The precision of 15m propagation

Well, although there have been recent upswings in the number of sunspots, the past few days have not been so hot on HF.

Still, undeterred, I have a go at CQing on 15m every day.  In fact, I first discovered the remarkable performance of a delta loop antenna, when I experimented with a 15m loop, way back in 2011.  As soon as I installed it, I was bringing in excellent DX, especially from the west.

This afternoon, the CQ resulted in a few PY stations responding.  Looking at PSK Reporter, it was amazing to see just how geographically limited the propagation on 15m was at this time, as the plot below shows:

Of course, an all-sea path to PY helps enormously, and that path is open quite regularly.  But it's not quite so common to see propagation so strictly limited to a very small area of PY.  Note also the very big range of received signal strengths at the same time, in the same area.  Strangely, the strongest signal comes from a station in the very built-up, and probably very RFI-infested area of Sao Paulo.

WSPR vs FT8 - more thoughts.

A couple of evenings ago, I was running 14MHz WSPR on receive-only.  By about 21UT, about an hour earlier than is usual at the moment, there was essentially nothing coming through to me. 

Not seeing the point of running overnight receive, I decided to have a quick look at the FT8 portion of the band.  Here, the band was anything but dead!  Several signals, clustered towards central and south America, were coming in at strong levels.

I chanced a 'CQ' at about 15W, and immediately completed a QSO with a station in Panama - HP8RY.

Now, WSPR has about 10dB better sensitivity than FT8.  Despite this, it's pretty obvious that, if WSPR is yielding a result where there is apparently no propagation, but a QSO is then completed with FT8 with only moderately higher power, then WSPR is not a reliable indicator of propagation.

This is more especially true when one considers the fragments of WSPR that momentarily appeared on the waterfall.  They lasted for only a few seconds, and could be quite strong.  FT8, on a 15 second cycle, can potentially make use of those brief openings, or bits of dying propagation.  WSPR can't.

Overall, I'm coming around to the idea that WSPR is perhaps of less use than once was the case.  One major advantage of FT8 is that it has lots of people listening, and doesn't suffer so much from other modes, like RTTY, because it's obvious that FT8 is popular, has a clearly-defined place on the bands, and is easily detectable.

What do you think?

Barbados rocks to the geomagnetic beat

Things have been very strange at 14MHz overnight recently.  Despite plenty of variation in the field conditions, the unusual tendency has been to lose all DX signals from about 23:00UT until the pre-dawn period.  Not even in the depths of solar minimum winter was this seen.

Last night saw some moderate disruption of the field to Kp=3:

Image: Tromso Geophysical Observatory.

The 5W, 14MHz WSPR signal from 8P9DH showed quite wild fluctuations as the field underwent its disturbance, although at this time of year, the greyline conditions are firmly superimposed on the propagation as well:

Other than WSPR, and the fact my WSPRlite transmitted has failed (the second in about two years to have done so), not very much is happening at the station at present.

Can you feel the aurora?

Aurora, seen from my QTH, 2015 October 07

As we await a G2 geomagnetic storm in the next few hours,  this recent research output is worth thinking about:

https://www.sciencedaily.com/releases/2019/03/190321083637.htm

Kp between 5 and 7 expected tonight (23/03/19).  Image: http://www.aurora-service.eu/aurora-school/all-about-the-kp-index/

Sunspots - wow!

Pretty extraordinary stuff has developed on the Sun, with a G1, maybe greater storm due next 48 hours:

15m Propagation - what's that all about?

15m is a band full of surprises.  I think most of my most unexpected and unusual QSOs have occurred on that band.

Today was no exception.  Sending some FT8 CQs into the void, I was surprised to see my signal hitting South Africa at up to -5dB SNR/2500Hz.  This resulted in a successful QSO.

Even more odd was that, with the exception of a single Argentinian station, none of the many other monitors were receiving me.

But!  Just a few minutes later, the situation was very different, with an EA8 station hearing me at up to plus 18dB! 

All most interesting - and probably down to Es.

Russian Digital Radio Club Birthday Activity Days 23-24 March

Dear Fellow Radio Amateurs, 

We invite you to the Birthday of RDRC - activity days «Made in Russia 2019». Our club was founded on March 21, 2014.
 

We welcome you to visit us on 5th Anniversary of the Russian Digital Radio Club from 03:00 UTC Saturday, March 23 to 15:00 UTC Sunday March 24, 2019 on 160, 80, 40, 30, 20, 17, 15, 12, 10 meters bands in OLIVIA and T10 modes.
 

Dupe QSO (SWL) can be conducted by different digital modes as on one band as well as on other bands.

The obligatory condition of each QSO is to preserve in adif file of the Log the received locator.

