EX0 country he has a ZS callsign with an EX0/prefix, and that shows us how important it is to promote VHF and higher. The seed planted in him now spread to a country that never had VHF and priveleges available for hams before. So yes the dream for Africa is not impossible. We must just stay positive and active.
This new amateur is ZS6AJZ Charles and he lives in Kyrgyzstan. His new call sign could be EXOCK. The officials collected his application on Thursday, and it is expected that licences will be issued by 7 May 2018. His old call sign was EXO/ZS6AJZ now he is being issued with a local call sign.
Africa has lots of thunderstorms and rain, which make it perfect for backscatter, lightning scatter and rain scatter as well as super seasons of Sporadic-E and Meteor Scatter. But how to get their interest? Pieter Jacobs, V51PJ, says he has friends in the communication department here in Namibia that have personal contact with the guys in the African States in communication departments. They regularly get together and discuss ITU regulations for Africa. I will contact them this coming week and see what we can put together. This I think is where it must start. Because the ITU gave frequencies, for hams but some countries don’t issue because no one asked for its use as a ham. They only stick to HF only!
UNEXPECTED OPENING TO REUNION ISLAND – Hugo van Zyl, ZS5HV, reported from Scottburgh that on 26 April 2018. He detected an opening to Reunion Island. He hooked up with FR5DN on 144,300 MHz JT65b. Phil TX-ed every fourth sequence, and was still ongoing at 06:04 UTC.
MESSAGE: .060400 5 – 13 0,2 474 3 * CQ FR5DN LG98 I 10
LATEST: 074800 2-7 0.6 458 2 * CQ FR5DN LG78 1 10
Try and be around during the next opening to Reunion Island, which could happen anytime. SSB on 144 MH to Reunion Island has been worked from the coast of Natal over a distance of around 2700 km and as far south as about 3200 km to East London
FR5DN submitted report of latest opeings to Reunion Island.
http://www.astrorun.com/~fr5dn/radio/tropo/2018-04-26/2018-04-26-tropo.html
A COLD FRONT WILL PROVIDE TEMPERATURE INVERSIONS AHEAD OF IT –
Ian Roberts, ZS6BTE, reported that a cold front stretched all the way from KG33 to Kimberley and Aliwal North. It is known that when a cold front approached the Western Cape then VHF signals along the South Coast are strongly enhanced with Tropo Ducting until the cold front passed along the coast and the ducting disappeared. Likwise when a cold front spreads across part of the country it could enhance VHF signals in the area ahead of it. In the Eastern part of the USA they have often observed this type of phenomena and worked many VHF stations under these conditions. Unfortunately the effects of Cold fronts across this country are not well documented.
FANTASTIC COMMS BETWEEN EAST LONDON AND RAMSGATE – Peter Tottle, ZS2ABF reports from East London: “The Hepburn predictions for this week showed lots of red blobs along the S. E. Coast and I was looking forward to great contacts. Monday “sked” night, was very poor up into Natal. Dave ZS5DJ and I had a very poor QSO. The next night Tuesday was also poor and not as the charts predicted, but then they are on predictions (for across the Oceans). We persevered and came on last night, Wednesday. What a fantastic QSO we had. Dave and I could not believe the difference from the previous two days. Dave ZSDJ came blasting into East London like an Express Tran. We switched to FM and the results were better than telephone quality. Dave said my sigals were 59+20 dB. Not bad for 325 km on FM. We then switched back to USB on 144,300 MHz, because other Hams may also find out that conditions were good along the S.E. Coast and if so they would be calling on USB. We called CQ and gave many breaks, but no one was heard. Guys you missed a good opportunity to have made great contacts. We will only be calling on frequency next Monday evening on our routine sked night. 73 Peter
”DO WE REALLY THINK THAT WE ARE THE MOST ADVANCED EARTHLINGS?
Imagine if, many millions of years ago, dinosaurs drove cars through cities of mile-high buildings. A preposterous idea, right? Over the course of tens of millions of years, however, all of the direct evidence of a civilization—its artifacts and remains—gets ground to dust. How do we really know, then, that there weren't previous industrial civilizations on Earth that rose and fell long before human beings appeared? It is a compelling thought experiment, and one that Adam Frank, a professor of physics and astronomy at the University of Rochester, and Gavin Schmidt, the director of the NASA Goddard Institute for Space Studies, take up in a paper published in the International Journal of Astrobiology. "Gavin and I have not seen any evidence of another industrial civilization," Frank explains. But by looking at the deep past in the right way, a new set of questions about civilizations and the planet appear: What geological footprints do civilizations leave? Is it possible to detect an industrial civilization in the geological record once it disappears from the face of its host planet? "These questions make us think about the future and the past in a much different way, including how any planetary-scale civilization might rise and fall."
In what they deem the "Silurian Hypothesis," Frank and Schmidt define a civilization by its energy use. Human beings are just entering a new geological era that many researchers refer to as the Anthropocene, the period in which human activity strongly influences the climate and environment. In the Anthropocene, fossil fuels have become central to the geological footprint humans will leave behind on Earth. By looking at the Anthropocene's imprint, Schmidt and Frank examine what kinds of clues future scientists might detect to determine that human beings existed. In doing so, they also lay out evidence of what might be left behind if industrial civilizations like ours existed millions of years in the past. Human beings began burning fossil fuels more than 300 years ago, marking the beginnings of industrialization. The researchers note that the emission of fossil fuels into the atmosphere has already changed the carbon cycle in a way that is recorded in carbon isotope records.
Other ways human beings might leave behind a geological footprint include: Global warming, from the release of carbon dioxide and perturbations to the nitrogen cycle from fertilizers rates Plastics, synthetic pollutants, and even things such as steroids, which will be geochemically detectable for millions, and perhaps even billions, of years uclear war, if it happened, which would leave behind unusual radioactive isotopes
"As an industrial civilization, we're driving changes in the isotopic abundances because we're burning carbon," Frank says. "But burning fossil fuels may actually shut us down as a civilization. What imprints would this or other kinds of industrial activity from a long dead civilization leave over tens of millions of years?"
The questions raised by Frank and Schmidt are part of a broader effort to address climate change from an astrobiological perspective, and a new way of thinking about life and civilizations across the universe. Looking at the rise and fall of civilizations in terms of their planetary impacts can also affect how researchers approach future explorations of other planets. "We know early Mars and, perhaps, early Venus were more habitable than they are now, and conceivably we will one day drill through the geological sediments there, too," Schmidt says. "This helps us think about what we should be looking for."Schmidt points to an irony, however: if a civilization is able to find a more sustainable way to produce energy without harming its host planet, it will leave behind less evidence that it was there. "You want to have a nice, large-scale civilization that does wonderful things but that doesn't push the planet into domains that are dangerous for itself, the civilization," Frank says. "We need to figure out a way of producing and using energy that doesn't put us at risk."
That said, the earth will be just fine, Frank says. It's more a question of whether humans will be.
Can we create a version of civilization that doesn't push the earth into a domain that's dangerous for us as a species? "The point is not to 'save the earth,'" says Frank. "No matter what we do to the planet, we're just creating niches for the next cycle of evolution. But, if we continue on this trajectory of using fossil fuels and ignoring the climate change it drives, we human beings may not be part of Earth's ongoing evolution.
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