No sooner did I think I had seen the last of idiotic people from the 50MHz community than I received a reply from another one.
Noctilucent clouds. Apparently, if you have personally never seen them, they don't actually exist for anyone!
In this email, the dear operator wasn't initially entirely dismissive of 'these clouds of [mine]'. Clouds of mine? Hmmm. Sounds familiar.
He then proceeded to tell me how people got "very excited" on chat rooms about the appearance of NLC, because they believed there may be a link between them and propagation at 50MHz.
"Yet, I have gone out to look and seen nothing?"
That inclusion of an incongruous question mark is very social media-esque. It's a different way of saying "If these clouds really exist, how comeI haven't seen any?" The 'I' is more important than anything else, in other words.
The man later revealed he had higher ground to his, erm, north and north east - precisely the area that NLC are normally seen, typically at low elevations!
I patiently referred the gentleman in question to various databases and scientific papers spanning decades, should he wish to see proper evidence for the existence of NLC, seeing as, he claimed, the weather was always too poor for him to check for himself.
Well, the weather has certainly been poor this year. But I'm not quite sure what this man's been doing in other years. Probably looking up into the sky whilst it was still full daylight, I guess...
A little 14MHz WSPR monitoring overnight shows that VK3QN, fixed on a long path, 130 degree beam heading from Australia, is now peaking roughly 20 minutes earlier than it did around midsummer, just over two weeks ago. Quite a sensitive indicator of the year's progression.
14MHz reception of 5W WSPR signal from VK3QN, 2020 July 07-08.
VK3QN 14MHz fixed long path array. Image (C) VK3MO, with permission.
Sorry if you've just arrived here from the blog of PE4BAS, but his superb recording of 50MHz bursts, which are certainly not aircraft scatter, and possibly not meteor scatter either, is really worth listening to.
So far, I am only hearing these precise type of bursts on long DX paths, in my case, to the US, and in Bas' case, on a path to JA. G4RRA also find these bursts on longer DX paths, and thinks they are meteor scatter. Perhaps the longer path simply gives a greater likelihood of such scatter, perhaps even combining to give multi-hop?
I'm not sure how we disentangle one thing from the other, except to see if the effect on DX paths increases during the upcoming Perseids (around August 12), by which time PMSE and Es will be far less common as we reach the end of the summer season.
Bas' poetic description of waves lapping at the antenna is very nice:
A diversion today, with construction of a simple hydrophone, to see if we can hear the sounds of our resident pod of Harbour Porpoises.
This is very easy to make, using a cheap and readily-available piezo speaker, which you can buy from Ebay or recycle from those musical greetings cards; both are remarkably sensitive.
All you need to do is glue the piezo sounder to the face of some plastic (I used perspex, 3mm thick), place an 'O' ring seal around it, and bolt the top plastic to this. Don't overtighten. In fact, I recommend you use brass or copper plate, rather than plastic, as plastic is prone to cracking.
Sealing the hydrophone. The gap between the perspex edges was later sealed with silicone as a first-layer barrier. I also added silicone under the bolts. But the O ring probably is enough on its own.
To pass the wire to the outside world, I cut a small 'nick' in the 'O' ring and added plenty of silicone sealant to restore the seal as the bolts clamp the housing shut - you can see this in the photo.
UPDATE: The perspex, somewhat predictably, is a little too fragile, and tends to crack. My second version is two food can end pieces, one from the top, one from the bottom (they will tend to give sizes slightly different, that fit, one inside the other. A small nick to allow the cable out, and sealed between plates with plenty of silicone, makes a much simpler, cheaper and robust microphone housing.
Piezo mic is between the two can lids. You can varnish or paint this (front) side to protect from corrosion.
I further siliconed the mic assembly to an old perforated aluminium backing, onto which I can attach weights and a rope for deployment.
Reverse of the mic assembly, silicone coming through the holes to provide secure attachment (I also soldered copper hanging hook to the mic assembly before I inserted the mic (obviously!))
No interesting recordings beyond the kitchen sink yet (it's raining with a 90km/h wind again), but the hydrophone works well and has very low noise. It's simply connected to a cheap handheld office sound recorder, the input to which can be monitored using some headphones.
Great fun! Costs were: perspex £3, piezo (5 pack) £3.95, bolts, cable, audio jack about £3. A resonable quality commercial version is a minimum of £60.
The past week has been interesting, challenging and, to some degree, despairing.
Interesting, because I've had a lot of fascinating discussions with the top scientists in the field of atmospheric science.
Challenging, because this field of endeavour attempts to study a region that is 85km up, inaccessible to all but sounding rockets.
And despairing, because I have really seen the worst of the amateur radio community. Luckily, I also saw the best.
The discussions were about the potential for PMSE to play some part in 50MHz radio propagation. Being science, one professor was sure PMSE has no role, whilst another said he "would not be surprised" if they did provide long-distance propagation - providing many reasons why that could be.
None of this, of course, is the same as saying that PMSE do, as a fact, assist DX radio propagation. Nothing is settled, but there is reason behind wondering about this. This is a subtlety that escapes some of the 'big gun' 50MHz operators I've had the distinct misfortune to come into contact with this week.
PMSE seen over mid-Wales by 46.5MHz radar.
Some of these 'big guns' behaved very predictably in not responding at all to enquiries about their beam headings during Europe-JA openings at 50MHz. Sadly, one of them is Welsh. I suppose their egos are so big that anybody asking a question is a 'weakling' that doesn't know something - unlike them, who know everything.
