Showing posts with label 2 metres. Show all posts
Showing posts with label 2 metres. Show all posts

Tuesday, April 13, 2021

144 MHz beacon on the US Virgin Islands to investigate 6000km TEP path to South America


The 2m NP2X beacon is now operational from St.Croix in the US Virgin Islands and its primary purpose is to investigate the TEP (Trans-Equatorial Propagation) path to South America.

The beacon is on 144.291 MHz and sends its ID in CW. It runs 100-watts into a 15-element Yagi antenna. The beam heading is 170 degrees as the primary target area is Uruguay (CX), the south of Brazil (PY) and Argentina (LU).

The beam width of a 15-element is about 30 degrees i.e. +/-15 deg. The map above shows the direction for the main beam heading as well as the -3dB points. The photo below shows the antenna and the sea path to the coast of South America.


Details...
Location: St. Croix, US Virgin Islands
Elevation: 91 metres above sea level
Transceiver: Kenwood TR-751A
Amplifier: RF Concepts 160 watt, reduced to 100 watts for beacon operation
Antenna: 15 element Yagi @ beam heading (QTH) of 170 degrees (Uruguay)
Frequency: 144.291 MHz
Grid / Locator: FK77pr

Analysis...
This 144 MHz beacon is well placed to investigate the 6000km TEP path to Uruguay and Argentina considering its power, antenna and location. It's likely that the possible paths at 144 MHz will be perpendicular to the Geomagnetic Equator (Uruguay & Buenos Aires) and the paths at say the -3dB points of the beam width are less likely on 2m.

It's really important that stations in South America monitor the SSB and CW part of the 2m band for possible openings. If everyone sits on the FT8 frequency then many TEP openings may go unreported as digital signals like FT8 are often distorted by TEP.

If you are in South America and you do hear the beacon, please report it on the DX Cluster.

Thanks to Fred, NP2X for the above information.

Link...

Addendum:
Additional report from Colossi, PY3DU in Brazil.... "My 144 MHz TEP VHF in October 2011, with NP2X, happened exactly after my old friend @Rafael_Haag , PY3FF,listened to NP2X/B and warned me over the phone, to be listening to USA in two meters. I was having dinner, which I didn't finish.. KKKK..., there were several days of openings."



Saturday, March 13, 2021

Example of a 3600km+ opening on 144 MHz from Ireland to Russia - June 2020

I'm always interested to hear about exceptional VHF contacts or reception reports and I like to keep a record of them here on the blog to encourage more people to get active on the bands. I meant to put up this post months ago but it kind of got delayed! šŸ˜„

Back on the 16th of June 2020, there was a Sporadic-E opening on 144 MHz over eastern Europe with stations in the south of Russia working into Poland and the Czech Republic. What was really unusual was that it coincided with another opening further west from the UK & Ireland to the Czech Republic, Poland and Ukraine.


The map above shows the signals that were heard by Mark, EI3KD on the 2m FT8 frequency of 144.174 MHz

This is a log extract of what EI3KD heard...

20200616_060700 -21 0.3 866 ~ CQ UC6A KN84
20200616_060730 -15 0.3 865 ~ CQ UC6A KN84
20200616_061200 -11 0.5 705 ~ CQ SQ9IVD KN09
20200616_061330 -14 0.2 1397 ~ EI3KD UX2SB -18
20200616_061330 -12 0.1 724 ~ YO6OBK UW8SM KN28
20200616_065200 -5 0.3 1562 ~ OE5JFL RZ6DD -18
20200616_065400 -19 0.2 1126 ~ CQ OK1VOF JN89
20200616_065430 -11 0.4 1800 ~ US5FZ RA6C -12
20200616_065430 -20 0.2 1126 ~ CQ OK1VOF JN89
20200616_065800 -22 0.0 1486 ~ CQ RX6DN KN94
20200616_065930 -26 0.1 1485 ~ EI3KD RX6DN R-07
20200616_070330 -11 0.3 1088 ~ CQ 9A2RI JN65
20200616_070400 -7 0.3 1089 ~ CQ 9A2RI JN65
20200616_070430 -22 0.2 1090 ~ CQ 9A2RI JN65


The normal maximum distance for single hop Sporadic-E is in the region of 2300 kms. What is highly unusual here is that EI3KD heard four stations in the south of Russia which were in the region of 3500kms!

