Wednesday, 27 September 2017

Some more thoughts on "above the MUF" propagation and the wool cycle

Thanks for the various posts and email which resulted from the last posting.

Leaving aside the obvious clash of meaning - the MUF we refer to here is not the actual maximum but above the calculated value for general use - I decided to have a couple of goes at being heard when there would appear to be no propagation (i.e. I was above the calculated MUF).

There was weak Es on 10m on 25 September, which seemed like a good time to try for the first time. Nobody was working anyone on 10m SSB, at least not in my area and not as reported on the DX cluster. The DX cluster is not a representation of activity but not very accurate - not everybody posts to it. Nevertheless the WSPR traces were rising and falling and there was some solid copy from that excellent reference station IU1DZZ.
10m WSPR at GM4FVM on 25 September
I cannot over emphasise how useful 10m WSPR is for watching VHF. Stations like Gianfranco's provide constant reference marker to monitor the progress of Es. In this case you can see the wavering trace, which lets you know that Es is just, and only just, reaching 10m.

For what it is worth, I try to reciprocate by transmitting on 10m WSPR as often as possible. Not only are the reception reports useful to me, but I cannot rule out the possibility that my signals may be useful to others.

It is worth noting too that there is general tendency for amateurs to listen on the band and if they hear nothing turn off. That is exactly the wrong attitude to WSPR, and it does not help on FT8 now that we know how it can receive unheard signals.

So, moving on to VHF, there were no SSB contacts on the cluster and nothing to hear on the SSB or CW parts of 6m. I turned to FT8 for two hours and worked these stations:-
6m contacts at GM4FVM on 25 September 2017
This was done at a time when there seemed to be little or no activity on SSB. Of course I cannot really be certain about this, as maybe everybody has deserted SSB and gone to FT8. However it is hard to argue that I wrote a piece on 1 September pointing out that my season had ended and I was winding down, only to work this lot on 25 September. So, maybe FT8 is extending my season. And they were not difficult contacts either ...
IZ4IRJ worked on 6m at GM4FVM on 25 September 2017

I must not get carried away either. It is a bit unusual for me to come on 6m on 25 September and actually try for contacts. Looking back through 10 years of logs I see that only in 2012 did I find a decent opening in late September. On that occasion I worked 5 stations in Italy on 70MHz on 22 September. That is fairly unusual, with the latest opening otherwise also being in 2012 when I was working into Czech Republic on 13 September. It is not impossible to imagine a Es opening at any time of the year, but a two hour opening like that was particularly pleasing so late in the year.

I cannot say that I ever really tried for 6m contacts as late as 25 September in previous years. Who knows what the results might have been, but experience suggested that it was pointless.

Anyway, whatever evidence this gave me that FT8 was extending my season, it wasn't enough. Not for me. So I chalked the 25 September event up to weak Es and resolved to try again when there was even less sign of Es.

I tried on 27 September. On this occasion there was no sign of Es on 10m WSPR. The plan this time was different. First I checked that there was almost no sign on Es on the MUF map (more or less anyway, as anyone on FT8 who gets an "above the MUF" contact will show up on the MUF map).
MUF map on DXMaps on 27 September 2017, just one square showing and it was an FT8 contact
Being fairly certain I was above the "MUF", I called CQ on FT8 for 6 minutes each on four likely beam headings. Then I looked to see if I had been heard, by checking the PSK reporter
PSK Reporter record for 6m FT8 reception of GM4FVM over a 30 minute period on 27 Setpember
In the half hour I was heard by 7 stations. I heard no-one and saw nothing on the FT8 waterfall.

So, what does this mean? I feel pretty sure that more than 7 stations received my signals, as not all stations using FT8 activate the PSK reporter service. But for the moment, let us stick with 7 as that should be plenty. Did any of those 7 reply to me, and why did I not seen any trace of them?

In fact this is similar to what I have been noticing since I first mentioned being reported by DK8NE back in June here and also here. Then it was on JT65 (which is slightly more sensitive but hampered by long tx/rx timing), now it is on FT8, but the results are similar. Back then we wondered if could this be ionoscatter or aircraft reflections.

Some other things are similar now too - for instance nobody is calling me back. Or, more accurately, I am not detecting anyone calling me back. Other things are different, for instance these reports came from various beam headings between East and South West, similar to the ones I used to transmit. Is that more likely to be aircraft reflections than the single path to DK8NE was?

The main conundrum remains - whether this is a novel method of propagation or just something we are more familiar with, why am I not having QSOs? When there was a little bit of Es in the background, I did have QSOs (on the 25 September), but then when there was no Es it seemed like "one way communication".

I began to wonder if nobody wanted to talk to me, or if I was doing something wrong. Then it occurred to me that those 7 stations were not working each other either. Nor any other station near me. Nor anybody else. Every so often PSK reporter would report a decoded contact, but no QSOs were reported on the cluster. So could it just be occasional random reception periods - but then again no. I only transmitted for 6 minutes in each direction and most stations reported me within two minutes of starting.

I spent a long time pondering the diagram for "above the MUF" propagation, trying to see if it would be non-symmetrical. Could it produce only one-way contacts? Maybe, but more likely reception would be widely dispersed so a weak signal would be received over a large area. This would also apply to any station who might reply. So, whilst I might not necessarily hear the stations I was seeing who had heard me, I am quite likely to hear any other station who might call. And I heard nothing on 27 September, and saw nothing on my waterfall.

So basically the puzzle from June goes on. My receiver is working as I can work stations during weak Es. Switching between all four rigs produces the same result. I can reach stations on otherwise flat bands, but I am not hearing them. Are they running less power than me? For this purpose I was running 200W, anything less does not seem to work when the band is "closed". Is it possible that no other station in Europe is running that amount of power and beaming at me?

Let me not personalise this, looking at the PSK Reporter and the cluster, it seems to affect everyone who is still on 6m. Have we all worked each other and are sitting on our hands now waiting for something more exotic?

What I think I need is a year-round FT8 sked with a station 600 - 1200 km from here running at least 200W of FT8 into a 3 element yagi (or better). Someone else who likes the sound of silence.
By the way, I am not sure if this is a seasonal thing but the alpacas have been shorn again.
The alpacas at Ayton Law on 27 September (looking like the previous photos but shorn of wool again)
I would have thought that they needed some reasonable covering for Winter. Now that the Es season is over (?) I would have thought that shearing was finished too.

Mrs FVM found some report which claimed that the average UK male spends more time sitting on the toilet than taking exercise. So I have extended my walk to avoid criticism and I have hidden the stop watch in case she tries timing me again. Timing me on the walk that is. My pedometer says it is 10,000 steps and generally it takes about an hour. Thus the walking route passes the alpacas and they do make a very odd noise. Rather like a grunt, but at least they do reply. Decoding it is not easy either.

Anyway, I thought alpacas were only shorn once per year.

I am listening tonight for an aurora. Maybe that only happens once a year too.



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