6m, Es to JA, and gravity waves.

Following on from a brief series of posts about summertime paths on 6m from Europe to JA, I undertook a mini-literature review on what science understands already.

I started off by thinking about E-layer detection by ionosonde.  That's because I didn't properly understand the detail.

I was very intrigued - but not surprised - to find a paper published only in March 2019, told of how Es intensity derived from ionosondes has been incorrectly assessed - for decades - because somehow, the entire community 'forgot' that a major component of Es layers is metallic ions!

As well as giving a crucial reminder that metallic ions - which are sourced from meteoric debris precipitating from higher up in the atmosphere - are important, it also shows how much we always have to check what we 'know' is actually not based on a basic mistake, made long ago.

I am no expert on 6m propagation, but it seems pretty clear to me that if you have a layer of metallic ions at the E height of around 100km (slightly above the mesopause), then those ions are going to move around in three dimensions fairly easily.   What we need to know is what mechanisms give rise to that movement.

Well, the usual cause that most texts on 6m Es propagation will give you is: 'wind shear'.  There's nothing wrong with this mechanism, and is neatly explains one way in which opposing wind directions lead to metal ions being concentrated in a thin layer.  Most scientists agree this is a correct model.

But wind shear is not the only mechanism.  We also have gravity waves.  These are simply waves in three dimensions that propagate upwards from the lower atmosphere - caused by various physical disturbances near the ground - and reach the mesopause, where they become unstable and 'break', just like a water wave, except in air and without the complication of two different media.

I then found, accepting it's fairly old by now, a professional scientist writing in the ARRL's QST magazine about what was, to him, the puzzling fact that Es has a strong seasonal bias.  His thoughts took him down what I can only really describe as a mental black hole.

To his credit Dr. Whitehead, unlike many folk, understood very well the critical importance of metal ions to Es.  But he then tries to explain the seasonality by suggesting that the metal ions must change in abundance with the time of year.  He then comes up with a rather convoluted mechanism that purports to explain this change.

Waves in a noctilcuent cloud layer, 2009.  The way sunlight is reflected off the waves' peaks shows how radio (also electromagnetism, rather obviously) could also propagate selectively off these surfaces.

But the phenomenon of gravity waves needs no such convolution of thought.  Their occurrence peaks in the few weeks either side of midsummer.  This is simply because the summer hemisphere's surface warms up strongly and quickly, leading to upward transport of enormous parcels of air.  This, by simple expansion as the pressure drops, leads to cooling.  By the time the parcels have reached the 'lid' of the mesopause, the temperature in summer at around 85km is a frigid minus 125 degrees Celsius or so.

Gravity waves just add somewhat to this background cooling.  They are kicked up by winds over mountains, thunderstorms causing local energy inputs, and even the other Es mechanism - wind shear.  Even infrasound, caused by ocean waves, is often given as one mechanism likely causing gravity waves.

As these waves break, they lead to localised extra cooling.  Often, they are the sole reason how the mesosphere is tipped just over the frost point, so that visible noctilucent clouds form.  Without the gravity waves, NLC - or at least visible NLC - might not have formed on some nights.

So, back to 6m summertime propagation to JA, and such far-flung regions.  First, credit to IK3XTV who, as long ago as 2008, published his thoughts on QSL.net about the role of gravity waves from thunderstorms in radio propagation.  I think we have to find IK3XTV was a considered analyser of what was going on, even if he was only really thinking about gravity waves from storms, and not all other mechanisms.

PMSE ('ice') occurs not in a single, narrow layer, but across several km in height.

What, then, do we know?

(1) We have a layer of metallic ions which become coated with charged ice in summer that occur roughly at E height.  This height is not fixed, but varies by many kilometres.

(2) The mesosphere (about 15km below E height), is largely quiescent in winter, when there is little energy to disturb it from below, but highly disturbed in summer.

(3) These disturbances are caused by - and form - large-wavelength wave structures at the mesopause.

(4) Windshear is not the only mechanism that can concentrate ions.  Gravity waves also can.

From these three things, we can pretty confidently suggest that it's very likely the waves present rapidly-varying reflective (or refractive, if you prefer) surfaces from which 6m signals can be propagated. 

The fact that 6m propagation to JA is transient, and not permanent during summer is simply because it requires the correct alignment of different areas of 'wavy structures' to allow a signal to hop successfully from Europe to JA.  This alignment, because the wind velocity at 85km is up to 400m/s, is never likely to last for very long for any given two stations.  But the occasional, continuous background of mass upward movement of gravity waves can give rise to several hours of conditions that will allow such propagation.

