As we continue through the summer Sporadic-E season, the FT8 mode is continuing to show up more really long distance paths on the 144 MHz (2m) band. On the 11th of June 2025, there was a Sporadic-E opening on the 144 MHz band and some of the paths on FT8 from CT9ACF on the Madeira Islands to stations in Europe are shown above.
The longest distance for one Sporadic-E hop might be say 2300kms. In the map above, this is roughly a line running from the west of England to the south-east of France. Any paths beyond this to the east like say to the Netherlands (PA), Germany (DL) and Italy (I) are in the region of 2700-2900 kms and are unusual.
The really exceptional paths were from the Madeira Islands to Greece. The longest of these to SV1NZX in Athens was just over 3700kms.
Propagation Mode?? ... It's hard to be certain what propagation mode was responsible. There was certainly a Sporadic-E opening but how was the range extended to 3000+ kms?
In the past, we've seen openings like this when there has been a Sporadic-E opening from say Germany to the the south-west of Spain and Portugal and the remaining 1000kms or so to the Madeira Islands was due to a maritime duct.
The area to the west of Portugal and Morocco is well known for maritime tropo ducts which can last for days if not weeks.
The map above shows the tropo prediction at the time of the opening. It's worth noting that in the map at the beginning of this post, there are very few stations in say Portugal spotting CT9ACF. I would have expected more 'short' distance spots if there was a strong maritime duct.
Perhaps on this occasion, it was a case of double hop Sporadic-E? A chordal hop between two Sporadic-E clouds without hitting the ground in between?
Appendix...
a) Some of the paths over 2800kms on the 11th of June 2025 are shown below...
Txmtr Rcvr Band Mode Distance Time (UTC) SNR
CT9ACF SV3BSF 2m FT8 3548 km 18:59:13 -4
CT9ACF SV8CS 2m FT8 3467 km 19:08:13 -18
CT9ACF IV3/HB9CAT 2m FT8 2993 km 16:33:42 -17
CT9ACF IT9GUL 2m FT8 2990 km 18:59:14 -17
CT9ACF DL3RL 2m FT8 2984 km 17:25:43 -7
CT9ACF IT9BOR 2m FT8 2975 km 18:53:43 -12
CT9ACF IV3DXW 2m FT8 2969 km 16:33:44 -10
CT9ACF IT9BDM 2m FT8 2968 km 19:06:41 -6
CT9ACF IV3HCP 2m FT8 2953 km 16:33:41 -8
CT9ACF 9H1GB 2m FT8 2914 km 17:54:12 13
CT9ACF IC8AJU 2m FT8 2911 km 17:07:26 -15
CT9ACF DF2IAC 2m FT8 2904 km 17:31:44 -7
CT9ACF IK3SSG 2m FT8 2850 km 16:33:41 -10
IK3SSG CT9ACF 2m FT8 2850 km 16:33:00 -6
CT9ACF DF1JC 2m FT8 2849 km 19:25:11 -17
CT9ACF IK4GNG 2m FT8 2845 km 17:42:44 -12
CT9ACF DG1KDD 2m FT8 2827 km 19:40:11 -4
CT9ACF DF2ZC 2m FT8 2815 km 19:17:41 1
CT9ACF DK5IR 2m FT8 2804 km 17:31:11 -8
PA3AIW CT9ACF 2m FT8 2801 km 18:38:57 -13
There were 3 or 4 different sporadic e events in the late afternoon/early evening of 11th June. The path to Madeira to somewhere near the Spanish/Portuguese coast was almost certainly assisted by a tropospheric duct. Hepburn and F5LEN predictions although good approximations they are not always super accurate in the actual position of ducts. I have conducted very many tropo + meteor scatter tests with EA8 and the tropo predictions produce about 60% probability of a tropo path for complex dual mode propagation. Also, Hepburn and F5LEN use slightly different modelling methods so it is wise to use both at the same time. Hepburn predictions at 18:00 utc on 11th suggests that there might be paths to Madeira particularly from SE Spain EA7.