The occupied places will be distributed according to the sum of the distances to correspondents.
 

Certificates in electronic form will be reawarded with all participants under condition of carrying out not less than 10 QSO (SWL).
 

Among members of RDRC, which on results in TOP-30, we shall raffle special prizes - two pendants with club symbolics.
 

All logs must be sent no later than 5 days after activity days.
 

READ MORE RULES: http://www.rdrclub.ru/dni-aktivnosti-rtsrk/999-anniversary-birthday-rdrc

73! - Russian Digital Radio Club -

WSPR vs. FT8

Over the past week or so, I've slowly been coming around to the idea of using FT8, together with online reporting at pskreporter, as a fast alternative to WSPR.

Whilst FT8 provides the benefits of high-speed, high-frequency probing of propagation conditions, it is very significantly less sensitive than WSPR.  The latest version of WSPR yields positive reception at SNRs down to -34dB.  FT8 offers reception only down to -24dB - a difference of 10dB, or a factor of ten less than WSPR.

FT8 reports can be downloaded from pskreporter as an adif file.  This can be opened as a text file in a spreadsheet package, which needs only basic skills in order to separate the fields and create an ordered table.  More advanced skills are needed to create a table of reports from only one station.  But it's a lot more protracted than simply interrogating the WSPR database online.

Where pskreporter is better than WSPR is in the sheer number of FT8 operators, relative to WSPR users.  There may be about 300 active WSPR users on the more popular bands, whilst FT8 yields over 1000.  The worked experience of FT8 vs. WSPR on, say, 15m, is that you could well see nothing on the WSPR frequency over some time, whilst you might immediately return several FT8 reports.

The other very useful aspect of pskreporter is that you get tabulated or mapped reports, with signal levels, in near-real time.  This is also the case with WSPR, but pskreporter is more immediate in some sense - and it doesn't keep breaking down, as WSPRnet is very prone to do.

So, for now, WSPR remains the gold standard in weak signal antenna and propagation testing.  Both modes can, of course, complement one another, and FT8 may well reach deeper into the noise in future iterations.

Wales to Antactica - the Equinox plot

DPOGVN is really to be conratulated for running a near-unique and very useful WSPR receiver at the Neumeyer Station in Antarctica.

As it's very nearly the equinox, the terminator is now almost a straight line directly from north to south.  Accordingly, one can plot the signal changes as the terminator advances westward.

Here's how my 1W WSPR signal at 14MHz was heard on March 14th by DP0GVN:

The peak signal, amounting to a signal enhancement over the previous hour of about 10dB, came when I was located in the centre of the grey line zone.  It's interesting to note how the signal then drops to undetectability within just 15 minutes. 

WSPR from ZL, and the Brexit herd.

40m has always been a band occupied, so far as I can see, by those of a disposition to have ragchews.

In the UK, those ragchews tend to be amongst people who don't much like foreigners, and to whom talking to a man in the neighbouring city by NVIS reinforces a sense of Britishness (as they perceive it).

A typical British 40m operator, 2019.

Of course, and tragically, it was legions of people of this age and mentality that led us into the Brexit debacle that is currently reaching dizzying heights of absurdity.

So maybe such people tend not to take an interest in WSPR, because it means interfacing with the wider world?  A low-hung dipole for 40m is more than enough to warm up the Great British Ionosphere, and ensures DX from 'Johnny Foreigner' is suppressed.

Maybe, then, that's why, this morning, only two stations in the UK received ZL1TJK's 5W WSPR signal?  Seems a shame, when these old-timers could widen their horizons and enjoy all the world has to offer.

An important post by KA7OEI

The following link takes you to a recent blog post by KA7OEI that reports on the very widespread problem of high RFI levels from cheap Chinese LED lights and, importantly, a practical solution beyond simply throwing them in the bin!

http://ka7oei.blogspot.com/2019/03/quieting-insanely-rfi-noisy-led.html

Lightning sprites.

Being just a few weeks away from my 50th birthday, I am now of the age when I get up at 2am for no good reason.  Mind you, I always enjoy the night and the experiences that hardly anybody else has because they are asleep.


As I looked towards the west, I saw a brief flash of light.  It was lightning, obviously very far away, its light scattered by a cumulonimbus parent cloud.

Sprites: completing a global ground-ionosphere circuit.

After looking at the lightning strikes map, it turned out a cluster of strikes had just occurred in County Mayo, western Ireland - 325km away.  That comfortably beat my previous sighting record of 280km from two years ago.