Altogether, this mechanism for explaining summertime Es propagation at 6m seems entirely non-controversial and simple.  But responses to JE1BMJ's article have tended to bring about a dismissal from other operators who think they know better.  This dismissal seems simply to have been yet another manifestation of people - often a bit older - who have become rigid in their thinking, coupled to not actually knowing very much about the atmosphere they rely upon.

But there's plenty we can do to shore-up the evidence.  Es propagation isn't limited to 6m, and my own interest with 12m, for which I'm much better equipped, shows it has a big influence there, too.  Over the past few days, I can see that, when there is NLC and/or PMSE present, I will get FT8 signal reports around midnight from at least the distance of Europe when beaming to the NNE.  On nights when there are no NLC or PMSE, it appears those signal reports do not occur, or are much more limited.

In the end, should we be be surprised if a layer of metal ions, with some charged ice as well, and disturbed in these complex and beautiful ways by waves, sometimes gives rise to 6m DX?  We may not be able to prove (yet) that any given QSO is due to this mechanism, but, in general, I think it will explain most such QSOs.

Where I will yield is that there is plenty more evidence to gather, and thought to give!

PMSE/NLC: more food for thought.

Yesterday saw extensive radar returns from mesospheric height above mid-Wales.  The physical 'thing' that this MST radar detects is ice - very small particles of charged ice that form around metallic meteor debris in midsummer, when the mesosphere is, seemingly paradoxically, at its coldest.  The individual ice particles are about the same size as the smoke in cigarette fumes - i.e., fractions of a micrometre, or the size of a modest bacterium.

Here's the plot from yesterday:

In the hours around midnight (27-28/6/19), there was a very extensive area of noctilucent clouds extending, visually, 120 degrees along the horizon.  Here is a stitched panorama of the view from north Wales at 23:44UT.  Incidentally, you can see the hills of the Isle of Man, 42km away, on the left of the sea horizon:

You can see, especially at the right, that the display was visible all the way to the sea horizon.  At zero degrees apparent elevation, the NLC is about 1200km away.  That's the latitude of central Iceland.  In fact, due to atmospheric refraction, it's likely to be somewhat further even than that.

So, this NLC was clearly covering a large area of the polar region, and is likely to have been covering most of the pole.  The daily AIM satellite 'daisies' show the typical extent, in this example, for midsummer's day (the satellite 'sees' at any illumination):

I did manage to fire a few FT8 'CQs' out last night on 24MHz, but I was reluctant to steer the Yagi from due east towards the north, due to very unseasonably high winds of over 60km/h.   Even so, my signal was heard:

The previous evening, there was no NLC.  When I sent the same signals at much the same time, no reports were returned.

More interestingly, perhaps, that this mid-late morning (28/6/19) saw several stations from Japan come through to western Europe.  I can tell the signals were arriving at low angles, because I have a low hill to my NE, and was entirely unable to get a signal across to JA, despite receiving some fairly strongly.  But MW0ZZK, a well-equipped station just a few km away from me, was merrily working several JA through the morning.

I think all this tends to suggest that some kind of organised, long-term campaign of relating higher HF and VHF openings to JA with mesospheric phenomena is well worthwhile.  I think we can be pretty confident it involves charged surfaces, waves, and multiple hops.  At least, that's my thinking...

12m - on fire!

DX got going quite early on 12m yesterday, as I completed a QSO with VE3BW at 11:05UT.

The afternoon continued with a modest number of US stations coming through, but nothing much to write home about.

Much later, just before and then after sunset, 12m sprang into the kind of action more typical of sunspot maximum, as strong reports came back from the American mid-west.

Here's the PSKreporter plot at around 21:25UT.  Notice the incredibly strong reports from Oklahoma (+7dB) and Cincinnati (+12dB).  I was transmitting a maximum 40W from my 3-ele LFA:

Some moments later, the Cincinnati report increased by a factor of eight:

Pretty remarkable and unexpected stuff!

UPDATE: at teatime the following day (25/6/19), I heard a West Coast station who, rather sadly, couldn't hear me, though at around 16UT, it was a bit early for that degree of DX on 12m.  Maybe later?

Midnight transmissions.

