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 22 September 2019
Audio version
In a previous series of tutorials, I discussed tropoducting in detail.
Today I want to tell you a little more about where you can get some relatively real time forecast data that can give you an idea of the possibilities for tropoducting.
Sunday 15 September was again a good day for VHF and above inland. Rickus ZS4A sent me a message with some videos at 08:18 that he and Carl ZS6CBQ recorded. Rickus says that they were working 5W FM on 70cm.
Video_ZS4A_ZS6CBQ.mp4
The only historical upper air data that I could retrieve was for the midday balloon from Irene and the Skew-T chart showed the temperature inversion that was most likely associated with the good conditions.
Now last week Carl ZS6CBQ mentioned Windy.com in his report. I had previously alerted Carl and Rickus and the rest of the guys who participate on the VHF Work Group about windy.com and that we need to try and see how the forecasts correlate to the propagation conditions experienced. This is at the moment the only source that I have managed to find where we can get some idea of predictions on upper air conditions over the land masses.
Let me describe what you need to do to see the temperature inversion forecasts. I have included some graphics on the text version of this program that will be posted shortly on the SARL webpage.
Open www.windy.com and zoom in to see South Africa.
1. On the right of the chart you can select the layer for relative humidity. On the bottom right of the chart is the button to switch on the pressure isobars if they are not displayed.
2. Next on the right middle of the chart is a slider that you can select the pressure level that you want to view. We know that temperature inversion is normally around 500 hPa. When you move this slider up and down you will notice that the humidity that is displayed changes.
3. Next select the place where you would like to see the upper air sounding data with your mouse and right click. A menu will open and select Sounding.
In the chart you will see the sounding forecast for Port Elizabeth at 00:00 hours SAST on 19 September 2019 and the temperature inversion is clearly visible in the forecast. If you look at the Hepburn chart for more or less the same time then you will see that there is also a forecast for strong tropoducting for Port Elizabeth. You will also notice on windy.com the change in pressure from high to low.
Play around and familiarise yourself with windy.com. There is an Android App as well that you can use. The nice feature that windy.com has is that you can play the timeline at the bottom of the screen and look ahead for what is forecasted.
Remember these are forecasts and the conditions are always changing.
Peter ZS2ABF also reported from Port Elizabeth that even though the Hepburn charts looked good earlier in the week, he and Dave ZS5DJ could not make contact along the South East Coast.
I have not received any other news at the time of compiling this program.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Focus on VHF and Above 15 September 2019
Audio Version
Today I want to introduce you to HamSCI or Ham radio Science Citizen Investigation.
What is HamSCI? HamSCI is an organization that allows university researchers to collaborate with the amateur radio community in scientific investigations and has the following objectives:
1. Advance scientific research and understanding through amateur radio activities.
2. Encourage the development of new technologies to support this research.
3. Provide educational opportunities for the amateur community and the general public.
The Lead HamSCI Organiser in the US is Dr. Nathaniel A. Frissell, W2NAF from the New Jersey Institute of Technology Center for Solar-Terrestrial Research. A couple of weeks ago Hans ZS6AKV played an interview with Dr Frissell and it truly was a very interesting interview.
Radio amateurs have been inadvertently involved in science projects for a long time collecting data that is analysed by scientists. Examples of this are reception reports and telemetry data collected from CubeSats . High Altitude Balloon Experiments like the BACAR balloon that will again be launched on 12 October from Secunda. Propagation data being reported and collected by the Reverse Beacon Network that continually monitors the HF bands. The WSPR beacon project and WSPRNet. These are all examples of projects where radio amateurs are involved in collecting and reporting data that can and is used by scientists.
Even here in South Africa, our very own HF noise floor monitoring project and the proposed VHF beacons and reverse beacon project are potential HamSCI projects where the data collected can later be studied by scientists to help us better understand the rising noise floor and VHF propagation. Collaboration between radio amateurs and scientists could even study the so called West Coast phenomenon to better understand the propagation and the effects on signal polarisation.