 

This sparked some conversation at home about lightning sprites.  As usual, to keep the kids' attention in dad's crazy science, a quick YouTube video helps get the essentials across.  At about 11m30s in to the video, I then realised that all this global current cycle, as mediated by sprites, should be something to keep in mind in terms of HF propagation.  See if you have the same idea:

40m Propagation window to ZL

I ran WSPR RX-only at 40m overnight, as extremely strong and prolonged winds of 120km/h and more have brought delta loop 20m operations to a standstill.  My 40m antenna is a half sloper, coupled to my tower with a 12m Yagi on top.

Usefully, I could determine that the window for good propagation to ZL opens rapidly at 05:15UT from Wales, and continues at reasonable strength for at least an hour thereafter.  5W from ZL2APV was yielding a steady -16dB or so here during that period.

It's very nearly the Spring Equinox, so go make the most of what 40m offers to the antipodes!

A Wow! signal arrives.

I casually glanced at my laptop screen early this evening, to find this absolutely unbelievable 14MHz WSPR signal from my friend, AJ8S (running 2W remote from Maine as AJ8S/1):

I contacted Jim to see if he'd turned up the power, or used a Yagi.  He replied that he was just using an extended double Zepp wire, with one of its lobes directed to Europe.

To put a +16dB signal into context, I can expect a signal of about that level from ground wave if I run a quarter wave vertical on 200mW, but only 9.5km away from my receiving vertical delta loop!

The plot below shows AJ8S/1 either side of the 'wow!' event:

AJ8S/1 shows an unbelievable, transient signal strength spike.

Here's how Jim was heard in general at the time.  On this side of the Atlantic, the next strongest reception report was 10dB weaker than mine:

Overnight WSPR report, 06-07 March 2019.

Conditions initially disturbed at high latitudes, tailing-off to quiet conditions early morning:

Image: IRF, Kiruna.

Nothing terribly unusual happened on 14MHz WSPR, except for the 5W from W1NCR disappearing as early night progressed, followed by a sudden and strong reappearance as the north-going Z deviation rebounded through a brief southerly deviation:

Signal from W1NCR at 14MHz.

(Non-radio) Clear signs of climate change.

When you live in a place that is 100m above otherwise flat land, 2km from the Irish Sea coast, and operate a radio station, you tend to notice the wind a lot!

But the strength of the wind, whilst it is increasing, is not so much something that is changing obviously these past few years, but the direction from which it comes.

Historically, the wind rarely blows from the NW to N directions on Anglesey.  This is a wind rose of data for the period 1981-1990:

Wind rose for Anglesey.  Image: Llansadwrn Weather, based on RAF Valley data.

I can't readily find a wind rose for the past decade, and whilst I have actually kept high quality weather records over about 7 years here, I haven't yet had time to computerise and analyse the data.

But it is pretty obvious as a lived experience that very strong winds of near-hurricane force now regularly come from the NW - N sector as deep low pressures travel from north to south.  They are pulled along by a jet stream that shows increasingly deep waves.

Deeper waves means greater weather extremes.

This increased deep waviness is in fact quite a well-modelled expectation for the jet stream under early climate change scenarios.  It arises because the Arctic regions are warming about four times faster than the rest of the planet.  This generates weaker temperature gradients between the cold air of the Arctic, and the warm air of more southerly latitudes.

So cold air from the Arctic can invade deeper south than has been usual, bringing the kind of very windy weather we are currently experiencing, and warm air is also able to invade much further north than has been usual.

Over the past week, we have seen the very real and obvious effects of these waves: 21 degrees Celsius and calm weather for three days, followed by 100km/h winds over prolonged periods and temperatures plummeting to just 7 degrees Celsius.

The timing of storms has also seems to have changed over the past few years, with many of the strongest winds shifting later into the winter and early spring.

Other examples of the effects of these waves in recent years have been the very damaging, ex-Hurricane Ophelia in 2017, which followed an almost unprecedented S-N track from the tropics to the UK, rather than the usual track from the Caribbean.  Winds reached gusts of 130km/h on Anglesey.

Ophelia brought an apocalyptic scene ahead of the winds by having sucked up so much Saharan dust and smoke from Portuguese wildfires that the sun turned red in a mid-day sky, as the air hung heavy in Wales with a strong smell of burning.  Local, RAF Valley pilots, checking the weather that morning at altitude didn't need their usual helmet sun visors - they could comfortably look directly at the sun.

Apocalyptic sky hours before Ophelia winds hit the UK.  Image: Express and Star.

Earlier in 2017, though only for a few hours, we had Storm Doris, bringing exceptional, 132km/h gusts from the NW, which my 12m LFA somehow managed to survive without damage.  Certainly, life on the west coast of Wales at altitude is becoming ever-more marginal, and will clearly need structural adjustments in the near future.

RSGB President pontificates...

On page 6 of this month's 'RadCom' - quite possibly the most dull magazine you'll ever not see on your newsstand (because it isn't actually sold anywhere) - the RSGB's president (bow, curtsy), gives us a bit of a telling-off.

