Wednesday 30 October 2013

KQ2H-R: Getting Worse.

It's about a month into the excellent 10m propagation conditions that has seen the KQ2H-R in upstate NY creak under the calls coming in.

But the operators attracted there vary enormously from the excellent to the downright inept.

Aye.  Settle down to a cuppa and hold up the world on KQ2H-R.  Nice one!

Sadly, some of the regular worst visitors to KQ2H appear to be from the UK.  Not content with short, polite exchanges than acknowledge the extreme numbers trying to call in, ol' George stations settle down to a nice cup of tea and a moan about the weather.  Inevitably, they are elderly.

KQ2H-R is not a place to thrash out, once again, the arguments about what makes a QSO.  It is simply a very busy place where you call in politely, say hello politely, and then leave quickly.  It's not a place to ask 400 other stations to 'stand by' whilst you take ten minutes to express how strange it is to 'work the UK the long way round'.  We've heard it all before, and we all understand how it works, thanks.

So, as they say in the US, home of KQ2H-R, "MOVE ALONG THERE!"

Wednesday 23 October 2013

The Positive Health Effects of Amateur Radio.

The electromagnetic spectrum is, or at least once used to be, the attention of all sorts of wild claims about adverse health effects.



Ham radio hasn't generally been the victim of widespread antagonism from the general public, at least in the way that mobile phone masts once were.  Strangely, phone mast health concerns appear to have vanished as soon as the operators gained the ability to install towers simply by informing local authorities, rather than asking for their permission.  Evidence, perhaps, that too much democratic influence isn't always a good thing.

But are there any positive health effects from radio, and more specifically, amateur radio? 

I'd argue that there certainly are.

As I've noted in recent blogs, I have been suffering from the intense pain brought about by a prolapsed vertebral disc.  It's not something I'd wish on my worst enemy.  Mercifully, I am now coming through all that nightmare.

But, between the pain, the back exercises and the pills, going on the radio from time to time also had a very positive influence on my recuperation.  Instead of wallowing in pain on my own, I could have nice QSOs with someone far away.  I could look up their QTH on Google and, for example, experience in some small way the wide, open expanse of the central Russian skies.

I don't know how much my pills cost the Welsh NHS over several weeks.  But they didn't come cheap.  It would be very interesting to see whether, for those who have the licence or for those who might like to get one, ham radio could complement treatment for various health problems, most notably those of depression and loneliness, in a cost effective manner.  It would be surprising if it could not.


Saturday 19 October 2013

Things To Do On KQ2H Repeater.

Picture the scene.  KQ2H repeater opens up on 10m.

It's busy.  Very busy.  People are calling in from Latin America, North America, Europe and the Caribbean.

Then, the inevitable happens. Some Brit ops come on to pontificate how others have been calling too much.  Being such experienced folk, they had earlier decided to "let them to it" and not bother with the repeater.

That 2 minute-long exchange took place whilst the repeater was in the aforementioned condition, groaning under the pressure of dozens of people hitting it at the same time.

So, thanks to 2E0UDX and one of his pals who let the world know - and at such length - how terribly fed up they were of people tying-up repeaters. 

On the other hand, congratulations to just about everyone else this afternoon, who kept it short and sweet.



Tuesday 15 October 2013

Mobile Antenna for HF

Yes folks, a rare occasion when I buy an antenna!

I've decided that mobile operating would be rather nice, and a good way to pass the occasional half hour whilst waiting for the kids to come out of school.

But which of the plethora mobile antennas do you buy?  They range from those sold for about £25 with very good reviews to those sold for well over £100, sometimes with not-so-good reviews.

The first impression you'll get of the G-Whip Pro Mobile.  It's a good impression.

Enter, yes, once again, Mr. Geoff Brown, aka G-Whip Antenna Products.  This is a man who knows how to make products and serve the customer as though he matters.

I looked-up Geoff's web site and quite liked the look of his G-Whip Pro Mobile antenna.  It comes with three coils of your chosen band as part of the package, and can be mounted on a tow bar, tow recovery hitch point, or standard mag mounts.  A mag mount on top of the car can be expected to have about 3-4dB better performance than tow bar mounting, also avoiding issues with rear screen heating wires and so on.

For £125, the antenna is not the cheapest, but then you are getting three dedicated antennas in one, so on that score, it's darned good value.  And that's without yet taking a look at the quality of the antenna you get.

The three coils (you can choose your favourite bands.)  Impressions even better...


So, I placed the order and twiddled my thumbs for a couple of days.  I got a test report and SWR curves for each of the coils just before the antenna was delivered.  Then, a sturdy cardboard tube enclosing the antenna which was itself encased within a further plastic carry-case, arrived by next-day delivery.