The longest distance was RZ6DD at 3638kms.

The propagation mode was double hop Sporadic-E and this is clear from the fact that stations at the mid-way point were being heard as well. What's not so clear is if the signal was reflected off the ground at the half-way point or if it was chordal hop with the signal going between two Sp-E clouds without touching the ground. Whatever it was, it's an exceptional distance for 144 MHz.

This is an extract from DXMaps showing the DX-Cluster reports on that day on 144 MHz which were over 2500kms...


First a word of caution! As we all know, some mistakes occur with DX spots with people putting in the wrong band or info data. However, there are enough reports there to show that something special was going on that day.

You'll note that G4RRA in the SW of England also heard RZ6DD but at the slightly lower distance of 3356kms. See addendum below.

Why does this matter?... Because if someone in Ireland can hear a station in Russia on 144 MHz who is 3600+ kms to the east then why not across the North Atlantic to Newfoundland which is even closer at 3200kms?


Surely even if the chance of double hop Sporadic-E over the North Atlantic is incredibly small, there must be times when there are single hop Sporadic-E openings from either side with 1000kms of tropo making up the difference?

Wouldn't it be interesting to have a permanent online receiver based in Newfoundland with a beam pointing east and listening all of the time on 144 MHz? Stations in western Europe could then beam west and listen for their own signals online to see if the path is open. Or people could just log in and check if the receiver is hearing one of the Trans-Atlantic beacons?

At the moment, the North Atlantic path could open up on 144 MHz and nobody will ever know because there is no-one listening at the Canadian end.

Addendum: Thanks to Paul G4RRA for the following info...


Here's how my screen looked during that event. Both Mark and I are always looking out for events like this which are very rare indeed in my experience.


This was only the second one I've participated in in over 40 years, at least I managed a QSO in the first one !


R6DB also mentioned seeing me on KST chat.  ...de Paul, G4RRA

Thursday, March 11, 2021

144 MHz beacon on St Helena heard 7000kms away in France by TEP - is it real?

Back in February of 2021, I had a post up about the new 144 MHz on St Helena Island in the South Atlantic. On the 3rd of March, I reported that the beacon had been heard over 3000kms away in South Africa.

Now just two days later, F0FYF in France claims to have heard it.

* * *

13th March 2021... Note that the recording from France does not match the recordings from South Africa.

For updates, scroll down to the end of this post.

* * *


The path is almost 7000 kms! If confirmed then it looks likely that the propagation mode was via Trans-Equatorial Propagation (TEP) from St Helena Island to the north coast of Africa and then via tropo across the Mediterranean.

An audio recording from F0FYF can be heard below...

Check out the audio of the beacon here...

The D7GWM/B in CW can be clearly heard. The beacons locator is IH74DB.

In a post on his website, F0FYF wrote..."The other day, I was touring the audible beacons from my house on a VHF. The spread appeared to be good especially to the south / southwest. The Pic Neulos arrived in excellent conditions on 144.4765 Mhz, even CN8LI was audible at times, with great difficulty but the LNA was there to help. I used for these receptions, a stack of 2 x 9 elements at 7m from the ground on a temporary pylon (the neighbors cannot stand the sight of metal and their nausea and headaches happen, as if by chance, as soon as I mount my pylon, even not connected ^^, in short ..)

During my little tour, I stopped on 144.47535 Mhz after hearing some very delicate pieces of walrus to decode. The antennas pointed at 200 ° and as soon as I turned more than 5 ° in one direction or the other, the signal disappeared. Surely a reflection on a massif. 200 ° de chez moi passes just between the Semnoz massif and Le Mont du Chat. I am still at 700m with a fairly clear view from my home. I started the recording and I was able to recover some bridles but I couldn't get it correctly. Another OM that I had warned could hear absolutely nothing from his position. I went around MMMonVHF , my reference for beacons, to try to know its origin but I haven't found anything yet. The beacon disappeared around 11 p.m."

