3275km opening on 144 MHz between Madeira Islands and Denmark - 17th Dec 2023

There has been some remarkable tropo conditions in Europe over the last few days with some stations completing contacts on the 144 MHz band in excess of 2000kms. 

One of the longest contacts was that shown above... an amazing 3,275 km contact using FT8 between Thomas, OV3T in Denmark and Stefan, CT9/OM3RG on the Madeira Islands. See report from Stafan at the bottom of the post. Thomas reports using 700-800w into a 2 x 11-element Yagi on a 18m tower. 

As can be seen from the map above, it is mostly a sea path but it does have to cross some land.

Bernd, DF2ZC in Germany also reports working CT9/OM3RG and the distance for this 2m contact was 2,818 kms. Bernd reports using EME power to 4 x 18-element M2 Yagi. Bernd also reports that the path had to cross over 1800m high mountains in the north-west of Spain. 

Propagation Mode???... The long path over the sea would suggest it was one of the marine ducts that we have seen in the past resulting in really long distance contacts. The obstructed path however from DF2ZC to the Madeira Islands would suggest an elevated duct. Was it a combination of a marine duct near the surface and an elevated duct?

The tropo forecast by Pascal, F5LEN certainly suggests a good sea path for some areas.

I think some people will have their own ideas but I don't think anyone can be certain on this one.

Update: See bottom of post for another propagation map.

Link... For examples of other long distance contacts on the 2m band, see my 144 MHz page.

Addendum 1: Thanks to Stefan, CT9/OM3RG for sending on this additional information.

Stefan reports that he was using 100-watts from an ICOM IC-9700 into 2 x 9-element LFA Yagi.

He reports that he worked as many stations as he could with his 100-watts. He heard lots of other stations from Germany (DL), Belgium (ON) and Netherlands (PA) but they couldn't hear him.

This is a list of stations that Stefan worked on the 17th & 18th of December 2023. 3000km+ stations in red, 2500km+ in orange. CW in bold.