Indeed, I was rather amused to read the response of one person, who has a vast collection of VHF antennas stuffed into a small area such that he must never have heard of adverse antenna interaction. I suppose the drive to be the biggest and best is just too much of a draw for some.
This man - I'll spare him the embarrassment of identification - did at least respond. Some of his response could be taken to be rational. But much of it wasn't. Having admitted he had never heard of PMSE before, and that was only "what YOU" call it (?), he then proceeded to very confidently - but very wrongly - decide PMSE was what radio people call "Aurora-Es".
Nope.
And, apparently, only "some researchers" call PMSE, erm, PMSE. He didn't enlighten me as to what the 'other researchers' call 'it'. Again, ?
In a second response, my dear correspondent was "sure" he'd "seen a paper somewhere" (haven't they all?) that showed PMSE only occur due to aurora, and that my information to him about how they actually occur - accepted in broad detail by all scientists - was a load of rubbish.
The underlying physics that leads to PMSE is pretty well understood, and aurora has no primary role in their formation. A very recent study by the South African Antarctic programme showed that aurora (high geomagnetic activity) suppresses PMSE formation. Not very surprising, given that these energetic events will warm things up, not cool them down.
PMSE plotted on a restricted height scale. Image: MAARSY.
I never did receive the reference he claimed to have seen, nor any explanation of why someone so involved in 50MHz had never heard of PMSE, regardless of whether or not it is involved in radio propagation.
It was clear that this man simply wanted to dismiss absolutely anything that anyone else had to say as nonsense, regardless of how ignorant he was - and admitted to being - and how self-evidently accomplished, yet at the same time careful in their conclusions the atmospheric scientists and their support staff are.
It really is very sad. I had a think about what motivates people like this. In the end, they are idiots who can't accept their very significant limitations but who feel that typing rubbish neatly out on a screen lessens their stupidity. The vast money spent on chasing their dream of being the biggest and best in the 50MHz world makes them omnipotent, apparently. No need to work for a degree, a Ph.D, and a professorship. Just stick an antenna up, buy an amplifier and rule the world! I suppose building up your reality in this way must be very difficult to let go of and, evidently, it is.
And the best side of radio? The responses from Bas, PE4BAS, about his experiences at 50MHz. Others were equally lovely, including Jim Bacon, G3YLA - a professional meteorologist who once graced our TV screens. And Tim Kirby, GW4VXE. Nice, open-minded discussions, with questions, critical and supportive back and forth, and some useful data that helps us all - not just me - wonder about PMSE and any role they may have. A big thanks to all of them. The others? Well...
To relax from all this, why not enjoy some classic Echo and the Bunnymen: 'When You're Strange':
Well, it's been a windy, wet few days, but it started to look a little better this morning.
So, instead of our usual walk around a local lake, we decided to take the 14MHz WSPR receive kit along with us.
Cefni reservoir, central Anglesey, taken when I went up in a helicopter a couple of years ago. Huge cyanobacterial bloom due to a very shallow, highly fertiliser-polluted lake. Operating was from lower right, near the dam.
It took about a minute before someone told me I wasn't supposed to be fishing from the shore at the moment. I get this all the time, coast or lake. I should really have a sign, saying 'I'm not bloody fishing!' on it, to save my effort of explaining!
Anyway, I was interested to see if the freshwater would bring benefits. I thought the much clearer boundary between what is water and what is dry land might give a sharper difference in the signals assisted by water to the west, and those not, from the east.
For comparison, I ran my identical 1/4 wave vertical at home at the same time.
At the lake. Foam in the water is from a decaying cyanobacterial bloom.
I couldn't stay more than about 40 minutes, and there were only four stations coming in from the US at the time, thanks to very strong D layer formation.
But this was enough to show that the signals over the water - it is only a small reservoir - were up to 10dB stronger than those being heard at home. There was one case - AJ8S/1, where the lake signal was -14dB, but was not heard at all from home. That might signify an even stronger enhancement by the water, but we can't quite be sure by how much.
Beautifully, all the signals from the east showed only a median 0.25dB better signal from the lakeside, which is near enough to zero, and shows that the cut-off at the lake is, as I expected, very much sharper than that seen at the seaside, where there are large areas of seawater-saturated sand all around the antenna, giving good enhancements from all directions.
This result also confirms the noise assessment I made a few weeks ago, which was a difference of only about 1dB less noise at the seaside.
So, to summarise, lakeside = +8.5dB to the west, compared with my home antenna, and ~0dB to the east.
A few days ago, I wrote about the very strange-sounding signals heard at 50MHz, which I've never heard before, and only in the direction of the USA.
Superficially, some of the signals seem to be meteor scatter, and one or two people have argued very emphatically - usually based on a peceived 'long career' on 6m, that this is all the signals are.
But the question is: why is this supposed meteor scatter not present at other times? And for that, there is no answer.
I can imagine someone saying that it's meteor scatter plus Es, so that meteor scatter happening very far away is then bouncing off Es clouds. I think that would ridiculous, all things considered.
I heard this strange effect again yesterday (01/07/20). I could again confirm that all the signals affected by the peculiar propagation were from the US. It really does sound a little like meteor scatter, but again, why only when there is Es propagation to the US? 30-37s and 56s onwards are where you can hear the strongest effect:
I'm open to other explanations, but for the moment, I think it has to be very shallow, transient reflections from locally electron-dense regions of the E layer. Moderated 'Comments' is now open again for any ideas you may have...
