In a software update released on the 30th of December 2020, it was announced that the JTDX software suite will now support operation on the new 8-metre (40-MHz) band.
YU7EF in Serbia is a well known designer of HF and VHF beams and many radio amateurs worldwide use his designs. In this post, we will look at two 5-element Yagi antenna designs for the new 40 MHz (8-metre) band.
(Updated 30th Dec 2020... Thanks to Pop, YU7EF for the additional information)
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A) Design #1 : EF0805S - 5-element Yagi on a 4.5 metre boom
The design with dimensions is shown below.
The calculated gain in free space is about 7.5dBd and has a front to back ratio in the region of 25dB.
There was a nice mid-Winter Sporadic-E opening on Tuesday the 29th of December of 2020 with plenty of signals on the 10-metre band.
As the map above shows, there were some F2 openings to South Africa and South America but the most interesting point was the sheer number of stations heard via Sporadic-E.
A total of 332 stations were heard which would be the same as a reasonable day during the Summer months. The Solar Flux on the day was 84 which was down slightly on the 88 of the last few days.
In December 2017, Norway became the first country to switch off its analogue FM radio stations on 88-108 MHz as they moved to a digital DAB+ system. Switzerland has now announced its intention to do likewise.
The Swiss Federal Office of Communications (OFCOM) said that members of the radio associations and the Swiss Broadcasting Corporation SRG SSR have agreed to migrate to digital broadcasting via DAB+ in 2022 and 2023. The SRG SSR will decommission its FM transmitters in August 2022 to make it easier for commercial operators to switch over. The private radio stations will deactivate their FM transmitters in January 2023.
A recent survey by GfK Switzerland showed that use of digital radio has risen by 22% since 2015 while at the same time, FM usage has dropped by 22% to 29 percent. By June 2020, only 13 percent of the Swiss population were using analogue FM radio only.
A survey also found that only 13 percent of the Swiss population listened exclusively to analogue VHF radio in June 2020.
In the car, DAB+ is now the most popular way of receiving radio programs. Radio usage via DAB+ and Internet radio together now make up 55 percent of total usage in the car.
All new cars are now sold with DAB+ fitted as standard.
Source: Swiss OFCOM office
The good news radio wise locally is that a new DMR repeater on 70 cms is now on air near Cork City in Ireland. It is co-sited with the existing EI7FXR analogue FM repeater at Farmers Cross near Cork Airport.
The callsign of the new digital repeater is EI7FXD and it has an output frequency on 430.250 MHz The input is 9 MHz higher on 439.250 MHz. This configuration is usually designated as DVU-R20.
The colour code is 1.
The Brandmeister ID of the repeater is 272015 should anyone wish to monitor the Brandmeister dashboard and hoseline.
Info from the Southern Ireland Repeater Group - DMR repeater for Cork City
A new 70cms DMR repeater was installed at Farmer's Cross near Cork city on Monday December 21st to provide DMR coverage to Cork City and surrounding areas. The set up consists of a Motorola DR-3000 repeater and the antenna is a CAT-C440 @ approx 50ft. It's the fourth digital repeater set up by the Southern Ireland Repeater Group and will complement our other three digital installations located at West Waterford, Waterford City and Mt. Leinster.
There was a nice opening to the Middle East and Australia on the 22nd of December 2020. The F2 opening coincided with some Sporadic-E to Europe so it was a pretty good day.
According to the PSK Reporter website, I heard 155 stations which is a reasonable number.
These are the stations I heard from Australia...
The Solar Flux was at 80 which is pretty low.
Every year, the Knights QRSS Group release their annual compendium. You can view the Winter 2020 (3rd edition) HERE
The Knights QRSS Group promotes the use of very slow mode code beacons to carry out propagation experiments on the HF bands. Often signals that are 15 to 20 dB below the noise can be seen on a computer screen as opposed to being heard by ear.
While newer digital modes can now be used for detecting very weak signals, they don't really show propagation effects. Either the digital signal was decoded or it wasn't. QRSS signals like the one shown below shows propagation over a 15-minute period.
In that image, you can see how signals fade with the Sporadic-E footprint moving and the polarisation changing. It also shows up slight doppler effects.