20231217 7:02 F6DBI IN88IJ FT8 2085

20231217 9:36 MW0AXA IO81FQ FT8 2371

20231217 9:37 GW7SMV IO81LN FT8 2378

20231217 9:38 G4CBW IO83UB FT8 2546

20231217 9:40 EI9KP IO54MB FT8 2450

20231217 9:44 G8JLY IO82WG FT8 2480 

20231217 9:45 G0PQO IO92UA FT8 2365

20231217 9:46 M0PNN IO82TS FT8 2516

20231217 9:49 G4FUF JO01GN FT8 2530

20231217 10:12 F6EGD IN88HR FT8 2110

20231217 10:14 G4EZP JO01GN FT8 2530

20231217 10:25 G8HGN JO01FO FT8 2530

20231217 10:28 EI8KN IO62IE FT8 2296

20231217 10:30 F6HRO IN88JQ FT8 2114

20231217 10:32 G7GXK IO90IS FT8 2378

20231217 10:40 G8TTI IO81WM FT8 2408

20231217 10:42 2E1EMK IO91BI FT8 2404

20231217 10:47 G4BNM IO93EV FT8 2644

20231217 12:04 G4ELW IO81MC FT8 2337

20231217 18:21 G4ZFJ JO01HO FT8 2538

20231217 18:22 CT7AUS IM58HT FT8 968

20231217 18:24 G0LGS IO81WV FT8 2444

20231217 18:25 G8GON IO80HP FT8 2281

20231217 18:27 G4KWQ IO92AQ FT8 2523

20231217 18:28 M0BUL IO82NG FT8 2450

20231217 18:29 G4NBS JO02AF FT8 2564

20231217 18:30 M6JAY IO90HV FT8 2387

20231217 18:30 G7RAU IO90IR FT8 2377

20231217 18:31 G4DCV IO91OF FT8 2442

20231217 18:31 G0BIX JO01CI FT8 2498

20231217 18:32 G0ODR JO02OP FT8 2651

20231217 18:32 G0JDL JO02SI FT8 2642

20231217 18:33 PA4ZP JO21RK FT8 2766

20231217 18:38 G1OJS IO90JU FT8 2391

20231217 18:43 G0LTG IO81RF FT8 2367

20231217 18:44 G6HIE JO00DW FT8 2467

20231217 18:47 PA3BIY JO22HB FT8 2768

20231217 19:22 G3TKF IO81SJ FT8 2386

20231217 19:24 M0CFV IO91UM FT8 2489

20231217 19:25 G4ZTR JO01KW FT8 2577

20231217 19:28 G7WIR JO01BJ FT8 2497

20231217 19:28 G3XDY JO02OB FT8 2602 

20231217 19:29 G3XDY JO02OB FT8 2602

20231217 19:31 F6EAS IN98LV FT8 2235

20231217 19:32 G4GFI IO91VH FT8 2475

20231217 19:34 OV3T JO46CM FT8 3275

20231217 20:09 GW4SHF IO82HP FT8 2466

20231217 20:11 G4RGK IO91ON FT8 2471

20231217 20:13 PA2M JO21IP FT8 2741

20231217 20:16 G4AEP IO91NJ FT8 2453

20231217 20:19 G4KPZ IO92WK FT8 2575

20231217 20:21 G0JJG JO02ME FT8 2605

20231217 21:42 PA2CHR JO32DB FT8 2854

20231217 21:48 DG6JF/P JO33QN FT8 3017

20231217 21:50 PA3DZL JO21LS FT8 2763

20231217 22:08 G4DHF IO92UU FT8 2605

20231217 22:10 PA3BIY JO22HB FT8 2768

20231217 22:20 G0LTG IO81RF CW 2367

20231217 22:21 G4DHF IO92UU CW 2605

20231217 22:27 G0LTG IO81RF CW 2367

20231217 22:42 ON4KHG JO10XO FT8 2626

20231217 23:21 G0GMB IO92NB FT8 2511

20231218 6:37 F6KHM IN78RJ FT8 2028

20231218 6:39 G4FUF JO01GN FT8 2530

20231218 6:46 F5DQK JN18GR FT8 2413

20231218 6:50 G4EZP JO01GN FT8 2530

20231218 6:51 F6GNR IN97FD FT8 2069

20231218 6:53 EA1M IN53TI FT8 1399

20231218 6:55 G4RRA IO80BS FT8 2272

20231218 7:24 G4MKF IO91HJ FT8 2431

20231218 7:37 ON4KHG JO10XO FT8 2626

20231218 7:46 ON4KHG JO10XO FT4 2626

20231218 7:55 G3XDY JO02OB FT4 2602

20231218 8:36 M0VXX IO90 FT8 

20231218 8:40 EA7JCR IM67WK FT8 1129

20231218 8:47 G3WZT IO90UX FT8 2443

20231218 8:49 G4DDK JO02PA FT8 2603

20231218 8:52 M0CKM IO90QT FT8 2414

20231218 8:54 G4FSG JO02PC FT8 2610

20231218 8:55 EA1YV IN52OC FT8 1268

20231218 8:59 G3WZT IO90UX CW 2443

20231218 9:02 M0CKM IO90QT CW 2414

20231218 9:10 EA1DFP IN53XI FT8 1416

20231218 9:12 G6HIE JO00DW FT8 2467

20231218 9:20 EA1CCM IN52QG FT8 1291

20231218 9:21 G3ZSS IO90NU FT8 2406

20231218 9:23 G3SJX IO91LC FT8 2420

20231218 9:44 DF7KF JO30GU FT8 2785

20231218 9:45 OQ4U JO20KV FT8 2696

20231218 10:01 PA1BVM JO21RO FT8 2778

20231218 10:15 PA3DOL JO22MT FT8 2845

20231218 10:30 PA3DOL JO22MT FT8 2845

20231218 10:35 G0JJG JO02ME CW 2605

20231218 10:47 G4CKS IO91VL FT8 2489

20231218 10:59 DF2ZC JO30RN FT8 2818

20231218 11:45 DL8YE JO32TC Q65A 2929

20231218 13:11 G4HSK JO01FS FT8 2544

20231218 13:18 G4BWP JO02FH FT8 2590

20231218 13:19 G0LQI IO80SP FT8 2319

