More TEP from Scotland?

Trans equatorial propagation, something I don't get here.

This was something I wrote on this blog back in March 2015. You can find that here if you want to read it (but I suggest you don't).

It is true. TEP does not work from here (or much of Northern Europe which is north of, say, Birmingham), because the path simply does not exist. There is no landmass as far south as I am north of the geomagnetic equator. This is true even though for those in the UK the geomagnetic equator tracks north of the geographical equator at our longitude. The stations have to be almost equidistant on each side of the geomagnetic equator. Maybe a tiny tip of the South America somewhere near Punta Arenas might just do the trick. I doubt, however, that there are many amateurs in Patagonia sitting all day listening to 6m in the vague hope of working GM4FVM.

So I still believe that direct TEP is impossible from here, at least until somebody proves otherwise. 

(I sense a "BUT" coming, Jim.)

 BUT, I also wrote this in the 2015 blog post

... perhaps Sporadic E could carry my signal far enough South to reach the Northern extent of TEP. The snag is that Es occur here in the Summer (and for a few days in Winter) whereas TEP generally occurs in Spring and Autumn. So there might only be a few days each year with the potential for it to work (if it would work at all).

Well, that seemed to happen back on 20 October 2022 when I worked TT8SW in Chad. I wrote that up in the blog posting before last (here) which was partly titled "TEP from Scotland mystery" and even had a photo of the mysterious Toyah Wilcox to prove it.

In that posting I said:-

I am left with assuming that this was Es, encouraged by the high K number, linking into TEP

It just felt odd. A sudden burst of unseasonal Es would be needed as TEP happens mostly outside the Summer Es period. And then it needs to link into TEP at just the right point and there needs to be some activity at the other end of the TEP. Most of the places covered from here would be in the Indian Ocean or the Southern Ocean, or some other watery locator squares. So that remained an untested theory as far as the Chad contact was concerned. Unless it all happened again of course.

And then on 18 February it all happened again.

Once again, a new country and a new square for me. But this time also a new distance record for me on 50MHz. My contact with ZS6NJ in KG33 square (9545km) beat my previous best to JG1TSG at 9281km by a large margin.

Contacts on 50Mhz at GM4FVM between 21 January and 19 February 2023

Not bad for the only 6m contact in 4 weeks. As usual, click the image to enlarge if needs be.

To say that I was not ready to work South Africa on 6m would be an understatement. I was sitting in the shack when I noticed that there was a lot of TEP activity from Southern Europe to South Africa. Not much hope of me joining it but then I also noticed what looked like a small upward blip in chart showing the X-Ray flow from the Sun. In addition to the disturbed geomagnetic conditions at the time I did wonder if this might mean some possibilities of Es.

Looking at the display of 6 metre FT8 activity on my PC I noticed ZS6NJ working into HA and S5. He was about -10dB so a contact seemed possible. As I said, I was not ready. I did not know the beam heading for South Africa, so I just pointed the beam south. If I had thought about it, all I had to do was put ZS6NJ's locator into my rotator control software and the beam would have pointed in the correct direction, but I was initially too confused to work that out. So I was about 20 degrees out, which is a long way off when you get halfway round the world. Only later did it occur to me that the mast was not raised and the HB9CV was pointing straight at the roof tiles. 

So with a two element beam pointing the wrong way, at only 5m elevation, below rooftop level, and 150W, I worked a station on 6m who was 9500km away. My report to him was -12dB, and his report to me was +00dB.

For the second time in a few months I cannot see how this propagation could have occurred if it was not by Es linking into TEP. I logged it on the cluster as "unknown" but DXMaps converted that into "multi-hop Es". I have only ever experienced multi-hop Es in the Summer so I think I can safely rule that out. 

Lots of other stations north of my imaginary TEP cut-off point at Birmingham heard and tried to work into South Africa and several seemed to have succeeded. Well done to them too if they did. At least one was even further north than I am.

Tim, GW4VXE, wrote in his VHF column in the March 2023 edition of Practical Wireless magazine, in answer to a query from G4MCU, "While a 'classic' TEP path might not work from the UK to South Africa, it may be that a compound Sporadic-E plus TEP might work". Well said Tim.

I feel pretty sure that what I stumbled upon was just what Tim described. I think that path to Chad in October was the same though obviously the point at which the Es linked to TEP would have been entirely different. The limiting factor to these paths seems to be the lack of Es here at times when TEP is active. You have to seize the moment - it only lasted just over five minutes and I missed the first three minutes of that due to dithering and having the beam pointing East.

Confirmation from LOTW of matching log entries for the contact on 18 February 2023

I must look for this type of propagation more often. 

Now that I am gradually recovering from my last operation I hope to restore one of my better antennas for 50MHz soon. Perhaps then run a bit more power. But this was not about power or antennas. The antenna was simple, not high, surrounded by buildings and the power was not excessive. This was about radio and being alert to the possibilities.

A stonking tropo opening one week (see last posting) and then this yesterday. And today - total silence.

Isn't radio propagation wonderful?

(Now, where next in Africa, and what about TEP to South America, Jim?)

73 

Jim

GM4FVM