Last night, I opened my door at 11am, at least 30 minutes before it's usually dark enough for noctilucent clouds to be seen, to witness this jaw-dropping scene:

The display was so bright (maximum on the 1-5 scale), that people were stopping their cars and getting out to have a look.  Without doubt, this was one of the brightest, if not the brightest and densest I  have ever seen in 20+ years of observing.

So extensively was the display seen that this morning's BBC news was even carrying stories about it.

As the sun descended and the display became dimmer, I spent a few minutes sending transmissions at 24MHz on a beam heading of 30 degrees.  Although it wasn't necessarily linked to the NLC or associated PMSE, I was surprised to find these reports coming back at between 23:47 and 23:54UT:

What made me wonder about the possible role of goings-on in the mesosphere was the fact that, after 23:54UT, despite transmitting every 30 seconds until about 00:05UT, I was not heard again.

It's very possible (i.e not certain) that the transient reception reports were due to reflections by wave structures, which were present in abundance in this display.  Indeed, the entire display was probably the result of a localised upward energy transport and wave breaking in the mesosphere, because just two hours later, as we moved into the morning sector in Wales, the NLC display had disappeared entirely.

Because the waves move very fast (anything from ~80-400m/s), this can explain temporary propagation effects.

After writing this post, I discovered PA0K had a superb image to show, and PE4BAS had even more interesting events to report up at 50MHz.

Close-up of gravity waves breaking in the mesosphere last night.

Midsummer maintenance.

Well, it really is gorgeous weather in North Wales for midsummer today!

Having had no sleep overnight due to observing noctilucent clouds until 2am, and having to get my son off to the school trip bus by 05:30(!), today hasn't been the most productive.  Mind you, I did spend some time up a ladder at 3am, greasing a length of cable on my tower.  It's very light at 3am now!

So, getting on for teatime, I decided to take a quiet sit-down and look at one of my tower's grounding points, and see if it was still working properly.

Now, tower grounding is one of those things that, quite often, we attach in a hurry, never really sure if we're doing it correctly.  Or, at least, that's how this particular ground point was installed!

One of the first questions that came to my mind with a sectional mast was: do all the sections have an adequate - or any - electrical connection with one another?  If not, then there's little point in attaching a connection for ground at the bottom of the lowest section.  In that case, one could of course 'daisy chain' each section.  Whilst mechanically easy, this arrangement would make for a very slow and complex lowering of the tower when bad weather unexpectedly hits!

It turns out that, testing with a simple multimeter, there was a good connection between the ground rod and the central section, showing that each section is electrically in contact with one another.  So the 'daisy chain' isn't needed.

After cleaning the ground connection point of one leg, no sign at all of corrosion.

One worry at the time of installation was that of corrosion due to the use of dissimilar metals.  I decided to use thick, tinned copper braid for this connection, because it's flexible and allows the tower to be luffed over without disconnection or other problem.  But the tower is galvanised steel, as is the hose clip securing the braid to the tower leg, and there's a lot of sea salt thrown at the whole thing during our frequent, violent storms.

So, off came the hose clip.  I was surprised to see the braid at the connection point was still - even after six years - bright and untarnished, like a new piece off the roll.   There was absolutely no sign of any electrochemical corrosion due to the dissimilar metals.

Very useful stuff.

I cleaned the whole thing, removed all traces of grease with acetone (nail polish remover), and applied a liberal amount of Innovantennas' wonderful, if extremely messy, 'ConductaSeal' conductive grease to the connection.  This is moderately expensive for a very small tin, but it lasts for years, and finds ever-more uses as time goes on.

Simple, and now covered in conductive grease, but it works!

There's also a much heavier, thick steel cable ground connection, more for lightning protection than anything else, off another leg of the tower.  That also proved to have a good connection to the other sections, so all seems well, if not beyond some improvement one day.

Russian Dominoes result

Well, I managed to get some kind of ranking in the recent Russian Digital Radio Club's Domino mode contest!

Hardly a big competitor, I had the idea that it was best to try to get a handful of QSOs in as many bands as possible.  But it seems I should have continued gathering calls on the easier bands to move up the table.

A 'Double 4' was gathered according to the rule: '4 x 4 = 16 QSO - the subgroup of participants who worked at least 4 QSO in DOMINO on each of any 4 bands.'

Not that I really care.  The interest was in doing something different, and I did enjoy the departure from the mindless FT8.

Apparently, there were 112 entrants, but I heard only a handful, and many contacts on different bands were with the same operators.  Propagation also was not very good at all.

