D4VHF on Cape Verde plans to be on the 70 MHz band during the Summer of 2021

The D4VHF team on Cape Verde Islands have just announced that they plan to be operational on the 70 MHz (4-metre) band during the Summer of 2021!

They will be using a 4-element Yagi (shown above) beaming towards Europe with an output power of 500-watts.

As the map shows below, the Cape Verde Islands are a long way from Europe and some multi-hop propagation will likely be required.

Analysis... The annual Sporadic-E season in the northern hemisphere normally starts in late April and runs until mid-August. 

It's likely that the first Sp-E openings from Cape Verde will be single hop with a maximum range of 2300kms or so. Stations in the Canary Islands (EA8) at 1500kms or so are ideally placed for a one-hop Sporadic-E opening on 70 MHz.

To get further up and into Europe, it will likely require a double hop opening with ranges of say 2500 to 4400 kms. This should allow stations in the UK and Ireland to work Cape Verde on 4m.

Obviously the more hops that are required for a path to open then there are statistically fewer openings. However, 70 MHz isn't that high a frequency when it comes to Sporadic-E and there should be occasions when even three hops or even four hops are possible. I suspect though that multi-hop openings like this to say central or northern Europe may only occur once per season? We'll see.

Tropo Ducting at 70 MHz???... The D4VHF station on Cape Verde has made many spectacular contacts on 144 MHz and 432 MHz thanks to a marine duct off the north-west coast of Africa.

This marine duct establishes itself for long periods at different times of the year and this allows stations on the coast of Spain and Portugal to work D4VHF on 2m with relative ease over a 3000km or so path. At times, this duct moves further north allowing stations in the UK and Ireland to get in on the action.

This duct behaves like a waveguide and it has certain dimensions. As such, like a waveguide it will have a lower cut off frequency below which signals will not propagate.

The big question is if 70 MHz signals with a wavelength of four metres will be able to propagate through this marine duct?

Will the 70 MHz signals from D4VHF be able to reach the Canary Islands (~1500kms) by tropo ducting? The south-west coast of Spain and Portugal at 2800kms? Will the frequency be too low?

If the marine duct does propagate 70 MHz signals then there is the possibility of it coupling to Sporadic-E openings more often. If not then it looks as if rarer double hop Sp-E might be the only option.

In conclusion... I'm sure many fans of the 70 MHz band will look forward to D4VHF from Cape Verde appearing on the band during the summer of 2021. Single hop and even double hop Sporadic-E contacts I believe are a forgone conclusion and these shouldn't be that difficult.

What I find most interesting however is the ability of a 70 MHz signal to propagate inside a marine duct. Is it possible? If it does happen, is it common? And how far?

It'll be interesting to see the results.

Opening to North America on 28 MHz - Tues 5th Jan 2021

 

Tuesday the 5th of January 2021 was a bit of a strange day on 10-metres. During the morning, there were hardly any signals from the East or South. In the afternoon, there was a nice opening to North America.

The Solar Flux on the day was just 75 which might suggest that East-West F2 propagation was unlikely but as the map shows, you can never be sure.

New 2380km record on 2.4 GHz between Australia and New Zealand

 

The Tasman Sea is an area where there are regular tropospheric ducting openings between Australia and New Zealand. On the 13th of December 2020, Hayden VK7HH and Richard VK7ZBX portable on an elevated location in Tasmania made successful SSB contacts with Nick ZL1IU in New Zealand on 144 MHz, 432 MHz and 1296 MHz.

As the tropo prediction map from F5LEN suggested, the 2380 km path from New Zealand to Tasmania was indeed open.

The really amazing contact however came at 05:58 UTC when there was a successful contact between VK7HH and ZL1IU on 2.4 GHz!

The contact was completed by using CW (morse code) as the signals were too weak for a SSB (voice) contact.

This 2380 km contact was a new Australian tropo record for 2.4 GHz breaking the previous record between VK4OX and ZL1AVZ by some 60kms.

27th Jan 2011 - 2317.5kms - VK4OX  - ZL1AVZ

A video of the contact is shown below. It starts at where the 2.4 GHz contact takes place although you can of course go back to the start to see the site location in Tasmania and the contacts on the lower VHF bands.

If you look at the video at 9:45, you can see that they managed to complete a contact on 144 MHz SSB with just one-watt which gives an indication of just how good the conditions were.

It was also nice to see that in a digital age, CW still has a place for very weak signal contacts!

Other paths???... Obviously the one constraint with making contacts on 2.4 GHz are the low number of stations on the band. This limits experiments with other sea paths which might show some suprising results.

The one that springs to mind for me is the sea path from Ireland/UK down to the Canary Islands.