You can find out more about QRSS signals by visiting the QRSS Knights Groups.io page... https://groups.io/g/qrssknights/topics
Back the start of December 2020, I had a post up about how radio amateurs in Croatia were now able to get permission to use the new 40 MHz (8-metre) band.... https://ei7gl.blogspot.com/2020/12/new-activity-from-croatia-on-40-mhz-dec.html
Interest continues to grow and tests have been done with stations in neighbouring Slovenia.
On the 20th of December 2020, Toni 9A2WB successfully received FT8 signals from Ivo S59F on 40.680 MHz.
This frequency is in the centre of the 40 kHz wide Industrial, Scientific & Medical (ISM) band at 40 MHz.
The signal between the two stations was in the region of 243kms over a very obstructed path. While the signals were weak and buried in the noise, they did seem to be consistent at about -16 to -19dB.
While this was a one way reception report on this occasion, it does bode well for a successful two way contact between the two countries in the near future.
More information about the new 8-metre band can be seen on my 40 MHz page... https://ei7gl.blogspot.com/p/40-mhz.html
After a quiet few days, there were some weak F2 signals on 28 MHz on Sunday 20th December 2020...
Besides the Sporadic-E signals from around Europe, there were F2 signals mainly from South Africa. The one that really stood out for me was VK2NSS in the south-east of Australia.
I found this one unusual. How can I hear someone from Australia and yet, I only heard one station from the south of Russia. Where are all the other Russian and Ukranian stations at the first F2 hop to the east of me?
Look at how far north the VK signal traveled. Was that the real path or was it skewed and came through on a more southerly path?
I had a look to see how else heard VK2NSS on the 20th of December...
Only a few people around Europe heard his signal. You'll notice how there seems to be skip zones in Europe. He was heard in two areas of Ireland but completely missed England, Scotland and Wales. He was heard in the NW of France but yet completely skipped Germany. It just goes to show that sometimes, you just need to be in the right place for signals to get through.
The solar flux was down at 82 so the sun is still pretty quiet.
Back in November and early December, it looked as if the sun had finally woken up from its long slumber of solar minimum as the solar flux climbed about 100. At the time, there were some nice openings on the higher HF bands including 10-metres.
It now looks as old Sol has turned over and gone back to sleep. The Solar Flux on the 18th of December 2020 was at 82 and the map above shows what I heard on FT8 today on 28 MHz. It's certainly no better than what it might have been 12-months ago when we were at the sunspot minimum.
It will probably wake up again in a few weeks but it's probably a timely reminder that it's a bumpy road out of solar minimum.
During an extensive Sporadic-E opening in Australia on the 15th of December 2020, WSPR signals from John VK2IJM and David VK2DVM in Sydney were heard by Peter VK6KXW near Perth in Western Australia.
The path was in the region of 3200 kms which is way beyond the usual 2300km or so one hop distance from Sporadic-E. It seems likely that on this occasion, the most likely propagation mode was double hop Sporadic-E which is very rare at 144 MHz.
It looks as if just one WSPR transmission from each of the VK2 stations was decoded at 10:16 and 10:36 UTC. This was about an hour after sunset in Sydney which is 11 hours ahead of UTC.
Every year, the Geminid meteor shower peaks around the 14th of December and many VHF radio amateurs make contacts by bouncing signals off the meteor trails left behind. The maximum distance tends to be similar to Sporadic-E i.e. in the region of 2300 kms.
During this years Geminids, Stamen LZ1KU announced a suprise reception on 144 MHz of Jon OY9JD on the Faroe Islands, a distance of 3075 kms!
A composite of the screenshot from LZ1KU is shown below...
As can be seen, the mode used was MSK144 and there is one decode from OY9JD.
On an online forum later, OY9JD did confirm that he was on air at that time...
According to info provided by SO3Z, Jon OY9JD is using an ICOM IC970 with 500W into an 8 el Yagi 3m long. LZ1KU is using an array of 4 x 12 elements and 1.7kW.
Even though there was no two way contact on this occasion, it is still an impressive distance for 144 MHz. Remember that 3075 kms is roughly the distance across the North Atlantic between Ireland and Newfoundland.
In fact, 3075 kms to the west from OY9JD actually reaches the remote areas of Labrador in NE Canada.
Mode of Propagation??? (Updated)...
(Theory 1) Double Hop Meteor Scatter... Most meteor trails capable of supporting propagation of 144 MHz signals last for a fraction of a second at best with the occasional one lasting several seconds.
Was it a case that that on this particular occasion, two meteor trails were in just the right spot happened at the same time?
