Thursday 16 November 2023

Unusual 6m propagation this Autumn

I have not been very present on this blog lately. There has been a lot going on, plus I am having trouble posting replies to other postings. I hope I can get the posting problem resolved soon.

This is an update. There should be a series of links at the end to the various surprised posting I have made on this subject earlier. 

I used to work almost nothing on 50MHz during the periods of the years which excluded May, June, July and August. In other words, outside the Es season there was little to hear, even though of course I still listened. Based on 14 years experience, both at the top and bottom of a (weak) solar cycle, there might be a few days of European contacts to be had. Maybe a little aurora or meteor scatter, but nothing outside this continent.

For the sake of simplicity, henceforth let me call the period September to March "Winter".

There was no "DX" outside Europe to be worked on 50MHz during Winter. That was the rule for over a decade.

What could I do during Winter? I could look at DXMaps and the DX Cluster and for a month or so around October and March each year when I could see Australian stations working into Japan and the odd contact from South America into Southern Europe. This was Trans Equatorial Propagation (TEP) and these contacts had nothing to do with me as I was outside the area covered by TEP. Frustrating.

Back in March 2015 I wrote about "TEP, Something I don't get here" accompanied by a map showing that it did not reach much further north than the Alps.

Proof of the rule was that listening produced nothing. Absolutely no DX. The minimal Es was truly sporadic, weak, fleeting and within 1500km. Nothing to suggest that Es was anything other than a rare event during the Winter. Perhaps a day of European contacts, but you could not rely on it any particular day.

This blog is full of reports of brief 50MHz openings during the Winter, but all of them are linked to specific solar activity. None of them involved any "DX". DX in this case means outside Europe. I am happy to work around Europe during these rare events but they are not startling. None of them showed an Es opening every day for weeks on end, just the odd day. Actually, they were interesting because they were so unusual and short lived.

During the Winter I could also read Don Field G3XTT's book "Six and Four" which listed all sorts of long distance DX from solar cycles long since past and estimated that for there to be classical F2 openings we would need the solar flux level of over 200 for two or three days for an F2 opening on 6m. As I write the flux number is 134 and it has only been above 200 for a couple of days and not since January. Not much chance of long distance DX on 6m then.

And then it all changed.

For me the change happened on 20 October 2022. I worked TT8SN. Very unusual during Winter as this sort of thing had only happened here before during the four Es peak months. In fact any African contact was unusual even during the Es season and not that far!

Here is my DX (over 3000km) worked on 6m since the end of this year's Es season.

50MHz contacts at GM4FVM between 1 September and 14 November 2023

As usual, click to enlarge the images if you need to.

OK, it took over 72 days to do it, but 7 countries all over 4500km. Nae bad. Best DX 11869km. Only one of these countries was worked by me on 6m before this year, and that was Brazil which I only worked during the Summer. This was all new Winter DX. 

This was when the flux index appears to be too low for classic F2, and when Winter Es has never produced multi-hop for me. Ihave a station well short of the bruising mega-gear used by some. All I can say is .. wow!

Since the end of the 2023 Es season - Brazil, Chile, South Africa, Reunion, Botswana, Senegal, and Burkina Faso. During the equivalent period before the 2023 Es season - Three South African stations - a first for me then.

For now I am assuming that this is TEP which I can link into thanks to Es. And there has been Es. Unlike previous years there has been regular Es openings during which I have been hearing or working stations in Southern Europe almost every day.

Here is a typical day on 6m these days:-

50MHz on PSK Reporter at 14:35 on 14 November 2023

This certainly looks like TEP, and I must assume that Es is what is linking stations as far north as me into it.

This is happening on many days when I might have expected it to be confined to the usual TEP windows during October or March. Also, it has taken regular Es to allow me to reach it, and that is unusual too.

It has become so regular that I declined to try to work some stations as I had already worked them. I am turning down contacts at 10,000km because they are currently every day contacts. I can watch other GM stations working them. Once or twice I have got involved simply because I can.

I now often report long distance 6m contacts to Mike, GM3PPE and he has helpfully done the same for some of the contacts I have made. Two days ago I worked a ZS but did not notify Mike because such contacts have become almost an everyday event. A year ago I would have been thrilled with this, now it does not seem quite so surprising.

Surely this has to come to an end. The theory behind TEP suggests that it is limited to the equinox along the geomagnetic equator. That means it should move along the equator for a few weeks and not exist along a set path for a long period. But it is mid-November and it is still happening.

Perhaps it has now come to an end. Today there was no opening and I only observed one contact between Australia and Japan. Even that was probably the shortest possible path between those countries - Darwin to Okinawa. Against that idea is that the considerable opening shown above was just two days before I write this. On 14 October I worked ZS6NJ. On the Es front, on 15 October I worked 12 stations in 11 countries (not rare DX, except possibly GI4DOH). Hardly signs that this is over.

Why is it not over when the books say it should have ended weeks ago? I have no idea. Why is it happening in the first place when it never happened here before 20 October last year? I have no idea about that either. 

In his book Six and Four Don Field distinguishes TEP from "East-West F2" propagation. There has been no East-West F2. This can hardly be classic F2 due to the paths. If it was East-West F2 then where are the stations due East or West?

So it cannot be F2, it cannot be just TEP alone as it needs Es at the same time. If TEP and Es are involved why are they both around regularly in Winter when they never were before?

If you live on the South Coast of England or further south you may be wondering what all the fuss is about. Well, you may be able to work TEP every year, though not normally for such a long period. Up here in IO85, for GM4FVM this coincidence of Es and TEP (if that is what it is) is totally without precedence.

Links to earlier posts:- 

March 2015

"TEP, something I don't get here"

October 2023

"Senegal on 6m"

September 2023

"Long Term milestone reached"

February 2023

"More TEP from Scotland?"

January 2023

"TEP from Scotland Mystery"

Finally - I do not really understand this propagation. At one level I don't care. I am happy to work the DX.

73 Jim



  1. Oh yes Jim, the mysteries of the magic band. This is the first year I left my 6m/4m duoband beam in the tower. It will probabely not survive the winter seaon weather. But is already was worth it. I made my first QSO on 6 with 3x a VK6 station. 73, Bas

  2. Bas. It looks like I have finally got my browser settings able to accept my reply!
    Well done. I have never worked VK on 6m. The conditions have been very good indeed. Keep that antenna up - ZL next. 73 Jim