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!