VHF, UHF and Microwave Record Table - the latest table of records is available from the VHF SA Record page. Click here to get a copy. Compiled and updated by Paul, ZS6NK - latest version 10 June 2019. Updates to zssixnk@gmail.com
Focus on VHF and Above 23 June 2019
Audio version
The highlight this week must be the historic contacts being made across the Atlantic between the Cape Verde Islands and the Caribbean Island of Guadeloupe.
The first contact was made on Sunday 16 June 2019 when the Atlantic was spanned for the first time when D41CV on Cape Verde Islands off the coast of Africa managed to work FG8OJ in Guadeloupe on 144.174 MHz using the FT8 digital mode. A distance of 3,867 kilometres
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Tropo prediction maps show a path right across the Atlantic and suggest that even more incredible contacts may be possible.
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The operator was Mark EA8FF using the beacon antenna as the "Pinocchio Yagi" had to be taken down to be improved after severe bad wind. The beacon antenna is an array of 6 horizontal polarised dipoles with an omnidirectional pattern.
Since this contact there have been numerous contacts across the Atlantic from D41CV. See the post Historic Trans-Atlantic Contact made on 144 MHz from Cape Verde to Guadeloupe on the blog of John EI7GL from Ireland for more information. The URL for John’s blog is https://ei7gl.blogspot.com/.
Now the challenge is to cross the Southern Atlantic between the West Coasts of South Africa or Namibia and Brazil.
Using AIS metadata to monitor propagation in the 2m band. Prognosis, monitoring and analysis of propagation conditions are a basis for kilometres and points in DX competition. As a new tool to monitor propagation in the 2m band, D4C has started receiving vessel AIS data.
AIS is a maritime NMEA standard, through which ships continuously transmit signals at approximately 12.5 Watts using a ground plane antenna. The evaluation of the AIS position data - which can, for example, be visualized by DXMaps under "AIS" - show when and how periods of enhanced propagation occur, in real time. Therefore, log data of successful radio connections are not used, but rather received signals on the 2 AIS channels at 162 MHz (+- 25KHz).
To receive AIS signals at D4C’s location (also D4Z and D41CV) on the Cape Verde Islands, the team concluded an antenna partnership with the company Vesseltracker.com in Germany, through which they received their AIS receiver equipment free of charge.
While at the preparatory meeting for WRC19 that I recently attended, I had the opportunity to chat to the folk from the Maritime Safety Authority about AIS. There are various AIS systems that are deployed on vessels. Some of these AIS systems make use of RF while others are satellite based, so when one uses websites like Vesseltracker.com then one needs to drill down to the vessel concerned to see which system the ship is using. Some of the long distances being reported could be from vessels using the satellite based systems.
Please remember that here in South Africa, you need a license to receive signals outside of the amateur bands so it is better to view the data on the websites than to receive the AIS signals yourselves.
While you are on the blog of John EI7GL, take a look at the post about Noctilucent Clouds.
In this week there have been reports about these clouds in Space Weather News as well.
The 2019 season for noctilucent clouds (NLCs) has been remarkable, maybe the best ever, with NLCs appearing as far south as Los Angeles CA and Albuquerque NM. What's going on? NASA satellites have just found an important clue. An unusual wave of moisture is surging through the mesosphere, boosting water concentrations to their highest level in at least 12 years. Visit Spaceweather.com for the full story and look at the fantastic photos of the Noctilucent clouds.
Hans ZS6AKV alerted me to this and I dug a little into it to find out more and whether there may be any chance of seeing these clouds locally and experiencing their effects on the VHF and above bands.
The Mesosphere is a layer between the Stratosphere and the Thermosphere. The Stratosphere being above the Troposphere. The Ionosphere also overlaps the Mesosphere. Looking at the numbers, the Troposphere is around 12 km thick. The Stratosphere extends to approximately 45 km, then the Mesosphere extends from 45 km to 85 km. Noctilucent clouds exist at a height of 76 km to 85 km. The D layer of the Ionosphere is from 60 km to 90 km and the E layer is 90 km to 150 km.
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The Mesosphere is the same layer where the meteors burn up in. We know that we get ionisation when the Meteors burn up that causes signal enhancement. We also know that the E layer of the Ionosphere is where Sporadic E propagation takes place.
Noctilucent clouds are known to exhibit high radar reflectivity in a frequency range of 50 MHz to 1.3 GHz. These radar echoes are called PMSE (polar mesosphere summer echoes). There are a lot of theories as to the cause of the radar echoes.
NASA has been studying these clouds through their AIM program since 2007.