One of the latest projects is a Personal Space Weather Station.
Like a weather station, the purpose of a PSWStn is to collect measurements of common parameters on a long-term basis to develop a historical record. Stations submit their data in a standard format to a central storage server. The resulting database is a long-term record for research. Most stations will measure the same parameters. Stations might change their measurement routines or support one-time events or experiments with special instrumentation.
Unlike a weather station, the PSWStn will be measuring electromagnetic
phenomena that usually changes much faster than the weather. In addition, transient events like meteors or radio bursts may be able to be captured. For measurements of fast-changing things to have value, time-stamping of each event using an accurate, precise clock, or time base will be required.
Sounds interesting. For more information about HamSCI and the Personal Space Weather Station take a look at the HamSCI website https://hamsci.org/swstation
If you are interested in becoming involved in HamSCI locally please send Hans ZS6AKV your name and contact details to hans@intekom.co.za
Now for some VHF and Above news.
Well Sunday 8 September seemed to be a good day for VHF and above.
Tom ZS1TA wrote to me with the following report.
“During the past week the Hepburn predictions looked favourable for Tropoducting along the West coast on Sunday 8 September.
Being situated behind Table Mountain and screened to the North West I yesterday took a 2 meter Yagi and a 70 cm Yagi to a parking spot on the side of Signal Hill from where I had previously conducted tests towards the West coast.
Started setting up at about 14:00 and shortly before 15:00 was ready and received the VHF beacon from V51PJ, weak just in the noise.
Started calling Pieter V51PJ on 144.300 USB and at 15:02 we made contact with reports of 4/1 and 5/1. During the QSO of 30 minutes this improved to 5/7 when we decided to try 70 cm.
After much fiddling with antenna direction by Pieter and long calling by myself we established contact on 432.100 USB at 16:30 with reports of 5/1. Although the audio improved and became a very comfortable copy there was no change in the S meter. Typical UHF!
Distance from Signal Hill, JF96eb, to Rosh Pinah, JG82ie, is 700 km.”
Look out for a more detailed account in an upcoming Radio ZS.
Carl ZS6CBQ also wrote the following about conditions inland on the morning of 8 September.
“Good conditions on VHF this morning. Free State stations Rickus ZS4A and Pierre ZS4PF were S9 +20 not using a pre amp. Mike ZR4MF in Bloemfontein was only heard on aircraft scatter, so the conditions did not stretch all the way down to Bloemfontein.
Windy.com showed a big low pressure situated over Lesotho and looking at the sounding charts there was temperature fold-back (inversion) from Pretoria and most of the Free State between 6000 m and 8000 m, but as I said not Bloemfontein.
Rickus ZS4A and myself spoke on 144.300 till about 09:20 when signals dropped quickly.”
Peter ZS2ABF reported on 10 September 2019 on the SARL Forum “Hi once again, last night Monday 9th September Dave ZS5DJ, and myself were both looking to have a good QSO. The Hepburn Charts looked good along the East Coast, and a "Red blob" was within our reach. We both called early on the Sked frequency, and listened for a strong needle bending reply. Well that was not to be. Silence remained, and we could not believe our ears. The frequency was absolutely DEAD. All we both heard was varying degrees of Static.
At 19:55 Dave called me on the twisted pair, and we managed to get through via Telkom. We both thought our Rigs and/or Yagis had faults. It is usual that one of us could not hear a thing but not both of us. I called again at 20:00, but no go. Just noise. Now going QRT, Bye all.
I don't know if our different WX conditions were to blame. East London had 37 degrees C, with no wind, and Dave at his QTH had 23 degrees C with wind.”
Thanks Tom, Carl and Peter for those reports.
Looking ahead for the coming week conditions look good around Tuesday 17 September 2019
afi102.jpg
Remember these are forecasts and the conditions are always changing and inland keep those eyes on Windy.com.
