Thursday, 18 May 2017

Some more thoughts on JT65 as Es gets under way

1) The two phase theory
Someone asked me what time of the day he should look for Es.

It is often said that Es features two peaks during the day. I have already said that my examination of my logs shows no distinct pattern, though despite this I do think that the two phase theory has some usefulness.

So what am I on about? Well, of course Es is sporadic, and some days there is none (no phase at all), some days there is Es only in the morning or afternoon, or even the evening or night (one phase). And sometimes there are two distinct phases with a lull in between.

Recently we had an example where Es first appeared around 08:00. It carried on until about 13:00, then faded to return at about 17:00. So two phases could be noted, on that one day. The difficulty in trying to interpret this is that on one day the first phase might start at 12:00 and finish at 14:30, whereas on a different day the second phase might begin at 15:00.

How is the possibility of this two phase characteristic useful? Consider a day when I am working Es and at, say 13:00 it fades out. My 28MHz WSPR station goes quiet. All the Es clouds fade from the Es MUF on DX Maps. I can then do some of the more important things in life, such as perhaps writing my will, or changing the wheel on a wheelbarrow. I can be fairly sure that there will be no Es for about 2 hours. Maybe three hours, or it might not come back, you never know, but there is a definite gap.

The Es may have faded that day at 12:00 and I will be looking for a return later, maybe after 15:00. But on another day it might only fade at 15:00, in which case the clock starts from there.

So the concept is useful in knowing when there will probably not be an Es opening, rather than when there will be. There generally will not be another phase right after the current one fades out.

It seems to be impossible to predict (reliably) when the Es will start or finish. However, when it fades it does not come back for a couple of hours. Or so it seems to me. There might be  no second phase that day, but I know I have some time to do other things before I need to worry about listening again.

Let us imagine I have some gardening duty to do. I would routinely look in at the radio in case there is some Es about in the morning. If there is I can put off the gardening until the gap between the two phases. It is very unusual for Es to run for the full day, as otherwise I would never do any gardening. And that would be terrible.

It is said that we should look for Es in "late morning or late afternoon". After I read that I worked into Greece at 09:25. (Nice contact by the way, SV9CVY in KM25, 3091km. I have worked him before, but still a good one). That was not "late morning". Also not "late afternoon" was a contact with SM5CNQ (JO78) the following day at 22:21. You cannot make too much of one or two contacts, but looking earlier than "late morning" and later than "late afternoon" proved worthwhile there. They have a general point, there does seem to be a lull, but trying to pin it down like that is tricky.

If there is supposed to be a lull in early afternoon every day, I have already worked stations on Es at 13:25, 14:42 and 14:50 (F6ECI, OE5OLL, and EB1AO), which suggests otherwise.

So far, 37% of my contacts have been outside the "late morning, late afternoon" slot. I just think that it is not helpful to put labels like that on Es, which might have the effect of limiting the times people operate and thus causing them to miss useful contacts. 37% of useful contacts, indeed.

For this year's Es season, only one day so far has had a "classic" two phase double peak.

As always, I need to say that this is what happens at this QTH, it might be different where you are, especially if you are in tropical regions.

I cannot predict when to listen for Es. I cannot say that if the morning Es has faded out that there will be a second phase. However, if there is a second phase there will often be a long gap in between. The useful thing is that you know that you can go and do something else for a while.

Given that both wheelbarrows now have new wheels, what else can I do?
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2) When to send you locator on JT65, and when to send 73?

Especially on VHF, JT65 can be an unwieldy beast. It takes six minutes between sending your CQ and sending it the next after having a QSO. In six minutes the propagation can have come and gone.
There is a shorthand way of doing this. I do not have any from today to show you, but I found this one in the FVM vaults, showing some Winter Es:
It may need to be clicked on to enlarged.

It goes :-
1) CQ GM4FVM
2) GM4FVM OH6WD +14dB (not his callsign and locator)
3) OH6WD GM4FVM R+05
4) GM4FVM OH6WD RRR

That would save 2 minutes if I left it there. In the short Es openings which we get, 4 minutes is probably long enough.

However, I was still stuck with the idea that I should complete the QSO in the classic way, and I sent OH6WD GM4FVM 73. That was silly. I should have gone on to call CQ again. If I did that, OH6WD would have realised that I had got his RRR, as otherwise I would have repeated my report.

If you reply to a CQ without sending your locator, but go straight to the report, the station at the other end does not know where to point their beam (if they are using a beam). It will also set the QSO off on the opposite segment, so you are giving your report and RRR when otherwise you would just be giving the report, and the whole thing ends 2 segments early if you do not send 73. If you do send73 you find yourself listening to silence for a minute when you could have been doing something more useful.

Coming from HF JT65 you might find all this a bit brutal and dare I say it, impolite. Coming as I do from VHF meteor scatter, it is quite common. When your QSO could last over an hour to confirm six pieces of information you are accustomed to short cuts.

The way I make sense of the example above as follows:-

1) I had worked OH6WD before, so he can feel free not to send his locator.
2) If he can take a shortcut like that, he will assume that me calling CQ at the end is the same as the 73 message - I have your RRR and I am moving on. Otherwise I would have repeated the previous message.

I personally would only skip the locator if I had worked the station before. For example, I have worked OZ1JXY 65 times now, and he knows where I am.

By the same token, I would always accept seeing a CQ as a confirmation that the QSO is finished. I do not need to exchange 73s if it takes 2 minutes to do it, and especially as I already have his report and his R, and I have confirmed this by sending RRR.

However, if the QSO progresses the normal way then the 73 costs nothing in terms of time, so I will send it. It is his frequency and it is up to him to call CQ next, so I fill the empty space with a 73. If I reckon I have the time I always do the whole thing by the book, 73s and all.

Polite, what, what?

What I need for a QSO is

1) his callsign
2) his report
3) "R" to indicate he has my details

The locator is required if it is the first time I have worked him from that QTH, otherwise I can live without it. 73 is nice but not required if the other station goes on to transmit again.

Contests, of course, are different.

If I ever do skip the 73 and the other station fails to hear my CQ, then I send a 73. It is what I do, but I see from several QRZ.com postings "you are wasting your time!". Now where did I hear that before? Buggleskelly, where the Porter told Will Hay all about it n the 1937 film "Oh! Mr Porter". That film was based on an original play by the great Arnold Ridley.

Ah well. You remember things like that if wheelbarrow wheels are the only other things you have to think about.
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3) Keep your head when all around are losing theirs.
During a strong opening, JT65 here turns into a bear pit. I have three locals within 5km of here, and when they come on I have little choice but to fall in line with whatever segment they are transmitting on. So long as we all stay together on first or second, and none of the four of us changes, then we are fine.

The snag here of course is that the best DX might be on the same segment. There is no rule applying to Es, as there is on meteor scatter, that beaming South and East is second, and beaming North and West is first. In any case, none of the locals has a directional antenna.

If I can work round this, I do. It is tricky though, with strong signals inside the SSB filter. There is not much you can do about it.

I often turn to JT9. There are not so many stations on it, but it is theoretically 2dB better than JT65 and it puts the locals outside my filter. You can often see JT9 signals appearing at the top of the JT65 waterfall. I find that JT9 is a useful mode to have.
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4) The last few days
13 to 18 May 2017 50 and 70 MHz Es contacts at GM4FVM
Nothing to complain about there, though I missed openings into the Middle East and across the Atlantic. Not that I am the complaining type. I am a cheery, "get along with things" person. But there has been another major aurora warning and yet again nothing has happened yet. Maybe today. This seems to happen a lot lately, the conditions seem right for an aurora but nothing happens.

Ah well, even though there is a ton of Es out there to be worked, you just have to make the best of things.

😁


73

Jim

GM4FVM

2 comments:

  1. Hello Jim, message is clear. I agree with what you write about shortcuts and do it just like that. Giving the locator and 73 is a waste of time. Even on HF. However not everyone knows about it and so you have to adjust to your opposite station. I think (hope) in some years the 4 minute JT QSO wil be a standard. 73, Bas

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  2. Thank you Bas. You used the correct words which I missed; "adjust to your opposite station" puts it very well. I did repeat myself twice with most points which is unecessary, but those few words make the point clear. 73 Jim

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