Some points here...

1) The ZD7GWM beacon is on 144.475 MHz so the frequency is correct.

2) The beam heading for F0FYF to St Helena is 193 degrees which is close to the 200 degree beam heading that F0FYF used.

3) The beacon was heard between 19:45 and 22:50. The recording was taken at 20:47. The time is in the late evening which matches some TEP propagation.

4) There are recent reports of 144 TEP on the DX cluster from the Caribbean to Brazil & Argentina. This suggests that it might be possible for the ZD7 beacon to be heard in Europe.

This is the second recording...

This one has 'E W M T'  & '7 E' in cw so I am not sure what that is??? Someone suggested that it might 'G W M /' with the start and finish cut off. If it is, the level of fading seems very sharp and severe.

It would be great if more people in southern Europe could listen for this beacon on 145.475 MHz. If it is TEP as expected then it should be heard again in the late evening.

Like any good science experiment, we need more data points!

Link...

1) F0FYF website

* * *

Update 1 of 2... 10th March 2021: There seems to be a difference between what the beacon really sounds like in South Africa and what was heard in France. This casts some doubt as to whether it was really the St Helena beacon. More to follow...

* * *

I was sent recordings of what the beacon sounded like when it was on the bench under test and what it sounded like as recorded by V51DK in Namibia.

I fed these audio clips and the one from F0FYF into the Spectrum Lab audio programme and this is what I found.

The three recordings are shown above. The dotted vertical line is a 2-second mark.

1) Callsign Length: The recording by ZS1NAZ when the beacon was on the bench is shown in the centre and this is essentially the reference. The callsign 'ZD7GWM/B' in morse as recorded by ZS1NAZ is 9 seconds long. The callsign as recorded by V51DK in Namibia over a 2250km path is also 9 seconds long. The callsign recorded by F0FYF is 10 seconds long.

2) Dash Length: If the letter 'M' is compared above, there is an obvious difference between the dash lengths. I measured the dot length from the ZS1NAZ recording to be roughly 220 milliseconds (mS), the dash length from the F0FYF recording was roughly 330 mS.

3) Dot Length: The dots in the ZS1NAZ recording are quite short. I measured them to be be roughly 65 mS. I measured the dots in the F0FYF recording to be roughly 130 mS.

4) Character Spacing: If you examine the F0FYF recording, the space between the letter 'M' and the character '/' is about equal to the length of a dash. In the ZS1NAZ recording, this is clearly different. 

I had wondered perhaps if the F0FYF recording was somehow changed to make it clearer, a bit like playing something at 80% speed to make it clearer. If this 10 second recording was reduced down to 9 seconds then the dashes and dots would get shorter as well. However, that wouldn't change the fact that spacing between characters seems longer in the ZS1NAZ recording.

I was sent recordings of what the beacon sounded like when it was on the bench under test and what it sounded like as recorded by V51DK in Namibia.

In conclusion, the signals as displayed above from the F0FYF and ZS1NAZ look different. To the ear, they sound different. The F0FYF recording as more of a T9 clean tone where as the ZS1NAZ recording sounding very different with the morse sounding more abrupt. As someone said to me..."The keying on this recording has a staccato nature".

The F0FYF reception recording was described to me as being probably a genuine reception of a non-genuine signal.

What really needs to happen now is for stations in countries like Spain, Portugal and the south of France to take their radios off the 2m FT8 frequency and listen for the ZD7GWM beacon on 144.475 MHz late in the evening. There are reports of 2m TEP in South America at the moment so there is no reason why it shouldn't be happening on this side of the Atlantic.

* * *

Update 2 of 2... 13th March 2021: Jeff, F0FYF has very kindly uploaded the full recording of what he heard. The full recording is nearly 2 hours long.

* * *

See below...