Now for some other news from around the world.
Mark M5BOP reports the complete set of amateur radio technical talks from this year's Martlesham Microwave Round Table is now available to watch on YouTube
Videos of these MMRT 2019 talks are available:
• Practical GNUradio - Heather Lomond M0HMO
• From Death Rays to Dinner - William Eustace M0WJE
• Equipment for Es'hail-2 / QO-100 Narrowband - David Bowman G0MRF
• DATV on Es'hail-2 / QO100 - Noel Matthews G8GTZ
• Low-pass Harmonic Filter for 23cm - John Quarmby G3XDY
• UKuG SDR Voice Transceiver Project Discussion
Watch the videos on the Martlesham Microwave YouTube channel at
https://www.youtube.com/channel/UCHV7cC7ZMehKjAM81QxUS9w/videos
There is an article by Karl-Heinz Krawczyk DL1GKK describing how to install amateur radio software on the Raspberry Pi to provide the popular data modes, SSTV, satellite tracking, SDR, rig control and logbook.
The English language article is available on the site of Indonesia's national amateur radio society ORARI.
Karl-Heinz says "I am a big friend of the small Raspberry Pi and use this gladly for amateur radio. With version 4 it is fast enough to fulfil all tasks. There are many ways and many software to make the Pi fit for Ham Radio. My choice of programs has the advantage that they are compatible with each other."
Read the article at
https://orari.or.id/index.php/2019/09/02/setup-raspberry-pi-for-ham-radio/
The September PDF of the GEO Newsletter weather satellite publication produced by the Group for Earth Observation is now available for free download.
The Group for Earth Observation's aim is to enable amateur reception of weather and earth imaging satellites that are in orbit or planned for launch in the near future. Membership of GEO is free.
This newsletter includes articles by Francis Bell G7CND, Les Hamilton and John Cooper G8GKU.
Download the GEO Newsletter from
http://www.geo-web.org.uk/geoquarterly.php
Well that is all for this week.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Focus on VHF and Above 8 September 2019
Audio version
As you know, I attended the fourth WRC-19 preparatory meeting of the African Telecommunications Union in East London the last week in August.
This was a very important meeting for us radio amateurs as it was the last chance for us here in Africa to influence the African Common Position that will be carried forward to the World Radio Conference WRC-19 that will be held in Egypt in November 2019.
This was by far the largest meeting that I have ever attended in my career, never mind my hobby. The meeting was attended by 310 participants from 35 African countries, 28 associate members of the ATU which are primarily the large industry players, the ITU and 5 regional organizations, 2 partner organisations and 25 observer organisations and companies.
The important items on the agenda affecting amateur radio were:
Agenda Item 1.1 the allocation of 50-54 MHz to the amateur service in Region 1 on a primary basis with provisions to allow Wind Profiler Radars and the amateur service to avoid mutual interference. This item, while not very important to us here in South Africa because we already have the 50-54 Mhz allocation, there are countries in the rest of Region 1 that do not yet have the full allocation to 54 MHz. Hence the importance for us to support the rest of the region.
Agenda Item 1.13 was the discussion on spectrum to be considered for International Mobile Telecommunications, which the ATU agreed should not include the primary amateur band at 47-47.2 GHz.
IMT2020 or 5G as it is referred to is going to be the next best thing with regards mobile telecommunications. The problem is that very large bandwidth is required and the only way to get the type of bandwidth required is to move higher up in the microwave bands. So you may say, but so what, who uses 47 GHz.
That is not the point. This is the only primary allocation we as radio amateurs have in the sub-millimetre bands. Here in South Africa we are not aware of any work being done in this band yet, but that is not to say that we will not use it in the future. In the UK there are already amateurs operating on this band. Until recently who would have thought that we would be operating on the 10 GHz band where the downlink of QO-100 is. We need to protect what we have for all it is worth because we are going to use it in the future.