Still, a nice new certificate for the collection.  Respect certainly due to the RDRC for their incredible efficiency in administering the whole event.

28MHz - all night long.

Conditions on the upper HF bands, and into the VHF ones, too, are proving very strong and interesting as we move through midsummer.

Hearing plenty of FT8 signals at 28MHz last evening, and lots of DX action on that band and 50MHz earlier on, I decided to keep WSPR running at 28MHz overnight.  My 5W was picked up, if weakly, by FY5KE, itself very pleasing, but I was too late to catch any further DX. 

Interestingly, signals from first-skip distance, though not very numerous, kept coming in (and being received from me) all night long.

In fact, FY5KE seemed to hear my 10m signal in much the same fashion, but much stronger, as he did a couple of weeks ago at 20m, i.e. a peak around 22:00UT:

 Meanwhile, back on 10m, EA1FBU was received here, peaking also at about 22UT, then intermittently being heard into the early morning:

IU1DZZ also reached a peak in the very late evening, about an hour later than EA1FBU:

IU1DZZ heard at MW1CFN, 28MHz, 5W WSPR.

In the reverse direction, I was also reaching a peak signal strength with much the same pattern, in this example, as received at 10m by OE9HLH:

Well, I was impressed...

Hardly a massive achievement for most, but I managed my first ever transatlantic 6m QSO this evening.

That old magic of something new...

Armed with just 50W from a 2-ele quad, but a good aspect out over the Atlantic, I managed to complete a QSO in a big FT8 pile up with HI3T - Ted Jimenez - in the Dominican Republic.  If the path was very low, the ERP was about 630W.  At somewhat higher elevations, more like 315W ERP.

6700km - very happy!

I thought it might be a good night, as I briefly heard an Eastern European commercial FM station on 94.70MHz in the car at 17:50UT, and switched on the rig straight away when I got home.

Old, cheap, and slightly rickety, but it worked!

Terrain analysis under HFTA (ARRL).  Up to +11dB gain at just 3 degrees.

Certainly, I need to keep the quad aimed across the pond more often from now on.  Maybe time for a new support and rotator?  But then, I'm still thinking about 2m SSB.  So much to do.  So little time.  Even less money...

A wow! moment on 12m...

Well, 12m has been open fairly regularly to the US in the past couple of weeks.  But I nearly fell off my seat when I saw this report come back for 25W through my 3-ele LFA!

So much for dead upper bands during solar minimum!

Brendan Trophy, yet not.

My blogging colleague, EI7GL, told us yesterday of fantastic news about a successful trans-Atlantic crossing at 144MHz.

The FT8 QSO was made between Cape Verde and Guadeloupe. 

Unfortunately, the rigid rules of men mean that, whilst the crossing is in fact a greater distance - by 26% - than between Ireland and Newfoundland, the QSO will not qualify for the Brendan Prize. 

Is this non-qualification for the prize fair?  Here are the rules, as presented by the IRTS web site this morning:

'The Brendan Trophies and Brendan Shields will be presented to each of the operators of the two amateur radio stations which first establish two-way communication in the relevant category between the continents of Europe and America (North or South) within the Two Metre Amateur Band'

Well, so far as I can see, that pretty much settles it.  Whilst Guadeloupe is on the North American continent, Cape Verde is part of the African continent (despite being 570km off the coast of mainland Africa).  It certainly isn't part of the European continent.

A couple of years ago, inspired by terrain modelling that predicted about 19dB gain (turning 100W output power into 8kW ERP!) towards the USA from a modest 6 element Yagi from my QTH, I thought about giving the Brendan Prize a go.  It seems I still could, although I think it won't be very long before someone will do it now.

At a low angle-optimised height of just 2m (yes, two metres!), I can get 19dB total gain with a 6-ele Yagi.

You might think me woefully overoptimistic, or even arrogant to believe I could do it.  But another factor that led me to think I could is that very regular operating from a comfortable, home location is the key to catching the right conditions.  Operating a DXpedition type outing for a week in late summer, as many have repeatedly done, is too short a time.  Early to midsummer is also more likely to produce a range of propagation effects that might bring about the sought-after results.

The main reason I didn't bother was that I don't have any 144MHz equipment, although I could buy a cheap transverter, I suppose.  But I'd rather a decent 2m SSB rig, which I can't really justify.