Wednesday, February 24, 2021

Twitter poll suggests that one-third of those using FT8 on 144 MHz are using vertical polarization

How it all started... After listening for FT8 signals on 144 MHz for a few days, I was suprised to hear some signals that were well over 500 kms away. 

Considering I was using just a basic vertical Slim Jim half-wave antenna in the attic, I began wondering if everyone was really using horizontal polaziation as I had expected?

I began thinking about it and I came to the conclusion that even though FT8 is a weak signal mode on SSB and horizontal polarization is the norm, there must be some stations using just a simple 'white stick' dual band vertical up on their roof. 

After all, if you have limited space or you're active on many different bands, you may not be interested in getting a dedicated horizontal antenna for 144 MHz.

The Poll... I thought it might be interesting to see just how many people are using vertical polarization on 2m FT8 so I contacted Tim, GW4VXE who writes for several amateur radio publications and has over 4000 followers on Twitter.

I suggested to Tim that it might be interesting to put a poll up on Twitter just out of interest. Tim duly obliged and put the following poll up on Twitter for about a week.

Tim asked his followers if they used exclusively horizontal or vertical polarization or if they sometimes used either for FT8 on 2-metres.


Results... A total of 76 people voted and the results were...

Horizontal Polarization - 55.3%
Vertical Polarization
- 32.9% and 
Both Vertical & Horizontal - 11.8%

There are a few caveats with the results...

1) The sample size was 76. It's not huge but I think it's still enough to give a good indication.

2) The poll was just on Twitter. Whether having the poll on Facebook or some other platform would make a difference, I don't know.

3) As Tim writes for UK based radio magazines, I would assume most of his followers are from the UK as well. Would the answer be the same in Germany, elsewhere in Europe or the USA?

In Conclusion... I think the poll results show that there are a lot more people using vertical polarization on FT8 on 144 MHz than might be expected. 

If you have a radio with 2m SSB on it then try tuning to 144.174 MHz when there is high pressure about and have a listen on FT8, you might be pleasantly suprised.

Credits: My thanks to Tim, GW4VXE for conducting the poll. You can find Tim on Twitter here... https://twitter.com/gw4vxe

Saturday, February 20, 2021

TEP contact on 144 MHz between 3A2LU and V51E - 1990-1991

At the end of 2020, I had some posts up on the blog about some remarkable 144 MHz contacts between Argentina and the Caribbean via Trans-Equatorial Propagation (TEP). Many of the contacts were in the region of 5000 kms.

The post sparked some discussion and someone mentioned a TEP contact on 144 MHz between 3A2LU in Monaco and V51E in Namibia which had taken place in the early 90's.


The path is shown above and is in the region of 7162 kms, a really impressive distance for 144 MHz.

This contact was made in pre-internet days but from what I can tell from doing a search, 3A2LU in Monaco was running 150 watts into a 15-element Yagi. Amazingly, V51E in Namibia was using an antenna for the 160m band!


The contact which was via CW would have taken place close to the peak of solar cycle 22 so conditions must have been really good.

If anyone has any additional information about this contact then please let me know.

For examples of other long distance contacts on 144 MHz, visit my 144 MHz page.

Tuesday, December 15, 2020

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?

Wednesday, October 21, 2020

TEP openings on 144 MHz between Brazil and the Caribbean - Oct 2020

 


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.

TEP propagation normally peaks around the equinox and there have been some interesting contacts made recently between the south of Brazil and stations in the Caribbean.


One such example was a recent contact on 144 MHz between FG8OJ in Guadeloupe and PY2PAL in Brazil. On the map above, the position of the actual equator is shown in Blue while the Geomagnetic Equator is shown in Red.

You can hear the SSB contact on 144.299 MHz below...

Note the curious warble on the signal. The distance was 4455 kms which is pretty impressive for 2-metres.

Thursday, July 16, 2020

Unusual Sporadic-E opening on 144 MHz in N Europe hints at possibility of Trans-Atlantic contact

In this post, we'll look at a recent Sporadic-E opening on 144 MHz in northern Europe and what it might mean for a trans-Atlantic contact on 2 metres.

First, the opening...


