Thursday, September 19, 2019

Opening on 144 MHz from the Azores results in several contacts over 3,000kms

On the evening of the 14th and the morning of the 15th of September 2019, there was a very good tropo opening on 144 MHz from the Azore Islands in the Atlantic Ocean to parts of the UK, France, Netherlands, Belgium and Germany.

A list of the stations worked by José CU3EQ using the digital FT8 mode is shown below...

Saturday 14th September 2019
20190914 18:30 G7RAU IN79JX JT65 -18 -10 2138km
20190914 18:47 G4LOH IO70JC FT8 -02 +01 2145km
20190914 18:54 F6DBI IN88IJ FT8 -16 -16 2193km
20190914 19:47 ON4KHG JO10XO FT8 -24 -16 2768km
20190914 20:39 F6KHM IN78RJ FT8 -20 -21 2107km
20190914 20:46 GW0KZG IO71LW FT8 -16 -09 2257km
20190914 22:12 G4RRA IO80BS FT8 -19 -23 2263km
20190914 22:15 G4KWQ IO92AQ FT8 +03 +05 2480km
20190914 22:49 M0JDK IO93KH FT8 -24 -19 2563km
20190914 22:57 G8VHI IO92FM FT8 -19 -21 2496km
20190914 23:17 M0CGL JO03BF FT8 -11 -19 2632km
20190914 23:19 G0GMB IO92NB FT8 -21 -19 2513km
20190914 23:20 PA2M JO21IP FT8 -14 -07 2852km
20190914 23:24 PA3FYC JO31AF FT8 -23 -21 2927km 
20190914 23:27 ON8KW JO20BW FT8 -14 -16 2790km
20190914 23:28 G4FUF JO01GN FT8 -19 2579km
20190914 23:49 PA3BIY JO22HB FT8 -24 -16 2861km

Sunday 15th September 2019
20190915 00:06 DJ6AG JO51EQ FT8 -22 -15 3231km ODX of all
20190915 00:08 G3NJV IO70JA FT8 -09 -16 2141km
20190915 00:45 ON4GG JO20AR FT8 -08 -05 2777km
20190915 00:59 PA2M JO21IP FT8 559 559 2852km
20190915 06:53 ON4IQ JO20AR FT8 -24 -04 2777km
20190915 07:10 DG1KDD JO31LE FT8 -22 -20 2988km
20190915 07:15 M0CKM IO90QT FT8 -17 -10 2472km
20190915 07:25 DF2ZC JO30RN FT8 -16 -17 3006km
20190915 07:26 ON4PS JO20KQ FT8 -12 -06 2832km
20190915 07:33 PA0JMV JO21PM FT8 -09 -13 2886km
20190915 07:34 PA5Y JO21VO FT8 -18 +04 2922km
20190915 07:35 PA3CMC JO21WI FT8 -19 -12 2920km
20190915 07:40 ON4LDP JO10UN FT8 -21 -15 2749km
20190915 07:44 G8BCG IO70RK FT8 +01 +00 2204km
20190915 08:00 PA2CHR JO32DB FT8 -15 -20 2970km
20190915 08:06 M0AFJ IO70IC FT8 -13 -03 2140km
20190915 08:36 DK4TG JO31LB FT8 -15 -21 2984km
20190915 08:54 DF1JC JO31OG FT8 -22 -11 3007km
20190915 09:12 DF6PW JO40AQ FT8 -17 -08 3049km
20190915 09:13 DL6YBF JO31OX FT8 -17 -06 3027km
20190915 09:23 PA3PCV JO20VV FT8 -24 -18 2901km
20190915 09:44 PA4EME JO20WX FT8 -17 -02 2909km

This is a more detailed view of the stations worked...

While a list of stations worked is interesting, it's only when you see a map of the contacts made by CU3EQ that patterns appear.

For example, the opening seemed to be along a relatively narrow corridor.

Only two stations in France were worked, both from the same area. All of the signals from the Netherlands were from the south of the country. All of the contacts from Germany were in the same general area and direction.

Amazingly, no fewer than five Germans stations completed contacts that were in excess of 3,000 kms. That is the same distance from Ireland to Newfoundland!

The longest distance contact made by CU3EQ was with Dieter, DJ6AG in JO51EQ, a distance of some 3,231 kms.

This is believed to the first tropo contact on 144 MHz between the Azore Islands and Germany and is further evidence on just how FT8 is allowing new paths to be explored.

DJ6AG was using 750 watts into a 13 element Yagi while CU3EQ was using 350 watts to an 11 element LFA.

Mode of Propagation?... It seems likely that the mode of propagation for most of the path was a sea level duct. At the eastern end of the path, there was probably some more normal type of tropo which allowed stations that were well inland to actually reach the marine duct.

It's interesting that the path to and from CU3EQ also lined up with the English Channel so this may well have been a factor in the signals getting so far to the east.

It's also interesting to note that the opening happened late in the evening and early in the morning well after the sun had set. This is probably when the tropo conditions at the eastern end of the path especially over the land was at its best.

This is the tropo forecast from F5LEN for midnight on the 14th of September.

It clearly predicts some reasonable enhancement from the Azores to the UK.

This is the pressure and temperature chart from the 14th of September....

It shows a high pressure system to the south-west of Ireland.

Trans-Atlantic on 144 MHz???.... As always with exceptionally long distance contacts of this nature, it raises the question of whether a 144 MHz contact across the North Atlantic is possible?

The longest distance contact between CU3EQ and DJ6AK was roughly 3230 kms. If you go west from CU3EQ's location then this is how far it reaches.

While CU3EQ would seem to be blocked by mountains to the north-west, perhaps the 144 MHz path could be bridged by another station on the Azores?

If we take the 3230 km distance from the west of Ireland then it comfortably reaches Newfoundland.

Perhaps the most likely path from Europe is from the NW coast of Spain due to its more southerly location.

While it fall short, it is still reasonably close.

Surely a mixed propagation mode signal of sea ducting and Sporadic-E / meteor scatter would be possible?

And finally, just to show how good conditions were on the 15th of September, this video from CU3EQ shows his contact on 145.500 MHz FM with Tim, G4LOH in Cornwall, England... a distance of 2145 kms.


Photon said...

What a fascinating report! I think the only thing stopping a transatlantic crossing now is time and effort.

For sure, my 2020 plan is to set up on 2m with a good antenna!

Photon said...

Incidentally, the apparent alignment of tropo with the English Channel may have been more to do with a WSW-ENE alignment of fronts, which you can see on archive satellite images for the date in question. Cool to the north, warm to the south.