With just a quick screwing-on of coil and then the adjustable tip assembly, the antenna is ready to go.  With a few minutes spent getting the antenna to resonance (yes, you even get a spanner for the job!), I was down to about 1:1.2 SWR and ready to fire-up.

A few QSOs were had with easy, predictable European stations with excellent reports.  I even had a QSO with a man in south Italy operating /M using the same TS-50S and 50W output as I was, both with 57-8 reports.

A fine-looking, well-performing G-Whip Pro Mobile, as seen on my car!


Stunningly, I heard a strong Indonesian station on 20m, and gave him a call out of curiosity.  No, he didn't get my full call, but clearly asked the mobile station to come back again and eventually said sorry, he had an S-3 noise floor, just where my signal was hovering.  There is no doubt whatsoever that, whilst this mobile antenna is obviously not always going to compete with home stations, it is going to put in a good show and probably beat most of the other mass-produced Chinese whips out there.

I will be updating this post regularly as I spend more time with the antenna.  I only report honestly, so you can judge for yourself whether this is the mobile antenna for you.  Certainly, even at this very early stage, I have nothing but praise for the superb build quality and evidently good performance of the G-Whip Pro Mobile.  By the way, I am only a customer of G-Whip, and have no other links with the business or its owner.

Out and About with the G-Whip Pro Mobile.

Going mobile is really rewarding!  Pull in on a hill, mountainside, or by the sea.  You may think it's a bit of a struggle, but with this antenna, you start to wonder if the QTH antenna is as good as you think!  What's more, you get more on-air time, so more chances to catch interesting DX.

Here is the best indication of the potential of this antenna.  The red lines are direct contacts; the yellow is to KQ2H-R, with green then from the repeater to the station contacted.  The QSO with OA6 is quite rare, and shows the usefulness of being able to be on air when otherwise you would lose out.  The bias to the west is exclusively down to operating during mid-to-late afternoon in late autumn.  What isn't shown on this spherical map is the 54 QSO with VK6MV from outside the kids' school on long path on 15/11/2013!

Just a few of the best QSOs over the first month or so...




Saturday 12 October 2013

A 2-Element Vertical Beam for 12m (Cheap Price!)

The 12m band is great for working far eastern countries from here in north Wales.  From early to mid-morning during the spring and autumn propagation periods, all sorts of distant and disparate areas come to life on the PSK screen.

But, I've never had a dedicated 12m antenna, so relied on forcing my 20m delta loop to radiate at a frequency quite unnatural to it.  OK it worked, but the radiation pattern is very distorted and obviously not an ideal way to work.

So, inspired by my friend 2W0MTD doing very well indeed into the east with his homebrew doublet, and the 12m band livening up a lot in autumn 2013, I grabbed two 7m fishing poles (I recommend you use 8m versions) previously destined to be part of a Moxon beam, and cut some wire for a vertical dipole for the 12m band.  A number of thin cable ties keeps the wire snugly attached to the poles.

The 2-element 12m beam looking towards the far east.

I fed the radiator with 300 Ohm twin, led into a homebrew 4:1 current balun outside the shack wall.  With no cutting, this came in at an SWR of about 1.7 at the bottom of the 12m band.  Because I'm using twin feed, the losses due to SWR, which tends to rise as the weather gets drier, are minuscule and utterly inconsequential. I cut the reflector element at about 5% longer.

Pounding (with a bad back!) some half round fence posts into the ground as tried-and-tested supports, I simply cable tied the poles to them, led the twin wire at a decent angle away from the radiator, and retired to the shack.

The result?  Excellent!  A noticeable improvement was that calling CQ almost always brought an immediate reply.  I started working all over Russia, out to the far east and even a QRP station running 5W into a dipole somewhere on the line between European and Asiatic Russia.  The gain is pretty respectable at anything between 6 and 7.4dbi, depending on which ground conditions you use; it's also DX-useful low angle radiation.  This is the only antenna I have which regularly yields better (objective, JT65A-based) outgoing signal reports than incoming.

Standing behind the reflector, the RF meter reads zero, showing excellent F/B.

I took out the homebrew RF meter to get a fell for the radiation pattern.  Remarkably, this extremely sensitive meter, even at its maximum setting, gave a zero reading directly behind the reflector.  The model suggests there ought to be a reasonable amount of radiation, as the F/B is computed to be a modest -6dB or so.  In reality, the F/B appears to be more like 10-12dB.

Here's the pattern for the vertical beam as computed for extremely good ground, bottom of the antenna at about 40cm off the ground.  The -3dB beamwidth is, for a manually-steerable beam, a usefully-wide 120 degrees.