Back in July of 2020, EI2FG and EA8CXN managed to complete a  successful contact on 1296 MHz over a 2714 km path.

What about 2.4 GHz?

As far as I can see, the current IARU Region-1 record on 2.4 GHz is between Malta and Israel.

Band Propagation Call a Loc Call b Loc Mode Date Distance
2,32 GHz TR 9H1GB JM75FU 4X1RF KM72LS CW 2018-07-22 1914 kms

Time for a new 2.4 GHz record in IARU Region-1???

Links...

1) IARU Region-1 records for 2.4 GHz

2) Australian VHF, UHF & Microwave records

Traffic to the EI7GL blog doubles in 2020

Now that we're into the new year of 2021, I decided to look back at some of the traffic stats for this blog for 2020. This is the average number of pageviews per month for the years 2018, 2019 & 2020...

Back in 2018, the blog used to get an average of 3,561 pageviews per month which is a reasonable amount for such a niche subject as amateur radio. In 2019, that had more than doubled to 8,475 pageviews per month.

As you can see from the chart above, I split 2020 up into two data points. 

In April of 2020, I had one post on the blog about the first trans-Atlantic contact on 432 MHz between Cape Verde Islands and the Caribbean. This story was picked up by the Hackaday website which reported on it and linked back to my blog. The result was a huge jump in traffic with that particular post getting over 54,000 pageviews in just a few days!

With the traffic from April 2020 included, the site got an average of 17,589 pageviews per month. If April 2020 is removed then the average for the other 11-months of 2020 was 12,669 pageviews per month which is a 50% increase on 2019.

Most Popular Posts... The most popular posts tend to be the ones where I report on unusual long distance contacts on the VHF bands. Quiet often, I stumble across news of these contacts on websites, forums, Facebook and Twitter and they might be just a comment left somewhere or just a bit of simple text. Sometimes, they hardly get noticed and can often go largely unreported.

I try to collect as much information as I can, generate maps and graphics and put the significance of the contact into context in a blog post. My posts are often picked up then by other amateur radio news outlets and a lot more people can find out about unusual VHF contacts.

My reason for generating these reports on these VHF reports is twofold. Firstly, I hope that to get other radio amateurs interested in trying to make long distance VHF contacts themselves. Secondly, I think it's important to have a record of significant VHF contacts with as much information as possible so that people in future can refer back to it.

The advantage of the blog format is that all of the info is laid out there. Sometimes with Facebook or Twitter or forums, it's a bit like writing something on a Yellow Post-it note i.e. fine for the very short term but very hard to find it again.

Most Popular Page... The most popular page on the blog in 2020 turned out to be the 40 MHz page with over 5,100 pageviews!

I started the 40 MHz page back in June 2018 around the time that Irish radio amateurs got access to large parts of the low VHF spectrum. At the time, there was very little information about any activity around 40 MHz and anything that was there was scattered across the web.

I had considered putting up a blog or website just to promote 40 MHz activity but I likened this to building a shop out in the middle of a forest i.e. the website might look great but if it hardly gets any traffic then what's the point.

My reasoning was that it was better to have a smaller shop in a busy shopping centre (Shopping Mall for our American friends 😊) i.e. Have a dedicated page on this blog where it might get noticed by others who are visiting for other reasons.

It may not be the neatest but at least there is a lot of relevant information in one spot. The main reason it is there is that anyone that is interested in reading the 40 MHz posts will leave with a better understanding of what is happening on the band. In that context, having the 40 MHz page get over 5000 pageviews in a year is great.

Sources of Traffic... The chart below shows the breakdown of visitors.

It's good to see plenty of traffic from countries where English isn't their first language. 

Plans for 2021??... More of the same! What goes up on the blog is really a reflection of my own interest in radio. If I find it interesting, I write about it.

I have a long list of news items and subjects to get through so there is plenty more to come.

JTDX Digital Mode Software now supports 8-metre operation

JTDX is modified WSJT-X software that many radio amateurs use for the JT9, JT65, FT4 and FT8 digital modes.

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.

Although this is a small change, it is another welcome step in getting more activity on this new VHF band.

5-Element Yagi for 40 MHz (8-metres) by YU7EF

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)

* * *

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.

Sporadic-E opening on 28 MHz - 29th Dec 2020

 

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.

Switzerland to switch off its FM radio stations in 2022-2023

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

New DMR repeater EI7FXD now operational in Cork - Dec 2020

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.

Nice opening to Australia on 28 MHz... 22nd Dec 2020

 

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...

