Monday, 28 December 2015

Difficult to take a step back in this hobby

Some people do not have the option to keep moving forward in this hobby. Life changes, house moves, job commitments, lot of things, can cause many amateurs to take a step back from time to time and simplify what they are doing.

It is not a bad idea sometimes. We can often let things get out of hand and lose sight of the basic simplicity of amateur radio. Sometimes it is a good idea just to clear a lot of "stuff" out and go for the simple approach again.

Whatever the logic, I tried to change the 4m antenna a few months ago (see here). A smaller antenna seemed to be the only one available, given my limit of 1.5 on one side of the beam (or roughly 3m maximum boom).

My existing 4m antenna then,  a 6 element Sandpiper, was a great performer. However, it was basically an extended version of their 4 ele, and that was its main failing. The boom was not sturdy and featured heavy support braces. The elements did not stay stable in the winds we have here and I decided that it was not able to withstand the winds here.
This 6 element is not longer made by Sandpiper, and when I took it down I could see that it was quite a lot out of line. It should be fine as a 4 element, but 6 elements was too much for that boom.

The replacement was a 4 element Vine antenna. Nothing wrong with that. It was also the last antenna Vine sold as they stopped making them the day I bought mine.

There is nothing wrong with the Vine. However, it has a 2.6 metre boom, and the difference between that and the 3m boom of the Sandpiper was immediately apparent. Changing back from a 6 element to a 4 element was a frustrating experience. The two most useful beacons nearest to me (GB3CFG in Carrickfergus and GB3BUX in Buxton) both disappeared and I had to rely on GB3ANG (not a favourite of mine).

The thing about antennas is that you never know how badly they are doing. You know how WELL they are doing, but you cannot say what you might hear if you had a better antenna. In my case, I could remember how well the Sandpiper did, and somehow the Vine was not as "lively".

I cannot really define "lively" as a quality of an antenna. It is a sizzling noise, a feeling that you are beating the background noise and you might hear anything that crops up. I could not really put my finger on it. I knew that in theory reducing the boom length by about 15% might lose me half a dB or so, but it just felt that I was losing out on something but I did not know what that was.

In the end I decided to change the Vine for a 5 ele PowABeam. There was some confusion about that, as I thought it had a boom length of 3.02m, but it turned out that it was 3.20m. There was an error in the website. So after I ordered it, it turned out that it would not fit. After some discussion with the dealer, The DXShop, it transpired that, unlike the other antennas, the PowABeam does not have a central mounting but the clamp can fit anywhere. Subject to placing some side load on the rotator I could put the mounting point anywhere along the boom.

The PowABeam arrived with the boom in one piece - 3.2m in a cardboard tube. "A very long snooker cue" was the delivery man's observation. The DXShop said it would arrive two days after they sent it, but it came the next day - well done.

Once I fitted the elements and tried for the balance point, it was nicely placed, with 1.4 metres on the back side of the beam and 1.8 metres towards the front. As my overall limit is 1.5m on one side, I was able to get it to balance and fit perfectly.
The two antennas look very different beside each other. The 5 ele is 800mm longer than the 4 ele was.

Thus I have increased the boom length this time by 30%, in theory worth about 1 dB, hardly noticeable, you may think.

There was nothing wrong with the Vine, other than I lost confidence in it. It was, theoretically at least, a tiny bit less effective than the Sandpiper. It was bound to be, being shorter. But I missed an antenna that used all the space I had available. In practice, the PowABeam fitted perfectly.

The improvement is largely in my mind. As soon as I put it up I could hear GB3CFG and GB3BUX. The following day I could hear neither of them. Isn't tropospheric propagation interesting?

The Vine has gone into the garage. For anyone who wants a 70MHz antenna of about 2.6m boom it would be ideal. For me, who felt disappointed when I went for a shorter boom, it was too short.

Am I saying that every antenna any amateur has needs to be bigger than the last one?

I guess so.

73

Jim
GM4FVM

Saturday, 26 December 2015

Christmas, and Sporadic What?

Best wishes for Christmas to all my readers.

I have been thinking along three themes over the past few days.

Theme 1 - Why short distance, regular, meteor scatter contacts?

I was just pondering on whether I could actually work SM5EPO under more or less any conditions via meteor scatter (as I mentioned in recent posts). PeO is in JO46 square, 651 km from me, and I had worked him 3 times on 6 metres over a week - though once was on Es after an aurora.

