432 MHz world tropo record extended even further to 4,644 kms - 1st Jan 2020

On Saturday the 28th of December 2019, Ian GM3SEK in the south-west of Scotland managed to work D41CV on 432 MHz to set a new world record for tropo on the band. The distance for this FT8 contact was an amazing 4,562 kms.

Considering the fact that it was on the 70cms band and that  the south-west coast of Scotland was one of the longest sea paths to Cape Verde Islands, it seemed as this might be a long term record.

It wasn't to be however as just a few days later on Wednesday the 1st of January 2020, Nick G4KUX in the county of Durham in the north of England managed to work D41CV also on FT8 on 432 MHz to push the record out a further 80kms or so to 4,644kms.

This is the screenshot of G4KUX having an FT8 contact with D41CV on 432 MHz.

Nick, G4KUX lives in an elevated location to the west of Bishop Auckland in County Durham in the north of England. His location is about 360 metres above sea level and he has a good take off for radio in all directions.

For the record breaking contact with D41CV, Nick was using 400 watts into a UHF Log-Periodic antenna as shown in the photo below. The suprising thing about this is that the gain of the Log-Periodic would be pretty modest and is probably no better than say a 3 or 4 element Yagi.

The gain of the Log is probably at least 10dB lower that say a box of four Yagi antennas like the ones Nick has for 144 MHz.

Mode of Propagation???... Looking at the path for the previous record contact on 432 MHz from Ian, GM3SEK in the SW of Scotland to D41CV on Cape Verde Islands then we can probably speculate that the mode of propagation was via a sea duct.

For G4KUX however, the signals had to cross over some hills and mountains in Wales and the north of England. Considering there were very good tropo conditions at the time across western Europe, it seems likely that there was an elevated duct for the most northerly part of the contact and this then coupled into a sea duct further south.

Record Limit... The map below shows the new limit of the 432 MHz tropo record.

Can the record be broken? Probably. We saw in 2019 several occasions during the year when a sea duct existed between Cape Verde Islands and the British and Irish Isles. If the only mode of propagation is via sea ducting then maybe the new record will be set from the western islands of Scotland.

What we saw in the last few days at the end of 2019 and the start of 2020 was the rarer occurrence of the sea ducting happening at the same time as an extensive tropo opening with elevated ducting. This will no doubt happen again but maybe not so often.

G4KUX contacts... This is a list of some contacts G4KUX made around the same time on FT8 on 432 MHz.

G4KUX IO94BP F6DBI IN88 FT8 -08 -15 20191229 105400  20191229 105500 70CM 432.174000  0
G4KUX IO94BP F5APQ JO00 FT8 -06 +03 20191231 153200  20191231 153400 70CM 432.174000  0
G4KUX IO94BP ON4QJ JO20 FT8 -12 -09 20191231 153500  20191231 153600 70CM 432.174000  0
G4KUX IO94BP F1ISM JN09 FT8 +03 +02 20191231 155300  20191231 155400 70CM 432.174000  0
G4KUX IO94BP ON4AOI JO21 FT8 -06 -14 20191231 160200  20191231 160400 70CM 432.174000  0 
G4KUX IO94BP F6KBF JN18 FT8 -03 -17 20191231 160500  20191231 160700 70CM 432.174000  0 
G4KUX IO94BP SP7CKH JO92 FT8 -13 -19 20200101 121100  20200101 121300 70CM 432.063000  0
G4KUX IO94BP SP2JYR JO92GP FT8 -15 -10 20200101 121400  20200101 121400 70CM 432.063000  0
G4KUX IO94BP DL1TRK JO63  FT8 -20 -14 20200101 121500  20200101 121500 70CM 432.063000  0 
G4KUX IO94BP HF1J JO73  FT8 -17 -21 20200101 151400  20200101 151700 70CM 432.063000  0 
G4KUX IO94BP DL1SUZ JO53 FT8 +00 +06 20200101 151700  20200101 151800 70CM 432.063000  0 
G4KUX IO94BP PH0TV JO32 FT8 -16 -11 20200101 152000  20200101 152100 70CM 432.063000  0 
G4KUX IO94BP D41CV HK76MU FT8 -15 -20 20200101 192900  20200101 201300 70CM 432.174000  0 

As you can see, Nick was able to work into France, Belgium, Poland, Germany and the Netherlands while there was high pressure and tropo ducting about.

