Tuesday 31 October 2017

VK on 12m!

Conditions on 12m continue to build, reaching the quite astounding level of permitting several VK stations to make successful QSOs with Europe this morning - something not seen for some time.

VK6YM was visible as an FT8 signal on the waterfall from about 08:00UT here in north Wales.  At 08:35UT, I managed a 2-way exchange, using my 3-ele LFA Yagi.  The initial call was at an input to the antenna of only 15W!
 
FT8 has now almost completely eliminated JT65 and JT9 signals from the bands.  Despite this, it does have a considerably lesser ability to be copied under difficult conditions.  It makes up for this in the speed of transmission, and perhaps taking advantage of brief propagation enhancements.

Remarkably, I logged another Australian station - VK5BC - at 11:21UT.  By this time, the sun had set on VK5 about two hours earlier.  Such conditions are sometimes seen from the UK after sunset to the daytime west coast US, for example. But it is very rare for the UK-VK short path, and almost absent under recent solar conditions.

My VK5 QSO spotted on the cluster map.  Wow!

Again, the MST radar at Aberystwyth, west Wales, showed reasonably strong returns from ~75km.  It's likely that the returns are from meteoric debris distributed around the world as the Earth crosses several meteor streams at this time of year.  With very long propagation and some very short-hop paths too, it seems likely this material was responsible for at least some of the strange radio conditions.

Potential meteoric debris radar returns.

Given it's near solar minimum, these are interesting propagation times, indeed!


Thursday 26 October 2017

Martin Lynch and Sons Ltd advert claim halted by ASA.

Martin Lynch and Sons Ltd (also known as ML&S) have received instructions 25/10/2017 from the Advertising Standards Authority (ASA) to discontinue making their long-used claim to be 'The World's Favourite Ham Store'.

The ruling came after the company failed to substantiate the claim to the ASA's satisfaction.

https://www.asa.org.uk/rulings/ml-s-martin-lynch---sons-ltd-a17-393843.html

Wednesday 25 October 2017

70 QSOs

Last evening, well into darkness at 18:00UT, I reached the end - actually I decided to end - a hugely successful day on 12m.

I reached the end of my diary page, split into two, containing no less than 70 QSOs in total.

Just point towards the Sun and enjoy!

The contacts ranged from nearby in the UK to the far south of Argentina.

Interestingly, the propagation became very short skip at times, indicating that 10m was probably open, which indeed it was once I hit the band button.

Believe it or not, this is the 12m waterfall yesterday!


I looked at the NERC atmospheric radar in mid-Wales, where a weak but definite reflection from mesospheric height was being received.


Could a weak layer of meteoric metals (around 8-11UT) have helped propagation yesterday?
It's open to debate, but the radar signal could be distributed metals from the Orionid meteor shower, about four days earlier.  I know from research work (most notably with the Chelyabinsk bolide event in 2013) that this is the time it takes for material to spread around the globe.  The difference with meteors, of course, is that they impact the Earth more or less evenly, and not from a single point like a large bolide.

Logbook full!


So it may be the case - and it has often been suggested - that the good propagation on 12m (and winter Es at 6m) is down to an enhanced input of metals from more significant meteor showers that occur during late autumn and winter months.


Sunday 22 October 2017

Surviving the Autumn Storms

It's been a rough few days here on the northwest coast of Wales.  For a populated area, this is one of the most severe locations from which to operate radio anywhere on the planet.

Last weekend, we had ex-hurricane Ophelia bring 85mph (136 km/h) winds over several hours.  This highly unusual path for a hurricane has not happened since 2006.  With warming seas as well as a warming atmosphere, it may not be so long before we see this phenomenon again.

The red sun of ex-hurricane Ophelia over the UK.
 
A very ominous accompanying phenomenon of Ophelia was a very red sun in the mid-daytime sky - a result of Saharan dust and smoke from Portuguese wildfires being sucked up high into the atmosphere.  For an hour or so, you could actually smell the smoke from Portugal at ground level over large areas of the UK.  With high temperatures as well, it felt  very much like walking around in north Africa!

Ophelia out at sea, on its way to the UK.

For the first time since moving here 9 years ago, I had to tilt the 12m beam and tower over to protect it from the severe gusts, which may have topped 90mph at times.  The tilt-over was prompted not so much by the wind strength, but by a gust managing to slip the antenna on its stub mast by 90 degrees.  Luckily, it stopped turning at that point, allowing time to stabilise matters by luffing.  The retractable tower is, fortunately, easy and quick to bring down in an emergency: it took about 1.5 minutes with the help of the Station Manager.

Luffed over for the first time in many years during ex-hurricane Ophelia.

Just five days later, this weekend saw storm Brian, the autumn's second named deep area of low pressure, which underwent explosive cyclogenesis in the NE Atlantic.  Another increasingly-common phenomenon linked to climate change.  Forecasts for maximum gusts were way off.  Instead of the 54 mph (86 km/h)predicted, we saw hours of gusts topping 75mph (120km/h) as the centre of the low pressure stalled somewhat in the eastern Irish Sea.

