Monday 29 February 2016

Chasing the F2 Layer

WSPR is a really fabulous, informative mode.  Far from being 'pointless' low power transmissions, WSPR is the first time - and only in the last decade - that we can track in real time where our transmissions are going to.

Critically, WSPR has also freed us from the chains of human subjectivity.  Gone are the days where old men, hard of hearing and stuck in their opinions, whilst trying to compensate for the effects of QSB, tried to guess the true signal strength being received, using nothing more than an 'S' meter.

Night transmissions, chasing the sunlit ionosphere...

Last evening, with plenty of family demands making normal operating impossible, I set the rig to WSPR mode on 20m, running 5W out into my trusty vertical delta loop antenna.

I chose K9AN as the reference receiving station, because I know this is a very well-positioned and well-operated station.

Here's how my 37dBm was received by K9AN over a few hours:

Interestingly, the signal strength increases steadily over the period of the run, which on my side of the Atlantic began from  about 30 minutes after local sunset.

But I want to focus on the sharp drop in signal, leading to total loss of signal at K9AN, around 22:34UT.  Clearly, this is not an immediate, but quite rapid fall-off.  

The reason for my falling away into the noise is clearly that my signal stops getting to the ionosphere at 22:34UT or thereabouts.  This corresponds with the last sunlit region of the radio-effective ionosphere being at 3300km away.  

This immediately tells us that my signal heard by K9AN at the time of weakest reception, is being refracted by the F2 layer, which would appear from my maths to be from a height of around 300km.  I think that's all consistent with how the ionosphere is understood to work.  

What's more revealing is this.  For me to continue accessing the F2 layer for that long in the evening, a good amount of my antenna's radiation is departing at very low angles - at or even slightly below the horizontal.  Measurements in the far field here with a simple RF meter have previously shown strong radiation about 5 degrees below the horizontal (confirmed again a few nights ago).  This is due to the site having exceptional ground conditions from the extremely high mineralisation (it's an old copper mine), and being on a ridge.  It once again confirms that the ground is so good that the radiation pattern is effectively that for an antenna over a perfect ground plane.

And I can see your point if you are now thinking I'm just bragging about something that's not real.  But if you look up the relevant section in the ARRL Antenna Book (section 3.30, figure 3.53 in my 2014 edition), there's a plot in there that confirms the highest recorded relative dielectric constant - roughly three times that of seawater at 14MHz - was found over highly-mineralised ground like mine.

There's a big difference with outstanding ground conditions (and my far field ground is below horizontal!)


Ground gain is also likely to help, although I have never seen any model that computes for a vertically polarised antenna.  At horizontal orientations, the ground gain here, using an accurate terrain profile, at 2 degrees elevation for a horizontal dipole is roughly +7dB. 

The exceptional siting of this QTH was confirmed also by another method - how long other stations were being heard, and at what strength.  Looking through the WSPR database, I was the last one to be heard from this side of the Atlantic, although a little later, a HB station with good, open skies but some hills fairly close by, on just 1W, that hard earlier vanished for about 90 minutes, suddenly appears again for about 45 minutes, and is then lost.  I can't explain that, nor why no other stations from anywhere east of the US were heard at the same time as the HB station. 

So, WSPR very usefully allows me to confirm, without any human bias being introduced at all, that this is certainly one of the best sites one could hope for for amateur radio.  Above all, it shows that simple equipment and antennas can work to very good effect in the right place.  Huge investments are definitely not needed!

I think I will have to sell the house one day as a radio operator's dream, armed with all this information.  It's just a pity most of the land that once belonged to this house has long since been sold!



Friday 26 February 2016

Graham Coomber

News in February 2016's RadCom declares that Graham Coomber, the incumbent MD of the RSGB, is to step down in a wee while.  A new MD is sought.

Graham Coomber.  Stepping down after steadying the RSGB ship.


I stuck-out membership of the RSGB for three long years, and left in 2015.  I joined just after Peter Kirby - the MD prior to Coomber - had left the society in early 2011 under a big cloud that saw him leaving employment there, and eventually, under threat of legal action, paying an alleged debt said to amount to £41,000, back.  Mr. Coomber, of course, was not involved in any of this alleged wrongdoing.

But this was quite a cloud to escape.  Others at the RSGB top table had been up to rather misguided activities - notably the use of members' subs to buy a vastly expensive antenna tower, notionally for the Bletchley Park site, before planning permission had been considered.

A big Luso tower was never going to make planners smile - and they didn't.