There was an extensive opening on 144 MHz on the evening of Monday the 13th of July 2020 as can be seen from the graphic above from DXMAPS.COM

Sporadic-E openings on 144 MHz are reasonably common in Europe but they are usually much further south. Radio amateurs in say the UK or Ireland are likely to catch several openings to say Spain or Italy during the months of May, June and July every year.

It is very unusual to have a Sporadic-E in northern Europe and it is rare for the radio amateurs in the UK or Ireland to hear the likes of Finland or the Baltic states on 144 MHz via Sporadic-E.

While the graphic above gives an illustration of the extent of the opening, let's have a look at some specific examples. The maps below generated by FT8 reports on the PSKReporter website are useful for examining the extent of the opening.

EI2FG on the south coast of Ireland was one of the most westerly stations listening on the FT8 frequency on 144 MHz for the opening.


The longest path was to UA1ALD at 2416 kms and the signal was +9dB which was certainly strong enough for an SSB contact. Note the beam heading... 55 degrees. OH6KTL was up at 44 degrees.

Note also that the path was open only to the northern part of Estonia, there was nothing further south.

UA1ALD... This is the FT8 sent/receive map for UA1ALD.


Note how concentrated the footprint is in the UK. There is no-one from the south-east of England shown.

ES4RM... Note how the results for ES4RM in the north of Estonia are pretty much the same with nothing from the south-east of England.


OH2FQV... This is the map for OH2FQV in the south-east of Finland.


Note the difference in the footprint in the UK compared to UA1ALD. This time, there are a lot more stations in the south-east of England except for an area south of London.

This suggests that the Sporadic-E cloud responsible for the 144 MHz opening was probably somewhere over the north of Denmark. What each station worked or heard was dependent on where they were relative to this Sporadic-E hot spot.

It's also amazing to see just how many stations in England are using FT8 on 144 MHz!

GI6ATZ... This is the map from GI6ATZ in the north-east of Ireland.


The more northerly location of GI6ATZ results in stations in Lithuania and Latvia being heard.

G7RAU... The send/receive map for G7RAU in the south-west corner of England shows that there was a 2445 km path open to OH6CT in the north of Finland, just three degrees or so south of the Arctic Circle.


Again, note the beam heading from G7RAU to OH6CT which was 35 degrees. The signal was -2dB which would have been enough for a CW contact.

OH6CT... From OH6CT's viewpoint, he was hearing the south-east of England this time and the rest of the UK and Ireland was missing.


Trans-Atlantic on 144 MHz??? .....First of all, lets recap.

a) Both G7RAU and EI2FG heard or were heard by stations on FT8 in Finland at beam headings of 35 and 44 degrees respectively i.e. very far to the north.

b) Both G7RAU and EI2FG heard or were heard at -2dB and +9dB respectively at a distance of about 2400 kms. Note that this is about the maximum distance for one hop Sporadic-E.

Now lets look at the path from St.John's in Newfoundland to the south-west of Ireland and the north-west of Spain.


First off, the beam headings of 68 and 80 degrees are a lot further south than the beam headings experienced by EI2FG and G7RAU. If there is a Sporadic-E opening on 144 MHz in the north of Europe then why wouldn't it also happen out over the North Atlantic?

I know some might argue that Newfoundland is closer to the geomagnetic pole and that might impact on Sporadic-E formation but Newfoundland is also further south than Ireland.

While the one hop of 2400 kms ends up in the Atlantic, the remaining distance to span isn't huge. Just another 800 kms or so would reach the south-west of Ireland. Just another 1000 kms would reach Spain. Both of these distances could be easily bridged by a tropo duct forming over the ocean to the west of Ireland or Spain.

Surely there must be times when there are Sporadic-E openings on 144 MHz to the east of Newfoundland? And there must be times when these openings coincide with tropo over the eastern part of the Atlantic? I would argue that there must be times when the path across the North Atlantic on 144 MHz is open although I would acknowledge that these openings are pretty rare.