Brian brings very rough conditions, almost as bad as Opehelia - and over a longer period.  Image: BBC

Despite Brian's fury, all my antennas, including the fibreglass pole-supported vertical delta loop for 20m, which is quite a big beast (shown below in mere 45mph gusts), stayed up and survived quite easily.  Nicely tightened-up on its stub mast, the 3-element beam remained valiantly flying headlong into the wind for the best part of a day as the storm moved over and away.



Thursday 19 October 2017

Solar Minimum and Radio

Yesterday morning, always interested to learn what G0KYA's blog has to say about things radio, I clicked on his Blogger site to find an article about solar minimum and propagation.

Much to his credit, G0KYA has allowed my lighthearted critique of an argument that:

'we can expect the minimum to be around late 2019 or 2020. It is hard to be precise, as the minimum is something you can define after the event, not before or during!' 

When I commented that 12m has been very strong to the point of regular, almost daily and very long-haul DX, G0KYA came back with:


'Yes, but we are not at sunspot minimum yet and won't be for a couple of years. This was looking ahead to 2019/2020. The recent DX has also been helped by ionospheric enhancements from the coronal holes and is not sunspot related.'

It's a decent comment, but does fall down flat on its face when measured against the earlier comment that 'it is hard to be precise' about the solar cycle length.  Even harder (though in favour of G0KYA's viewpoint), when the solar activity is reducing, and cycle lengths (probably) increasing.

Then there is the fact that the depth of solar minima varies quite a bit.  Like the financial markets, historical data does not necessarily provide a reliable indicator of the future. 



Like maxima, minima vary in profundity and duration.  Image: NASA.


Is it reasonable to pin our radio hopes (or despair!) on a minimum not happening for the next two or so years?  It depends on what you term 'solar minimum', for a start.

To me (a first in Astronomy and Planetary Sciences, former Fellow of the Royal Astronomical Society (they pay their bosses too much for my liking!)) and most scientists, solar minimum is a period within a solar cycle, not a discrete, single point.  

So discussions that try to dance around some hallowed future day (or month), where we can raise our hands to the sky and shout 'we are at MINIMUM!' is simply misguided.  In fact, you can never know in real time and with that degree of accuracy.

We could be at solar minimum now.  In a late 2014 web release discussing then new research, NASA asserted:

'This research paper forecasts that the sun will enter solar minimum somewhere in the last half of 2017, with the sunspots of the next cycle appearing near the end of 2019.'

That prediction seems to have been pretty good in terms of predicting an earlier than G0KYA's minimum forecast.  But it may have been way off on cycle 25's commencement, because in January 2017, the Royal Observatory of Belgium announced that the first sunspot of solar cycle 25 had been identified.  A video shows some more detail.

That doesn't necessarily mean that the solar minimum period is over, of course, precisely because it is a period, not a single point.  The Sun is a chaotic mass of endless layers of swirling plasma.  It doesn't run like a machine with fixed cogs.  That's what makes it very hard to predict.

Here's how the plot of 10.7cm radio flux is going right now.  You can see that there has been, for a near-minimum point, an unusually pronounced spike in activity recently.  That, of course, will probably come back down to the trend line shortly.  It may even collapse to a new low for the cycle.  Or it may begin a new, upward trend.  We don't know and can't know with our current state of knowledge.



From the solar physics point of view, it's clear that the Sun is already within a minimum period of its sunspot cycle.  Whether or not it has reached, on average, the very lowest point is something that we can never know until at least 6 months after it has happened, because it relies on smoothed data gathered over that length of time.  Even then, there are periods within the low that are higher than weeks or months previously.

But there are unambiguous signs that the Sun is beginning to wipe away the sleep from its eyes.

From the radio operator's perspective, the effects of a solar minimum are already evident.  Prediction software and printed propagation guides in the magazines are very pessimistic (PredTest seems to be a bit less so of late), especially about the higher bands.  For example, according to RadCom, I can expect a couple of hours or so of very poor propagation no further than Europe at 12m for November 2017.

But does this pessimism mean that the higher bands aren't worth bothering with?  When I bought my Yagi for 12m in 2013, It cost about £230.  A year later, clearly anticipating poor propagation and thus low antenna sales for that band, the maker was selling it for half that price.  

This might well have been a mistake, because my log for 2017 is full, almost every day, of very good 12m DX contacts on digital modes.  FT8 has brought an upswing in higher band use as well, I would say.  YB0, 3B, JA is as good as it gets.  Most propagation predictions for 12m are way, way off.  As off as you can be, in fact.