20231218 13:23 PA0CAB JO22DA FT8 2748

20231218 13:34 PA3DOL JO22MT FT8 2845

20231218 15:38 DL1YDI JO42FA Q65A 2969

20231218 16:02 DM1CG JO30GU Q65A 2785

20231218 16:26 DM1AC JO30IV Q65A 2797

20231218 18:46 PA3BIY JO22HB FT8 2768

20231218 18:48 PA3FYC JO31AF FT8 2783

20231218 19:11 PA5Y JO21VO Q65A 2795

20231218 19:39 DL5EBS JO31NH Q65A 2848

20231218 19:54 ON4CLQ JO11SE FT8 2647

20231218 20:09 F5RZC JO10JG FT8 2539

20231218 20:50 ON4MU/P JO20ET FT8 2663

20231218 21:01 DL5EBS JO31NH FT8 2848

Addendum 2: PA3AUC supplies the following chart which suggests that the opening was due to an elevated duct at 500-750m.

144 MHz contact between Denmark & the Canary Islands exceeds 3000kms

Long distance contacts on 144 MHz that are in the region of 3000kms are always of interest as that is the distance across the North Atlantic between Ireland and Newfoundland. In this series of blog posts, I will look back at some of the 3000km plus contacts on 144 MHz during the Summer of 2020 that I haven't reported on yet.

Back on the 12th of July 2020, there was a remarkable contact made on FT8 on 144 MHz between EA8CXN in the Canary Islands and OV3T in Denmark at about 19:55 UTC.

OV3T in Denmark was using 400 watts into a 10-element Yagi for the contact. I'm not sure what EA8CXN was using.

EA8CXN gave OV3T a report of +8dB while OV3T gave EA8CXN a report of -10dB. This probably meant that CW or FT8 were the only viable modes for making a contact.

Mode of Propagation... The distance was in the region of 3710 kms which is well in excess of the usual 2300km limit for one hop Sporadic-E. So what is the likely explanation?

First off, we can look at the Hepburn prediction map for tropo for the day...

If you examine the right hand side of the map, it shows an enhanced maritime duct from the Canary Islands (EA8) to Spain and Portugal. This tropo path was confirmed earlier on the 12th when EB1DJ spotted EA8CXN on the DX  Cluster.

EB1DJ 144174 EA8CXN 10:30 13 Jul 20  TR  FT8 +4 dB 863 Hz Canary Islands

While OV3T was working EA8CXN at 19:55 UTC, another Danish station OZ1CCM worked EA1YV at about the same time which suggests a short Sporadic-E opening from Denmark to NW Spain & N Portugal.

While we can never be 100% sure of what exactly happened, this is the likely scenario....

There was an marine duct from the Canary Islands to the west coast of Spain and Portugal for most of the day. This maritime duct probably didn't get more than 100kms inland and probably didn't cross over the mountains on the Iberian peninsula.

At about 19:50 UTC, there was a short Sporadic-E opening from Denmark to NW Spain & N Portugal. The Sporadic-E signals from Denmark got coupled into the marine duct and on to the Canary Islands.

The tropo part of the path probably accounted for 1500kms of the total while the remaining 2200kms was Sporadic-E.

In conclusion... This contact yet again shows the value of the FT8 digital mode in exposing propagation paths that we didn't know were possible. 

It also shows the paradox of FT8... i.e. The problem with FT8 is that it is overcrowded because there are too many on the one frequency but it's because there are so many on the same frequency that there is a better chance of catching unusual openings.

The opening from Denmark to the Canary Islands also raises the possibility of a further extension further south to the Cape Verde Islands. The maritime duct off the west coast of Africa often extends from Cape Verde to Spain and Portugal and if that coincided with a similar Sporadic-E opening again then perhaps contacts in the region of 5,200kms might be possible.

Links...

1) OV3T blog post

2) EA8CXN blog post

3) VUSHF post in Danish