Agenda Item 1.16 was an agreement to an AFCP that retains the current regulatory position in the 5725-5850 MHz frequency band which includes secondary allocations to the amateur service and the amateur-satellite service. In other words no change to the Radio Regulations.
So why is this important? Have you hear about mesh networks?
I recently mentioned on Focus on VHF the AREDN Mossel Bay Mesh Network. AREDN stands for Amateur Radio Emergency Data Network and has been developed to support emergency communications. To put it in a nutshell, using AREDN we can deploy and provide WLAN services over amateur radio networks not dependant on any commercial data networks that works on amateur frequencies and that does not have any congestion problems experienced on commercial wireless LAN networks. The 5 GHz band is one of the bands that are used. More information about AREDN can be found at https://www.arednmesh.org/. Again 95% of the amateur community do not play here, but there systems being developed and tested for emergency communications.
Agenda Item 9.1.6 goes about changing the radio regulations to accommodate Wireless Power Transfer or WPT devices. Now there are already many WPT devices available world wide. Devices such as wireless cell phone charges and so on. These devices are what are known as short range devices and they are also very low power devices. And then came electric vehicles. Now the ball game changes. There are specifications for the short range devices which are low power devices, but no specifications for high power devices. The manufacturers are trying to slip their devices through as short range devices and we cannot allow this. The proposed WPT-EV devices to be use in electric vehicles will be high power in the order of 11 kW. Initial testing and calculations show that because of the power, duration that these systems will be operational, the proximity of the devices to residential housing and projected density of deployment that the HF spectrum will be effectively wiped out. The ATU agreed to support no change to the Radio Regulations but continuation of studies in ITU-R to ensure that appropriate frequency ranges and technical limits are incorporated into standards to protect radio communication services.
What I have mentioned so far are current agenda items for WRC-19.
There is another agenda item that is just as important and that is Agenda item 10 which deals with proposals for the next World Radio Conference in 2023.
My mouth literally hung open during this session. It was like a free for all at an open air market. At the end one of the biggest surprises was the request for studies on frequency-related matters for International Mobile Telecommunications (IMT), identification including possible additional allocations to the mobile service on a primary basis [in portion(s) of the frequency range between 6 and 24 GHz] for the future development of International Mobile Telecommunications for 2020 and beyond. Remember, there are already large allocations made for IMT in the bands 24-86 GHz and now they are looking for frequencies below 24 GHz as well. The 10 GHz amateur allocation is part of this study! So now we need to yet again defend our bands leading up to WRC23.
This was a very interesting couple of days watching and listening and making notes. I have learnt a lot and one thing is very clear, we cannot be complacent. We need to continually be vigilant and make sure that we get involved in all spheres that could have an influence on our hobby. Legislative and regulatory and standards bodies. We need to be there. We need to make sure that no decisions are made that will prevent us from being able to use the frequencies allocated to us.
Now for some VHF and Above news.
Rickus ZS4A reports that on Sunday 1 September 2019 he and Carl ZS6CBQ completed a SSB contact on 23cm over a distance of 236 km. What is remarkable is that they did it with less than half a Watt at the antenna feed point.
Pine ZS6OB also heard Rickus’ 23cm beacon over a path of 266 km with obstacles as high as 260m and 216m high.
Well done guys. The conditions were extraordinary for you.
Peter ZS2ABF reported on 3 September 2019 that he and Dave ZS5DJ had their usual Monday evening sked on 144.300 MHz the previous evening, 2 September. The Hepburn Chart predictions did not look very good for long distance contacts along the East Coast but, to their surprise they established a contact straight away and had a 20 minute chat. The QSB picked up and soon they were both in the noise, putting an end to the contact.
The West Coast also experienced good ducting this past week with 70cm contacts between Cobus ZS3CVB and Charles ZS1CF over a distance of 440 km and Koos ZS3JPY and Charles ZS1CF over a distance of 388 km.