Txmtr Band Mode Distance Time (UTC)
VK3GYH 10m FT8 17467 km 09:27:59
VK3EW 10m FT8 17464 km 09:32:29
VK3PT 10m FT8 17461 km 09:21:29
VK3MH 10m FT8 17420 km 10:09:14
VK3BDX 10m FT8 17408 km 09:42:14
VK2QV 10m FT8 17406 km 10:10:14
VK3JA 10m FT8 17379 km 10:28:59
VK3FNJ 10m FT8 17274 km 09:14:00
VK5ST 10m FT8 16787 km 09:16:59
VK5IR 10m FT8 16784 km 09:16:59

The Solar Flux was at 80 which is pretty low.

Winter 2020 release of the QRSS Compendium 3rd Edition

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

40 MHz signals from Slovenia heard in Croatia - 20th Dec 2020

 

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

Australia heard on 28 MHz - 20th Dec 2020

 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.

Sun goes back to sleep - 18th Dec 2020

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.

3200km opening on 144 MHz in Australia - 15th Dec 2020

 

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.

Timestamp UTC   Call MHz SNR Drift Grid Pwr Reporter RGrid km az Mode
2020-12-15 10:36 VK2DVM 144.490519 -25 0 QF56og 10 VK6KXW OF87jr 3199 263 2 
2020-12-15 10:16 VK2IJM 144.490507 -8 0 QF56ni 10 VK6KXW OF87jr 3192 263 2

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.

It's also worth pointing out that the reports from the WSPRnet website say that the VK2 stations were running just 10 watts.

Tropo?... As the path cross the Great Australian Bight, it's always worth checking to see if that was a factor.

The forecast was for some weak tropo across the Bight but nothing special and it doesn't seem to extend inland.

VK6CPU in Perth was also heard by VK5AYD in Adelaide at around the same time over a distance of 2149 kms which was likely to be via Sporadic-E.

Timestamp UTC Call MHz    SNR Drift Grid Pwr Reporter RGrid km  az Mode
2020-12-15 10:56 VK6CPU 144.490510 -24  3   OF78wb 5  VK5AYD  PF97ja 2149 99  2 

It would seem as if double hop Sporadic-E was the most likely mode of propagation.

Update: Just to clarify that when I say double hop Sporadic-E, I am referring to two areas of ionisation that are capable of supporting 144 MHz propagation. The signal may well be chordal i.e. Ground to cloud to cloud to ground ... as opposed to reflecting off the ground at some mid way point.

Links...

1) More info about long distance openings on 144 MHz can be seen on my 144 Page... https://ei7gl.blogspot.com/p/144-mhz.html

144 MHz signal from the Faroe Islands heard 3000kms away in Bulgaria during Geminid Meteor Shower - Dec 2020

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.

It seems unlikely that any sort of tropo ducting played any part in this reception report.

Theory 3... Refection from the International Space Station??? It would seem as if the International Space Station (ISS) was above the horizon at the same time.

In response to my original theory that it was double hop meteor scatter, Alejandro LU8YD from Argentina writes... 

"My opinion is that the QSO analysis is not correct. You have to check the location of the ISS space station at the time of the QSO and you will see that it was crossing the path between stations LZ and OY. In my opinion it is a QSO by Spacecraft scatter and not by meteor scatter. Reflections of amateur radio signals by the ISS as a passive reflector has occurred before. Despite this, it must be considered an extraordinary QSO and achievement by LZ1KU and OY9JD for which I congratulate them.

Please send my regards and congratulations to Stamen and Jon

Kind regards Alejandro LU8YD"

After receiving Alejandro's message, I checked out the position of the ISS on the morning of the 14th of December.

The beam heading from the Faroe Islands to Bulgaria is 147 degrees. The time stamp on the MSK144 signal was 11:03 UTC.

It's not a perfect match but the ISS was certainly in the same general area of sky at the time. The ISS reached a maximum elevation of 10 degrees during that pass and it was probably around 4-5 degrees at 11:03 UTC.

This is the view of the pass from Bulgaria...

From the Bulgarian perspective with a higher pass, the time and beam heading seem closer aligned. The Faroe Islands are on a beam heading of 327 degrees from Bulgaria.

Considering the size of the ISS and the size of the reflective surface, it has to considered a strong contender for the reception report.

However, I still have some questions. What about doppler shift? Would the doppler shift have moved the signals outside the receive passband of the receiver? What impact does doppler have on a MSK144 signal and the ability to decode it?

Conclusion (Updated)... My original thinking was that it was probably double hop meteor scatter. After all, there must be occasions when two meteors trails just happen to line up in the correct position at the same time.

The fact that the International Space Station was in the same area of sky at the same time must make this the most likely reason although in retrospect, I don't think we can be absolutely certain but it does seem likely.

I'd be inclined to say 90:10 in favour of refection off the ISS as opposed to double hop MS but others may have different opinions.

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?