I'd suggest that one of the biggest problems is the lack of activity on the western end. I don't believe there is anyone in Newfoundland transmitting or listening on 2-metres for signals across the Atlantic. For all we know, some of the trans-Atlantic CW beacons in Ireland, England or France may well have made it across the ocean to Newfoundland but there was nobody there listening to report it.

Look at the distance from Newfoundland to the Azores (CU). That's within Sporadic-E or meteor scatter distance and yet as far as I am aware, there has never been a contact on 144 MHz from Newfoundland to the Azores.

Solution... The most obvious one to me is the establishment of a station on Newfoundland that can be operated remotely, just like D4VHF on the Cape Verde Islands. Something like two stacked 5-element Yagi antennas beaming at 70 degrees with 100 watts?

Digital modes like FT8 could be used to see if the path was viable by transmitting and receiving on the 2-metre frequency of 144.174 MHz.

It is of course easy to say how it might happen, it's another thing for a group to implement it.

Friday, July 3, 2020

5000km plus opening on 144 MHz from Cape Verde Islands to Italy, Slovenia & Croatia - 2nd July 2020


On Thursday the 2nd of July 2020, there was another remarkable opening on 144 MHz between Cape Verde Islands off the west coast of Africa and Italy, Slovenia & Croatia.

This isn't the first time that this has happened but any terrestrial opening on 144 MHz which reaches 5000kms or more is always special.


This edited list shows the stations that heard by D4VHF in Cape Verde. It also lists those hearing D4VHF on FT8 but not weren't heard by them (in order of distance)...

Txmtr Rcvr Band Mode Distance Time (UTC)
D4VHF S51ZO 2m FT8 5028 km 19:09:59
9A5BWW D4VHF 2m FT8 5013 km 19:02:42
D4VHF 9A6NA 2m FT8 5013 km 18:51:56
D4VHF S50TA 2m FT8 4885 km 19:17:44
D4VHF S57A 2m FT8 4809 km 18:41:59
D4VHF IV3/HB9CAT 2m FT8 4798 km 18:27:59
D4VHF IV3GTH 2m FT8 4792 km 18:41:56
9A5CW D4VHF 2m FT8 4790 km 19:17:57
D4VHF IV3GBO 2m FT8 4786 km 19:11:44
9A3CX D4VHF 2m FT8 4776 km 19:03:12
D4VHF IV3BLQ 2m FT8 4776 km 19:17:41
D4VHF 9A5CW 2m FT8 4774 km 19:17:14
D4VHF 9A3K 2m FT8 4774 km 19:15:44
D4VHF 9A1UN 2m FT8 4766 km 19:04:29
9A2RD D4VHF 2m FT8 4766 km 19:01:41
IK3VZO D4VHF 2m FT8 4643 km 18:35:12
D4VHF IW3GJF 2m FT8 4639 km 18:35:29
IZ3NOC D4VHF 2m FT8 4636 km 18:32:11
D4VHF IK4DRY 2m FT8 4624 km 18:59:29
D4VHF IK4FMT 2m FT8 4596 km 18:59:26
D4VHF IW4AZY 2m FT8 4548 km 19:11:15
D4VHF IK2MKS 2m FT8 4528 km 15:51:44
IK2LHP D4VHF 2m FT8 4517 km 15:57:56
IK0SMG D4VHF 2m FT8 4506 km 16:44:56
D4VHF IW0FFK 2m FT8 4505 km 16:46:44
D4VHF IZ2MHO 2m FT8 4480 km 15:52:11
D4VHF G7RAU 2m FT8 4086 km 16:02:14

FT8 screenshot from D4VHF
This is a list of the 20 stations in Italy, Slovenia & Croatia that D4VHF actually completed a contact with on FT8...