All in all, an amazing week or so of propagation on the VHF and UHF bands.

Links...
a) F5LEN tropo forecasts

Remarkable start to the New Year with a new 144 MHz tropo record from Cape Verde Is to Western Scotland

Back in September of 2018, G3SMT in the west of England managed to work D4Z on the Cape Verde Islands on 144 MHz to set a new IARU Region-1 tropo record of 4,431kms.

On the 28th of December 2019, Ian, GM3SEK worked D41CV from the same location on the Cape Verde Islands to extend the 144 MHz tropo record to 4,565kms.

On the 1st of January 2020, the New Year was hardly a few hours old when Calum, GM0EWX on the Isle of Skye in the west of Scotland managed to work D41CV on FT8 on 144 MHz. This now extends the IARU Region-1 tropo record to an amazing 4,776kms.

For the contact, GM0EWX was using an IC7100 with 400 watts into two 15-element long Yagi's about 15 metres above ground level.

Calum kindly sent on screenshots of the FT8 contact and they are added to the end of this post.

Mode of Propagation... It's very likely that the bulk of the path was due to a sea duct extending from the west coast of Africa, up past Portugal and up to the British and Irish Isles.

Tropo forecast from F5LEN - 03:00 UTC 01-01-2020

You'll notice however from the first map that the most northerly part of the path crosses over the island of Ireland. It seems likely that there may well be an elevated duct for this part of the path and it is then coupling into the sea duct for the remainder of the journey.

New limit... As the tropo record extends north, the number of potential stations capable of breaking it reduces.

The one intriguing possibility is a tropo path from the Cape Verde Islands up to the Faroe Islands, a distance in excess of 5,000kms. Is it possible?

Just how far is the new record?... As outlined in previous posts, it's fine to be quoting numbers for new records but sometimes you need a map to put things into perspective.

If the record was say east-west over the North Atlantic, a signal from St.Johns in Newfoundland, Canada would reach this far into Europe...

...and a signal from the south-west of Ireland would reach this far into North America...

Addendum... Here are some screenshots of the FT8 QSO courtesy of Calum, GM0EWX.

4,400km opening between Cape Verde Islands and the City of London on 144 MHz - 30th Dec 2019

On the afternoon and evening of Monday the 30th of December 2019, there was another amazing tropo opening on 144 MHz from the Cape Verde Islands off the west coast of Africa to the UK.

On previous occasions, the openings have been mostly confined to the western parts of the UK where there is almost a complete sea path to the Cape Verde Islands. On the 30th of December however, the opening was further east.

The map above and below shows the stations that heard the FT8 signals from D41CV or were heard by D41CV.

As you can see below, the opening seems to have been confined to a narrow corridor and had to cross over Brittany in France and the north-west part of Spain.

In a separate tropo opening a few months back, only the most westerly French station on the Brittany peninsula managed to work D41CV as they could just about clear the Spanish coast for a complete sea path. On the 30th of December however, more French stations got in on the action.

The most amazing reports however were those from around London. Up until the 28th of December 2019, the IARU Region-1 tropo record for 144 MHz stood at 4,431kms.

Now look at the map above. The distance from D41CV to the stations in London is...
G7LRQ (4,436kms), M0HRF & M0ICR (4,427 kms) and G7LXP (4,435kms).

In terms of making a two way contact, I believe G4DCV, G7LRQ and M0ICR were successful. Others may have been as well but I don't have any further info.

Now consider this. The distance from London to St.John's in Newfoundland, Canada is 3,735kms. The signal from Cape Verde Islands is an extra 1,000kms further.

It is really incredible that a signal a VHF signal at 144 MHz could travel 4,400+ kms from some islands off the west coast of Africa and get as far as the capital city of the UK.

Tropo ducting... The map below shows the tropo forecast from Pascal, F5LEN. As you can see, there is a maritime path from the west of Africa to the UK and Ireland.