Remarkable 13,000 km opening on 6-metres between Australia and South America - 12th Dec 2020

At the moment, our colleagues in the southern hemisphere are in the middle of their summer Sporadic-E season and there are of course plenty of openings on the VHF bands.

On the 12th of December 2020, there was a remarkable opening on 6-metres between Australia and South America. For example, the map below from the PSK Reporter website shows the sent/received reports for VK3BD in the SE of Australia.

What is truly remarkable about this is the sheer distance and the path of the signals.

For many, the distance between the stations in Australia and the stations in Brazil, Bolivia and Paraguay was in excess of 13,000 kms! 

To put that into perspective for European readers, the distance from say the UK to Japan is about 9500 kms. Every year, there seems to be multi-hop Sporadic-E openings from Europe to Japan on 50 MHz which cause a lot of excitement. This opening from Australia to South America was significantly further.

The second interesting point was the path. In some instances, the Great Circle path crossed part of Antarctica with the most southerly path going as far as 78 degrees south. Again to put that into perspective for European readers, 78 degrees is about as far north as say the island of Svalbard to the north of Norway.

Far northern or far southern latitudes are not areas normally associated with Sporadic-E.

To get a view from the South American side, I took a screenshot of the map for CP6UA in Bolivia.

As the map shows, the stations in New Zealand (ZL) were also getting in on the action and the distance to them was an impressive 11,000 kms or so.

Mode of propagation???... The million dollar question. I presume it was multi-hop Sporadic-E but it was a lot of hops! One of the longest paths that I saw was between VK5BC and PT9FD, a distance of 13,530 kms.

VK5BC PT9FD 6m JT65 13530 km 22:17:50

The maximum distance for one Sporadic-E hop is about 2300 kms. Was it six hops of 2255 kms? Seven hops of 1933 kms? If it was multi-hop Sporadic-E then a lot of patches of Sporadic-E had to line up in a row and at the correct distance for it to work.

Addendum... Someone suggested that Polar Mesospheric Summer Echos (PMSE) with electrons gathering around ice crystals may have been responsible for this opening. I include it here for reference reference.

Contacts... I'm sure many contacts were made but the purpose of this post is just to highlight the fact that the opening occurred.

Looking at the PSK Reporter website, these were the stations that I saw listed...

Australia...

VK1JA

VK2ZQ

VK3OT, VK3BD, VK3DUT, VK3OER, VK3WE, VK3KU

VK5PW, VK5BC, VK5PJ, VK5RM

Brazil - PY5HOT, PT9FT, PY5KD, PY5EK

Paraguay - ZP5DPC, ZP4KFZ

Bolivia - CP6UA

Argentina - LW2DAF, LU3CQ, LU9DO

Chile - CE3SX, CA3SOC, XQ3MCC

Uruguay - CX6DRA

DX-Cluster... Here are a selection of spots from the DX-Cluster...

PT9FD 50276.0 VK3OT 22:19 12 Dec JT65A GG27OR <> QF12ag TU 73 Australia

PT9FD 50276.0 VK5BC 22:00 12 Dec JT65A gg27or PF95jj tks 73 Australia

CE3SX 50276.0 VK5PJ 22:00 12 Dec FF46<>PF95MK TU Peter Australia

CP6UA 50276.0 VK3DUT 21:35 12 Dec Thanks New One Norm. 73 Australia

PY4AQA 50276.0 VK4QG 22:18 10 Dec JT65A -24 dB Australia

VK3OER 50276 PT9FD 23:24 12 Dec 20 JT65 -25 CQ Brazil

VK3OT-@ 50277.3 PT9FD 22:18 12 Dec 20 QF12ag GG27 jt65 qso 73 Brazil

VK3OT-@ 50277 PT9FD 22:14 12 Dec 20 cq pt9fd gg27 jt65a -19 Brazil

VK3OT-@ 50277 PY5HOT 21:42 12 Dec 20 cq gg46 jt65a Brazil

VK3OT-@ 50279 PT9FD 21:34 12 Dec 20 jt65 cq -23 Brazil

VK3OT-@ 50277 ZP4KFX 20:55 12 Dec 20 wow thanks JT65A Paraguay

VK3OT-@ 50277 ZP5DBC 20:50 12 Dec 20 JT65A thanks -19 Paraguay

I also kept a record for some of the Australian stations logs of the signals that they heard from South America for this opening. PSK Reporter normally wipes all records after 24 hours so it's nice to have some record of the opening. See below...

Mid-Winter Sporadic-E opening on 28 MHz - Sun 13th Dec 2020

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.

Columbian radio station on 93.1 MHz heard 4580kms away in Chile by TEP - Nov 2020

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.

Links...
1) YouTube channel of Mauricio Toro.

28 MHz gets quieter as the Solar Flux drops - 11th Dec 2020

 

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.