This curiosity stems from my ability to work Henning, OX1JXY in JO46 square (735km) on 4 metres meteor scatter, on a very regular basis, sometimes daily.

Many reference books are pretty useless on propagation, particularly the RSGB Radio Communication Handbook. Once again a book influenced by the "HF dx-nutters" who seem to control that organisation. The ARRL Handbook is a bit better saying of meteor scatter "contacts between 800 and 2300km can be made at 28 through to 432 MHz via reflections from the ionised trails left by meteors as they travel through the atmosphere". I have corrected the text to remove the American spelling and grammar, and they deserve praise for actually dealing with the subject.

From reading things like this I seem to have formed a view that meteor scatter is not very effective over ranges less than about 800km. This will of course depend on the "elevation" of the meteor shower relative to my observation position and that of the other station, plus a lot of other complex influences. However, I tend to use random meteors rather than specific showers, so the elevation I use is pretty variable. So less than 800km seems fairly possible, fairly regularly.

I have read of large commercial projects which used meteor scatter, usually for military purposes. There were all long-distance, e.g. trans polar, and I was not really expecting to have quite so many short distance random MS contacts.

Recently I had a 4m MS contact with OK2BRD on 22 December (JN99 1528km), though it took a hour and eleven minutes to complete the exchange of 5 pieces of information. That is the sort of QSO I had been led to believe would be my lot on meteor scatter. Once again working OZ1JXY on 24 December makes me wonder.

Theme 2 - Es in December

I had a few minutes to spare this morning for meteor scatter, or so I thought. I heard some JT6M on 6m. Quickly turning the beam I worked SM5EPO again. This time though it was not at all like a meteor scatter contact. PeO was putting in a colossal signal. People talk about Winter Es as a pretty thin opening, but this was really powerful.

This screen shot is not the clearest, but it shows me with both 10m WSPR and 6m WSJT JT6M running, as I do when I am watching for Es propagation. I have blanked out the 4m side of the screen for clarity (!).

At the same time as receiving 10m Es from the South, I was receiving 6m Es from the North East. This is unusual for winter Es openings, which are supposed to be very selective.

I was expecting meteor scatter and what I got was Es.

Sadly after that I only had a few more minutes before I was called away from the radio. EI stations were working into Nordic countries for hours.

Theme 3 - Winter Es and solar activity.

I happened to mention to Tim, G4VXE, that I see an association between Es and solar activity, especially when the solar activity is raised but less than what would trigger an aurora, or still raised after an aurora. Tim printed my comments in his column in Practical Wireless magazine with a rather shocked suggestion that it might be a way to predict Es. Well, it makes more sense here than believing the Weather Man's waffle about Es being a wind driven phenomenon.

What did I see today on Solar Ham?

X-Rays elevated, but not enough geomagnetic disturbance for an aurora (though later in the day it got almost active enough for an aurora).

Theme 1, 2, and 3 --- Bringing all this together ---- a comment from Gianfranco IU1DZZ.

Just at the right time, I received an e-mail from Gianfranco, IU1DZZ. He pointed out that "Sporadic E" is just a conventional name. Es occurs regularly, but often for short periods and it is not always useful to us. Great point.

I think that I have been applying myself to the wrong task. My task is not looking for summer Es which we can often use. It is finding winter Es which is frequently hidden and not always of a lot of use. Especially, it is not much use to the many who have turned their rig off for the Winter.

Moving on with this idea, I see that Sporadic E is not really sporadic unless it is viewed from an HF DX viewpoint. OK it is not yet predictable, but it is frequent, maybe even regular, in the sense that it is moderated by certain things (and maybe Solar X-ray emissions).

And moving further away from the original thought, is meteor scatter also more dependable and less random than we thought, as we have been looking on it as a DX tool and not as a short range mode?

Conclusion.

I don't know.

But I will be thinking about it.

73

Jim
GM4FVM

Monday, 21 December 2015

First aurora, then the Auroral Es. A good VHF day

In a posting yesterday I said that there were signs of an aurora coming which I doubted might come, but I would be listening anyway.

The aurora had been suggested by the SolarHam site and was predicted to arrive the day before it did. However, I was ready and still waiting for it.