Links... 
1) F5LEN Tropo Forecasts

D41CV and GM3SEK set new 144 MHz tropo record of over 4500 kms

In what was probably the best tropo opening to Cape Verde Islands to date, Ian White GM3SEK in Scotland managed to work D41CV on the Cape Verde Islands on FT8 to set a new IARU Region-1 tropo record for 144 MHz. The contact was made on the 28th of December 2019 and the distance was estimated to be in the region of 4565 kms which is about 130 kms further than the previous record which was set by D41CV and G3SMT in September of 2018.

GM3SEK used 400 watts into an 11-element beam to complete the record contact.

A number of other stations in England, Wales, Ireland and the Isle of Man managed to complete contacts with D41CV as well.

To put the opening into context, the stations that heard D41CV on FT8 on Saturday the 28th of December 2019 are shown below. Also shown is the limit of the previous record.

What really stands out is the number of stations that heard the signal from D41CV and were further than the old record.

Of these, GD3YEO and GD6ICR both managed to complete a contact for what were probably the first ever contacts between Cape Verde Islands and the Isle of Man on 144 MHz.

John, MW1CFN on the Isle of Anglesey did not make a contact but managed to hear D41CV with a small 3-element yagi!

MI0XZZ to the north of Belfast managed to hear D41CV despite the fact that the signal had to travel over the island of Ireland.

Possibly the most interesting reception report was that of 2M0TNM in the far west of Scotland. The distance was an impressive 4,710 kms and was almost completely a sea path. If anyone is likely to break the new record then it's likely to be from there.

432 MHz... Amazingly, GM3SEK also managed to work D41CV on 432 MHz for a new world record distance for tropo. That report is in a separate post HERE.

Mode of propagation... As you'll notice, it's those with a sea path that were able to avail of the opening. It was likely to have been the usual maritime ducting.

The tropo prediction map below from Pascal, F5LEN shows the path from Cape Verde to the UK and Ireland.

Links...
1) F5LEN tropo prediction website
2) Excellent end of year tropo opening results in new world record 432 MHz contact of 4562 kms

Excellent end of year tropo opening results in new world record 432 MHz contact of 4562 kms

On some days, there are good openings on the VHF and UHF bands. Saturday the 28th of December 2019 was not only good, it was exceptional.

As outlined in a previous post, some record breaking signals from the Cape Verde Islands were heard in the UK and Ireland on Friday the 27th of December. On Saturday the 28th of December, those tropo conditions got even better.

The day got started with Mark, EI3KD working D41CV on FT8 on 432 MHz at 09:06 UTC for a new IARU Region-1 70cms record of 4,170 kms. Mark later went on to work the Cape Verde Islands on 432 MHz SSB.

Like on previous occasions, the record only lasted a few hours. At 11:09 UTC, Ian GM3SEK in the south-west of Scotland managed to work D41CV on FT8 on 432 MHz extending the record distance to an amazing 4,562 kms. GM3SEK was using 100 watts and a 23 element on 70cms.

It would seem as if this is not only a new IARU Region-1 70cms tropo record but also a new world record!

To put that into context, the red dot on the map below shows the limit of the old record of 3,284 kms which was between D44TS and CT1HBC back in July of 2014.

This is a screenshot of the FT8 contact between D41CV and GM3SEK on 432 MHz.

144 MHz... GM3SEK also worked D41CV on 144 MHz for a new IARU Region-1 tropo record. This is covered in a separate post HERE

More of propagation?... The tropo prediction map from Pascal, F5LEN is shown below. The key point to note is that the path between D41CV and GM3SEK is mostly over water.

It's probably unlikely that GM3SEK would have managed the contact if it was not for the fact that he is located on the northern edge of the Irish Sea between the UK and Ireland. Like on previous occasions, the most likely mode of propagation for most of the path was marine ducting with the UHF signal getting trapped in a layer above the surface of the ocean.

New record... Can it be broken? The map below shows the how far the new record distance reaches.