ReplyDeleteLooking at the PSK reporter flags, many stations including myself reported stations in CT and EA7 around this time. Indeed, when those in the low countries and nearby parts of Germany were working CT9ACF I was working EA8TJ in the Canaries and being heard by several other EA8 stations at just over 3000Km. This is consistent with an ES event to possibly just off the EA7/CT coast and tropo paths to the final destinations
During the time when stations in N Italy and surrounding countries were working CT9ACF I worked 7X2RF in Algiers JM16 and heard stations in the Balearic Islands EA6. This suggests that again the path from N Italy to Madeira was assisted by a maritime duct South of EA7.
The paths from Greece, SV to Madeira is a far more complex problem to analyse. There was a very intense tropo duct from Greece to Sicily and indeed ducts much further along the Mediterranean. I have attached the Hepburn plot covering the Mediterranean. It is unlikely that the duct extended much further that the Balearic Islands, so e layer reflection is likely to be the propagation from around Sardinia, IS0 to just beyond the EA7 coast. Whether the complete path was a combination of single hop ES plus tropo, one or two ducts or chordal ES plus tropo is hard to say without the LiveMuF maps at the time in question. Unfortunately, EA6VQ’s MuF Maps only allow an animation for the previous 1 hour.
73
John G4SWX
For the record, my antenna is a 9 element Tonna with a bend in the middle and i was pointing 300. I have been using FM DX sites to "guesstimate" the 2m openings this seasons and, with yesterday's openings, gauged that there was a likelihood of F/EA, thus the direction. During the day there was Tropo paths from IT9 to 4X and enough tropo paths from my QTH (Athens) to IT9 and 9H. I heard no other stations in the meantime, apart from two entries from EA7 working 9H:
ReplyDelete250611_184930 144.174 Rx FT8 -13 0.1 1286 9H1CG EA7KBX xxxx
250611_185000 144.174 Rx FT8 -20 0.1 1286 9H1CG EA7KBX xxxx
The rest of the log reads as:
250611_185030 144.174 Rx FT8 -16 0.2 1381 SV8CS CT9ACF RR73
250611_185100 144.174 Rx FT8 -12 0.1 1381 IT9GUL CT9ACF xxxx
250611_185115 144.174 Rx FT8 -12 0.1 1580 CT9ACF SV3BSF KM08
250611_185145 144.174 Rx FT8 -11 0.1 1582 CT9ACF SV3BSF KM08
250611_185200 144.174 Rx FT8 -16 0.1 1383 SV3BSF CT9ACF xxxx
250611_185215 144.174 Rx FT8 -13 0.1 1582 CT9ACF SV3BSF xxxx
250611_185245 144.174 Rx FT8 -11 0.1 1582 CT9ACF SV3BSF 73
250611_185330 144.174 Rx FT8 -18 0.2 1381 CQ CT9ACF IM12
250611_185900 144.174 Rx FT8 -17 0.1 1381 CQ CT9ACF IM12
250611_190000 144.174 Rx FT8 -17 0.2 1380 CQ CT9ACF IM12
250611_190200 144.174 Rx FT8 -14 0.1 1380 G0JCC CT9ACF RR73
250611_190230 144.174 Rx FT8 -12 0.1 1380 GW4SHF CT9ACF xxxx
250611_190300 144.174 Rx FT8 -17 0.2 1380 GW4SHF CT9ACF RR73
250611_190600 144.174 Rx FT8 -17 0.1 1380 IT9BDM CT9ACF RR73
250611_190630 144.174 Rx FT8 -19 0.1 1380 CQ CT9ACF IM12
250611_190700 144.174 Rx FT8 -13 0.1 1381 CQ CT9ACF IM12
250611_190730 144.174 Rx FT8 -21 0.1 1381 CQ CT9ACF IM12
from WSJT logs and below is JTDX (entries that were different to the above):
20250611_185330 -17 0.2 1382 ~ CQ CT9ACF IM12
20250611_185900 -17 0.1 1381 ~ CQ CT9ACF IM12
20250611_185930 -25 0.2 1381 ~ CQ CT9ACF IM12 ^
20250611_190000 -17 0.2 1380 ~ CQ CT9ACF IM12 ^
20250611_190030 -23 0.2 1380 ~ CQ CT9ACF IM12 ^
20250611_190100 -24 0.1 1382 ~ CQ CT9ACF IM12 ^
73 Alex SV1NZX