Wednesday, March 8, 2023

30,000km Long Path opening on the 50 MHz band between Europe and Japan - 7th & 8th March 2023

After a decline in solar flux at the end of February, there has been a marked bounce in conditions in early March with the solar flux going back up to around the 180 mark.

Late on the 7th of March 2023, there was a very good long path opening on the 50 MHz band from the south of Europe to Japan.

José, CT1BOH reported the long path opening to Japan on Twitter and looking at the PSK Reporter website, one of the longest paths was to JR4ABB which is around 29,000kms. The path is shown above and the key thing to note is how far to the south the path travels.

The reality is that there were a lot of paths on FT8 between stations in the south-west of Europe and stations in the south-west of Japan. It's not really feasible to list them all and I don't think it would anything of value, the key point is that there was a long path opening on the 6m band.

However, we can look at the specific example of CT1BOH and JR4ABB in more detail.

The map above shows the Japanese stations that reported CT1BOH or were reported by CT1BOH. You'll notice that they are clustered in the south-west of Japan. The long path signals are coming in from the south-east and JR4ABB is one of the furthest away.

A list of the Japanese stations are listed at the end of the post. The opening lasted an hour.

There are two points here...

1) The further north a station is in Japan then the maximum usable frequency (MUF) is lower and may not reach 50 MHz. 

2) The further to the north-east a station is in Japan, the further south the long path travels and the closer it gets to Antarctica and a more difficult path.

This image above shows the stations in Europe that reported JR4ABB or were reported by JR4ABB. In this scenario, the long path signals from Japan are coming in from the south-west. 

You'll notice that it was an opening that favoured the south of Europe, again the MUF is better in the south of Europe. Note that there was also a long path opening to I8IGS in the south of Italy, a distance of about 30,000kms.

For a long path opening to Japan, it gets harder the further to the north-west you go in Europe. It's likely that EA5 and EA6 stations in the SE of Spain had a distinct advantage over their EA1 compatriots in the NW of Spain even though the long path distance was similar.

In conclusion... It's remarkable to see long path signals not only reach as high as the 50 MHz band but to travel around 30,000kms as well. It will be interesting to see if there are any long path 6m reports from stations further north.

Link... For other examples of long distance paths on the 6m band, see my 50 MHz page.

1) A list of Japanese stations reporting or being reported by CT1BOH

JF4VZT 6m FT8 23:15:14 -19
JA5SUD 6m FT8 23:16:14 -16
JE6KYA 6m FT8 23:23:45 -18
JA4LKB 6m FT8 23:29:44 -15
JH6NKZ 6m FT8 23:31:14 -20
JA6QHP 6m FT8 23:33:14 -11
JA6GDI 6m FT8 23:36:14 -16
JE6BHT 6m FT8 23:40:12 -18
JE6AZU 6m FT8 23:40:14 -15
JA6CRP 6m FT8 23:40:14 -20
JE4URN 6m FT8 23:40:14 -20
JA6RJK 6m FT8 23:51:44 -6
JR4OZR 6m FT8 23:56:14 -13
JR3REX 6m FT8 00:00:14 -16
JK2TTP 6m FT8 00:05:13 -14
JR4ABB 6m FT8 00:05:14 -19
JH3FHQ 6m FT8 00:05:15 -19
JA4EVN 6m FT8 00:14:14 -18

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