The other reason was that one of those who try every year - with huge ladder Yagis and high power - to achieve the qualifying QSO was of the firm view that very low angle paths - such as the one likely to have brought about the Cape Verde-Guadeloupe QSO - probably suffers far too much atmospheric extinction to be considered important. 

It does now look as though this 'expert' opinion was misguided, and I always thought so after I heard it.

Let's visit the FBI!

 

 

I came across a fascinating link to declassified FBI documents today, all about assessments of amateur radio as a potential intelligence source about the then Soviet Union.

The very first page I looked raised a wry smile.  The FBI were clearly unimpressed by the fact that politics is rarely of any on-air interest in radio, and that all we do is talk about the hobby!

The FBI might have been more fruitful in examining how amateur radio transcends differences, and brings people together.

Far East DX

The author of RadCom's HF section seems to have put me on his mailing list of late, after I sent him some long-term data about 12m propagation, published this month in the RSGB's magazine (even though I am not a member!)

He tells me about a new DXpedition that is, mercifully, not a holiday outing of ageing, white, rich Americans this time.

R205NEW is to be active from today (14/6) only until 18/6., from Ioanna Bogoslova island, just off the NE coast of Russia's highly volcanic Kamchatka peninsula.


Propagation predictions from the major web site facilities are woefully out of touch with reality at present.  R205NEW is likely to be a short and long path proposition from Europe, with a distinct possibility of propagation even at the higher HF bands.

PMSE, NLC, and other things rarefied.

I was very interested to learn from fellow blogger, Bas, PE4BAS, that radio friends in more northerly latitudes had, earlier in the week, enjoyed extensive contacts on 6 metres with Japan and other far-eastern regions.

I thought I'd take a moment today to write about the mesosphere, and ideas on how things that happen up there may allow DX to occur at 6m.

At the moment, as midsummer rapidly approaches, the middle atmosphere region known as the mesosphere, is undergoing rapid cooling.  Temperatures there dip at midsummer to about minus 125 degrees Celsius, making it the coldest region of the atmosphere.  This is because of strong upward transport and expansion of warming air from below - a bit like how a refrigerator works.  The graphic below shows how the mesosphere exquisitely follows the changing seasons.  You can get up-to-date data here.

AURA satellite-derived temperature and water levels over several years at mesopause height.

The mesosphere is host to many different, but related phenomena.  The degree to which these things are all related is not always a settled matter, but they are undoubtedly related.

PMSE - Polar Mesospheric Summer Echoes - are regions of ionisation that scatter radio frequencies, probably by constructive interference (simple addition of waves), from the approximate range 45MHz up to, on occasion, GHz levels.

Recent PMSE activity over mid-Wales.

PMSE is not at all well understood.  But they occur at much the same time as noctilucent clouds (NLC), and in the same region of the atmosphere.

NLC are clouds of extremely small ice particles of the order of 1 micrometre in diameter, that nucleate around much smaller, metallic particles of meteoric debris.  NLC occur only in the period late May to early August each year, coincident with temperatures being low enough and water levels high enough, for the frost point to allow them to form.  They can only be seen in the approximate latitude range 45-60 degrees N and S (there is practically no inhabited land in the southern hemisphere for them to be seen from - and it's almost always cloudy anyway!)

Due to their great height - typically 80-85km - the clouds remain sunlit in the NW-NE sky during midsummer's night-long twilight.  Most displays reach about 15 degrees in elevation, with occasional displays covering the whole sky.

A late season NLC display, early August 2001.

There are no known records of NLC prior to 1885, probably because the mesosphere had then reached a tipping point after roughly 100 years of the Industrial Revolution had warmed the planet just enough to allow their regular formation.  NLC are probably one of the earliest manifestations of climate change.

I've studied NLC and, to a lesser extent, PMSE, for many years, and operate a Facebook and Twitter account aimed primarily at public understanding of these phenomena.  This week, @newman_ronan decided he would become the latest 'expert' on PMSE:

I know it's the Trump era of 'truth doesn't matter', but sadly for Mr. Newman, his assertion of fact is simply wrong.  A 2011 peer-reviewed paper (Atmos. Chem. Phys., 11, 1355–1366, 2011 (Coincident measurements of PMSE and NLC above ALOMAR(69◦N, 16◦E) by radar and lidar from 1999–2008) N. Kaifer et al...) explains succinctly why:

Mr. Newman chose not to apologise or make further expansion on his assertions, so he ended up banned from my Twitter account - the only one ever to prompt such action.