2020-07-02 15:49:15 IZ2MHO JN45 144.175900 FT8 +03,-06 
2020-07-02 16:30:30 IK0SMG JN61 144.175900 FT8 -03 -11 
2020-07-02 18:25:00 IK3VZO JN55 144.174900 FT8 -19 -01 
2020-07-02 18:28:00 S50TA 144.174900 FT8 +08 +01 
2020-07-02 18:28:30 IZ3NOC 144.174900 FT8 -03 -12 
2020-07-02 18:33:00 IV3NDC 144.174900 FT8 -06 -06 
2020-07-02 18:34:30 IW3GJF 144.174900 FT8 -12 -06 
2020-07-02 18:36:45 IV3GTH JN65 144.174900 FT8 -17 -11 
2020-07-02 18:37:45 IZ3QFG 144.174900 FT8 -05 
2020-07-02 18:42:30 S57A JN65 144.174900 FT8 +02 -06 
2020-07-02 18:44:00 IK4FMT JN54,144.174900 FT8 -15 -21 
2020-07-02 18:46:45 IK4DRY 144.174900 FT8 -11 -07 
2020-07-02 18:52:00 9A3CX JN65 144.174900 FT8 +00 -01 
2020-07-02 18:57:30 9A3K JN65 144.174900 FT8 +05 +01 
2020-07-02 18:58:15 9A6NA JN86 144.174900 FT8 -12 -19 
2020-07-02 19:02:00 9A2RD JN65 144.174900 FT8 +13 -09 
2020-07-02 19:02:45 9A5BWW JN86,144.174900 FT8 -05 -16 
2020-07-02 19:04:30 9A1UN JN65 144.174900 FT8 -10 -07 
2020-07-02 19:05:45 IV3GBO JN66 144.174900 FT8 +17 -07 
2020-07-02 19:12:30 9A5CW JN65 144.174900 FT8 -06 -13 

Another screenshot from D4VHF
Mode of Propagation... How exactly did these 5000km signals travel so far on 144 MHz? It seems likely that it was via a combination of a marine duct from Cape Verde up as far as Morocco and via Sporadic-E from there to Italy.


The tropo prediction map from Pascal, F5LEN shows some tropo in the Mediterranean Sea so that can't be discounted either. However, there must surely been at least one Sporadic-E hop in there somewhere.

Full D4VHF log including the EA & EA8 stations shown below...

Wednesday, May 6, 2020

VHF & UHF Trans-Atlantic path between Cape Verde Islands and the Caribbean opens up - May 2020

Back in early April of 2020, there was an amazing opening on the 144 MHz and 432 MHz bands across the Atlantic from Cape Verde Islands to the Caribbean.

............

On the 5th of May 2020, the trans-Atlantic path opened again...


These are some of the FT8 reports for D4VHF on the PSKReporter website...

Txmtr Rcvr Band Mode Distance Time (UTC)
FM5CS D4VHF 2m FT8 3861 km 22:40:26 (Martinique)
KP4EIT D4VHF 2m FT8 4393 km 22:28:58 (Puerto Rico)
D4VHF FG8OJ 2m FT8 3867 km 13:00:44 (Guadeloupe)
D4VHF J69DS 2m FT8 3865 km 12:30:14 (St.Lucia)
FM5CS D4VHF 2m FT8 3861 km 11:56:26 (Martinique)
D4VHF 9Y4D 2m FT8 4006 km 04:34:14 (Trinidad)
9Y4D D4VHF 2m FT8 4006 km 04:12:56
D4VHF FM0LU 2m FT8 3867 km 02:28:14 (Martinique)
FM0LU D4VHF 2m FT8 3864 km 01:35:56 (Martinique)


QSO between D4VHF and J69DS...

Thursday, June 20, 2019

Historic Trans-Atlantic Contact made on 144 MHz from Cape Verde to Guadeloupe


A historic contact was made on Sunday the 16th June 2019 when the Atlantic was spanned for the first time on 144 MHz.

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. The distance was an incredible 3,867 kms.

To put that into context, the distance from the west coast of Ireland to Newfoundland is 3,000 kms.

See Updates Below

The map below shows the tropo prediction from F5LEN and it shows a path right across the Atlantic.


The mode of propagation was most likely marine ducting with the signal traveling in a layer near the ocean surface.

This is a screenshot from FG8OJ of the historic contact made on FT8...


D41CV was using 500 watts into stacked dipoles while FG8OJ was running 100 watts into a 14 element Yagi with a 3.7m boom.

