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

RSGB Presentation on VHF baluns by GM3SEK

At the 2018 RSGB Convention, Ian White GM3SEK gave a presentation on VHF baluns and that has now been put up on YouTube.

It is perhaps not the most exciting of subjects but it is required viewing for anyone with an interest in build their own VHF and UHF antennas.

There are some good nuggets of info in there including how to feed a beam properly and what pitfalls to avoid.

It's interesting to note that GM3SEK does not recommend the use of the Gamma match which is used in a huge number of antenna designs.

Video below...

These are Ian's websites...
http://www.ifwtech.co.uk/g3sek/
https://gm3sek.com/