Considering that it's probably likely that a maritime path will be required, somewhere slightly further north in Scotland. Someone in the north-east of England might do it but it would require crossing a lot of the UK.

The one stand out location however is from the far western isles of Scotland.

4,562 kms.... Just how far is it? Sometimes it can be difficult to really appreciate just how far distances are, especially when the numbers get really high. I have prepared 3 maps which help illustrate just how far the new record is. And keep reminding yourself, this is 432 MHz!

If you put the transmitter on the south-west of Ireland, this is how far it would reach into North America...

If the transmitter was at St.Johns in Newfoundland, this is how far it would reach into Europe...

And for our Australian colleagues, this is how far the signal would reach if the transmitter was located on the north island of New Zealand...

Will the record be broken? ... I guess you should never say never but the potential number of stations to the north of GM3SEK seems to make it unlikely.

An amazing day for UHF radio and records.

Links...
1) F5LEN tropo propagation forecasts

New 432 MHz station on Cape Verde Islands raises possibility of new records being set

144 & 432 MHz Yagi antennas on Cape Verde

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 kms in distance. See links to posts HERE.

The D4C team have recently announced that they are now active on 432 MHz (70cms).

"We are now capable to be active on #70cm #432Mhz #uhf using a 16 El yagi "Pinocchio" model (wooden boom) home made. Transverter connected to @FlexRadioSystem 6600M driving a solid state PA running 100W seems working as we have worked on SSB loc IM66 for 3000 km dx #hamradio"

As the tropo prediction map from F5LEN shows below, a marine duct off the west coast of Africa seems to exist for long periods of time during the Summer and Autumn months.

This should allow D41CV on the Cape Verde Islands to work up to coastal stations in Spain and Portugal on 432 MHz, a distance of roughly 2,900 kms.

Potential for new records???

Before we look at the potential of D41CV setting new records, we should probably look first at what the current IARU Region 1 record for tropo on 432 MHz is.

Back on the 9th of July 2015, G4LOH in the south-west of England worked D44TS on 432 MHz CW. This was a sea path of roughly 4070 kms, an amazing distance for 70 cms.

This contact was as a result of the marine duct extending much further north so that it managed to get as far as England.

Just to show how good conditions were that day, here is video clip showing G4LOH hearing the D4C/B beacon on 432 MHz...



One important point here is that G4LOH worked D44TS where as D41CV is actually on a different island. As you can seen from the map below, Cape Verde is spread out over several different islands...

You'll also notice that D41CV is further south than D44TS.

If we now look at how far 4070 kms is from D41CV then we get this map...

This means that if anyone in Ireland, Wales or England managed to work D41CV on 432 MHz then it would be a new IARU Region 1 tropo record.

I would suggest that as long as there is a 432 MHz capable station active on Cape Verde Islands then this is probably a case of 'when' rather than 'if '.

Trans-Atlantic on 432 MHz???

It's hard to imagine a 70cms signal getting across the Atlantic but it's something that can't be discounted.

Earlier in June of 2019, there was a tropo duct across the Atlantic from Cape Verde to the Caribbean which lasted several days and allowed the propagation of 144 MHz signals.

If 144 MHz signals lasted for several days, was there a shorter period of time when 432 MHz signals would have propagated inside the marine duct?

If it were possible then this is what the 4070 km distance from D41CV looks like...

If a 432 MHz signal can travel 4070 kms from Cape Verde Islands to England then perhaps trans-Atlantic is not impossible?

There should be some interesting times in the months and years ahead as these possibilities are explored.

Links...
1) Archive from G4LOH's blog
2) IARU Region 1 tropo records for 432 MHz
3) F5LEN Tropo Forecast

Remarkable opening on 144 MHz from Cape Verde Islands to Germany - 23rd July 2019

On Tuesday the 23rd of July 2019, there was another remarkable opening on 144 MHz from Cape Verde Islands off the west coast of Africa to Germany, Netherlands, Belgium and France in Europe.

This is the third such opening this year on 144 MHz where there has been a maritime tropo duct from Cape Verde Islands up to the south-west coast of the Iberian peninsula and then a Sporadic-E opening from that region.