The important thing for us is that PMSE are strongly, but not perfectly, related to NLC.  The imperfection is almost certainly simply due to some NLC not reaching a point where they can be detected visually.  

PMSE, incidentally, also occur at much the same time as winter Es does, which is usually explained by enhanced meteoric input at that time.  It's much too warm and dry in the mesosphere for NLC to occur then.  An alternative explanation for winter echoes could lie in the knowledge of a teleconnection between northern and southern hemispheres at mesospheric height.

The question now is, do any of these related phenomena of the mesosphere contribute to 6m propagation?  

Well, there has certainly been plenty of debate about it - and even what appears to be  entirely reliable evidence.  For example, this neat account of PMSE from a ham radio perspective tells of JA contacts during midsummer.
 

Gravity waves modulating NLC ice particles.  PMSE are modulated in the exact-same way.

The original account by JE1BMJ of Short-Path Summer Solstice Propagation (SSSP) can be read here.  Many of you who have contacted me, wondering about 6m, NLC and PMSE, will be very interested to absorb it, I'm sure.

I am no expert in 6m operating by any stretch of the imagination.  But the underlying ionisation structures that are modulated by shear wave turbulence and gravity wave breaking in the mesosphere surely present themselves as obvious ways in which, at the very least, they might provide a 6m propagation path over the North Pole.  The brief openings mentioned in accounts of 6m SSSP are almost certainly due to the rapidly-changing wave and other structures that occur in the mesosphere, where the underlying NLC and PMSE particles are moving westward at speeds if up to 400 metres per second!

As for sporadic E propagation, well, I'm no expert on that either.  But, lying just above the mesopause region, it seems to me that Es has the same fundamental physics as PMSE, in that they are both simply complex areas of ion 'clouds' - both (if they are indeed distinguishable from one another) ready to reflect radio waves from our antennas. Some interesting academic stuff can be read here about possible relations.

Things have changed fundamentally in amateur radio recently, thanks to the plethora weak signal digital modes now at everybody's ready and free disposal.  There is a lot of activity at 6m, so plenty of opportunity now to gather more data and see what they tell us.

FLDIGI - some help if you're new (or just frustrated!)

This week, I turned again to FLDIGI, a great piece of software for what are, these days, sadly underused but very capable weak signal 'ragchew' digital modes.

For modes like HELL, OLIVIA, DOMINO and so on, the choice of software is very limited - you can choose FLDIGI, fairly easy to understand, MULTI-PSK, which very much isn't, and HRD's Digital Master-780, which I've never really found very intuitive, either.

So, the aim was to get proper CAT control under FLDIGI.  This is important for challenges and contests, so that the frequency is recorded accurately in the log.  It also speeds things up.

Now, you can of course use FLDIGI without CAT control, as I did for very many years with OLIVIA.

But you have to load an associated piece of software - FLRIG - in order to achieve CAT control.

When I read about this - which was not very well highlighted anywhere - the advice was to make FLRIG - the CAT program - run automatically when FLRIG was started, which is simply done by checking a box in the configuration settings of FLDIGI.

On first doing this, everything worked just fine.

Then I switched off, only to find it wouldn't work the next time I switched on!

After lots of changing things around, I had to ask the FLDIGI user group, which is actually very helpful and quick to respond to problems.

So, here's what I eventually learned:

(1) FLDIGI works with proper CAT control when you manually start FLRIG first, and then start FLDIGI.  VFO changes are properly reflected in software and rig in both directions.

(2) If you select 'autorun' for FLRIG under FLDIGI's configuration, then CAT will generally not work.  I have no idea why, but it's not really important, because (1) works fine every time.

KB7AA - lonely spot

Always good to add further evidence of outstanding performance, thanks not to me, but the antenna environment.

 

This isn't, as some occasionally think, to show off.  It's because I've had so many (mainly US-based) operators dismiss antenna environment as not very important that I really got fed-up with their ignorance and reliance only on big antennas, big power.

So, for the last time (maybe!), here's yet another EU-unique RX spot (of KB7AA, time period ~19:15-07:15UT, 2019 June 13) from my simple wire, vertical delta loop with base at 'just' 2m.

Incidentally, the VE7 spot in Africa is curious, because VE7EXH (a new member of WSPRnet in the last six weeks, who also has an incomplete entry on QRZ.com) reports himself as being, as expected in CN89lg grid, which is exactly what the spots on WSPRnet's database also show.  So it seems some strange map error is placing him in South Africa, at grid KG-something.

