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

Tuesday, 24 November 2015

UK Amateur Radio licensing - what's wrong?


I have been a trainer and assessor under the UK licensing system for some years, and a holder of a licence for 40 years or so. It is difficult for me to understand what it must be like to be a new entrant to our hobby.

I have had discussions with many people about this, from those wishing to become licensed to those who have held licences for longer than me. There are a lot of opinions about what is wrong with it, and almost no common aspects to all the views about what to do.

From what I can see, decisions tend to be taken about these things during panics or when the licensing authorities are putting pressure to sort something or other out. There is not a lot of logical thinking. Instead of planning in advance, things tend to get left until it is too late to sort them out. I think we should have a plan now, discuss it with the authorities and be ready for when we next need to visit this thorny topic.

There are three classes of licence in the UK - Foundation, Intermediate and Full. There are three exams, Foundation, Intermediate and Advanced, and they give you access to the related class of licence. You have to take each one in turn (you cannot skip the lower ones).

I do not really have a problem with the three exam and three stage system - in theory. It is supposed to encourage people to learn about radio as they progress, and some of them do, while some do not progress beyond whatever level they are now. It is hardly surprising that many stop at Foundation level, as they are new entrants and may find amateur radio is not to their liking. But quite a few get to Intermediate and stop there, so they have been in the hobby and taken a second exam, but choose to go no further.

Recently I heard from a former work colleague of mine who has just become a radio amateur with a Foundation licence. I am really impressed with his enthusiasm. He does not have a radio technical background, he has just taken up a new hobby. I knew him 20 years ago as a respected colleague, and I would never have expected him to take up an interest in radio. So, good for him. He tells me that he wants to learn and progress through the exam stages as he learns more about the hobby. I do wish him well and I am very pleased that he has joined us.

So this brings me to wonder just how the current system encourages him. And I reckon it doesn't.

The basic difference between the levels in UK licensing is a series of power restrictions. So a new entrant to the hobby gets almost full access to the amateur spectrum, but is limited to unmodified commercial equipment and 10 watts (PEP at the antenna). Intermediate gives 50 watts and broadly the same bands, but they are also entitled to build and modify their own equipment. Full licence gives 400 watts and a few odd slices of bands, plus the ability to operate abroad under CEPT agreements, maritime mobile, etc.

We can think about the Foundation as being equivalent to a start-up amateur getting at least slightly better terms than someone starting out in CB radio. That was how it was put to me by an RSGB President. He said that Foundation entry was to make amateur radio as accessible as CB. The power level of 10 watts and the requirement for commercial equipment was a trade off to allow the licensing authorities to permit those with just a basic set of skills onto the bands (but from the RSGB's point of view, still be in a better position than going into CB).

I can see that argument. But those going into CB only get very limited VHF and 11 metres. So why do Foundation amateurs get almost every band? That RSGB President replied that to attract new entrants to amateur radio you need "the lure of 20m and worldwide DX".

At this stage it might be worth noting that that particular RSGB President (and this was a few years ago) was a DX-obsessed nutcase, and not all of us a quite so stirred by the idea that 20 metres is the biggest draw for the new entrant to the scene. Just for example, I haven't used 20m much for decades. In fact, I never have. In my day it took me 2 years before I was actually licensed to use it, and yes it was an issue, but not the only one for me. He seemed to be talking about a licensing system to attract people just like himself, whereas I am thinking about a wide range of people, technicians, earth scientists, Moon-bouncers, rag-chewers, data-nuts, UHF gurus, repeater junkies, antenna jugglers ...

Now here is the gaping hole in the system for me. Yes, I agree with him that for many the lure of world wide DX is useful. But do you need to get it all (in frequency terms) at Foundation level? From what I can see of progressive licensing levels in other countries (e.g. USA, Australia), those starting off at a "Foundation" or "Technician" level may get similar (or more!) power, but they are restricted in the bands they can use. Yep, sure the lure of worldwide DX on 20m is there for them, but not until they have progressed a bit further. And I think we should do the same in the UK.

I cannot believe that my friend would not have joined the hobby if he was offered 10 watts, all UHF and VHF bands, 10 metres (so far better than CB), and then maybe WARC bands, 80 metres and/ or Top Band. And with some of those higher bands, maybe I would offer even more power than 10W if the licensing authorities would allow it in certain bands. But the elusive HF "DX" bands would have to wait until they had progressed a bit further, and that would be a big encouragement to progress further.

I could have had a ball on those bands with a Foundation licence, and I would have had far more incentive to progress than the present system provides. Also, I think it would have wide appeal to those others not totally besotted with 20 metres as well as those poor souls who are. Enough to get you hooked, but not so much that you don't progress.

Then for Intermediate I would offer the same bands as Foundation, but add 40m, 15m, and more power (at least 50 watts). And now you would see the lure of worldwide DX becoming a spur to progressing even further. And I might offer Intermediate licences 100W on VHF and UHF, making this more like a technician level and something which is just fine for those who love the higher frequencies (and in doing so, maybe they will stop there if they choose).

Finally for the full licence I would leave things as they are. This would mean that Intermediate licensees would be bringing activity to 15m and 40m while they study for the Advanced exam, and at the same time realising that that lure of worldwide DX and full power is just around the corner. 15m and 40m would be a great apprenticeship for progressing 20m (just as much as 10m and Top Band would have been a great apprenticeship for them earlier in their career).

