4000km VHF opens up from NW Europe to Cape Verde Islands - 22nd July 2020

Over the last few days, there have been another opening from the north-west of Europe on the VHF and UHF bands to Cape Verde Islands off the west coast of Africa. The map above shows the opening on 144 MHz on the 22nd of July 2020 with many of the FT8 signals from D4VHF around the 4000 km mark.

xmtr Rcvr Band Mode Distance Time (UTC)
D4VHF GW4VXE 2m FT8 4280 km 19:01:11
D4VHF GW1JFV 2m FT8 4264 km 21:31:14
D4VHF GW6TEO 2m FT8 4249 km 20:44:14
D4VHF EI8KN 2m FT8 4230 km 20:57:11
D4VHF EI2FG 2m FT8 4182 km 19:51:41
D4VHF M0BKV 2m FT8 4181 km 22:49:14
D4VHF EI3KD 2m FT8 4170 km 22:22:14
D4VHF G4LOH 2m FT8 4098 km 23:26:14
M0AFJ D4VHF 2m FT8 4094 km 19:52:26
D4VHF G3NJV 2m FT8 4090 km 21:34:14
D4VHF G7RAU 2m FT8 4086 km 23:25:11
D4VHF F6KHM 2m FT8 3966 km 22:25:14
D4VHF F8DBF 2m FT8 3963 km 22:39:14
F6DRO D4VHF 2m FT8 3870 km 15:30:26

The path was also open on 432 MHz...

As with previous openings of this type, the path is marine ducting. There seems to be almost a permanent 3000 km path from Cape Verde to Spain & Portugal at certain times of the year and this pushes northwards towards the UK and Ireland from time to time.

Just to give an idea of how good this opening was, Tim GW4VXE in the far SW of Wales reports hearing D4VHF on 70cms with a vertical!

It would be really interesting to see if this path extends up into the microwave bands, especially on 1296 MHz.

World First FT8 Moonbounce contact completed on 432 MHz...

One of the niche areas of amateur radio and perhaps one of the most difficult is trying to make contacts by bouncing radio signals off the moon. 'Moonbounce' or EME (Earth-Moon-Earth) has its proponents who squeeze every last bit of improvement out of their antennas and equipment to overcomes the huge losses involved.

On a posting on the Moon-Net, Joe Taylor K1JT said he believed that the first moonbounce contact had taken place with the FT8 digital mode.

On the 21st of May 2020, an EME contact on 432 MHz had taken place between W2HRO in New Jersey and PA2V in the Netherlands.

While the weak signal FT8 mode is hugely popular on the HF and VHF bands, modes like JT65 are more popular for EME due to its better sensitivity.

Here is the posting from K1JT....

Some here will be interested to learn that earlier (21May20) today W2HRO and PA2V easily made (as far as I know) the first EME QSO using the FT8 mode.

Paul and Peter used WSJT-X 2.2.0-rc1, a beta-release candidate for version 2.2 of the program WSJT-X. Both stations have moderate 4-yagi setups on 432. Conditions today were not particularly good: degradation around 3 dB, and the Sun only 20 degrees from the Moon.

For terrestrial use the FT8 decoder searches over the range -2.5 to +2.4s for clock offset DT between transmitting and receiving stations. When "Decode after EME delay" is checked on the WSJT-X "Settings" screen, the accessible DT range becomes -0.5 to +4.4 s. Just right for EME.

FT8 uses 8-GFSK modulation with tones separated by 6.25 Hz. At the time of this QSO the expected Doppler spread on the W2HRO - PA2V EME path was 8 Hz, which causes some additional loss of sensitivity. Nevertheless, as you'll see in screenshots posted here, the copy was solid in both directions:

Why might you want to use FT8 instead of "Old Reliable JT65" for EME QSOs? FT8 is about 4 dB less sensitive than JT65, but with 15-second T/R sequences it's four times faster and it doesn't use Deep Search.

When I was active in EME contests on 144 MHz, I was always frustrated that even with reasonably strong (for EME) signals, one's maximum JT65 QSO rate is about 12 per hour. With FT8 you can do 40 per hour, as long as workable stations are available.

What about FT8 EME on 1296 MHz? It might sometimes work, but Doppler spread will probably make standard FT8 a problem. But if there were sufficient interest, we could make an "FT8B" or "FT8C" with wider tone spacing.

Please try FT8 for EME on any of the bands 144, 432, and 1296 MHz, and let us know your results.

-- 73, Joe, K1JT

For the FT8 moonbouce contact on 432 MHz, W2HRO was running 1KW into 4 x 15 el Yagis. PA2V was running 1KW into 4 x 27 el Yagis.

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.

144 MHz report here ... 432 MHz report here

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

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...

Historic first Trans-Atlantic contact made on 432 MHz - Tues 7th April 2020

On Tuesday the 7th of April 2020, a remarkable contact was made with the FT8 digital mode on 432 MHz between D4VHF on the Cape Verde Islands off the coast of Africa and FG8OJ in Guadeloupe in the Caribbean.

This was the first 70cms trans-Atlantic contact without using satellites or the moon. The most likely mode of propagation was marine ducting with the signal being trapped close to the ocean.

* * * * *

Update: Saturday 11th April 2020 - D4VHF in Cape Verde and WP3ND in Puerto Rico complete a contact with FT8 on 432 MHz. This extends the trans-Atlantic distance to approx 4,367 kms. Full info further down this post.

* * * * *

(Make sure to scroll down for updates)

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

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

EI8JK works Japan on 70cms Moonbounce for an EI first

Working Japan on any band from Ireland is pretty good but what about doing it on 432 MHz? That's exactly what Tony EI8JK did on Monday the 10th of September 2018 when he worked Toshia JA6AHB by bouncing 70 cms signals off the moon!

The pair have been trying to make the contact for several weeks with Tony making small incremental improvements to his system to squeeze out every fraction of a dB. In the end, they managed to complete the contact using the JT65 mode on Monday morning during a 2-hour window to make it an EI-JA first on the UHF band.

In terms of equipment, JA6AHB was using 500 watts into a 7 metre dish while Tony was using 4 x 21 element yagis with a medium powered amplifier. His antenna system is shown below.

Tony lives on the scenic Sheeps Head peninsula in West Cork and no doubt the remote location with low noise background really helps on the VHF and UHF bands. With his current set-up and more improvements on the way, he hopes to work many more stations off the moon on 432 MHz.