How MMANA-GAL computes the 2-element 12m beam.  The F/B is, in reality, much better than this.
I've modelled the antenna spun 90 degrees to one side, as a horizontal beam at half a wavelength up (about 6m.)  The gain below 10 degrees is in fact better for the vertical, even though the horizontal has a better peak gain of 11.7dBi, but which doesn't occur until 27 degrees.

So, the vertical is better at rejecting higher angle signals, having a peak gain of 7.6dBi at 12 degrees, and this was evident in on-air tests.  By a combination of grey line working and this modest beam, I've managed to log several African stations in the space of just a few days, after a long period of being a bit tough in the southerly direction.  Given the sparcity of African stations, that's pretty good going!

I've added three more fence posts to enable the reflector to be moved around the radiator (at a separation of about 2m), making a manually-steerable beam. I'm now using 40mm drain pipe clips as an easy way to locate and relocate the reflector, but I did need to rotary-tool sand away the ring on the base of the screw butt-end of the fibreglass pole to make it all go smoothly.

An unexpected bonus is that this beam works more than decently on 10m as well, allowing nice contacts into KQ2H-R when the propagation is running.  

Happy vertical radiating!


Friday 4 October 2013

Going HF Mobile, G-Whip Style.

Yes folks, I've finally decided to go HF mobile.  Having recently acquired a new car and pondered on the comment by a colleague that "radio's more fun when out and about", I sat down to view my options online.


I am by no means an antenna expert; that much is clear.  I also have little time at the moment to learn about coils, measure their characteristics, and build a successful antenna.

Towbar and tow hook mounts are available, but magmount atop the car makes for significantly better performance, essentially doubling the signal strength.  Image: G-Whip.


In short, I've decided to buy an antenna!  This is a very rare event indeed for me, as I've previously only bought a 10m and 20m end fed from Geoff Brown, AKA G-Whip.

Anyone who's bought from Geoff will know the clear benefit of doing so: personal, prompt and polite customer service, coupled to very high quality products, usually of military standard.  This is despite being a very busy man who essentially hand-builds every product he offers.

I've not yet received the antenna, but the magmount and rig are all sorted out, ready for the off.  It all feels a bit like the CB days of old, but better!

As soon as I get out and about, and especially park at the seaside, I'll let you know whether or not the £125 I parted with for Geoff's Pro Mobile antenna was a good investment.  Quite what parents waiting outside school will make of it will be equally interesting!

Wednesday 2 October 2013

High Geomagnetic Activity - Does it Affect Human Health?

I woke up this morning, with usual renewed excitement about what DX might be coming in.

Although I could hear a couple of VK stations, they were quite weak, and the band was clearly wiped-out by geomagnetic activity.  A visit to NOAA's space weather site confirmed a G2 storm had been underway overnight.
Neuropathic pain such as sciatica is tremendously distressing and debilitating.  Does the Sun make it worse?

Now, I suffer from very severe sciatica.  I take GABA inhibitors to block the intense pain that otherwise renders me a crippled man of 44 years.  Until I took the GABA inhibitors, I couldn't sleep, which sent me on a road to hell.

So, for a couple of weeks, I have slept with no pain at all using these miraculous drugs, more usually prescribed for epilepsy sufferers.

But, last night, at 02:30UT, I woke up with a pain as though I hadn't taken the pills.  I checked I had taken the correct ones, and I had.  With a combination of drugs, I eventually drifted off to sleep, and the morning brought renewed positivity.

Could this be a warning that a higher dose of painkillers might be needed?  (warning: do not exceed your prescribed dose)


Now, was the fact I had pain this morning related to the G2 storm, which commenced just after midnight and so coincided with the onset of my pain?  Correlation, of course, does not prove causation; I'm well aware of that.

However, a search this morning on the internet revealed a surprising number of peer-reviewed papers on the negative effects of enhanced geomagnetic activity on human health.  Some of the statistical probabilities recorded clearly indicated more work was necessary.  Others were much more robust.

So it seems that not only can the Sun's tantrums wipe out our beloved HF bands, but can also make life a misery (or worse) for humans too.  I find that fascinating because I had never before heard anyone mention such a possible link despite a lifetime in science, and for the mechanism behind the effects.

Postscript.

For those looking for evidence that ham radio is bad for human health, the above is nothing to do with that topic; it's about entirely natural, solar-induced effects. Current conclusions on ham radio are that the low powers used do not represent a health hazard to humans.  The UK has a very low power maximum of 400W, compared to 1kW or more in other countries.  Most UK hams use 100W or less.