This is the FT8 signal from D41CV as heard by FG8OJ in Guadeloupe...



D41CV later worked FG4ST who was slightly further away at 3,911 kms. This contact was even more amazing as this station in Guadeloupe was running just 50 watts into a simple vertical on FT8.

FT8 Screenshots from FG8OJ
Now that this historic contact has been made, more 144 MHz contacts across this part of the Atlantic are sure to follow.

Update : Sunday 23rd June 09:20 UTC... The 144 MHz trans-Atlantic opening seems to have come to an end although there is a hint it may open again for a day or two? The two metre opening lasted for the best part of five days, starting on Sunday the 16th of June 2019 and finally closing some time on the early hours of Friday the 22nd of June.

These are the trans-Atlantic spots on the DX cluster from the last few days...



Update : Saturday 22nd June 13:30 UTC... The number of spots have greatly reduced.

This is the log from the PSK Reporter website of the stations hearing and being heard by D41CV on FT8 on 144 MHz in the last 24 hours... one on the afternoon of the 21st and two in the early hours of the 22nd.




Update : Friday 21st June 08:30 UTC... It looks as if there has been a large cloud of dust from the Sahara blowing across the Atlantic for the last week. Is there a link?

"Large amounts of dust create a stable layer of dry, sinking air, which can suppress hurricane development." from NOAA. Link....  https://www.nesdis.noaa.gov/content/plume-saharan-dust-envelops-republic-cabo-verde

This is the log from the PSK Reporter website of the stations hearing and being heard by D41CV on FT8 on 144 MHz in the last 12 hours...



Update : Thurs 20th June 23:20 UTC... Incredibly the path on 144 MHz from Cape Verde Islands to the Caribbean is still open. D41CV completed an FT8 contact with J69DS in St. Lucia during the day.

This is a screenshot from the PSK Reporter website of the stations hearing and being heard by D41CV on FT8 on 144 MHz in the last 12 hours...


This is a log of the stations in the last 12 hours...


Update : Thurs 20th June 2019 14:20 UTC... D41CV has now worked 9Y4D in Trinadad on 144 MHz with FT8...


9Y4D was running 100 watts and a 7 element.

The screenshot below from the PSKReporter website shows part of  the send/receive map for D41CV on 144 MHz (12 hour window as of 10:00 UTC 20th June 2019). It clearly shows that the trans-Atlantic is still open after several days with 9Y4D in Trinidad being one of the latest contacts.


CW QSO.... The Cape Verde team now have a Yagi up and running and are using the call D4Z on CW. FG8OG managed to work them on CW for a trans-Atlantic first on that mode on 144 MHz...








Update : Wed 19th June 2019 20:45 UTC... This map shows the stations that have seen or heard D41CV on 144 MHz FT8 in the last 24 hours...


The orange dots on the list indicate those that have heard D41CV. It looks as if this trans-Atlantic path has been there for the best part of 48 hours.

D41CV completes on FT8 with KP4EIT at 4.392 kms and NP4BM at 4,460 kms.

Update : Tues 18th June... D41CV has now worked WP4G in Puerto Rico on FT8. WP4G was using 4 x 12 el array. This is a distance of 4,358 kms!

D41CV working WP4G on FT8 on 2 metres
D41CV has also completed with FG4ST in Guadeloupe. Signal -20. 3,911 kms.

D41CV has completed with FM5AN in Martinique. Distance 3872 kms. FM5AN was using 50w into a 9 el DK7ZB yagi.

Brendan Trophies... Now that the Atlantic has been crossed on two metres, a question was asked if it qualifies for the Brendan Trophies from the IRTS.

As can be seen from the rules, they are for contacts from Europe.

"The Brendan Trophies and Brendan Shields will be presented to each of the operators of the two amateur radio stations which first establish two-way communication in the relevant category between the continents of Europe and America (North or South) within the Two Metre Amateur Band. "

Links...
1) FG8OJ on Twitter
2) D4C team on Twitter
3) D4C on Facebook