Thank you very much!

Radio: where people meet

Well, I started having a go at the Russia Day Domino challenge yesterday, organised by the Russian Digital Radio Club.

Propagation is proving pretty elusive.  Although most bands are open up to and including 10m (6m is not included in the challenge), signals come and go in rough geomagnetic conditions.

I was quickly down to 40m last eveing, where I was pleasantly surprised to find my blogging colleague, PE4BAS chasing a Russian signal down.  After a while, we got our own QSO in:

I've only really ever used FLDIGI for OLIVIA work.  There were never very many users of that mode, which is a shame, because it's a fantastic weak signal ragchew mode.  Because of this, I never bothered to get FLDIGI to CAT control the rig - there simply wasn't any need.

So I had a frustrating afternoon trying to speed-read manuals and online help screens to get CAT going.  Eventually, I learned I had to download and run FLRIG as well as FLDIGI.

I did get this all to work properly, but it's not a stable system, and the .IO user group for this is full of similar complaints.  After getting it all running, then shutting down, one usually finds it won't work when next started because FLDIGI doesn't reliably save the settings you put in.  Luckily, changing settings in FLDIGI didn't mess up other software controls - a huge relief.

If you have any idea how to stop FLDIGI losing its settings, let me know in comments, please!

Anyhow, there haven't been very many stations taking part in the challenge or, at least, I can't hear very many, even over on 12m and a 3-ele beam, where propagation is variable, but often very strong this morning.

Still, a nice change to the usual mind-numbing FT8 operations!

Let's play Domino!

It's Russia Day tomorrow (12/6).  I was therefore quite amused, in a pleasant sort of way, to see the Russia DC Club has arranged the Domino Contest - where real Dominoes meet the digital mode!

I do like the humour of the Russians.  Never taking themselves too seriously, and providing more than just a dumb contest.  I firmly plan to fire up FLDIGI and go to Domino mode for the first time in a long while!

There's no doubt, summer's here!

After a period of very unstable weather here in wild and windy north west Wales, some clear skies returned overnight.

This allowed me to see (at 3am!) this great, early season display of noctilcuent clouds, which the media here likes to call 'space clouds':

Over in mid-Wales, the MST radar also saw a lot of action at mesospheric altitudes past few days:

Meanwhile, back on our beloved amateur radio bands, propagation is open to at least 6m, with notable, very short skip on 12 and 10m today.


For sure, it's nearly midsummer!

Skewed path

An interesting skewed path arose on 24MHz this morning.  Initially listening with the beam at 120 degrees, you can see how much weaker - by about 9dB - the signal became (top two time slots) when I turned to 160 degrees - the great circle path.  The explanation is almost certainly Es.

20m Delta loop - the antenna that keeps on giving!

Being a private pilot, I've recently started using my RSP1a SDR to receive AM aviation radio, especially London Information (125.475MHz), which provides simple en-route information to aircraft.  It's a busy frequency!

Weekend at Caernarfon Airport.

London Information is quite a long way from me for a ground-based VHF station, so the receiving antenna needs to be pretty good.

I tried a broadcast FM vertical dipole, which gave rather weak reception due to low height.  I then tried a simple quarter wave vertical for the aviation band, but that wasn't very much better, even with good height.

I then started to consider buying (yes, buying!) a log periodic from Innovantennas, which is £200 and so not justifiable for this use.  Building a three-ele quad came to mind, but I'm not in the mood for that at the moment.

As a last effort that involved no money, I tried my vertical delta loop for 20m.  This is almost exactly 9 wavelengths long for the aviation band and, remarkably, it yields a strong signal from London Information, with aircraft, benefiting from altitudes of typically 2500 feet, being strong all the way out to northern France.


Good old delta loop!

Aloha Hawaii!

 If you're interested in working the Hawaiian archipelago on 20m, it's a good time to try now!

There's a consistent link with Hawaii each morning, lasting around two hours as the greyline passes over those islands.  The route is probably long path.

Here's how my 1W WSPR signal was getting out this morning (the plot spans the entire period of propagation open to Hawaii):

Situation at start of peak propagation to KH6 (short path shown).  DX Atlas, with permission.

KL7L, at almost the same longitude, shows much the same pattern, though the propagation opens earlier, due to the higher latitude: