Summer peak of VHF propagation

I can see a lot of stations on 6m trying very hard to work Japan (though it seems that China or India would do). There seems to be a lot of frustration. The God of Propagation does not listen to prayers, and is playing hard to get. So far.

Me? I have not got involved in that pursuit so far. I doubt very much if I can make a QSO like that and I am not willing to devote the hours of activity necessary to find out. Anyway, it is early morning activity so that is not appealing to lazy old me.

I would have thought that working Kazakhstan on 4m would be an early morning thing until I heard somebody mention that it is more likely in the afternoon. I am not yet too old to learn so I kept a watch on the DX Maps page and when I saw that UN7MBH was active at what looked like a suitable time I gave him a try.

4m (70MHz) stations worked at GM4FVM on 5 June 2020

I worked him first on 5 June 2020 at 16:44. He is in LO51 square and the distance is 3478km (which would be a 4m record for me if I had not worked 4X1TI at 3956km on 18 May). Needless to say that is a new square.

Calling CQ AS (or whatever) repeatedly as done by the 6m DX hunters is not in my style. I prefer to hang around and work people by stealth. I like the long game. Instant gratification is not necessary here. That meant that I missed Cyprus on 4m last year, but worked it this year. And my approach has probably put off working Kazakhstan for two years, but I like it this way. Maybe if I was chasing awards or entering contests things would be different. On the other hand, maybe I work this way because I am not doing those things.

I am not the type of operator who only comes on for Tuesday and Thursday evening between 20:00 and 22:30. I am not against contests; I think that they are "a good thing". I just think that there is more to radio than just that. I hear it said that there is "no activity" outside contest hours - well my experience seems to disprove that. I know some people actually take their antennas down outside those contest hours. They do their thing and I do mine. However, I find it is true that activity is definitely low during periods I have taken my antenna down.

Likewise, I cannot imagine just coming on for the Es season, or only for 2m for meteor scatter during shower periods. I cannot see the point in limiting myself by excluding large parts of the operating year. We have all these different bands for a reason. What I do works for me.

Not content with my first Kazakhstan station on 4m, on 16 June I worked both UN7MBH and UN3M (LO61) and then went on to work UN7IZ and UN9L (MO12) plus UN3GX (MN83) on 6m for one new country and two new squares there. Things like that tend not to happen during contests on Tuesday or Thursday nights, and they were all between 14:00 and 15:00.

You do not need a very big antenna to make contacts like this. Worst report from UN was -14dB so I could have done it on a dipole, though maybe not as easily.

Looking at the map of the first contact on 5 June, we can see that I then worked YL2CA (KO06, 1478km). This was at 16:53. Apart from G1CEY, which at 108km is a bit more "run of the mill" (though still welcome), these were the only two stations I worked all day on 4m. Thus you can see a distinct shape of one hop propagation to YL2CA and two hop to UN7MBH. Often there is so much activity that the pattern is lost amongst other QSOs.

The distances do not quite match 1478 and 3478, but the QSOs were nine minutes apart so propagation may have shifted slightly. I would not expect the distances to be exactly 50% and 100% anyway, as even with the low height of Es propagation and the limited area of ionisation effective at 70MHz, there will be some area of land half way between the maximum which will be "illuminated" by my signal even during a chordal hop. Although we represent radio signals by straight thin lines, radio energy spreads out into space and would be better represented by a cone. 

There are a lot of variables here, so it is good to see the pattern so clearly. The map projection means that the paths will not be shown as straight lines. This is because the Earth is curved but the map is flat. Despite this we can use the maps as a guide to propagation prediction and I may write something about this later. Also, the area covered at the end of the first hop is generally unknown to us, and may be in the sea or somewhere where there are no amateur activity, so we do not always see it. 

Then again, the signal may not actually touch down at all. For best DX there is no "reflection" of the signal off the ground at the mid point. The usual drawing we see in text books of two hop propagation is misleading. All the best DX paths are what is sometimes called "chordal hop" where the mid point may pass quite high over the ground, though for a near-maximum path length such as this one it will be quite low. The conical nature of propagation into free space will tend to bring the signal to ground at mid point, but the idea of it "bouncing" off the Earth to produce great DX, as we read in books, is fanciful. Sure it happens, but you don't work very far using it.

The remarkable thing about double hop Es, or even more amazing for multi-hop Es with more than two hops, is that it is possible at all. It becomes a big advantage that our signals spread out into free space in a conical fashion. The narrow straight lines we see in the books would never make it. The inverse square law makes it weak, but also makes it possible. As the frequency goes up, the ionised area we can hit gets smaller. Getting two roughly in a line is very difficult. When I studied for my licence it was thought to be impossible. I would like to say that we were taught that even single hop Es was possible, but they did not think Es was worth mentioning. Once I was licensed I looked it up and this revealed only single hop Es was covered by the books. 

Those guys spending hours calling CQ AS on 6m are proof of how hard multihop Es really is, but it is possible.

I write this two days after the Summer solstice. "The nights are drawing in". The next two weeks or so tend to produce the best of Summer Es. Whilst no doubt there will still be some Summer Es in September, these are the days to capitalise on it at its best.

73

Jim

GM4FVM

Four days of Sporadic E, and why a superstation would not help me (much).

Four days of Sporadic E.

Not Four Days of Dunkirk, which is a cycle race, nor Four Days of Ghent, which was an important battle in Flanders in 1789.

Obviously Sporadic E is something you cannot count on. If you are a 10 metre band enthusiast you might get it four days in a row, mind you not necessarily all day. On 6m you might get parts of four days too, perhaps at the peak of activity during the two weeks around the Solstice at the end of June. On 4m four days in a row would be very unusual, and the most days in a row I have experienced on 2m is one.

Yes, maybe I have led a sheltered life, but my experience is for one day of Sporadic E on 2m, followed by a week or two of none. On average I might find two days of 2m Es here all season, with hopes for three days in the year. I might miss it too because "a day" of Sporadic E on 2m here might be three stations worked in 15 minutes and then curtains.

So let us consider (1) what happened (2) what it was like and (3) why I am not going to do anything to be ready when it happens again.

1 What happened.
There was a series of Es openings on 2m between 29 May and 1 June 2020 days. Not only was this unusual, the results on 4m were excellent too, and I could not find enough time to even think about going on 6m or 10m.

144MHz contacts at GM4FVM 29 May to 1 June 2020

Click to enlarge as usual.

This does not look like a 2m map, and nor do the statistics sound like 144MHz, in just short of 4 days operating (my logging mistake included 1 tropo contact from the evening before) resulted in 37 QSOs into 30 squares in 12 countries.  That is a very good month for 2m, in fact 12 countries is more like what I might do in a year. ODX was UR5FLN at 2482km.

On 70MHz I managed this:-

70MHz contacts at GM4FVM 29 May to 1 June 2020

I have left the callsigns off because they just overlap so much you cannot read them. 62 QSOs into 51 squares and 23 countries. ODX was EA8DBM at 3278km. There were lots of new squares worked, such a  new one in Iceland, a hard to get one in Poland and one in Germany which has been outstanding for years (even though it is the closest one). I now only need one square in Germany and two in Poland. I will soon need to find something else to occupy me.

I even managed to work a square in Italy on 4m, which is odd because as far as I know Italian stations are not currently on 70MHz. The rules in Italy are not my area of expertise but I am pretty sure that one was not quite fully licensed. I have twelve squares in Italy from the previous operations there so let us see.

In truth I could have claimed even more. I think I worked the Balearic Islands on 2m but I did not see the confirmation and events moved on quickly. Contacts like that go down in my log as doubtful, though they are complete from my end. By doubtful I mean that they do not count as contacts at all unless I get confirmation from the other station that they view them as complete too. Even though 73 is not part of the contact, despite what some over-zealous individuals might have you believe, if I send RRR but do not receive 73 I do not claim it. That is my choice, and everybody can do whatever they like in this regard. I do not make the rules for what constitutes a contact, mostly because there are no rules. There might be if I applied for an award or entered a contest, but I don't do that. So my rules rule.

2) What was it like?
Stressful.

Does 2m open up and look like 20m? Yes but only briefly.

WSJT-X screen at GM4FVM 31 May 2020

I had to make a quick decision. Do I want to work Romania, Ukraine or Moldova on 2m? All of them, but I have to decide. I have worked Ukraine before, but what chance do I really have with Moldova? Try them all of course, but which one will still be there after I work the first one?




With Es on 2m you often get barely enough time to complete the contact. In fact, most of the time you do not complete and you are left high and dry. So you have to cut every corner and make some guesses, such as if the band is likely to open in a certain direction at a certain time. DX Maps certainly seems to help with the Es MUF chart:-

DX Maps Maximum Uusable Frequency chart on 31 May 2020

I sat and peered at that map as it was updated, looking at where is green, where yellow and where red, planning and plotting. Did it help? Well it kept me occupied.

I watched 6m, looking for clues as to where I might work on the higher bands. This helps distract me. In the past I looked at 10m for clues for 6m, this time it was looking at 6m for clues for 4m, and 4m for clues for 2m. No time for working anyone on 10m, and no time for anyone on 6m either. I did go down for a scrappy contact into USA on 6m, but it did not really work for me. Too stable to be fun really.

So it really comes down to me taking hunches, and regarding the ones that pay off as signs of my remarkable wisdom and operating ability.

What was surprising was the repeated way this happened, day after day.

As for the ones that do not come off, well I know that another chance is not likely to come along again soon. When I noticed on the 24 hour PSK Reporter chart that I had been seen in Portugal on 2m (which would have been a new country if I had heard a call) I reckoned that it would be next year at least before the chance would arise again.

24 hour PSK Reporter summary of GM4FVM FT8 reports on 144MHz on 31 May 2020

Next day I worked two stations in Portugal. The chances of that happening on 2m under normal Sporadic E conditions must be tiny. These four days were extraordinary.

It was nice to work Azores on 4m after 7 years. It was nice to get an opening into France on 2m when I worked three new squares around Lyon and Grenoble in the space of a few minutes, whereupon they were gone. It might be years, or never, before I will hear those squares again.

Of course, I have no real idea when conditions are going to help me. I spent ages trying to work a station in Greece on 4m which would have given me a new square. I watched when he was on and tried to point in the right direction when I could. It never happened of course. I ended up working another new station in Greece with a different new square. That means the first one is still up for grabs, and I still have no clue how to do it.

3) What am I going to do to be ready for when it happens again?
Nothing.

Like many amateurs I am tempted to think that my input on all this is crucial and if I was only better equipped and better prepared it would all go better the next time. What a silly idea, Jim. You will never be ready for something like that, if it ever happens again, which it might not.

Were conditions really so different, or was it just normal conditions and lots of amateurs stuck at home due to lockdown? Do openings like that happen but just most times there are not droves of hams sitting at home wishing for something to turn up? We shall never know. I am not going to lose much sleep over it.

What could I do anyway? Sure I got things wrong and I could have worked more stations if I had been a better operator. I kept pressing the wrong button, sending CQ when I should have been calling a specific station, or sending my locator rather than a report when short of time. Those things I could improve. But I can never be 100% perfect (yes, I wrote that) and nor would that change conditions if it were ever to happen.

And I certainly will not be improving my station just in case. When I moved here 12 years ago I got going with an FT-897 and a 4 element 2m yagi. I now reckon I have made at least 10dB improvement over that - 6dB to 200 watts, 1dB in the coax, 4dB in the antenna. Receive performance is also better thanks to the masthead preamp, plus the coax and antenna gain on receive too.

Some of the superstations round me have another 10dB more than me, and some more than that. I could easily get 4dB more with a linear, another 1dB in the coax and 6dB or more with antennas. Plus more, and more height gain with a free standing 20m mast ... but no.

Those superstations are quite entitled to do what they want, and when the going gets tough they will beat me every time. However, I am quite content with what I did and that is that.

For sure, for weak signal work another 10dB would be handy - certainly for moonbounce. But most Es is not weak signal work. All more power will do is perhaps extend the time I have to complete an Es contact and maybe secure a few more contacts. However the cost of the next 10dB is vastly more than the cost of the first 10dB, and the gain in results is likely to be much less. I feel my station is in balance, and to raise the power further without improving the receive side will only work when contacting other more powerful stations. So I am not about to do it.

Maybe with weak signal work on 70cms or 23 cms I could do with making improvements, but then Es is not really an issue up there.

What we had here was nature treating us to a wonderful display. Such things only come around from time to time. I am not about to try to recreate a fleeting event by changing everything. I like nature to have hand it things, even if they are hectic while they are underway.

For the future I will take my chance.

Just calling CQ and taking a chance is a wonderful thing. When it pays off it is great fun, and I learn a lot about radio by doing it.

I saw some familiar callsigns and I hope you had a good time too.

To those of you who missed it, or who were outside the area it covered, you have my sympathy.

Better luck next time (but I suggest that you don't buy a 20m tower just in case).

73

Jim

GM4FVM