He says that the RSGB has "only 16 members of HQ staff" (not bad for a limited company concerning a hobby), and that he has to "admire" their "stoic make-up - even after being lambasted by those who sit on the sidelines and criticise, often without offering any solutions or even contemplating offering their time to put right what they see as being wrong".

Well!  That's us put to rights!

Now, it's all very well for a chain-wearing, white, middle-class, ageing man to puff out his chest and waggle his finger at the naughty membership that won't shut up.  The other reality, of course, is that the RSGB is often accused of 'bunker mentality' when under criticism.  Certainly, in most of my dealings with them in the past (I long ago stopped being a member), responses were often aggressive (e.g. exchanges about planning permission), evasive (e.g. pay), or ignorant (e.g. WSPR QRM).

Ask RSGB members about the society, and they often shrug their shoulders and say they are only members "for the magazine".  The imputation is that they don't really see the RSGB as representing their interests and achieving change.

Sure, there are many people who just want to complain and find fault.  No doubt the RSGB staff do receive a lot of that kind of thing.  But there is, actually, plenty to complain about, and plenty of scope to point out the RSGB isn't responding as we would wish quite often.

Take, for example, the RSGB's generous pay packet to its General Manager.

In the past (not involving the current incumbent), the RSGB paid "more than" £60,000 to its GM.  It didn't, by accounting law, have to declare how much above £60,000 it was.

When I repeatedly made the point to the RSGB that law was one thing, but how it obtained that money - mostly from member subscriptions - was quite another.

That members were paying a good proportion of that salary should have led the RSGB and its GM to waive its right to secrecy, and declare the salary in full.  That way, the membership could have decided whether or not the substantial pay (at least 2.5 times that of a fully time-served NHS nurse), was a good use of society money.

But the society and the GM chose to keep it secret.  In more recent years, the salary has gone below £60,000 if we are to believe the RSGB.  But by how much, is still undisclosed so far as I know.

And, month after dull month, all I see in the pages of RadCom are rows and rows of pictures of old men, hardly any women, thinking that, because they are doing all very well thank you and looking forward to their next ocean cruise, they need not worry about the hopeless age profile of the hobby, the lack of planning freedoms for antenna installations, or much of anything else, really.

The RSGB has surveyed the membership about age and many other aspects, and been handed some nice statistics on which to base their decisions and strategies.  They have addressed some issues.  But quite what they have done to address others - the ones that are really tough to crack - like rapidly ageing membership, is a mystery.

The things you see on FT8...

Seeing who was around on 30m FT8 just now, I came across this little departure from normal operations:

At least it wasn't about Brexit!

Atlantic storms return.

Last Monday to Wednesday saw the winter temperatures for Scotland, England and Wales break instrument records, reaching over 21 degrees Celsius.

Newborough beach, 25/02/2019.  Air temperature about 15 Celsius.

But by Saturday, an intense area of cold invaded into the Atlantic from Canada, giving the jet stream a huge boost.  By Saturday afternoon, we were in 95km/h gusts, which is not too bad.  Friday night had actually seen snow deposited at higher levels on the Snowdonia mountains.  But Storm Freya was then immediately to follow on Sunday, forecast to bring 115km/h gusts.

Freya, forecast to hit overhead Anglesey.  Image: UK Met Office.

With the able help of my wife, we wound down the 12m Yagi and luffed it over onto its side.  The 20m delta was retracted, as (unusually) was my 17m delta.  I was left with only a 15m delta for a station!  For the first four-and-a-half years, I had to leave the tower and Yagi up permanently, whatever the wind, in order to qualify for exemption from planning permission (which I'm happy to say occurred back in March, 2018).  During those years, we saw one storm of 85mph (137km/h) gusts!

Ready for Freya.

Luckily, Freya lost a lot of energy on its way to us, and passed further south than forecast, leading to what we would consider a normal windy day - about 80km/h gusts.

By this morning, all-band coverage had been restored!

Interesting to note that a very small, but definite positive-leading, Cycle 25 sunspot has developed on the sun.  It's quite difficult to see on the magnetogram (above, and on the other side of the equator to the much more obvious, Cycle 24 spot), but is clearly detectable at UV:

Both images: SDO, via SolarHam.

Rough again!

Significant geomagnetic disturbances overnight, leading to G1 (Kp~6) conditions:

Image: IRF - Kiruna

Propagation did not continue after around midnight UT.  Prior to this, the signal from LU7AA showed interesting fluctuations as the field underwent its own changes.  In both cases, the peaks just after 20UT and just before 23UT coincide with the field recovering (though briefly) from deep southerly (Z) variations in the field, which is my usual finding: