Continuing the discussion from It's time for.... the 2024 10m Challenge. (Part 5) - #100 by G4OBK.
Previous discussions:
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Answering the points raised by Pete, WA7JTM:
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I donāt know if there are regional differences between the USA and EU, but I find that 6m Es openings are frequent, in fact almost daily from mid-May this year to the present day. Sometimes they are short, other times they can be variable so that although any particular path may only be open for a few tens of minutes, others open in turn. Sometimes they are very prolonged, the longest I remember was 36 hours, on that occasion the transatlantic path opened in the evening. This all too frequently means that there is no path open from here to where an activation is taking place, made even more frustrating when you can hear chasers in other countries working activations that you cannot hear! But then, it is after all a challenge, if it was easy there would be no point in issuing a challenge!
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Yes, F2 openings are rare, but spectacular.
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I think most modern base radios have 6m, and the ubiquitous FT817/8 does well on the band. There are some HTs that cover 6m FM. In the end, if you want to work a band you will get a rig for it - and it only takes one experience of the āmagic bandā in full cry to make it essential!
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Yes there is a lot of digital activity on six, but thete are a good number of activators with that capability.
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The Es season is as you say but I would add May and January, F2 if we get any is a bonus, and donāt forget the occasional chance of Ar, I have had SSB contacts by aurora, a wierd experience! With the sun so active there may well be some opportunities for Ar.
The bottom line is that 6m WILL be a challenge, which is why it was chosen for a SOTA challenge. There is absolutely zero point in issuing a challenge for an easy band, overcoming the difficulty is the whole point. The SOTA Challenges were started with the intention of encouraging activity on underused bands, and six certainly qualifies! Those scores will be EARNED, and therefore more highly valued. I expect that we will get a decent level of participation, we Sotari are always up for a challenge!
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Iām not sure 6m WILL be THE challenge.
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Hi Brian,
Unless you and WA7JTM are at the same latitude, I doubt the validity of any conclusions that could be drawn from the Es experiences of each station. Iāve experienced 6m from two main locations, the first is my vk1 location where Es and F2 etc occur rarely and could not possibly be compared to the propagation you have described, allowing for the inversion of latitudes from north to south of course. The Es contacts you describe are almost fantastic compared with what is experienced here in vk1. Our latitude is 35 S, approximately. Yours would be 50+ N?
The other location I have operated from is Brunei, V85. 35 years ago. Latitude 5 N approx. There one could operate all day on 6m working JA and a few YB stations, using 60W output from a 5 el beam, on SSB and CW. I have a shoebox full of JA 6m QSL cards from over 200 JA cities and the thousands of contacts I made over 2 years were a far cry from what I can do from VK1. My brother Chris has a 6 el beam and max legal power available, he works ft8 contacts when the band is open, but says any time he checks the ssb/cw end of the band it is dead quiet.
If I took those experiences and assumed they were normal for 6m all over the world, I would be asking you what is wrong with your station if the activity level you report is considered ānormalā. Clearly that would be a case of generalising from the specific and any conclusions drawn could be very misleading.
73 Andrew VK1DA
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When I was QRV on 6m from about 53N (1992-1999) there were about 8weeks of active 6m E season. Normally the last week in May to middle of July were you would have a period of lunchtime-early afternoon and then late afternoon-early evening of European Es. Some days only one opening, some days none. But I never recall there being 2 days on the run without something happening. Some openings could be localised and others were massiveā¦ from OY in the North round through LA/SM/OZ/ES and then 5B4/9H1 to S5/9A/I/OE/SP/F/EA/ZB. Youād hear weak EU Es say 9pm local and then East Coast W1/W2 and VE1 stations on a few days.
Iāve heard a few massive openings starting in LA etc. early morning and have run and run and run all over Europe for over 24 hours. Probably 1 super massive opening every other year.
Iāve heard EA8 and OYs on the same frequency at the same time each with a massive pileup depending where I beamed with my 25W to a 5ele beam low down was just adding to the QRM. Iāve worked 5T5 Mauritania, N. Africa CW for one of my first ever CW QSOs and Iāve worked 7Q7 Malawi, southern Africa) on SSB.
Iāve had SSB, FM and CW QSOs on tropo, Es, Es assisted TEP, Aurora and Auroral E. I donāt think I managed an F2 QSO in that period. But I very much doubt Iāll be doing much 6m SOTA operation. I seem to have got the 6m magicness out of my system.
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Iād forgotten about auroral E, despite having experienced it a number of times!
Iām told that the season for Es starts earlier and finishes later for the Mediterranean countries, about 10deg further south than here, they also seem to have a higher frequency of openings. They would be about the same sort of latitude as the northern tier states of the USA. Iām not sure but I think that we should be thinking in terms of geomagnetic latitude, if so then in effect that would move the USA north! Andrews latitude would be about the same (with sign reversed!) as the Med. It would seem that something other than simple latitude is affecting the differences between regions. There is a lot to be discovered, perhaps the SOTA challenges can provide research data.