When that permission was refused, the society was left looking like a big, fat lemon, quickly moving to try and rid itself of the expensive white elephant for a fraction of the price they paid for it.

Bletchley itself became another, very sore point for the RSGB members.  A hut was bought to site the National Radio Centre for a vast amount of money that, under depreciation rules, quickly became next-to-nothing as an asset.

The RSGB's National Radio Station.  Controversial and expensive.  Image via CQHQ blog.


Despite repeated, optimistic assertions from the society, it was clear from their own published statistics that only a handful of folk were going through the NRC's doors on any given day.  The claim that this was a good way to recruit new hams and new members was always, frankly, ridiculous.  It was also the most expensive way imaginable to achieve those aims.

During the NRC's opening ceremony, then-Minister Ed Vaizey made a point (at about 2m 32s in) - laughed away as an unimportant point by the society invitees - that the hobby attracted a "certain demographic".  In other words, overwhelmingly retired, white, middle-class men.  That's why PR material sent to me for handing out at a school consisted of (i) a stick of red-and-blue banded RSGB rock and (ii) a blue pen with gold RSGB lettering.  Hardly inspiring, relevant - or indeed healthy - for today's kids.

Some suspected that the NRC had been conceived by some as a rather good, DX-attractive site from which to operate a world contest-class station, mostly for their own feeling of wellbeing, and thus another taking of the membership for a very big, expensive ride.

Why did the RSGB claim it supported the 'K' RSL, when meeting minutes showed it opposed it?

Indeed, the feeling that the RSGB is led by contest-hungry bigwigs could be seen as reasonable when one considers the opposition the society presented to the 'K for Kernow' campaign.

Whilst superficially supportive, documents obtained by this blog reveal an immediate opposition to the concept. The Cornish societies have been very diplomatic in public in their response to OFCOM's decision not to grant a permanent RSL.  But, privately, people have told me my blog posts on this issue are "spot on" as to how they perceived matters.  More specifically, they think the new RSL was seen as a threat to contest operators unduly influencing the RSGB.  OFCOM looked like incompetent idiots by performing not only an U-turn on the matter, but a perfect S-turn as well.

So it would never do to simply pin all the blame on Kirby.  The RSGB had become wayward in the contempt some had, through their almost unilateral decisions to spend money as they saw fit - towards members.

Enter Graham Coomber.  The steadying hand for the RSGB in a time of crisis.

Under Coomber, a considerable amount of soul-searching took place at the society.  Coomber certainly saw an end to financial dubiety - so far as the accountant's statements allows us to know (the then accounting firm for the society didn't raise the debt with the wider society until it had reached a point where it was a sore thumb sticking out.)

For the past few years, Coomber has been the polite, perhaps rather establishment yet calming influence on the society whilst it pulled its pants back up over its bare backside.  In that, Coomber was just what we needed.  There haven't been any particular controversies that I'm aware of since Coomber took over.

Not that Coomber was entirely free of controversy.  The right to privacy means that, even for a member paid-for society like the RSGB, we don't ever get to know just quite how much the MD gets paid.  We're only glibly told that "one member of staff" gets "more than £60,000".   That reporting limit has recently gone up by £10,000, but I haven't seen the latest accounts, so can't comment.

£60,000 and, maybe, a lot more, is a lot of money to most people.  The society didn't really welcome my enquiry about it, saying that Mr. Coomber was in early, and went home late, working weekends and evenings, answering letters and emails, blah blah blah.  Try that justification on a top-tier NHS nurse, who gets just £28,000 a year. 

I can't quite remember what the calculation was that I made some time ago now.  I seem to recall that about 11% or so of the annual subscription went to paying one person's salary.

Whilst Coomber is simply taking home what the society decides to pay him, I do think the society should be much more open and move beyond accounting and data law, and publish the exact salary.  It could easily gain the permission of the MD to publish - and now, when recruiting a new one - would be a good time to obtain it.

Given we already know that it's more than a large amount of money, publishing the exact figure will be no more a breach of anyone's privacy, in my view, provided, as present, the name of the person isn't published.

Graham Coomber fielded a number of sometimes rather irritated questions about my pet interests: accountability, promoting the hobby beyond its own incestuous circles, and accepting ordinary members into running the show.  Always impeccably polite and prompt in responding, Coomber nevertheless struck me as simply keeping the boat unrocked.

Those dead hands of oppression from the past also made their precence felt during Coomber's watch, when I enquired how much input they'd made into changes to the planning system and associated consultations of late.  Despite a lot of hot air and some futile, angry attempts to show Wales was no different from England in planning law, the basic answer was: the RSGB had made no input into the relevant consultations.   So much for the RSGB defending its members interests in that vital arena.  For me, living in Wales, it inevitably smacked of an Anglocentric society, having little awareness of anywhere outside middle England.  It's quite telling that I've never seen any accommodation for the Welsh language at the RSGB.

Another dead hand appeared when I asked why an online search for news about ham radio in the mainstream press yielded, astonishingly, zero results, I was told the society was addressing this problem by appointing a new PR person.  I was happy to hear that at the time.  Yet, two or more years on, there's still precious little, if anything about ham radio appearing in the newspapers, TV or other places where people who've never thought about ham radio might have their interest pricked.

So, well done, Mr. Coomber, for getting the RSGB back onto some form of steady course.  You were the right man for the right time.

But what of the future?  Quite a few of the old guard are still lurking in the corners where less light shines.  It is to be hoped that those folk, who some claim are obsessed with contests and points-earning, don't appoint a new MD that allows the old ways to return.  I'm sure we won't see allegedly criminal debts being run up again, but there are other ways to run a bad radio society.

As always, this blog, and plenty of others, will be keeping a close eye on how the RSGB develops in the coming months and years, and whether it becomes sufficiently representative of its members that I might consider re-joining the society.

Time will tell...






Monday 22 February 2016

Mind Your WSJT-X!

I love the JT weak signal modes.  They've revolutionised QRP working, and allow a family man like me to continue operating, quietly, when kids are in bed!

I try to keep my software up to date, and this has never posed any problems with Joe Taylor's excellent work.

Until, that is, I tried using WSJT-X.  Whilst the system decoded very quickly, being a big improvement over v1.3, I just couldn't get the darned rig to CAT-talk to the program, and vice versa.  The further problem was that, unlike the earlier versions, the software would go into a meltdown and start doing strange things, with bizarre numbers being returned into the QRG window.  I could only achieve software stability by going through this meltdown half way through the first TX cycle, which was irritating for all concerned.

Frustration soon set-in, and I decided to continue using the old WSJT 1.3, without CAT control as I had always done.  No big deal.

But then, I was banned from a DX cluster!  Why?  A polite e-mail from an operator asked if I knew I was spotting onto 60m, when I was clearly not working there!  This was the kick I needed to sort out the WSJT software once and for all!

After consulting another blogger's page about CAT and WSJT for the Yaesu 450, and some fiddling of my own, these are the settings that have proven to work for me tonight.  Only these settings give full CAT control, read the frequency, and give the proper power output on WSJT-X so make sure to set them all exactly as shown.

Actually, after an evening of successful operation, I've found the settings didn't yield stable working longer-term.  There seemed to be some conflict between the various control lines.  These are now the settings that seem to work just fine:



Thursday 18 February 2016

VY0ERC - Both Ways!

Sometimes, life is too busy to stop and concentrate on a QSO.

During times like these, I often switch either to JT modes if I'm cooking, or WSPR when I really have no time at all.

Eureka weather station - very far north!


A few days ago, I was happy to receive VY0ERC, though he didn't hear me.  Based near Eureka, in the very far north of Arctic Canada, the Eureka Weather Station is a pretty inhospitable place.  Whatever they have as an antenna must be a pretty resilient design!

This grey line time, I set the radio to 20m WSPR.  Immediately, I spotted Eureka, lying just behind the sunset line in a great arc linking my location with theirs.  I was then very happy to see that Eureka had heard me - one of only two EU-based stations to be heard over the preceding hour.

Plenty hearing Eureka, but only two being heard all the way up there!  Terminator is at time of map creation, not transmissions.


It's very nice to have a 2-way report with such a remarkable and unique station so far north.  It's also great to see a simple vertical delta loop performing outstandingly well.  The elevated position, proximity to the sea and superb ground conditions does make a big difference.  But the message to those considering a delta loop, providing you have a relatively uncluttered environment, is: put one up!


Thursday 4 February 2016

Slim Jim Antennas and the Fixing Problem Solved.

For a few years, I've enjoyed good service from my homebrew 15mm copper pipe SlimJim.

With a compressed, low angle pattern of radiation, the SlimJim, whilst hardly a 'supergainer' antenna, does put the gain it has in an ideal place for operating repeaters and point-to-point FM.

My current fixing method is a 4 metre piece of timber with a few PVC pipe clips holding it fast against the violent, 85+mph winds we get here on a regular basis.