The first such mixed propagation mode was back on the 9th of June 2019 to Italy, Slovenia and Austria. The second was on the 3rd of July 2019 when three stations in Germany heard D41CV.

What was significant for the third opening however was that there was a successful FT8 contact made with DK5AI in Germany, an amazing distance of 4966 kms.

The map above shows the stations that were heard by or had heard D41CV on FT8 on 144 MHz.

While the tropo duct off the coast of Africa was probably stable, the Sporadic-E opening up into Europe seems to have come in two distinct phases.

The four German stations were around 15:08 to 15:40 UTC. The other signals were around 16:34 to 17:40 UTC.

Update : This is the log of FT8 contacts made by D41CV on the 23rd of July. Red contacts are Sp-E + tropo. Black is tropo only...

This is a screen shot of the FT8 contact between D41CV and DK5AI...

This is the tropo prediction map from F5LEN showing the maritime tropo duct up along the west coast of Africa.

Considering this is the third such opening this ear, it might be easy to take it for granted but we shouldn't. A distance of 4,966 kms on 144 MHz is really incredible.

Just for fun, lets suppose that DK5AI was able to work that distance across the Atlantic. This is how far his signal would reach...

The future...5000+ kms??... It's very likely that we haven't seen the maximum distance yet for this mixed propagation path. The marine duct off the west coast of Africa seems to exist for long periods of time so that is a significant factor. The big variable is of course the requirement for a Sporadic-E opening on 144 MHz to complete the path.

Stations in the north of Germany near Hamburg or in Denmark may well be within one Sp-E hop of the coast of Portugal. If this coincided with a marine duct to Cape Verde, contacts in the region of 5,200 kms may be possible.

Links...
1) D4C contest team on Twitter
2) F5LEN Tropo prediction for D4

A closer look at the 144 MHz opening from Cape Verde Islands to Italy - 9th June 2019

Over the last few weeks, there have been several remarkable openings on 144 MHz from Cape Verde Islands off the west coast of Africa.

On the 16th of June 2019, there was the incredible opening from Cape Verde Islands to the Caribbean which lasted on and off for roughly five days. See previous post.... https://ei7gl.blogspot.com/2019/06/historic-trans-atlantic-contact-made-on.html

On the 29th of June 2019, the same trans-Atlantic path opened again for roughly 36 hours. See previous post... https://ei7gl.blogspot.com/2019/06/144-mhz-trans-atlantic-path-open-again.html

On the 2nd of July 2019, there was a combined Sporadic-E and tropo event which allowed signals from Cape Verde Islands to be heard in Germany. See previous post... https://ei7gl.blogspot.com/2019/07/144-mhz-path-opens-up-between-cape.html

There was however another remarkable opening on the 9th of June 2019 which wasn't well reported at the time. See map below...

Thanks to a log extract provided by the D4C team, I have been able to put together a reasonable record of what took place.

The map above shows the stations that D41CV worked on 144 MHz with the digital FT8 mode. The chart below shows their log and what was worked. The 'normal' tropo contacts are in Black. The combined Tropo Sporadic-E contacts are in Red. The reception report from OE3NFC in Austria is in Green.

Evidence - Tropo... First off, lets have a look at some of the information available from that time. This is a map of the tropo predictions on the day which indicates the likely marine ducting path from Cape Verde Islands up along the west coast of Africa to Morocco and the the south of Spain.

As can be seem from the log, D41CV managed to work two EA7 stations and CN8LI which suggests  this sea path was open..

Even though the south-west coast of Spain is some 2,800 kms distant, this marine ducting path seems to be a regular feature in this part of the world and is no great suprise at this stage.

Evidence - Sporadic-E... These are the spots from the DX Cluster showing Italian stations hearing CN8LI in Morocco by Sporadic-E at the time.

Considering the distances involved and the evidence above then it would seem likely that the Italian stations managed to catch a Sporadic-E opening on 144 MHz to an area near Morocco where the signals then entered the marine duct which extended down to Cape Verde Islands.

Some points....
1) 16... There were 16 FT8 contacts made which were via a combined marine tropo ducting - sporadic-E propagation mode.