Sometimes, as G0KYA points out, this good propagation is due to coronal hole effects.  But that's certainly not the whole story.  Indeed, the experience of operating 12m in October 2017 is very much like operating when the solar cycle was at or near its peak: in essence, signals come from the direction of the Sun, and you have a nice day tracking DX west (from the UK) across the globe until just after sunset.  If you extend the current activity point back across the past cycle, you get equivalent activity for early 2011 and 2016 - both periods where the log is chock-full of higher-band activity.

As most wise radio men will say: if you call out, you will  probably get a reply.  This sounds silly, and that you can't fight ionospheric physics.  But if you don't call - if everyone doesn't call - then you will certainly not get a reply!

It's a consistent feature of 12m that as soon as a QSO is made and reported to the cluster on that band, within a minute or two, the band will be full of callers.  There is a very strong herd mentality in the radio community, reinforced by the herding effects of web clusters.

Whilst I respect the people who try to predict propagation, I've never found it an area that is worth bothering with.  It is, in the end, a binary phenomenon: you switch on your radio and call CQ.  There either is propagation (and someone has been optimistic enough to listen), or there isn't. But it is always, always, worth calling and listening.

Oh, and just o underline the message, here's what happened during 90 minutes of WSPR on 10m at 1W this (22/10/17) afternoon, using a vertical delta loop cut for 20m:a 2-way exchange with Reunion!




















 

Thursday 12 October 2017

Geomagnetic Propagation Enhancement

The past week has seen a period of quiet solar activity ramp up over the past 24 hours to a Kp between 4 and 5.  Despite being close to solar minimum, disturbed days are quite frequent, no doubt helped by coronal holes.

Luckily, I've been running WSPRlite at 50mW for the past few days as well.  This provided a valuable insight into the propagation enhancements that can occur during more active geomagnetic conditions.

Here's how things panned out geomagnetically, courtesy of NOAA's Space Weather Centre:



Here's the plot at 14MHz, where my 50mW is in blue, and my reference, GI8 comparison station is in red:


As you can see, during the preceding few days, conditions were quiet and propagation drops off in the late evening until early morning, even at 200mW (red).

But with the onset of active conditions, the nighttime propagation shows quite strong enhancements, with fairly rapid variability during darkness.

Here's some detail:


With the restoration of quieter conditions later, propagation returned to the normal drop-off in the middle of the night. Here's the plot either side of the disturbance (ignore the accidental inclusion of a distance label!):



So, the next time you see an active geomagnetic forecast, don't think it's all bad news.  It could surprise you with some unexpected DX!

Wednesday 11 October 2017

RadCom Review - November 2017 Edition

I'm no longer a member of the RSGB, and I can't say I have missed out on anything since cancelling my subscription a year or so ago.

But my daughter is getting some kind of benefit from the fact that she enjoys free membership as a youngster until she's 21 - a full ten years' (about £600) worth!  Someone at the RSGB didn't figure on young kids passing their exams, I think!

Accordingly, my daughter's copy of RadCom came through the post this morning.

I was struck by the significant number of articles this month about IARU Region 1.  Somebody at IARU R1 seems to have seen a ghost in the form of EURAO.  There's certainly been a lot of angst this year between the two.

As a result, IARU R1 appears to have decided to start cranking up the publicity machine using RadCom as a handy conduit to thousands of RSGB members.

It's all rather entertaining, if too late, to see IARU trying to make itself look hip and happening.  Like all things committee and neck chain-like that make endless and mind-numbingly dull appearances in RadCom, none of the glitz is persuading me that IARU is the horse to back for future representation.

As in all editions, this month's copy contains plenty of products where you can part with £6000 to buy a radio. This month focuses on an SDR transceiver, though I doubt it copes with the all-band destroying SkyQ RFI any better than a £450 unit.

Hang on!  On the back cover, it gets even better: a rig costing 'ca. £10,799'.  WHAT?

Elsewhere, perhaps a bit fed-up with complaining members, some anonymous comments from various RSGB Board members are printed.  I think we're supposed to feel sorry for them.  I don't, even though they are volunteers (albeit with expenses repaid).  I feel much more sorry for the poor NHS nurse who works long shifts for at least 2.5 times less money than the RSGB's General Manager.

I'm not sure why the RSGB is carrying on as though all is well in the radio community, other than to persuade themselves that their position as Top Dog in UK radio is secure.  Maybe those running it live in places where RFI doesn't affect them.  Maybe (very probably) they are of an age where a good pension allows them to spend £6000 on a hobby radio.  And maybe they think EURAO is just a bunch of over-excited 'Johnny foreigners' where, in fact, only retired middle class, white Brits know how to run things, like in the days of Empire.

So, if you are 20-something years old, have a £60,000 debt from paying for your University education, can't find another £50,000 deposit for a house nor, indeed, the £1000+ per month you need to mortgage an average UK investment vehicle for the old home, then look forward to buying your top-flight rig sometime around 2125.  Things will be fine by then.  Possibly.

Here's looking forward to next month's RadCom, where Christmas cheer will solve all our problems.  Bah!  Humbug!