They were using 35W on FM. Well done guys.
Looking ahead for the coming week conditions look good from Monday morning 06:00 UTC for the West Coast.
Conditions along the South East Coast looks good for Monday evening.
Remember these are forecasts and the conditions are always changing.
I received the following news Item from Dennis ZS6BS.
Lance, W7GJ will be active as S79GJ from La Digue Island (AF-024, grid LI75VP), in the Seychelles between 21 and 29 September. This will be a 6 m EME DXpedition: Lance says "I urge you to gain experience with JT65A and especially review the QSO procedure that I use most effectively on these DXpeditions". Lance also adds, “When not aimed up at the moon, I very well may be on SSB or FT8 mode. For FT8, I will be using 50.313 MHz". Plans are to tear down on 30 September, but he might "be able to get on 20 m FT8 for some activity during the first few days of October" before departing for home on 5 October. QSL direct only to home call. See http://www.bigskyspaces.com/w7gj/ for planned operating schedules and other information.
Well that is all for this week.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Focus on VHF and Above 1 September 2019
Audio version
I have been away this last week attending the 4th African Preparatory Meeting for WRC-19 in East London. I will give some insight into this meeting next week as I still need to finalise my report to the SARL and the IARU.
Hans ZS6AKV has also sent me some very interesting information that I'm in the process of digging into. More about that as well next week.
In the last couple of weeks, I have become aware of things happening in the amateur radio community that is just not right. Listen to Onno VK6FLAB and think about how much you hear this amongst the local amateurs.
VK6FLAB.mp3
Does this sound familiar? I hear and see it so often. Most times the folk who do the bullying and the gate-keeping themselves do not even actively participate in the hobby other than sitting behind their keyboard and spewing garbage onto the internet. They seem to be bored with the hobby and now do everything in their power to make it unpleasant for others as well. It is as if they are protecting some right that they have apportioned to themselves.
Please do not let these characters make the hobby unpleasant for you. Come and participate in the workshops and activities that are presented and learn from your fellow amateurs who are willing to share knowledge and experience and who are themselves also open to new ideas. Do not be afraid to try something. Everytime you fail, you are learning as well.
Have you heard of Packet Radio? This is sometimes described as pre-historic email because it was used in the early days to send messages between amateurs prior to the internet. It could also be post apocalyptic internet! How else would you be able to send data when the internet as we know it today fails? Take a look at this video where Dr Aaron Jackson demos packet radio https://www.youtube.com/watch?v=lx6cm1rNDLM
Let us look at what the propagation forecasts are showing us.
Conditions may be good this coming week on Tuesday 3 September and then seems to deteriorate up the South East Coast later in the week.
Well that is all for this week.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Focus on VHF and Above 25 August 2019
Audio version
There is no tutorial today. Please send us some ideas, questions, and so forth that we can use to create a tutorial.
I however found this podcast by Onno VK6FLAB titled New Entrants are Everywhere that is very relevant to us here in South Africa as well.
New_Entrants_are_Everywhere.mp3
Let us look at some propagation news.
Peter ZS2ABF writes on the SARL Forum “Hi all, Dave ZS5DJ is back on the air, and eager to work long distance VHF. Last night 22 August the Hepburn Charts looked good along the South East coast. Dave, and I both gave several long calls on 144.300 MHz Horizontal LSB , but all we achieved was that we knew someone was replying but we could not identify who. It was obvious that it was us but low signals, combined with noise won the Dual this time round.”
Looking at the Hepburn charts for this coming week it looks like tropo ducting will not be favourable for the West Coast or South East Coast.
Hopefully conditions will pick up and you will experience some good contacts during the week even though the predictions do not look good. Remember that they are only predictions and the weather and atmospheric conditions that we rely on changes all the time.
Yesterday the 46 Group were active on all the VHF bands and were experimenting how low they could drop their power to still get good FT8 digital contacts. Pine ZS6OB and Rickus ZS4A managed to still get a copy on 5W. Just shows that when the conditions are good then you do not need hundreds of watts.
Some feedback from the VHF work group meeting that was held on Thursday evening.
Work is still being done on the beacon radio. The biggest problem still to be resolved are the key-clicks. Brian ZS6YZ and Ivan OZ7IS have been talking via email and Ivan who has modified many commercial land mobile radios to be used as beacons has given Brian some pointers based on his experience.
The work group is also looking into an alert system that can be used to alert on all on air activities regardless of the frequency and mode. The alert system will be purely a notification system and will be strictly controlled, no chit chat or other activities.
A requirement has arisen from the last VHF workshop where some of the new amateurs have a need to learn how to make up good cables. This includes knowing which are good connectors to use and how to solder the connectors onto the cables. Those of us with experience in VHF and above understand all the issues that lurk around this relatively simple task which most time is not that simple. Are there any guys who would like to share their expertise and help with a workshop on soldering and making up of cables?
I will be away in East London this week attending the final African Telecommunications Union’s WRC19 Preparatory meeting to make sure that our interests in the VHF and above bands are protected and to provide the IARU Region 1 with the necessary feedback regarding the outcomes of the meeting. All the issues currently on the table affect frequencies from 50 MHz and above. So far the Southern African states are all supporting our views. We need to make sure that the rest of the African states follow suite.
Well that is all for this week.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za.
Focus on VHF and Above 18 August 2019
Audio File
As we heard last week tropoducting has advantages and disadvantages depending on what you are doing.
This week I want to take a look at the upper air data and try to understand a little bit about the relationship between temperature, pressure and humidity and the actual conditions experienced.
As mentioned previously upper air data is collected by weather balloons that are sent up twice daily. There are other methods used, such as sounding rockets and radiosondes that are dropped from aircraft, but balloons are by far the most common method used.
Locally these balloons are launched by the South African Weather Service from various weather stations around the country. There is a map in the text version of this program on the SARL webpage showing the world wide distribution of stations that record upper air data. Interesting to note that the number of stations in Africa peaked on the ‘90s, but by 2015 has decreased considerably.
igra_stationmap.jpg
So what is the relationship between temperature, pressure and humidity?
Of the three atmospheric variables that influence refraction, water vapor has the greatest effect. The more moisture there is the more refraction there will be.
Temperature on the other hand needs to be low. In other words the higher the temperature the less refraction.
Moisture and temperature are the two factors that affect refraction the greatest.
Pressure variations have a small influence on refraction.
Normal refraction occurs under normal (standard) atmospheric conditions in which moisture, temperature, and pressure all decrease with altitude.
Normal refractive conditions are found in areas with very weak (or no) inversions, deep moisture, moderate to strong winds, and very unstable, well-mixed conditions. There are often showers in the area, and distinct cloud elements (Cumulus or Cumulonimbus, open convective cells, wave clouds, streaks, or convective cloud lines). Synoptic influences include a cyclonic influence, post-frontal or unstable prevailing conditions.
Sub-refraction occurs when the temperature and moisture distribution creates increased refractivity with height, the wave path bends upward and the energy travels away from the surface.
In hot, dry areas (temperature > 30 degrees C, RH < 40%), solar heating produces a homogenous surface layer, sometimes hundreds of feet thick. Sub-refractive areas are also formed by warm, moist air moving over a cooler, drier surface, and near warm fronts because of warmer temperatures and an influx of moisture.
Ducting is an extension of super-refraction because the meteorological conditions for both are the same. The conditions that form a trapping layer are more intense than those that form a super-refractive layer.
With knowledge of the overall synoptic weather pattern, it is possible to make a rough determination of the refractive conditions associated with the high and low pressure areas and associated frontal regions as shown in the synoptic chart and sea surface temperature table.
