Sunday, April 2, 2023

Opening on the 50 MHz band from Europe to Fiji - Short path or Long Path?


Andreas, SV2JAO in Greece sent on a report of his JT65 signal being heard by 3D2AG in Fiji in the Pacific on 50 MHz (6m) band on the 31st of March 2023. This then raises the question... Was it short path or long path?

The screenshot above was taken by Andreas from the PSK Reporter website just after the signal was heard. That site will always by default show the shortest path but it doesn't mean that it's correct.

3D2AG to Europe... First of all, I checked the PSK Reporter website myself and I had a look at the paths from Fiji to Europe.


As you can see from the map above, there were three stations in Europe. These were the reports in the last 24 hours...

31st March 2023...
Txmtr Rcvr Band Mode Distance Time (UTC) SNR
IZ8FWN 3D2AG 6m JT65 17124 km 22:02:50 -21
SV2JAO 3D2AG 6m JT65 16634 km 22:02:50 -23

1st April 2023...
3D2AG SV9CVY 6m FT8 16801 km 07:39:44 -19

Long path or Short path??? ...If it's on the higher HF bands or 50 MHz then the guide is to follow the sun. The JT65 signals from IZ8FWN in Italy and SV2JAO in Greece were heard in Fiji at 22:02 UTC UTC, the sun is now somewhere over the Pacific and the short path over Asia has been in darkness for quite a few hours. Conclusion, it's most likely long path.


The other path was from SV9CVY on Crete to Fiji at 07:39 UTC which is about 10 hours after the other reports. Now, the Pacific path is in darkness and the path over Asia is in sunlight. Conclusion, it's most likely short path.


This doesn't rule out that the path may have been skewed somewhat but we can't come to any conclusion about that with some information about the various beam headings from the respective stations.

In conclusion... I know the above will sound obvious to a lot of experienced radio amateurs but I do think there is a tendency for newer operators to just look at a map, see the line presented and take it as fact.

The reality is that PSK Reporter 'suggests' the most likely path, you have to use your own experience and knowledge to decide if it's correct. A good guide is to follow the sun and then decide if it's long path or short path.

Links
1) Other examples of long distance paths on the 6m band can be found on my 50 MHz page.

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