In other words, the MSK144 signal from OY9JD was reflected off the ionised trail of one meteor, then hit off another trail several hundred kms later and then was picked up in Bulgaria.
As you might imagine, this isn't that common as it requires there to be two meteor trails to be just in the right place and at just the right time.
(Theory 2) Tropo Assist?... As for did tropo play a part in the path? The conditions looked pretty poor as can be seen from the image below.
North Atlantic on 144 MHz??? ... Here is an intriguing thought: If the signal at 144 MHz can get 3075 kms from the Faroe Islands to Bulgaria was via double hop meteor scatter then why not across the North Atlantic from Ireland/UK to Newfoundland?
The map below shows the FT8 signals that I heard on 10-metres on Sunday the 13th of December 2020.
With the Solar Flux at 82, there were some weak F2 openings to the USA, South Africa, Thailand and Australia. Interesting but much less than say the end of November when the flux was over 100.
What was interesting about the Sunday the 13th was the number of signals from Europe.
As the map shows, I was hearing a lot of stations from Germany and Poland, all in the region of 1000 to 1800 kms. These signals were via Sporadic-E.
While the main Summer Sporadic-E season in the northern hemisphere lasts from about May to July, there is a much smaller Sp-E season in the middle of the Winter in December and early January.
Geminid Meteor Shower... The Geminid Meteor shower peaks around the 12th to the 14th of December every year. The dust left by meteor showers acts like a fuel for the formation of Sporadic-E layers at about 105 kms above the Earth.
It might be just a coincidence but the Geminid meteor shower may well have been the reason for this Sporadic-E opening.
With a meteor shower in progress, there is always a possibility that all I was hearing were 15-second reflections coming off a succession of meteor trails. However, there seemed to be a complete lack of stations from Spain and Italy which kind of discounts that theory. I'd be pretty sure it was mid-Winter Sporadic-E.
Over the last month or so, I've had several posts up on the blog about recent Trans-Equatorial Propagation (TEP) openings on 144 MHz between Brazil / Argentina and the Caribbean. Most of these contacts have been in the range of 4500 to 6000kms. See my 144 MHz page.
Today, I came across a post on a forum about a commercial FM radio station on Band 2 (88-108 MHz) in Columbia being heard in Chile, a distance of some 4580 kms.
Radio Rumba is a radio station in the city of Caucasia in Columbia in South America. It's FM transmitter is on 93.1 MHz and it has as far as I can tell an output power of 5 kW.
On the evening of the 20th of November 2020, Mauricio Toro in the town of Villa Alemana near Santiago, Chile heard Radio Rumba on 93.1 MHz, a distance of some 4580 kms.
Considering that both the radio station and Mauricio were both equidistant from the Geomagnetic Equator, were at right angles to it and the local time was 21:30, the most likely mode of propagation was Trans-Equatorial Propagation (TEP).
Mauricio was using a SONY XDR-S10HDIP receiver with a 7-element horizontally polarised Log Yagi.
Trans-Equatorial Propagation (TEP)
With Trans-Equatorial Propagation (TEP), zones of high ionization occur either side of the geomagnetic equator in the F layer of the ionosphere. What makes the mode so interesting is that it can allow propagation on the VHF bands from 50 MHz to 144 MHz. As the zones of ionization is roughly 400kms above ground level, the propagation paths achieved are in the region of 4000 to 5000 kms, much greater than what might be usual with Sporadic-E.
In the last few days, I noticed a noticeable drop in the level of activity on 28 MHz as the Solar Flux drops. There is still evidence of F2 propagation as can be seen from the opening to the USA and Israel as shown in the map above but this is in marked contrast to say the 26th of November 2020 when I was hearing lots of stations from the United States.
Back in December 2019, the sunspot cycle was at its minimum when the solar flux was down around 70. In October of 2020, solar cycle 25 really woke up when the solar flux began to rise reaching a peak of 116 on the 29th of November 2020.
After that, there was a gradual decline and it was back down to 83 on the 11th of December 2020. Hence the drop in radio conditions on the HF bands including 28 MHz.
The ARRL 10-metre contest is on this weekend and conditions for it are likely to be modest at best but not as good as it would have been two weeks earlier.
It'll be interesting to see what the flux is like around say the equinox in March 2021. We'll be a few more months into the new cycle and the sun might hopefully be a bit more active.
Thanks to Dragan, 9A6W for sending on this YU7EF design for a 4-element Yagi antenna for the new 40 MHz (8-metre) band.