The existing SlimJim fixing arrangement.  Strong, but it's too low.

Over the past weeks, it's become clear that my fairly low position for the antenna, whilst fine in almost all directions due to our high ridge position, is causing a loss of signal towards the southern parts of north Wales.

So, it's been time to consider moving the SlimJim up a little.  As luck would have it, I have some spare capacity on an old satellite TV mast, which is fixed on super-heavy duty double brackets that will take any wind thrown at it.

Attaching a SlimJim to a metal mast is more problematic than you might think.  It really needs to be isolated from the mast, so some insulating arrangement is required.  That said, I have attached a SlimJim directly to a metal mast, which seems to have little effect, other than an increase of about 0.1 in SWR from 1:1.2 to 1:1.3 - which you can cancel by adjusting the feedpoint position a little. 

I've come up with two solutions that both hold up to strong winds with this very top-heavy antenna.

First, you can take a small piece of aluminium plate and attach Stauff clamps to them, such that these firmly hold the bottom of the antenna.  You then use a couple of the usual 'U' bolts (stainless, to avoid electrochemical problems), to fix the bracket to your pole.

A fine bracket solution by G0SXC, selling on Ebay for very good prices.


The second method is more rough-and-ready, but it is strong.  You use a 15mm to 22mm copper coupler, which you solder onto the small tail at the bottom of the SlimJim.  Simultaneously, you solder a shortish length (maybe 6 inches) of 28mm copper tube onto the coupler.  

The pipe at right is 15mm - a 'simulated' lower tail of the SlimJim - fitting into a 15-22mm coupler, soldered to a 28mm pipe.  PVC tube of about 21 or 22mm (or slightly larger) fits over the tube.  You need two split lengths to make a correct, tight fit inside a 1.25" mast pipe.
 
Whilst this is cooling, take a similar length to your 28mm copper pipe of 21/22mm PVC pipe, and slit it lengthwise with a rotary cutter.  You then slip this over your 28mm pipe, forming a sleeve.  It's a tight fit! Take another slit length of PVC tube and slip that over the first sleeve.  This is an even tighter fit!

With all this in place, you'll find that it will fit very snugly indeed inside a 1.25" aluminium or steel mast tube.  You can use a small collar made of tape or a hose clamp to stop any downsliding, or fit a stainless bolt through the mast tube where the inner tube can rest on it (you will need to make sure there is a length of PVC resting on the bolt, and not any copper tube, to maintain the electrical insulation.) 


Monday 1 February 2016

RSGB Books - A Bad Case of Deja Vu.

Regulars will know that I gave up my membership of the RSGB during 2015.  This was a result of very many aspects of the society, not least its apparent domination by 'big guns' in the contesting world, its failure to support the Cornish in their bid for a secondary regional locator, and their inability to properly promote the hobby in the mainstream, lay media.

I feel I know every brick in that bloody chimney by now...  Image: Amazon UK


I've a friend who is a new ham, who has joined the RSGB recently.  So we swap society magazines.  He gets my old QSTs for a while, and I get his RadComs.  I can quite confidently say that I am the one drawing the short straw in terms of what is worth reading!

We also swap books.  This week, I received the loan of 'Backyard Antennas', notionally by Peter Dodd, recently deceased.

Once again, the RSGB has produced a book firstly by a bread-and-butter author and, secondly, one that is as near as one can get to a reprint of the same old rope contained in very many other RSGB books.  It's so bad now that one comes to think that putting a new cover on old material is not far off a blatant rip-off of those buying them.

There is a considerable incentive for the RSGB to keep issuing and promoting its own books, because it obtains a very considerable fraction of its income from those sales.  Recent statements about the position of the society are quite clear that books were going to be pushed - and pushed hard - to maximise income in the face of a dwindling membership.  In the same breath, the society admitted it had difficulty finding new authors for both books and RadCom articles.

True, there is only so much you can write about antennas.  It's not likely some fundamentally-new wire antenna will suddenly be thought up by someone after a century of thought and practice.  But there is an awful lot of repeat-issue material by the RSGB, and it really will need to change tack on this, before the rip-off becomes embarrassing.  I think it's pretty close to that point, to be honest.

And if you're interested, the only two books I've found to be long-term, good investments are the ARRL Antenna Book, and the International Antenna Collection volumes.

Unsurprisingly, I haven't found any reason in the past year to consider my leaving the RSGB a mistake, and plenty of good experiences with the ARRL to consider it to have been long overdue.