As to the exams, I would leave them much the same as they are. From my point of view, the leap from Intermediate to Advanced exam looks very daunting for anyone who does not have a background in the electronics industry - like myself and my friend. So I would tweak the exams to be more like the reality of the current situation. It now matters less that someone might not be able to open their rig and fix it, as very few of us do that any more. But there are lots of areas in which amateurs still make advances and are still experimenting --- but these areas are poorly covered in the exam. Areas like antennas and propagation.

Why should it be that an amateur needs to know how to build a rig (which almost nobody does) when they don't need to know about how to build an antenna or understand Sporadic E, which most of them have to deal with in ignorance of the basic principles.

But the major flaw in the current UK rules is a really glaring error in my view. At present the distinction between the grades is set in power terms, which is unenforceable. If you heard a Foundation licensee under my plan on 20m you would know they are cheating, whereas under the present system if you hear a M6 using 400 watts you would be none the wiser. We should not have set up a system which is impossible to enforce.

The Intermediate exam of today still requires candidates to understand a block diagram from a 1960s valve era superhet rig. With SDR rigs becoming more and more common, how can we persist with this? How can we pretend that knowledge of building a rig is necessary when many existing amateurs (including myself) cannot do it? Yet I can do useful research into other aspects of the hobby, and I am not alone.

So my plea for the future is this ... please bring in an enforceable system which offers the big prize at the end of your study rather than the start, and please make it obvious when someone is cheating.

By the way, the CB book in the picture has been loaned to me by Doug, GM6ZFI. It dates from 1977. It probably gives as much information about radio theory as most amateurs need, but rather a lot more about propagation and antennas than they seem to know at present.

73

Jim
GM4FVM

Wednesday, 18 November 2015

What happened to the Leonid meteor shower?

Most meteor showers are leisurely affairs, with peaks lasting a day or two. Yes, there may be a sudden burst, but in general you get a reasonable period to enjoy them. Also, for a week or more on either side of the peak you get enhanced random meteor propagation.

Not so the Leonids. For an hour or two the Leonids can be spectacular, but usually that is it. After that you can pretty well sit down and await the Geminids, with a peak around 14 December.

This year the Leonids were expected on 17 November.

I spent a lot of time on 17 November waiting for something to happen. It didn't. The day looked like any day with reasonable random meteor activity, at least on the DX cluster. Here I saw a Serbian station on 2 metres (that would be a new DXCC for me) but it was just a single burst and I did not reply. I replied to a Polish station who did not hear me.

Of course, the exact timing of meteor showers is a bit hit-and-miss. The earth's rotation is not exactly 365 days, and the timing depends on the leap year, and on the effects of other planet's gravitation on the meteorites. Whilst the predictors try to estimate what effect all this may have, they cannot be too accurate. Also, we amateurs are inconveniently located all over the world, and we all have different angles on the shower. It might be good for some and bad for others.

Meteor showers have more effect if they strike the earth between late evening and early morning. This is simply due to the rotation of the earth and angles they arrive at. Put simply, the meteorites find it hard to catch the earth when it is moving away from them. Or harder to reach the day side of the earth when it is turning away from them. The night side is turning towards them (usually).

So maybe the shower is just late and it is still about to arrive. So on the morning of 18 November I tried again and this time I worked SP9HWY (JO90 1543km) on 70MHz and SM0EJY (JO89 1229km) on 144MHz. Very nice, and I can assure you that Poland and Sweden count as DX from here on VHF. However, these are stations I might work under random scatter conditions. I have not seen a meteor shower yet.

Neither has anyone else. There were two meteor scatter QSOs showing up on the DX cluster on 50MHz for the past day, and only one on 70MHz (mine!). On 144MHZ there were six excluding mine on the morning of 18 November, which is pretty much an ordinary day.

Meteor showers bring a few hours of intense activity which stands out from the occasional random contact which we scatterers all enjoy. Maybe it did happen but we in Europe missed it. There is no sign of that.

Anyway, I will try again later on the 18th. You never know.

I am not sure how to illustrate this so I am putting in a photo of a tram in St Etienne in France.
Why a tram and not a trolley bus, you ask? I stood around in the right places, but I saw no trolley buses. I suspect that St Etienne trolley buses are a bit like the Leonid meteor shower. Blink and you miss them.

I did see diesel buses in St Etienne, but you wouldn't expect me put a photo of a diesel bus on a radio blog, now would you?

73

Jim
GM4FVM

Monday, 16 November 2015

6 metre band Bremi linear project

News of progress on this long-lived project.


A few years ago I bought a second hand (i.e. "used") Bremi linear. These valve linears were sold in the 1980s for use with SSB Citizen's Band radios. They use two 6JB6 valves. Theoretically they could produce about 200 watts peak of SSB on the "11 metre band". Or so the legend goes.

The initial plan was to convert it to 70 MHz operation. This hit a snag when the valves would not oscillate in a stable manner at that frequency. However, they would work happily at 50 MHz, so it became a 6 metre linear. This was an early sign that the valves in the linear when I bought it were shot. A sign I managed to miss.

Although it seemed to work happily with the FT-817, producing about 20 watts for 2 watts input, it was clearly getting pretty hot. Even though several people who have used these linears on 4m and 6m have commented that they fitted a fan, I just continued without one. After all, I was only running 20 watts, not 200. Oh, I can be so reckless.

Eventually it became harder and harder to get it to tune and I noticed that the HT choke, positioned between the two valves, was sagging. Closer examination noted heavy deposits on the inside of the valves and they seemed to have run very hot as the choke was scorched. Then I touched one of the valve caps and the valve shattered.

So the Bremi was sidelined for further work.
With some difficulty I located a new 6JB6 valve. "New" of course means unused for valves, as they are all pretty old now. Then I came across a section of circuit board on sale on eBay from the Netherlands, with two valves, an HT choke, plus a relay and some capacitors. I bought that too.
Here we can see one of the heavily scorched valves and the bent and scorched HT choke. The thing about the choke is that the sag in the former has allowed the wires to distort and overlap, making the tuning of the linear increasingly difficult to set.


With the help of John, G1VVU, the various items we needed were recovered from the donor board and installed in the Bremi. There are still a few goodies on the board should I ever need them.

John drilled some holes in the top panel for extra ventilation. I had intended to use a 80mm ex-computer fan, but it looked as if 70cm fans would be better. I ordered two 70mm fans, only to find that they caused a lot of electrical noise on 50MHz. They fit very neatly, but they are no use if they create interference, so for now I have gone back to an 80mm fan.
This photo shows the Bremi back in the shack. At the time I was trying the 70mm fans. I had organised the screws and nuts to fix them to the case, but just in time decided to try them first. Now I have just got a single 80mm fan sitting on top of the case and I may not fix it down at all. It seems to work. I can run it on the heater supply from the linear, but at present it is running on 6 volts, as do all my other fans.

The issue which arises here is - "is it better to suck or blow" on linear valves? In this case the air is being pulled over the valves from below, and blown out of the top. That seems to aid the general flow as hot air rises. However, I have seen several articles saying that you are better blowing cold air onto valves from above. I just don't know.

It has the two valves from the eBay board fitted. I still have the "new" one too.

I have now added four 10mm feet. The linear used to sit on tiny rubber bumps, close to the shelf it sat on. I felt that it needed better air flow, so it is now raised enough to let cooler air flow in from below.

When it came to trying it, the FT817 at 2 watts produces 20 watts out of the linear. It now runs cool like that all day, on WSPR, 2 minutes tx and 8 minutes rx. On JT6M I can get about 30 watts out of it fairly easily. I tried driving it with the FT-450. For 12 watts input it produces 120 watts output.I could probably get more out of it, if I want to try 6 metre meteor scatter.

So at last I have a fairly competent 6 metre linear.


73

Jim
GM4FVM

Monday, 9 November 2015

Electret microphone project, 6m Sporadic E opening and 2m aurora

Some time ago I bought an electret microphone insert for the Yaesu MD-100 desk microphone. This was sold by W2ENY, who was offering them on eBay for a tiny sum. It arrived successfully, but the plan to install it got delayed behind various "more important" projects.

Pending some parts arriving for other projects, this one reached the top of the pile. It is not difficult to fit, you just have to be careful that your new insert does not move in the fitting and make a noise, or the leads do not have dry joints etc.

W2ENY gives an instruction sheet which takes a bit of figuring out. The mic base seems to have very complex wiring (for a lot of rather unnecessary switches). Basically you change over the inserts and use a dropper resistor to provide low voltage to one side of the new insert. Electrets need to be polarised.
Here we see the mike body, the top section removed on the left and the old insert on the right. I have just wired in the new, much smaller and lighter, insert. I fixed it into the mic body using double sided tape.

The alteration to the base allows the insert to receive a small voltage. I must put a label underneath it reminding me not to use the mic without the base. You could connect it directly and use it as a hand mic, or at least you could before I did this change. Now it will just convey silence if it is not connected via the base.

Electret mics are generally better than the dynamic ones (fitted by Yaesu in this case). Not only is the characteristic tone range closer to the sort of audio we want for DX, they are usually clearer and have higher output.

Initial results seem positive. Doug, GM6ZFI found it better than the supplied Yaesu handmic (which also has a dynamic insert). I can even see that the meters kick up a lot better with the new insert. I may even need to back off the mic gain. The ALC is reaching, but not passing, the end of it's "happy zone".

As luck would have it, the Sun fired out an X-Ray burst today, so I got a chance to try the new mic out on 6m. Well, as it is connected to the FT-450, that is the only band it is used for at present. As usual I was alerted by a burst of Sporadic E on 10m, showing up on WSPRnet as a band of spots from Europeans. What do I do when a band opens ???? - yes, I got to the next band up and try harder there.

The energetic burst triggered off some Sporadic E on 6m. At around 14:00 on SSB I worked IU1FRV, F1RHS, I0KIB and IK5YJY is quick succession. Then I turned on WSPR and heard IK1WVQ.
Those other stations are missing it entirely. Actually, WSPR is not so good for Sporadic E on 6m - as you can see no stations in Spain, Portugal, France and half a hundred other countries, which gives a very poor coverage.

Next stop was 2 metres where I hoped for an aurora. This duly came - at about 16:00. No contacts though, as my key stayed out of use. I heard several GMs working SMs, LAs, OHs and OZs, but it was all too fast for me. I think I heard the Faeroes beacon briefly on 4m, but that was it there.

During the aurora the 10m Sporadic E faded out. No doubt most of HF faded too. Now at 17:20 the 10m Es is back and the aurora has faded out. So I am going to leave it there and see if anything happens later.

I would guess that the X-rays came from a solar flare which might or might not send us some material over the next 36 hours or so. That might mean more fade outs and auroras ... or not as the case may be ...

73

Jim
GM4FVM

Wednesday, 4 November 2015

Another 2 metre band tropo opening

Chris, GM4ZJI, warned me about the possibility that a tropo opening might be on the way after looking at the Hepburn maps (link to the Hepburn site on the sidebar).

I had trouble getting the link to Hepburn's site working, it should be here now as well as on the side bar..

This was the Hepburn map for1 October.
I was a bit dismissive, because I have seen Hepburn overplay high pressure systems before, only to reduce the prediction as it gets nearer. Chris agreed, but we promised to keep it under observation.

In fact nothing much happened here on 1 November, all the activity was further South, between G stations and PA and OZs.

As it turned out it was the 3 November picture which delivered results.
Hardly very prepossessing. You can see a pattern to the East of Scotland and a link to a more developed system over Denmark.

Things got underway at about 10:40, and between then and 11:45 we worked 3 x OZ, 3 x DL and two SPs. I have been trying a new mapping system and here is what I got:-
As usual, click to enlarge if you need to.

This is still experimental mapping and so far I have not put lines in between me and the stations (they would not be "great circle" lines so not very accurate). Anyway, the pattern looked like the Hepburn map. This version of the map also missed a few stations out for technical reasons which need not detain us here.

I said "we" worked these stations as for a long period Chris, GM4ZJI, joined me. Anybody who worked us worked both, so that was two squares for them (IO85 and 86). We were comparing new antennas and generally both performed fairly well. Chris has a better antenna than me, but then we have two different sites. I bet he will do better on meteor scatter for instance.

I came back to work another OZ at 13:47. The Nordic activity contest started at 18:00, so I came on and worked 4 OZs and 2 SMs. I went QRT at 18:36. The RSGB UK Activity Contest started at 20:00, by which time most of the good propagation had ended, so I left it until 20:48 to come back on and give away some points to local stations.

In total the results outside the UK were like this:-
As you can see, the new mapping can also feature the stations as squares without callsigns, which is clearer in some ways. However, the squares are not "Maidenhead" locator squares, they are centred on the station by their 6-figure locator grid.

More work to do on the mapping, but it might have its uses. You can find it at www.mapability.com/ei8ic/gom/intro.php. It is free to test and costs $15 after the 30 day trial period.

Of the 14 stations worked outside the UK, all but one was over 700km. Only OZ3MC (JO46) was 694km. Best DX was SP1MWK in JO74 square - 1138km, not bad for VHF. It was all on 2m. I tried 4m several times but with no success.

I spoke the GM4GUF who went portable on the cliff tops at St Abb's Head, about 4 miles from here - he worked 1800 km into Russia and Belarus, but of course that was on CW. Do I regret my lack of CW ability? Not really.

I cannot say that tropo openings really thrill me. Yes, they are great for amassing squares and so forth, but they lack the excitement of short-duration openings. Something that lasts 10 hours does not grip me the way half an hour of sporadic E or aurora does. With the other modes you need to make the contacts quick and effective. After a short opening they are gone. With tropo you often have all day.

Anyway, there were auroral conditions about, as the coronal hole which caused the opening I posted about in early October has travelled round the Sun and is back facing us again.

If anything comes of that I will be back to talk about it. Otherwise it is another "might have been".

73

Jim
GM4FVM

Sunday, 1 November 2015

Getting started on VHF DX

This is a basic introduction for those who are interested in what happens at VHF but who have yet to take the plunge.

It assumes that you have already dipped your toe into VHF via some FM operation, and you have a VHF rig or might buy one which has VHF bands.

It used to be so easy. In my day, my licence only allowed me to operate on 144MHz and above, so I had to. And then to begin with, there was only one rig - the "Belcom Liner 2". Before the Liner 2 you could use an HF rig with a transverter, a complex and expensive solution. Then in about 1973 the Liner 2 appeared which offered 2m SSB in a single, dumpy, heavy, awkward box. It also did CW, but the "Class B" licence did not allow me to use CW (and no doubt created my life-long fear of the CW mode).

There was this large pool of enthusiastic Class B licencees, and suddenly there was this rig. So hundreds bought Liner 2s and went up hills. And as the Liner 2 was awful (it has been called the worst rig ever sold) things were a bit fraught, especially when people started trying to increase its 7 watts or feed amplifiers.

After a while the big three manufacturers followed suit. I bought the Kenwood offering - the Trio TR-7010, which had the SSB bits from the (about to be released) TS-700 multi-mode 2m rig. Yaesu had the FT-290 and Icom the IC-202. These rigs were all aimed at different segments, but the one thing they all had in common was that people took them and went up hills, or worked with good antennas from their homes. VHF, or at least 2m, was transformed into a band where you could get good long distance DX contacts almost all the time.

It isn't like that now. There are no "Class B" licences in the UK any more, as they were all converted into Class A. There seems to be a lot less enthusiasm for 2m portable work, and we now have 4m and 6m to compete for our attention. There are no 2m only SSB rigs either.

We now have an exam syllabus that barely mentions VHF, and quite a few pass their exams unaware than VHF is very well suited to DX working. VHF does not mean "FM". OK, there is a lot of FM on VHF, but there is also lots of CW, SSB, data modes and so forth. And VHF is no longer just 2m in Europe, but is now 4m and 6m too.

So this posting is realistic enough to accept that you are not likely to find the same heights of activity as people fondly remember from the last three decades of the last century. But what you will find is a lot more, better equipped, well located stations, usually working from home, and a lot of keen contest operators. And of course some of the most astounding propagation you could imagine. The scene may have changed, but the bands are still as good as ever.

So let us assume that you have a rig which covers VHF. Plenty of folks do. They have a rigs which they use for HF, like the FT-897, the FT857, the IC-7000 or the TS-2000. These are fine equipment for VHF. Having said that, a lot of operators never use them on VHF, but stick to HF. And a few have rigs like the FT-817, often kept as an HF standby, which could well be used for VHF DX.

What would be needed to get this equipment going on VHF so that some DX could be worked? Not much actually. If you want to try 6m (50MHz), you may already have an HF antenna which would do some service. I have a G4MH mini-beam. OK, it does not work very well on 6m, but well enough to bring me summer Sporadic E (don't worry about the propagation modes, more of that in a later posting). Summer is a great time for VHF DX, but there is always something happening.

If you already have a "white stick" vertically polarised VHF antenna and use FM, you are only seeing a very small part of what 2m can do. VHF DX is mostly sent with horizontal polarisation, and if you are working on the wrong polarisation your losses are huge. Yes, you can listen about on your FT-817 or whatever using a vertical, but you will not get much in the way of results.

So the solutions I am going to suggest are for simple horizontally polarised antennas which will certainly get you going.

Antenna 1 - the 2m band Diamond A144S10R (not to be confused with their 10 ele 70cms antenna!).
This is a compact (2.13m boom) yagi-type beam which offers 11.6 dBi gain (which is about 9dB gain over a dipole). It is light (just over 1Kg) and small enough to look pretty inconspicuous. It looks a bit like a TV antenna and the neighbours will hardly notice. Of course with a directional antenna you will need some sort of a rotator, but this one can be turned by a light duty "TV" rotator. Or you can slip it onto the pole above your HF antenna if that already has a rotator. The only reall snag with this antenna is that the maximum mast diameter is 47mm which is too small for most "2 inch" poles. I just drilled another hole in the boom and fitted a larger mount, or you can use any general "boom to mast" clamp, but be careful not to over-tighten it and squash the boom flat. Presently available, on eBay, this Diamond antenna can be bought for £90.

Antenna 2 - the 6m band Diamond A502HB
Another compact from Diamond, this one offers about 6.3dBi gain (or about 4dB over a dipole). It is small and light with a very short boom (0.75m). This antenna is often described as a yagi, but actually it is more like an HB9CV antenna. It has two driven elements with a phase matching connection running along the boom. Of course it is a lot wider (3m) than the 2m antenna listed above, but it still looks very inconspicuous. It could easily sit above an HF beam and be hardly noticeable. And despite the weather here, I have mounted it above a "TV" rotator. This is an effective 6m antenna and capable of working modes like aurora and meteor scatter. For sale as I write, on eBay, for £93.

The photo above shows a Diamond A502HB on a Conrad TV rotator. The common Hy-Gain TV rotator is similar.

So these two Diamond antennas are recommended by me after having used them for several years. They are NOT the best DX antenna, but they are the sort of thing you can put up to try out VHF and see how you get on. Both would fit above an HF beam, and either could go above a lightweight rotator.

I might add that Comet make an antenna very like the 6m Diamond one, but over the years I have found Diamond construction to be better than Comet (just my personal view). And then others make HB9CVs too, but I have not tried them out.

So we have two antennas which remove the idea that VHF antennas have to be expensive, bulky and difficult to get. Then there is the co-ax. By all means try cheap co-ax, but RG-213 is really the place to start for higher VHF. RG-213 is thicker and more difficult to work with than normal HF co-ax, but it offers many advantages.
On top is RG8 (mini) which I often use for HF. Below is RG-213, which I use for VHF. Obviously the 213 is thicker, but the key advantage is that the losses caused by attenuation at VHF are much lower with 213. At 100MHz, on a run of 100m of co-ax, 213 will have about 10dB less attenuation than normal HF co-ax. Even at my lengths (30 metres or so) at 2m the result of using 213 is to just about double the power reaching the antenna, and also to double the signal on reception. Worth having.

Actually, for 2m I use Ecoflex 10 co-ax for even better results than 213. At 50MHz, where standard HF co-ax could be used, I also use 213, which some would view as a bit over the top. OK, but I am a bit of a VHF enthusiast. For general use, RG-213 would be the standard for 2metres around here, though most people use standard HF co-ax for 6m.

What could you hear with these antennas and this co-ax? Answer: a lot further than you can with FM and a vertical white stick. 150km on 2m should be possible under flat conditions. If there was any tropospheric propagation then up to 1000km should be possible. With sporadic E I have worked as far as Belarus on 2m - though that is reasonably rare on 2m. I have often worked 1500 km on 2m meteor scatter using the Diamond. For 6m, I have worked all over Europe on meteor scatter, and likewise all over Europe on summer Sporadic E. Best dx from here on 6m so far is Puerto Rico. Remember this was worked on a simple Diamond 2 element and 100 watts.

Maybe now I have moved up a step with better 2m antennas and better co-ax. But I still did amazingly well with just the Diamond and RG-213. And for a rig I also have the FT-817, plus a little RM linear which boosts my power by a useful amount. On 6m  I still use the Diamond. Yes, I have made life a lot more complex but it does not need to be. Certainly for starting off, these simple antennas are very effective.

There you are really. Why not try VHF DX? With a rig you probably already have, some co-ax, and a fairly lightweight antenna, you can make a start.

73

Jim
GM4FVM

Monday, 26 October 2015

Ham radio is a big enough hobby for everyone ...

I did not start this blog to pour out home-spun philosophy.

(Why did I start this blog ?)

Anyway, here are some more thoughts from my forehead.

I just wrote a very long outpouring justifying every thing I do. The idea was to graciously allow you lot to do what ever you want so long as I can do the same. I've deleted it.

In brief (this is brief?), the idea was:-

I don't do CW (mostly because I don't think I am any good at it, but also I am scared of people who go too fast)
I don't enter contests (mostly because I am uncompetitive)
I don't support my local club (mostly because they don't support me and the work I used to do there)

But because I do not do any specific thing, that does not mean I want it to be stamped out.

You are all welcome to do it. I do not want to convert you to my way of thinking. I just want to explain my motives and my odd ways of doing things. You are free to ignore me, do your own thing, and generally carry on as before. It is a free world and it is up to you (and me) what we do.

I am just glad you read this stuff. Use it or not - it is a free world.

Sometimes I hear from people who maybe get the idea that in this blog I am trying to promote some great plan or something. No, I just want to explain what I am doing. I am not trying to convert you. I just put out my ideas, and you can ignore them all you like.

I think this comes about after a conversation with a great VHF DXer with a superb location and HUGE towers. He said that he would "see me on KST". KST is a VHF-ers chat site. I tried it and found it the most boring place in the world (WORSE than our local club).

So I said "I am not on KST" and he replied in an agitated way "What, you want us to go back to the dark ages without the cluster and no computers or e-mail and all that?".

Erm, no, that is not what I said. I pointed out to him that I am all for things like KST, I just do not do that particular part of the hobby myself. He did not seem very impressed. I told him I get contacts by calling CQ or replying to others. What a shock for him that was.

What I find with KST is that people sit there and watch it as a substitute for listening on the bands or calling CQ. Well, that is up to them, but it is not what I do.

Just because I do not do KST or Echolink, or something else, does not mean I want to go back to using smoke signals or carrier pigeons instead.

There are large parts of this hobby I do not do. You are just as entitled as me to do parts and leave out other parts. You can even leave out the parts I like. Work away. Just because I don't do it does not mean I want it stamped out.

Or you can do any part of it your unique way. I listen on 50.999 for DX, copy the morse, and post the reception reports on the DX Cluster. I don't work them on CW because generally they are sending so fast I have no hope of working them. So I do it at a level I am comfortable with. I like it that way. What's the problem? And you do it your way, and I am keen to hear of your success.

I do not enter contests because I am not competitive. At school I hated competitive games (the games master had a need to line us all up and examine us for "unhealthy" underwear by pulling down everybody's shorts in quick succession, which never helped). I could not see the point of trying to win the sprint race. But when he set us gruelling circuit training of climbing bars, jumping vaulting horses and lifting huge weights, I excelled. Because that was competition against myself and the watch. I was trying to do better every time in an absolute sense, and I loved that.

So I am not competitive, I never have been, but I love setting goals and beating them myself. No contest entries from me, but if I can work somebody further away in a contest and learn something, that is what I do and we both gain.

Please take this blog as a simple (!!!) explanation of what I do,. If any of it is useful, feel free to use it to develop YOUR hobby. But there is no need to do it like me, and I think you are fully entitled to do it whatever way you want to (even if you use KST, enter contests and run sprint races competitively).

That other photo was just the "red" cooking apples, by the way. Here are some of the "green" cooking apples. Some of the red cookers are partly green, and some of the green cookers are partly red. I have to leave it up to Mrs FVM to sort it out. Had a great apple crumble last night though.



73

Jim
GM4FVM

Sunday, 25 October 2015

VHF is not "line of sight", or not more than HF already is.


Well, the image is some of the apple harvest Chez FVM, minus the red eating apples off the new tree, and minus the russets. No doubt there will be a few more to pick over the coming days. No pears this year though.

But anyway ...

Yesterday I visited the "Fog on the Tyne" radio rally at Gateshead. That was the first time I have been there. It was smaller than our "local"one at Galashiels but still crowded.

At the rally, I found myself chatting about VHF to Gordon G8PNN and Eddie G0EHV. We agreed how awful it is that VHF is often dismissed as "line of sight" communication. Well, this is also said of UHF, microwaves, and really anything that lazy amateurs do not want to bother with. I can be lazy myself.

Yes, VHF is used for point-to-point line of sight commercial communication. It is also used by amateurs for similar VHF purposes. And a mighty fine line of sight method it provides. It is used for mostly FM mobile chats using vertical antennas and often repeaters. But it does far more than that. And it means far more than that to me.

VHF radio signals are no more "line of sight" than any other radio frequency. Essentially all radio energy is identical to all the rest save for a few factors, and radio is the same as light. So it is hardly surprising that radio signals follow lines of sight, as apart from the frequency radio is light.

So we look along lines of sight and think, "light travels along lines of sight". Obviously this is true as we can see things far away, and if anything gets in the way, we do not see them. But what if the thing that gets in the way is a mirror? Well, although we still think light travels in straight lines, we are happy to look at it after it has been bent back through 180 degrees. Or if we put a pencil into a glass of water we see the light bent by refraction, so we know perfectly well that some things bend light. The light is bent, not the pencil.

And we are happy that some things bend radio. The old HF hacks who dismiss VHF as being "line of sight" know that their HF frequencies are refracted (and partly reflected) in the ionosphere. But they do not seem to realise that the same processes which bend HF signals do exactly the same for VHF signals.

What I am saying here is that all types of electro-magnetic radiation, radio "waves", light, ultra violet and infra red radiation, X-rays, gamma rays, the whole lot, go straight or are bent in exactly the same ways.

We can look up to the sky and see stars which are so far away that the light takes thousands of years to reach us, so we know pretty well that it can travel in a straight line uninterrupted for a long way, so what can bend it?

Light and radio and all the rest of the EM spectrum will travel in a straight line unless affected by:-

Reflection ("bounced back" as in light from a mirror)
Refraction ("bent" as by water in glass or a lens in your glasses)
Scattering (randomly changing direction after hitting something)
Gravity (tiny effect of passing huge objects like stars)
Absorption (entering a dense medium which stops the photon and releases its energy).

We do not see much effect from gravity as we do not usually encounter star-sized objects to do it. But the others we do meet.

VHF radio signals (and the millions of packets of energy in them - photons) can be bent and scattered and reflected just the same way as HF radio signals. It is just that it does not so happen that they get regularly sent back to earth from the ionosphere. Instead they get irregularly sent back to earth by all sorts of things.

It is true that the difference in frequency between HF, VHF, UHF and everything else (e.g. light) means that different results occur, but the processes are still the same. The ionosphere might be more or less transparent to the light frequencies (just was well for the apples ripening), but it might refract some frequencies and not others. However, the basic ideas are common throughout the spectrum.

So VHF amateurs have fancy names to explain their particular means of bending their signals, but the processes are just the same.

Reflection
Sporadic E is largely reflection (or so we think) - from an ionised layer in the ionosphere. It also affects HF, so there can be no argument that it is OK. The reason why this process occurs is not well understood but the result is pretty common. Today (on 6metres SSB in October) I worked EA5/G3XGS in IM98 square in Spain, 1981km away. Line of sight does not carry to Spain. I cannot look out the window and see Spain because of the curvature of the Earth (and absorption and scattering too!). My signal was bent (reflected?) back down to earth by a layer in the "E region".

Radio signals can reflect off objects too (that is how radar works). However, it is a surprisingly inefficient process. As Earth-Moon-Earth operators know to their cost, only about 7% of the energy hitting the moon comes back, and the path losses have to be added to that. Radar generally works with huge power and short paths. Still you can have QSOs using reflections off aircraft and ships.

Refraction
It is not just the HF boys who get to use refraction. Tropospheric refraction brings irregular "lifts" to VHF stations. This process also works very well at UHF too. I can regularly (well, occasionally) get 1000km+ paths on VHF using "tropo". Normally, the air density declines with height, but during tropo this can be reversed. This can bend the radio signals back to earth.

The process of tropo refraction is fundamentally just the same as F-layer refraction. A difference in density of the medium causes a deflection of the radio energy path. OK, ionisation is not present, but then ionisation is not the cause of F-layer HF refraction, it is the necessary pre-condition for it. I know that idea gets a lot of folk jumping up and down, so no doubt we will return to it.

Scattering
VHF types love scattering. For HF people scattering is just a thing that happens, and it allows them to work some extra stations. VHF enthusiasts go out and look for it. Two common methods used are auroral and meteor scattering.

Essentially the process is the same. If light hits a (non-reflecting) surface like a wall, it gets scattered all over the place (just as well or we would walk into the walls). So the same is true for radio. Auroral and meteor scatter happen at about 100km about the Earth thanks to the density of the atmosphere at those levels, which is very handy for us. You can get scattered radio signals from other things too (like rain!), but these two are very handily placed for VHF contacts at 1000 to 2000km .

The radio signals reach the ions spiralling down the magnetic lines towards the North Pole, or reach ion-trail of the meteor as it burns up in the atmosphere, and they try to pass through the denser material. If it was too dense they would be absorbed, but luckily for us, enough get thrown in all directions for a useful proportion to head back to earth. The process is complex - as they hit, say, an electron spinning round an ion they will be thrown out, affecting their energy level and quite possibly causing slight change in frequency and direction (causing Doppler effect distortion). So they might be hard to copy, and the signals will be weak as scatter is not directed but thrown all over the place, but it works.
====================
OK, you get the picture.

VHF is not just "line of sight". VHF signals are reflected, bent and scattered in much the same way as HF. Different frequencies and energy levels make different things happen, but the processes are exactly the same.

There is no mystery about all this. I really believe that the current (UK?) amateur radio training syllabus is too heavily biased (!)  towards electronic theory and covers too little of the physics of radio. This leaves me and others spending years finding out the most basic principles of our hobby, without the help of well written text books. 

Rant over.

73

Jim
GM4FVM

Saturday, 24 October 2015

India, and GI4DOH's propagation predictions

I have been enjoying popping up on 40m around dawn and dusk to see what can be done with my simple wire antenna for that band.

I was amazed to have my first CQ on 20 October at 21:31 answered by VU2ABS. OK, he came back with a -27dB signal report (!!!) but I called on low power and I later shoved it up to about 50 watts for the end of the QSO. I gave him -13dB and the QSO went according to plan. By this I mean it took the standard JT65 mode minimum of 4 minutes, plus an extra minute each for him to request a QSL and for me to thank him for a new DXCC on 40m. No need to repeat any detail and signals were perfectly stable.

Now when I report something like that I am not trying to "big" myself up. I did nothing special. I am just reporting that I am surprised how well a low dipole is doing for me. Everything else might be fancy beams and towers, but the 40m set up is just two bits of wire. To say that I was taken aback would be an understatement. Yes, I have been heard regularly further away on WSPR, but WSPR is a beacon mode and takes 2 minutes to send a very limited amount of information. This was a proper QSO.

So I was pleased with 8349km on 40m, and next night netted UA9CR (MO06 3762km) and AI4VR (EM64 6608), which made me pleased too.

Surprise is certainly my reaction. A local OM heard of what was going on here and said that he did not take up 40m at present as he would not have room for an efficient antenna. I know what you mean, but it looks like an inefficient antenna does good work too.

Of course, any antenna (however inefficient) has an infinite gain figure over no antenna at all. So I suppose it all proves that just getting on and doing something is always better than not doing anything.

GI4DOH posted here a few days ago that the solar flux index looked to stay above my magic 100 level for a while. So I decided to test out his predictive powers. With the official forecast for 10m propagation as "poor" I set up WSPR to run early on 23 October. Was the official view right that it would be poor, or was Richard right that there was hope of DX?

