Indications suggest the path could work on higher frequencies too. I have not been checking 6m FT8 until yesterday.
See https://sites.google.com/view/g3xbm4/home/vhfuhfmicrowaves/super-dx
Simple QRP projects, 10m, 8m, 6m, 4m, FT8, 160m, WSPR, LF/MF, sub-9kHz, nanowaves and other random stuff, some not related to amateur radio.
Indications suggest the path could work on higher frequencies too. I have not been checking 6m FT8 until yesterday.
See https://sites.google.com/view/g3xbm4/home/vhfuhfmicrowaves/super-dx
The most credible explanation is this is caused by ionisation in the mesosphere linked to the formation of noctilucent clouds that form at this time. From research, this path could work at even higher frequencies, possibly microwaves! What is needed is for keen people at each end to try.
This is definitely a case when research by radio amateurs could advance radio science. There is much to be gained from this research. I think noctilucent clouds are becoming more common as a result of climate change, but don't quote me on this. Certainly Far East stations have been spotted here on just a vertical omni on 6m FT8 for several years in July.
Now is the time to arrange some skeds on 2m, 70cm or 23cm. Records could tumble.
See https://sites.google.com/view/g3xbm4/home/vhfuhfmicrowaves/super-dx .
My own theory is this is some sort of chordal hop E layer propagation. It always seems to be in late spring/early summer and is linked to noctilucent clouds which form in the mesosphere around this time (late June, early July in the northern hemisphere).
I get the impression that these modes may well work at far higher frequencies, possibly even microwaves.
See https://sites.google.com/view/g3xbm4/home/vhfuhfmicrowaves/super-dx .
See also John's blog at https://ei7gl.blogspot.com/ .
NOCTILUCENT STORM: Last night, sky watchers in Europe witnessed the finest display of noctilucent clouds (NLCs) so far this year. Electric-blue tendrils spread as far south as France:"I could see the NLCs from my window," says photographer Alexandre Croisier of Brittany, France. "So I rushed down to the beach to take this picture--a 6 second exposure with my Canon 350D.
In England, the same display stretched from horizon to horizon. "There was quite a lot of detail visible, including swirls and tiger stripes," reports Mark Jones of Leamington Spa, UK. Even city lights did not overwhelm the NLCs. "I had no trouble seeing them from southwest London," says onlooker Maurice Gavin.
July is often the best month of the year to see these mysterious clouds. High-latitude sky watchers should be alert for electric blue in the nights ahead.
Amazingly, EA8BFK (2880km) has spotted my extreme QRPP 6 times already!! I had to double check it really was 500uW (0.5mW). It definitely ...