Synoptic Chart.jpg
Sea Surface Temperature and Zd Table.jpg
Sounds very complicated to me. What is interesting is that sea temperatures are mentioned. May this be the reason we only get forecasts for ducting over the oceans? How is the refractive index for moist or humid air calculated? What about inland? Again more questions, than answers.
Well I have been following another thought process. We know that we need to look for temperature inversion, relative humidity and pressure. On the morning of 7 August the Long Distance VHF Group reported good conditions between Bloemfontein, Bethlehem and Gauteng.
So I went and looked for the Skew-T charts for stations that reported upper air data for the morning of 7 August. I could only find data for Irene and Upington.
Irene Skew-T Chart.gif
You will see that the chart for Irene shows a very sharp and narrow temperature inversion at the height of 4331m and pressure level of 609 hPa and then another temperature inversion around pressure level 450 hPa.
The relative humidity is not shown in the Skew-T chart, but if one examines the data that was recorded you will see that the relative humidy at 609 hPa was only 2% while between 450 and 500 hPa the relative humidity was higher at 12%.
Irene Data.png
Now Upington is way out to the West, but we know that our weather patterns move from West to East and the atmosphere is dynamic and continually changing, so let us see what Upington's data shows us.
Upington Skew-T Chart.png
Upington Data.png
Here we also see that where we have temperature inversion, the relative humidity tends to be higher.
Could this be an indicator of a tropoduct over divisions 4 and 6, albeit weak compared to that experienced over the oceans? Interesting isn't it.
I've no dought in my mind that this needs further study and data needs to be captured everytime we experience good long distance communications so that we can work out what is happening in the upper atmosphere and the relevance of it to our long distance weak signal communications on VHF and above.
Now for some VHF and above News.
The D4C contest station on the Cape Verde Islands now have a 432 MHz station up and running.
John EI7GL posted in his blogspot “So far in 2019, the D4C contest team on Cape Verde Islands off the west coast of Africa have made some pretty amazing contacts on 144 MHz. Using the call D41CV, they have worked across the Atlantic to the Caribbean, up to the UK, France and Ireland via marine tropo ducting and into Germany, Italy and Slovenia with a combined Sporadic-E / marine ducting mode.
Many of these contacts were well in excess of 4000 km in distance.
The D4C team have recently announced that they are now active on 432 MHz using a homemade 16 element "Pinocchio" Yagi with a wooden boom. A Transverter is connected to a FlexRadioSystem 6600M driving a solid state PA running 100W.
It is now only a matter of time for the team at D4C to start making long distance 70cm contacts as well.
Take a look at John EI7GL’s blogspot where he discusses the possibilities of making long distance contacts on 70cm.
144 & 432 MHz Yagi antennas on Cape Verde
D41CV-VHF-UHF-antenna.jpg
Last week we reported on UK radio amateurs who made a CW contact on 288 GHz over a distance of 175m.
This week we report on Australian radio amateurs reporting a first FT8 contact on 122 GHz. Roland Lang, VK4FB, and Stefan Durtschi, VK4CSD, completed what is being claimed as the world’s first FT8 contact on 122 GHz. The distance spanned during the August 11 contact was 92.08 kilometers. Signals were –17 dB on one end, and –20 dB on the other. Earlier this summer, VK4FB and VK4CSD claimed a new Australian record for an SSB contact on 122 GHz — 69.6 kilometres
We know of amateurs playing in the 10 GHz band primarily the downlink for QO-100. Are there any amateurs in South Africa working in the millimetre bands that is the bands higher than 10 GHz? Please let us know at vhfnews@sarl.org.za.
Looking at the Hepburn charts for this coming week it looks like tropo ducting will not be favourable for the West Coast, however conditions may be improving for the South East Coast from 18:00 UTC on 21 August 2019.
Well that is all for this week.
Please send your news snippets and information about activities on VHF and Above to vhfnews@sarl.org.za
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