2) N Italy... Notice how the contacts in the north of Italy are laid out in a line... typical of a Sporadic-E footprint which tends to be be long and narrow. They are also crucially far enough north so that the Sporadic-E signal from Italy lands near the water off the west of Morocco.

3) C Italy... The three Italian stations in central Italy are interesting. Notice how they are all on the coast. Perhaps they were availing of some tropo enhancement from the Mediterranean to allow the Sporadic-E signals to land near the ocean off the very southern part of Morocco.

4) S57A... The Slovene station S57A was the best DX that day with a distance of about 4,809 kms.

5) D41CV... These are the working conditions for D41CV... Sunsdrpro2 by expertsdr, 12 el yagi home brew, 500W from single LDMOS homemade (pallet from ITALAB)

6) Austria... Remarkably, D41CV was also heard by Norbert OE3NFC. Norbert was using 4 x 7el LFA at 12 metres above ground level to a Low Noise Amp & G4DDK transverter into a Flex radio. He was hearing the FT8 signals from D41CV at -17dB.

On that last point, OE3NFC in Austria was roughly 5,107 kms from Cape Verde Islands.

It's very easy to look at the figures and not actually realise just how far that distance is. To put it into context, this is what 5,000 kms looks like.

Imagine putting a 144 MHz transmitter on the west coast of Ireland and it reached this far into North America....

We can repeat the exercise by imagining there was a 144 MHz transmitter in St.John's Newfoundland and it reached this far into Europe....

In conclusion..... Overall, a remarkable set of contacts by the D41CV station. Considering how often there is a marine tropo path off the west coast of Africa, there should be more openings like this in the future.

Links...
1) D4C website
2) D4 team on Twitter

Acknowledgement : Thanks to the D4C team for providing a log extract which was the basis of this post.

Correction : 18th July 2019 - Corrected locator square for S57A from JN76TN to JN65TW.

144 MHz path opens up between Cape Verde Islands and Germany - 2nd July 2019

The D41CV station on Cape Verde Islands off the west coast of Africa continues to show new paths on 144 MHz that would have been unimaginable a few years ago.

On Tuesday the 2nd of July 2019, a Sporadic-E opening from Germany to the south of Spain coincided with a marine ducting event from the coast of Spain down to Cape Verde Islands.

As the map clearly shows, D41CV was hearing and was being heard by stations in the Canary Islands, Portugal and Spain. This is as a result of a marine duct which can stay established for days at a time and the distance from Cape Verde to the south-west of the Iberian peninsula is in the region of 2,800 to 2,900 kms, an impressive distance for 144 MHz in its own right.

What was exceptional on the afternoon of the 2nd of July 2019 was that there was also a Sporadic-E opening from Spain to Germany allowing stations from there to access the marine duct.

As this screenshot from D41CV shows, he was hearing Spanish stations who were working German stations on 144 MHz FT8.

The three German stations hearing and were being heard by D41CV were DL8SCV (JN48RV - 4725kms), DL1NEO (JN59KV - 4870 kms) and DK1FG (JN59OP - 4875 kms).

The map below shows who was hearing and was being heard by each of the three German stations over a 12 hour period on the 2nd of July.

It clearly shows the Sporadic-E path that was open to Spain as well as the continuation by marine ducting to the Canary Islands and Cape Verde Islands.

The distance from the German stations to the Canary Islands is about 3320 kms which is an incredible distance in itself.

It's the distance from the German stations to Cape Verde Islands that it truly amazing... an incredible 4,870 kms. To put that in context, that's the distance from the west coast of Ireland to New York City!

This is the tropo map from F5LEN showing the marine ducting path off the coast of Africa...

While on this occasion, it looks as if no actual contacts were made, it does show the potential of what might be achieved.

For example, if we put the put the opening of the marine duct off the south coast of Portugal then this shows the approximate limit for Sporadic-E from there...

If the marine duct were to extend up further then places like Scotland would come into range.

The big unknown in all of this is of course the requirement for a Sporadic-E opening at 144 MHz.

Part of the FT8 log for D41CV on the 2nd of July 2019...