As per usual, the hour or so before it appeared I could hear the OY6BEC beacon on the Faroes and the Carrickfergus beacon in Northern Ireland on 4m. Also present was the GM8RBR 4m beacon on Skye and the GB3NGI beacon on 2m. These beacons had "gone auroral", in other words I needed to beam North-ish, and they had lost their tone. This indicated scattering from the curtain of charged particles streaming down the Earth's magnetic poles and heading for the Arctic Circle (-ish).

The magnetometers I watch had shown sudden signs of life from the days before - this was the start of the wobble which kicked off the "Scottish Aurora" earlier in the week:-



By the day in question (19 December) I was ready and waiting with the rigs poised on the right frequencies. I knew the beacons were blasting away, but you cannot replace hours of good listening.

Suddenly, on the 2m calling frequency was a seriously distorted signal which I could just work out was GM4JJJ in IO86 working a station in Shetland. Then the 4m rig sprang into life on 70.200 with a garbled version of a CQ call. This turned out to be OZ5AGJ, 678km away on JO47 square. New square on 4m! As usual towards the start of an auroral radio opening there was heavy distortion caused by the "Doppler" shift applied by the charged particles swirling their way down the lines of magnetic force.

I tested things out on 2m and worked GS8ASD, but apart from that, all my auroral work that day was done on the 4 metre band (70 MHz). Next I worked G4ODA (IO92 367km), and after that it was a long slog working through a pile up. GM4JR, OZ1BNN, OZ1W, G4BZM, GM4PMK, G0BPU, GU8FBO, EI4EY, GW0GEI, G4IOQ, G3NPI, G3LVP, G4VCJ, G3SHK, GM4DIJ and GM3WIL. Hard to set all that out, so I have made another of my trial maps:-

No lines this time. Not sure how clear this is without them - I am still fiddling around with this. As usual click to enlarge, but you may find it a bit "blocky" if you do.

Anyway, You can see that the 3 stations in Denmark worked early on appear to be the only "DX". Not true, each of the contacts that day was in a different square (apart form GM4JR and GM4DIJ) and several were memorable for other reasons. GM4PMK was a real surprise. He is on the Isle of Mull, and seems to share my interest in things ionospheric. He has his own magnetometers! Anyway, IO66 was a new square. Also, GU8FBO was blasting in here, not only is IN89 a new square, but Guernsey is a new country for me on 4m. With G3SHK being in a new square too (IO90 - how have I missed that!), this was a very worthwhile exercise.

However, I have to say that after days of listening and waiting, plus two and a half hours of operating, I was exhausted. I could never be a contest operator. I like my DX at the end of a long hunt. I could never handle pile-ups like that for hours and hours.

Anyway, on 4m I have now reached 33 countries and 166 squares. It took me 33 years on 4m to work outside my own DXCC. Then a contact in 2010 with Ivan S51DI gave me Slovenia on 4m FM, and since then I have powered away. Joy of joys, I did not even need to try, they came to me, on FM, on meteor scatter, aurora, even occasionally even on CW. Only in a pile up does it become a burden. No need for high power, no need for big antennas. What a marvellous band.

Grand so. But my work was not over. I know very well that after an aurora there can be very nice Sporadic E, often called Auroral Es, but I use that term with some doubts. Anyway, on 10 metres WSPR I was noting OH1KK, OH5XO and SI9AM, from about 16:10 onwards. The aurora lasted here from 15:20 to 17:50. I kept an eye on the 10m Es, and they were still going at 21:00. That is a classical Auroral Es path so I thought that I should give VHF a try later.

It helped that Mrs FVM needed to watch something on the television. Some show were they line up daft dreamers, turn them into supercharged bullies, and then select the worst personality and give them a highly paid job for a year. It seems to be run by a quarrelsome barrow boy who runs around in a Bentley and wakes these duffers up at odd hours of the morning. Then they make eedjits of themselves running stalls selling some dire product, trying to outperform the others. I cannot see the point of it. So as it was the final I had two hours to spend too, which I used listening hopefully while doing my QSL cards.

At 21:53, right on queue on the 4m SSB calling channel came OH1AXT (KP10TJ 1582km). Great QSO, and he was a clear as a bell and a huge signal. No need to struggle with the distortion using Es, unlike aurora. I could not raise anyone else on 4m, but 6m was humming, and I went there and worked SM5EPO - again. I had worked PeO twice last week during the Perseids meteor shower. Good to hear his voice. Then OH1LDI and OH3VZ, (KP11 and 12, 1589 and 1584km).
Oh, I don't know about these maps. I am not sure if they add much.

Anyway, what a great day. I let the 10m WSPR work on until about midnight, and it had finally faded out at 23.22, but not before the Nordic stations mentioned earlier had been joined by TF3HZ proving the Auroral/Polar connection, but also EA8BVP. Canary Islands are a regular here, even when the band is not good. Is that Es? If so, is it auroral? If not auroral, what is it? Oh yes, and there were even a couple of Stateside WSPR stations too.

The Es session was shorter than the Auroral one, but a lot more pleasure. I enjoy that challenge of aurora, but this one was pretty limited.Of course I am happy to work all over the UK and Ireland, plus Denmark, but some real auroral DX would be nice. How do I manage that? Oh yes, CW. I know I am missing out on a lot of DX because I can hear it on CW but cannot respond. Why not? Erm. Because I am spooked by the high speeds they all do (and don't say they will slow down, because I tried that and they definitely do not slow down). Anyway, Es was a real doddle and with Es you can forget CW, which I do quite happily.

There are a good few people who turn off their radios in December and reckon there is not much on. Once upon a time I would have done the same. Yesterday was a good day to have the radio turned on.

73

Jim
GM4FVM

Sunday, 20 December 2015

Geminids meteor shower 2015, and a "Scottish aurora".

The Geminds this year were "scheduled" to start around 7 December, to peak around 14 December and end around 17 December.

I found some enhanced meteor scatter activity between 12 and 15 December. The result was that I worked:-

6 metres:-
OE5MPL (JN78, 1387km), EI4DQ (IO51 369) and SM5EPO (JP80, 760)
4 metres:-
SP9HWY (JO90 1543), OZ1JXY (JO46 735) SP2JYR (JO92 1387) and OZ1JXY (JO46 735)
2 metres:-
OZ3KGJ (JN65 1544), IK5YJY (JN53 1696) and SP2IQW (JO94 1319).

I actually worked SM5EPO twice on successive days, which is interesting in itself. Could I work him almost every day (like OZ1JXY)? I never expected these things to occur on meteor scatter, which I thought produced very random results.

I mentioned all this to Bob, G3KML, who pointed out that 2m was getting me furthest.

Leaving aside working SM5EPO twice, the average distances are
6 metres: 838
4 metres: 1100
2 metres: 1519.

It is a very small sample, but he has a point. This supports my own experience, from which I draw the anecdotal theory that on 6m the reflections are weak and long lasting, on 2m they are strong but very short, and 4m is a mixture of the two. So you can get further on 2m with strong reflections, but the contacts take longer with long gaps between the bursts. On the other hand, 6m allows you to have reasonable contacts with simple equipment a lot of the time.

I have finally bought a licence from EI8IC for his mapping software. The delay was due to a quirk in Windows 10 at my end. I had to sign in on another computer, pay and register, and then register this computer to that subscription. My problem, and $15 isn't much for such a useful tool

I have made a map and added some lines, with 6m Blue, 4m Green and 2m red. Sorry, I forgot to add OZ1JXY, and I hope Henning will forgive me. I had to use several bits of software and it has lost some of its crispness due to compression at various stages. On reflection, adding the callsigns and leaving off the country names might have been better.

Anyway, you can see what Bob means. 2m does seem to get further as you might expect, but not much. But the maps are not based on great circle paths. Although several of the contacts were roughly the same distance, the best DX was actually IK5YJY followed by YL3HA. The maps does not make it look that way, so the projection is not ideal for some purposes. Still I will press on and I might correct for the projection later.

Still, I remain convinced that meteor scatter is an entirely different beast on 2 metres. Most people use JT6M for 6m and FSK441 for the higher bands. That supports the theory that 2m bursts are shorter, as the modes are tailored for those characteristics.

Also, I could hardly work Italy on 4m at present as Italian stations are not licenced for the band just now. I have worked Italy on 4m meteor scatter in the past, but it was hard work. Nor is 4m available in Sweden, nor 6m in Russia. So the pattern I find may be skewed by these issues.

There is another underlying factor. Perhaps I do not work as far on 6m as my heart isn't in that band. 100W and two elements (even though they are phased elements) does not look like a lot of commitment. On the other hand, on 2m I have 200W and 7 elements. Or maybe it is the reverse, perhaps I NEED a better station on 2m due to the characteristics of that band.

Either way, my station is modest by meteor scatter standards. Most meteor scattter stations have huge linears and vast towers. My station is modest on all bands by that standard. But I still get results.

Moving on, there was a "Scottish" radio aurora on 14 December. Amateurs in The Beautiful South tend to call any aurora which does not reach them "Scottish". In other words, hardly an aurora at all. Here I heard the Faroes beacon on 70.035MHz (OY6BEC, IP62, 735km) with auroral tone. A Scottish aurora might be small beer to those in the "Home Counties", but up here 735km is a fair old haul. Hey, down there they get Trans Equatorial propagation, which we do not get in the frozen North.

Also heard aurorally during the 14 December event were the Carrickfergus and Buxton beacons on 4m, and the GB3NGI beacon near Ballycastle on 2m. Then I worked Clive, GM4VVX on aurora on SSB. OK, a "Scottish" aurora, but good fun all the same.

As I write (20 Dec), the follow up shower to the Geminids, the weaker Ursids shower, is with us. I am hearing various reflections on 6m. Also, we have an ionospheric disturbance from a pair of coronal mass ejections. These two outpourings form the Sun are not having much effect here so far (it is the middle of the day and I usually expect things to liven up, if at all, after 15:00).

Will things liven up? Probably not.

But I will listen anyway.

Jim
GM4FVM

Thursday, 10 December 2015

Wind, not vertical antennas and 6m activity

It has certainly been windy over the past few days.

If you needed any evidence of climate change, you just had to spend a week on the English/Scottish borders.

Last weekend there was a 36 hour period when we were constantly battered by high winds, with gusts up to 120km/h (known as Storm Desmond!). Then overnight last night (nameless!) we had some more, at higher strength.

Fortunately, although it rained a lot, this part of the Borders did not have the severe flooding which occurred on the West Coast and in Carlisle in particular. I could have been worse here, and I am grateful that we got off so lightly.

The wind does cause disruption. Last night the road visible from the shack window (the "A1" trunk road from Edinburgh to London) was closed after several HGVs (semi-trailers and their tractor trucks) were blown off the road round the headland at Burnmouth. In other words, within two miles of here.

Today the railway is plagued with blown down trees and branches. The line was closed for a while but now it has got a bit easier:-
Description
An object caught on the overhead electric wires between Berwick-upon-Tweed and Alnmouth is causing delays of up to 60 minutes to trains between Edinburgh and Newcastle. This is expected to continue until approximately 11:00.
Back here at GM4FVM the immediate effect of high wind is that I do not raise the Tennamast at all, or only to a limited extent. That protects the antennas and reduces the noise, but it limits what I can do on the radio. On the other hand, the 6m antenna and the 4m vertical are on T and K brackets and cannot be wound down, so they stay in the full force of the blast. The idea is that a simple HB9CV does not catch much wind, and the vertical should be able to stand it.


After all that wind, the 4m vertical is slightly off vertical. The 6m HB9CV looks to be in fine form, and you can just see the 40m dipole passing, and all those stood the wind OK.

The support for the 40m dipole has the 2m vertical on it, but it is lower down and guyed. I am pondering whether to put up a bigger 2m antenna and raise the 40m dipole, but not in this windy weather.

OK, it isn't a big lean. A few degrees. I do not have much to complain about. This place was not flooded, and my car has not been blown over (yet). But I am going to have to go up there and fix that.

This is the second time this has happened, as the antenna which was there before the present 5-8th, a Sirio J-pole, also got the bends. I just have to face it that the wind coming off the moors from the South West can bend just about anything.

Just to prove that the Diamond HB9CV is working on  6m, I went on during last nights wind and worked DF6HT on meteor scatter. As I cannot tilt or lower that antenna, I might as well use it in the winds.

That was a good contact for me (939km). Meteor scatter has been poor from here over the past few weeks (and months). With the Geminids meteor shower due over the next few days I am hoping for better results soon.

What can I call my 4m FM antenna now? It cannot call it a "vertical". It is a bit more bent than the photo shows (I could not get to the right angle to photograph it).

"5/8th wave not quite vertical 70MHz antenna"?

73

Jim