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:

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!

Saturday, 30 September 2017

DXplorer - Interpretation Care

This afternoon, I ran a 1/4 wave vertical (MW1CFN) on WSPRlite down on a lowish clifftop overlooking the sea.  At the same time, I had my vertical delta loop running (as M1CFN) just about 2 miles away, on top of Parys Mountain.  Both antennas were running 200mW.

Now, on the above comparison, the 1/4 wave vertical (MW1CFN) comes out at over 3dB - twice the signal strength - of the vertical delta loop.

So, the conclusion could be: forget the delta loop.  But that is a dangerous thing to do.  First, you have to consider the pattern of spots hearing both antennas. Here's the plot, delta in red, vertical in green:

Clearly, the conclusion has to be modified.  The reason the vertical initially appears to be better than the delta loop is that the stronger (sometimes much stronger) reports are coming from close in, within Europe.  From the overall pattern, it's clear that the delta loop is reaching much further into the eastern US than the vertical.  This plot shows how that works out in numbers:

But note the exception: the highlighted receiver in the map of spots shows that KB1VC heard both antennas at the same strength at the same time.  From that, you would expect a few more receivers to have heard the vertical in the US, but they didn't.

The overall conclusion is clear enough: the delta loop (which, as effectively a pair of closely-spaced, phased verticals) should enjoy roughly a 3dB advantage over the 1/4 wave vertical, is indeed the much better antenna, enjoying a significantly lower radiation pattern (as indicated by the weaker short-skip reports) where that gain is realised and turned into DX spots.  Sloping ground only means an even better low-angle performance.

The modelled pattern below shows clearly the suppression of high angle signals for a delta loop:

And here's the vertical's pattern, with a nice (but mostly undesirable) high angle bulge.  Note how different it is to all those lovely, symmetric patterns you see in books and magazines, who invariably use misleading 'free space' settings (and, sometimes, infeasible radial numbers) to do their computations.

The next test will be placing the vertical at the water's edge.  With winter coming, that may have to wait for a while!

Sunday, 24 September 2017

12m is GO!

Wow!  12m is like a dream today!  For a couple of weeks now, DX is rolling in from all over the planet on FT8 throughout the day.  There's even some SSB activity!

Thursday, 21 September 2017

EURAO - The Future of Representation?

Regular readers - if there are any - will know that, whilst I support the idea of the RSGB as a society, I have never really supported it in the way it works.  Or, rather, doesn't work - for me.

The RSGB is, I think it's reasonable to say, a society struggling to stay relevant in an electronic age where opinion, dissent and discussion is easy and immediate, and can no longer be stifled by glacial, impenetrable committee structures that have only ever really served as a place for those who seek self-importance to find comfort.

I've been quite encouraged, therefore, to discover EURAO - a nascent representative body for all amateurs across Europe - and even beyond.

Recently, I joined EURAO after some time of keeping an eye on how it developed.  I was eventually persuaded to join by a very public clash between the then president of EURAO and (Region 1) IARU's bigwigs (some of whom are, of course, ex-RSGB bigwigs).

The nature of this clash exemplified the kind of conflict that the more comfortable, established radio organisations have with a new generation.  IARU seemed, to put it mildly, threatened by a new body in the form of EURAO claiming to represent all of ham radio.

The problem for the likes of IARU and the RSGB is that their very legitimacy derives, ultimately, from the goodwill and support of the radio community.  If, in future, they display what might sometimes be seen as a 'Little England' mentality, then they will, given a few years, probably find themselves washing up on the shores of irrelevance.  Personally, I would cry no tears if they did, and it would be a mistake to think that the attempted return to Colonial Britain via Brexit will bring a New Golden Era for the likes of the RSGB.

The great thing about EURAO is that it isn't fixed in one country.  That makes it considerably more dynamic and open to different ideas.  Just have a read of this fascinating interview with EURAO's new President, YO9RIJ, to see how very different life and political experiences can bring so much more to understanding the future of amateur radio.

Perhaps the best words I have read from EURAO so far are these, from YO9RIJ's interview:

"EURAO will remain an independent entity that defends the interests of ham radio in Europe and the world, regardless of the actions of other societies."

That is the absolute crux of the matter: representing the grassroots experience of radio, and ignoring, where appropriate, foot-dragging playground politics by dinosaur-like traditional societies.

True, EURAO is still very young and its degree of influence within any individual state is almost absent - at least for the time being.  But that can change.  I hope it will, because under the RSGB in its present form, simply trying to 'keep calm and carry on' in the same way as it has always done has largely failed to save our hobby from RFI, over-restrictive planning and ever-increasing pressures on the spectrum.

Friday, 8 September 2017

12m is Dead. Not this year, it isn't!

12m is my favourite band.  I fell in love with it when I had a reasonably good, vertical 2-ele yagi set up (and how infrequent they are!), with pole fixings that let the reflector be moved around the radiator.  Since then, I've upgraded to a 3-ele LFA Yagi.

No other band I've operated on follows the day quite so well.  Mornings are announced with lots of Russian stations.  Then it's across to Europe for a good fraction of the day, with the odd opening to the Indian Ocean, Africa and, sometimes, the Pacific.  Sunset brings a brief period of US Pacific coast stations, and again, sometimes the odd Pacific island QSO.

2016 was notable here for quite a drop in 12m QSOs.  Certainly, 2017 hasn't seen any 12m ragchew sessions that were common until early 2016, across to the US. 

But the band isn't dead.  Far from it!  In fact, 2017, a point that should be lower in solar activity and quite close to minimum, has been substantially more active than 2016.  Almost all days have at least one QSO, with the equinoctal periods turning up the QSO rate significantly.

A lot of the QSOs are on the back of various Es mechanisms, of which there are many.  Normal summer Es, plus lots of solar outbursts that give a good kick to propagation.

Thanks to fast modes like the recent FT-8, it's now quicker and easier than ever to test the waters and see if someone answers.  Most times, someone will!

Saturday, 26 August 2017

JT9 Pushback!

FT-8 mode has been stealing the digital show of late. 

Not that it's been all excitement and good news.  FT-8 has been pushing into traditional JT65 territory, with so many users active at the same time that it has often seem as though, soon, there would be nothing but FT-8.

So I was glad to see early this morning that 20m was packed full of JT9 signals from across the world.  It seems that JT65 is being infringed so much that JT9 is a relatively FT-8 free area to set up shop.

I think this is a good thing.  FT-8 is just ridiculously fast, often struggles to decode, and has absolutely no reward merit at all.  It really might as well be a fully-automatic points gathering mode. That is not how I do radio, and if the number of JT9 signals fighting back this morning is anything to go by, it's also not the way very many others want radio to go.