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AIM’s data has led to more than 200 papers on Earth’s upper atmosphere. Here are a handful of key scientific discoveries:
· Overturning assumptions about the sun and noctilucent clouds: Observations from the 1980s and ’90s suggested that the appearance of noctilucent clouds is linked to the sun’s activity, which rises and falls in about 11-year patterns. But AIM’s data tell a different story: noctilucent clouds have been steadily increasing over the past decade, despite the sun’s regular changes in activity. The precise reason for this is still unknown.
· Noctilucent cloud and greenhouse gases: Scientists suspected that increased sightings of noctilucent clouds could be related to increasing greenhouse gases. Combining AIM’s data with 36 years of measurements from satellite instruments showed a correlation between more frequent noctilucent clouds and increases in water vapor, a greenhouse gas, and decreasing upper-atmosphere temperatures — a side effect of warming near the surface.
· Meteors help create noctilucent clouds: The ice crystals that form noctilucent clouds must form on a foundation of some kind. AIM’s data showed that this base is actually smoke from meteors — tiny microparticles produced when meteors burn up in Earth’s atmosphere.
· Tracking meteoric smoke: Before AIM’s launch, scientists primarily watched meteoric smoke — the tiny particles created when meteors burn up in the atmosphere — from just a few viewpoints with sounding rockets. AIM’s measurements have given scientists a new tool to watch this meteoric smoke, revealing for the first time the dynamics of how meteoric smoke moves through the atmosphere.
· Understanding the upper atmosphere: AIM helped scientists track how heat moves in the upper atmosphere, showing that heating in the mesosphere is more likely linked to circulation in the atmosphere rather than direct heating from the sun.
· Studying atmospheric waves caused by Earth’s rotation: AIM measures planetary waves, planet-scale waves caused by Earth’s rotation, that can influence weather across the globe. Over its 10-year mission, AIM has observed three of the four most extreme springtime planetary wave events seen since satellite observations began in 1978, raising questions about possible changes in the dynamics of the atmosphere.
· Teleconnection between the poles: AIM’s data showed that conditions in the stratosphere near the North Pole influence conditions in the mesosphere near the South Pole days or weeks later — even going so far as to influence the transition between seasonal conditions.
· How Earth’s weather affects the upper atmosphere: AIM’s measurements have also helped scientists track how air in the atmosphere moves vertically, as well as between the hemispheres. This helps scientists understand how events near Earth’s surface — like thunderstorms — might trigger changes in the upper atmosphere.
· Understanding the atmosphere from bottom to top: This new understanding of vertical linkages in the atmosphere was integrated into the first weather model that describes the entire atmosphere from the surface all the way to the upper mesosphere.
· The source of radar echoes: AIM solved the mystery of radar echoes in certain regions of the atmosphere during the summer. The same ice layer that produces noctilucent clouds is to blame for radar echoes, and the size of the ice crystals can even play a role.
Thanks for NASA for the information supplied.
Could we see these clouds in Southern Africa? Most likely not, but if they were to be seen it will probably be in the Southern Cape.
Could there be propagation enhancement from these clouds? Very possible, however there are very few amateurs at the latitudes where these clouds exist, so it could be more possible over the Northern Hemisphere than the Southern Hemisphere.
RF Noise just how bad is it? Recently large parts of South America were without electricity. When Argentina was plunged into darkness by a nationwide power cut Luciano Petruccelli LU3DX made a video showing just how much RF pollution is produced by electronic devices.
Watch his video showing how little interference there was during the power cut on June 16, 2019, followed by massive RF pollution when power was restored. At 42 seconds into the video clip you will see and hear a sudden increase in noise when the power was restored.
https://twitter.com/ure_es/status/1141397089047519234.
Do not forget about the VHF workshop that will take place on 20 July 2019 at the National Amateur Radio Centre in Honeydew.
For registration and the agenda go to either the AMSAT SA website at http://amsatsa.org.za/ or the SARL website www.sarl.org.za
Looking forward to seeing you there.
The next meeting of the VHF Work Group will be via Skype at 20:00 on 27 June 2019. If you want to join the VHF Work Group, send us your Skype name to vhfnews@sarl.org.za and we will add you to the call.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Focus on VHF and Above 16 June 2019
Audio Version
Last week we listened to what typical Meteor Scatter signals sound like. You could clearly hear the bursts of ionisation caused by the meteors burning up in the atmosphere.
This week we are going to listen to a couple of other VHF propagation modes.
Here in the inland areas of the country the long distance VHF communications are most likely Tropospheric Scatter. This type of propagation is also normally associated with changing weather such as a high pressure cell moving away and temperature inversions.
This first recording is a typically weak but stable CW tropospheric scatter signal of a beacon.
Tropospheric Scatter f5xal Beacon.mp3
And here is a SSB tropo scatter signal
Tropospheric Scatter 7x2ls SSB.mp3
Now along the coastal areas especially on the West Coast we get tropoducting taking place. Here is what tropoducting sounds like.
Tropoducting rw1zd.mp3
And another one recording locally the West Coast and St Helena Island.
Tropoducting ZS3JPY QSO ZD7GWM.mp3
Here in South Africa, Sporadic E season is usually late December and January. Sporadic E is strongest on the lower VHF bands. So what does Sporadic E propagation sound like over the radio?
This recording is a very strong SSB signal.
Sporadic E cn8st.mp3
Here is another recording, this time of a CW signal
Sporadic E yo6afp.mp3
While I have just said that usually Sporadic E openings occur in the summer months, this past week has seen Sporadic E openings between the northern provinces and Cape Town.
Mike ZS1TAF reports that he worked Willem, ZS6WAB and Servaas, ZS6SER on 50.200 MHz SSB between 16H10 and 17H20 UCT on 7 June.
QSB on band but great contacts both ways.
ZS6TWB Beacon was also heard on 50.044 MHz CW with a report of 57.
There were multiple ZS1 stations that worked both Willem and Servaas.
On 11 June Mike only worked Carl, ZS6CBQ. There were however other ZS1 stations who worked Carl and a few other ZS6 stations as well.
The following beacons were also heard:
ZS6TWB Beacon on 50.044 MHz CW reported as 56
ZS6WAB Beacon on 50.025 MHz CW reported as 59
ZS6JON Beacon on 50.050 MHz CW reported as 54
Mike says “This was a Sporadic E opening which is usually concentrated during the summer months.... Maybe this changes that Theory somewhat....”
That was a great opening and congratulations to all the guys that managed to exploit the favourable conditions.
We have previously reported that the frequency bands allocated to the Amateur Service are under attack. This threat has come to our attention.
France proposes 144-146 MHz for Aeronautical Mobile Service
The next meeting of the CEPT WRC-19 Conference Preparatory Group takes place June 17-21 in Prague
France has submitted a paper with the subject Agenda Item 10 revised proposal for an agenda item for new non-safety aeronautical mobile applications.
The paper says:
"The list of bands that are proposed for study of possible new allocations to the aeronautical mobile service on a primary basis is revised by adding the band 144-146 MHz, the bands 5000-5010 MHz and 15.4-15.7 GHz being maintained."
"The decisions of previous conferences have introduced some restrictions to the use and have imposed constraints on the development of aeronautical mobile applications within some existing mobile allocations traditionally used by the aeronautical mobile applications.
At the same time, the number of manned and unmanned aircraft equipped with sensors has grown significantly in the past 20 years together with the need of bidirectional low to high data rate communications.
Aeronautical applications like fire surveillance, border surveillance, air quality and environment monitoring, traffic monitoring, disaster monitoring, terrain modelling, imagery (visible, infrared, radar, meteo), video monitoring require non-safety communications between various types of aeronautical platforms.
Consequently the need of non-safety data communications between various types of aeronautical platforms increases and so the need for new frequency bands."
Remember, we are part of Region 1 and this is how it starts. It will now not be long and we will need to justify and defend our usage of the 2m band here as well.
Do not forget about the VHF workshop that will take place on 20 July 2019 at the National Amateur Radio Centre in Honeydew.
For registration and the agenda go to either the AMSAT SA website at http://amsatsa.org.za/ or the SARL website www.sarl.org.za
Looking forward to seeing you there.
The next meeting of the VHF Work Group will be via Skype at 20:00 on 27 June 2019. If you want to join the VHF Work Group, send us your Skype name to vhfnews@sarl.org.za and we will add you to the call.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Focus on VHF and Above 9 June 2019
Audio version
We have previously in tutorials spoken about the various propagation modes.
Bernie ZS4TX sent VHF news an email this week with some great information which I’m going to use as an introduction to how do you identify what VHF mode of propagation you may be experiencing and what it sounds like on the radio.
The ZS5KT beacon is being heard very well in Bloemfontein. Bernie says “I have been hearing the ZS5KT 144.420 CW beacon from grid KF50MF in grid KG30BX almost all the time during the few days I have been monitoring since I was alerted about the beacon being active.” The ZS5KT beacon has a 9 element Yagi with an output of 25W and Bernie has a 4 x 14 element Yagi array. The distance between KG30BX & KG50MF is 483.55 km.
Bernie also attached two screen shots with an audio recording at about the time the screenshots were taken. You need listen carefully and sometimes it may be difficult to hear the changes in the signal, but it will get easier over time.
Bernie says “On the first recording you will hear a short meteor burst at the beginning followed by the normal troposcatter signal.
Recording 1
On the second recording you will hear the signal enhancement for a few seconds as typically caused by aircraft scatter. The 2nd screenshot of the WSJT waterfall clearly shows the stronger signal and doppler shift caused by the aircraft scatter.
Recording 2
In the first recording Bernie sent you probably did not recognise the meteor burst. So what do meteor scatter bursts sound like?
Here is a recording of more pronounced meteor scatter pings recorded during the Leonids meteor shower in 2002. You will clearly hear the pings when the ionisation of the air takes place and then a burst of radio activity being reflected or scattered by the ionisation.
191102_0415_0430.mp3
Here is another recording of some meteor scatter bursts
svdl5mae.mp3
and lastly one of two short FSK441 meteor scatter reflections
k1uhf.mp3
If you now again carefully listen to the recording sent by Bernie, you will recognise the meteor burst.
Thank you Bernie for this information and thanks to EA6VQ for providing the other MS recordings.
The screenshots and recordings are available on the SARL web page.
Next week we will listen to another VHF and above propagation mode.
Now for some VHF and above news.
For those of you who like to play with Slow Scan TV or SSTV, the Raspberry Pi magazine, MagPi has a very nice article that describes how to set up a Raspberry Pi and a RTL-SDR dongle to receive SSTV pictures from the International Space Station. Follow the link https://www.raspberrypi.org/magpi/pictures-from-space-via-ham-radio/
The ISS regularly transmits SSTV images on the downlink frequency of 145.800 MHz. To find out when the ISS will be making SSTV transmissions keep an eye on the Amateur Radio on International Space Station (ARISS) SSTV blog page at http://ariss-sstv.blogspot.com/
Talking about satellites, Lightsail-2 is scheduled for launch June 22 and will have a Beacon on 437.025 MHz
LightSail is a citizen-funded project from The Planetary Society.
This cubesat will be propelled solely by sunlight, to Earth orbit. LightSail 2 is scheduled to launch aboard a SpaceX Falcon Heavy on June 22, 2019, and they will attempt the first, controlled solar sail flight in Earth orbit.
LightSail 2 will ride to space aboard the Department of Defense Space Test Program-2 (STP-2) mission which will send 24 spacecraft to 3 different orbits. LightSail 2 itself will be enclosed within Prox-1, a Georgia Tech-designed spacecraft originally built to demonstrate close-encounter operations with other spacecraft. Prox-1 will deploy LightSail 2 seven days after launch.
After a few days of health and status checks, LightSail 2's four dual-sided solar panels will swing open. Roughly a day later, four metallic booms will unfurl four triangular Mylar sails from storage.
The sails, which have a combined area of 32 square meters [344 square feet], will turn towards the sun for half of each orbit, giving the spacecraft a tiny push no stronger than the weight of a paperclip.
For about a month after sail deployment, this continual thrust should raise LightSail 2's orbit by a measurable amount.
LightSail 2 will fly in a 24-degree inclination, 720 km, circular orbit.
At latitudes of 42 degrees north it will reach a maximum elevation of 10 degrees above the horizon.
Lightsail-2 has been issued an experimental radio license WM9XPA and transmit on 437.025 MHz. A morse beacon will transmit the callsign every 45 seconds. A packet beacon will transmit AX.25, FSK 9K6 bps data.
Beacon information is available at:
http://tinyurl.com/ANS-153-Lightsail-Morse-Beacon
Documentation of the downlink telemetry data structure is posted at:
http://tinyurl.com/ANS-153-Lightsail-Telemetry
The VHF workshop will take place on 20 July 2019 at the National Amateur Radio Centre in Honeydew.
The main topic will be: Which is better, Vertical or Horizontal polarisation?
Come to the VHF workshop and listen to what Dick ZS6BUN has to say about Vertical vs Horizontal propagation.
We are also privileged have a presentation by Jan Pienaar ZS6OB or "Pine" as we all know him, and he will talk about Antennas, the most important link in VHF communication and discuss what is really important to look out for.
There will also be feedback on the progress of the two new beacons, a discussion on the West Coast propagation phenomenon and some quick fire sessions on the Reverse Beacon Project, a growing concern regarding the HF noise levels and why VHF and UHF has an important future in Amateur Radio.
The registration fee is R50 for SARL and AMSAT SA Members and R100 for non-members. For registration and the agenda go to either the AMSAT SA website at http://amsatsa.org.za/ or the SARL website www.sarl.org.za
Looking forward to seeing you there.
The next meeting of the VHF Work Group will be via Skype at 20:00 on 27 June 2019. If you want to join the VHF Work Group, send us your Skype name to vhfnews@sarl.org.za and we will add you to the call.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Examination
home or while mobile in cars, boats or on foot.
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Worked
All ZS award
SA
Maritime Net
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