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Iād not be surprised to find that Es formation looks more complicated the deeper you look. For instance, Iāve read discussions linking Es with jet stream activity, and I can see how changes in air pressure (and thus atmospheric density at altitude) brought about by air movement (which might also be affected by physical geography) might affect the formation of zones of ionisationā¦
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I highly recommend reading Jim G3YLAās daily Es blog during the season: PROPquest | Es Blog
I was having a hard job trying to understand the concept of āatmospheric gravity wavesā that gets talked about in relation to Es creation. I had chance to talk to Jim about this at this years field day and Jim gave me an analogy to what happens with a fast moving stream that flows where there are rocks on the river bed, the rocks causing disturbances on the surface even when they are much deaper. In the atmosphere the winds flowing above mountainous regions similarly create disturbances higher up - these are the āatmospheric gravity wavesā. Well thats how I understood it anyway. Which is a way of agreeing with @M0LEP about the affect of the underlying physical geography.
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If it was as simple as that you would expect the ionisation to always be in the same place for similar alignments of the jet stream, since the mountains donāt move, and for the ionisation to change its position in accordance with movement of the jet stream. Changes in the ionisation seem to me to be more rapid and random than that, changing on a timescale of minutes. In addition you often get Es when the jet stream is nowhere near the assumed location of the reflector.
Another theory that I have heard is that thunderstorm activity influences Es, but I keep a real time lightning map on the desktop and I see few signs of correlation. These influences may have an effect but it looks to me as if they are secondary, and I donāt know what is primary.
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Oh Iām sure its not as simple as that, I was just trying to point out one of the contributiing factors. I know Jim is still researching Es propagation. On his website his summary says:
Weather features have been known to generate turbulence, which in turn produces gravity waves that can propagate upwards to reach the E region, where in turn, they interact with the atmospheric tidal winds and may result in Es (Sporadic-E).
Other weather features which may cause weather turbulence are thunderstorms, and rapidly changing upper air patterns.
I think the key words here are āmayā. But Iāve been reading Jimās daily Es blog and his Es prediction map page (PROPquest | EPI) over this season and his predictions based on these weather conditions do often correlate with the regions from which I can hear stations on 6m. Thereās a nice graphic on Jimās QRZ page showing all the various components that may contribute to Es, its still a very active area of research.
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Back to 10m ā¦
(C) Google Earth 2024, radio paths courtesy https://www.adif.uk/
10m was still okay this afternoon to some parts of Europe despite the summer doldrums. [10W CW to 40/20/10 trapped EFHW inv.-L on 5m pole on Englandās lowest SOTA summit]
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A thank you and Kudos to Jerome @F4IVI
If you read this - thank you Jerome. After seeing your spots on SOTAWatch I find I can work you activating in the south of France from NE England on the 10m band on most of your activations during recent weeks.
In my log 7 X 10m QSOs with you this month, and 2 X 10m in July. Today you were a good strong CW signal at 12:56z coming from F4IVI/P on F/CR-328. I was using free electricity from my energy provider Octopus from 12-13z. I guess it is some kind of experiment with their customers. I could have wasted more by turning the linear on but I didnāt! During the hour I was able to draw over 12 kW from various appliances (Now I am going off topic and ramblingā¦)
It was Greece and Stavros SV2RUJ (with Ionna) that UK Chasers could rely on for 10m QSOs early in the year, but now it seems for me certainly, it is the south of France!
73 and MNI DX OM
Phil G4OBK
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Simon GW4TJC/P on GW/NW-038 is getting out well on 10m this afternoon on FT8 (Ā±1500z). In the dead zone unfortunately here in North Yorkshire 
73 Phil G4OBK
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For about 30 mins in late morning I was hearing VK and VU on 10m SSB, then Herbert OE9HRV was blasting in at S9 on SSB but other than a few weak Iberian chasers no other Es stations were heard. There was a brief opening on SSB to the Middle East on the 22nd, also about a half hour long. I did wonder if these brief F2 openings were triggered by solar flare UV but havenāt followed the thought up.
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OK Brian. Didnāt look around for DX today on 10m but the better equipped VK fixed stations can be heard here most mornings. CT2IWW/P Paulo was in my headphones on SSB at 1534z on a different summit to his morning one. Probably my last 10m QSO today. Like you Herbert OE9HRV was booming in early this afternoon on 10m.
73 Phil
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Hello Philip,
Nice to read you 
Thank you too dear OM, as 10m is so difficult
Especially when my Jpole broke and I had to use my pac12 , working far less good.
Propagation is always surprising me 
Take care, CW or SSB or FT8 soon my friend.
73 88, J. F4IVI
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20 Sept was surprising on 10m SSB. Can you work Chile 6200 miles from California on a summit? How about on 5 watts? Been done often on CW, but try on SSB with both stations using verticals. Impossible? It happened yesterday. First time in my 70 years of ham radio. KX-3
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Geoff vk3sq
It was certainly better compared to the last couple of weeks. I had a bit of a pileup, but it was all within the US.
Hereās hoping it continues for a while.