The design with dimensions is shown below.
The calculated gain in free space is about 6.2dBd and has a front to back ratio in excess of 20dB.
Recently on the blog, I had several posts about some remarkable Trans-Equatorial Propagation (TEP) contacts made on 144 MHz between stations in the Caribbean and South America. Most of these were in the region of 5000 to 6000 kms. See my 144 MHz page for a list of posts.
Gabriel, LU1DL in Buenos Aires has kindly sent on some information about his 144 MHz TEP contacts during the months of November & December 2020 and it's interesting to see what can be worked from someone on the southern end of the TEP path.
You'll notice that all of the TEP contacts that LU1DL made were at right angles to the Geomagnetic Equator.
Here is the log from Gabriel...
With Trans-Equatorial Propagation (TEP), zones of high ionization occur either side of the geomagnetic equator in the F layer of the ionosphere. What makes the mode so interesting is that it can allow propagation on the VHF bands from 50 MHz to 144 MHz. As the zones of ionization is roughly 400kms above ground level, the propagation paths achieved are in the region of 4000 to 5000 kms, much greater than what might be usual with Sporadic-E.
Equipment... For these 5000-6000km contacts on 144 MHz, LU1DL was running 180 watts into a single 10-element Yagi with a 5m boom.
This is the antenna system for P41E in Aruba...
HI8DL in the Dominican Republic...
Video... Have a listen to this TEP contact on 144 MHz and note the distortion on the audio...
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| Astronaut Shannon Walker |
Students from a secondary school in the midlands are hooking up with an astronaut on the International Space Station this afternoon to try and find out how space travel is affecting life on earth. https://t.co/ljwoI4jaOW pic.twitter.com/T3wTcRTdEi
— RTÉ News (@rtenews) December 7, 2020
Preparation for our live space call on Monday starts at 1:30 pm with great music, guest speakers and more, before the direct contact is made at 2:50 pm 🚀☄️ https://t.co/yy6T8TOlEB pic.twitter.com/aMQaDVsnfh
— Athlone Community College (@ccathlone) December 4, 2020
In a message by email, Dragan, 9A6W writes...
In April I have applied for an experimental license to transmit on 40 MHz hoping to be QRV for the E-sporadic season. To make a long story short, national telecom authorities have just issued me an experimental license for 8 m band, 40,66-40,70 MHz. I am QRV with FT-897 (100 W) and a dipole antenna at the moment.
The license is valid for a year and then it could be renewed. There are rumors that some other stations will follow my example.
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Croatia is now the fifth country in which it is possible to operate legally on 40 MHz. Ireland, Slovenia & South Africa already have allocations on the band while Lithuania is willing to allocate spot frequencies for experimental purposes.
The frequency allocation that 9A6W has obtained is from 40.660 MHz to 40.700 MHz. This 40 kHz wide slice of spectrum is referred to the Industrial, Scientific & Medical (ISM) band.
There are a number of ISM bands but this is the one nearest to 40 MHz. In many countries, much of the low band VHF spectrum is allocated to military or other services. Licensing authorities may be unwilling to grant radio amateurs an allocation that hasn't been agreed internationally.
The ISM band at 40 MHz is an exception and it might be a good way for other countries to proceed i.e. individual licenses in the ISM band.
Range... As the map shows above, 9A6W is at an ideal distance for Sporadic-E openings to Ireland and Lithuania. As the most southerly 8-metre station in Europe, there is a possibility of some TEP openings to South Africa or perhaps via F2 near the peak of sunspot cycle 25.
The distance to Slovenia is about 200 kms which might be spanned by tropo or even meteor scatter during the major showers.
The map above shows the FT8 signals that I heard on 28 MHz on Tuesday the 1st of December 2020. As well as evidence of some Sporadic-E signals from around western Europe, there were plenty of F2 signals from southern Russia, SE Europe, South Africa, South America, the Caribbean and the USA.
The one unusual signal of note for me was BV6CC in Taiwan. I have heard Thailand, Indonesia and Australia on 28 MHz over the last few days but Taiwan is the most northerly of the 'eastern' F2 signals that I have heard for this new cycle.
We still have some way to go yet before we start hearing Japan and California on 28 MHz here in NW Europe.
The solar flux on the 1st of December 2020 was at 104, a big change from 12-months ago when it was down around the 70 mark at the bottom of the sunspot cycle.