Make up your own mind from the table below, but I have to admit that I know who I am going to have to listen to in future, Richard ...

Time    Stn              Freq            Rpt       Locator     Pwr dBm/W   Heard by     Locator      km

08:30  GM4FVM  28.126082  -15  0  IO85wu  +33  1.995  VK2KRR  QF34mr  16748 
08:28  LZ1OI  28.126044  -16  -1  KN22jc  +40  10.000  GM4FVM  IO85wu  2463 
08:28  VK3KCX  28.126081  -11  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
08:26  VK2KRR  28.126175  +4  0  QF34mr  +40  10.000  GM4FVM  IO85wu  16748  
08:24  RA3APW  28.126112  -17  0  KO85uv  +20  0.100  GM4FVM  IO85wu  2450 
08:22  VK3KCX  28.126082  -11  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
08:18  LZ1OI  28.126047  -22  -1  KN22jc  +40  10.000  GM4FVM  IO85wu  2463 
08:14  VK3KCX  28.126082  -9  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
08:14  RA3APW  28.126112  -27  0  KO85uv  +20  0.100  GM4FVM  IO85wu  2450 
08:14  VK2KRR  28.126176  -2  0  QF34mr  +40  10.000  GM4FVM  IO85wu  16748 
08:12  GM4FVM  28.126083  -22  0  IO85wu  +33  1.995  VK2KRR  QF34mr  16748 
08:12  GM4FVM  28.126106  -23  0  IO85wu  +33  1.995  VK3KCX  QF22qd  16884 
08:08  VK3KCX  28.126082  -4  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
08:02  G0JEI  28.126008  -27  0  IO93ic  +37  5.012  GM4FVM  IO85wu  310 
08:00  VK2KRR  28.126177  -5  0  QF34mr  +40  10.000  GM4FVM  IO85wu  16748 
07:58  VK3KCX  28.126082  -1  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
07:52  GM4FVM  28.126112  -22  0  IO85wu  +33  1.995  FR1GZ  LG79rc  10097 
07:52  GM4FVM  28.126084  -19  0  IO85wu  +33  1.995  VK2KRR  QF34mr  16748 
07:52  GM4FVM  28.126107  -21  -1  IO85wu  +33  1.995  VK3KCX  QF22qd  16884 
07:50  VK3KCX  28.126082  -8  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
07:50  VK2KRR  28.126176  -3  0  QF34mr  +40  10.000  GM4FVM  IO85wu  16748 
07:42  VK3KCX  28.126082  -11  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
07:36  VK3KCX  28.126082  -12  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
07:34  VK2KRR  28.126177  -16  0  QF34mr  +40  10.000  GM4FVM  IO85wu  16748 
07:30  VK3KCX  28.126081  -25  -1  QF22qd  +40  10.000  GM4FVM  IO85wu  16884 
07:20  VK2KRR  28.126177  -18  0  QF34mr  +40  10.000  GM4FVM  IO85wu  16748 
06:54  GM4FVM  28.126112  -25  0  IO85wu  +33  1.995  FR1GZ  LG79rc  10097 

WSPR is not a QSO mode, but a report of -1dB means that an easy QSO would have been possible.

Since then I have gone on to make quite a few QSOs across the Atlantic but VK is always hard to beat. Thanks for that piece of wisdom.

73

Jim
GM4FVM

Thursday, 22 October 2015

What a great hobby ham radio is.

I know that amateur radio can be technical and social. Certainly it can involve electronics, physics, earth sciences and all sorts of complex science. But it is often promoted in the UK as being a social pastime.

In the UK, our "national society" promotes the social side as participation in local societies and their contesting activities. To me this conjures up the image of old codgers moaning about the biscuits at the meetings, and poor souls up to their oxters in cold mud pounding vainly on morse keys. So the social side, as represented by "the powers that be" does not really appeal to me. You can guess which clubs created those images in my head.

But another aspect of the social side is very important to me. Being "communication" people we can always keep in touch. For example by this podcast and others, by emails, and even by radio. So it is my contacts with individual amateurs over the past few days which have struck me.

Richard, GI4DOH, posted a nice note on my last posting, wishing me good DX with my new antennas. Thanks for that. A bit of encouragement is what we all need sometimes and this was particularly well timed.

And then Andy, GM4JR sent me an email agreeing with my comments about the poor element fixings on the Sandpiper beam - he uses one too. And he suggested what I had been thinking, it might be possible to re-engineer it. My own plan was to replace the element fixings, change the boom mount, and replace the braces. I was great to hear from someone who can confirm and develop these ideas.

Doug, GM6ZFI, contacted me and we agreed to go out for an early lunch (which turned out to be a sausage roll). Doug had asked for the 10 element Diamond. It is a bit bent and there was no cash charge for it, though Doug paid me with:-


a tin of Diet Coke,
a caramel slice, and
half a bag of cable ties.

Very nice. Good to have a chin wag and complain about everything which is wrong about the in the radio (and railway) world. I worked Doug on 2m later after he had put the Diamond up on his mast in 60kph winds.

When I got back, the postman handed me an envelope which contained a book called "The Radio Amateur's Hand Book". I had loaned this book to Bob, G3KML. I might point out that it was written in the 1920s (no date on it), and has been reprinted. I missed the Galashiels rally on Sunday so Bob posted it back because he couldn't hand it over there.

It was a pity that I could not make the Galashiels rally, but I hope to go to the "Fog on the Tyne" rally on Gateshead on Saturday. I might meet some more of these interesting people.

This evening Chris, GM4ZJI, phoned me up to tell me he was on 2m working a German station on meteor scatter. I went straight to the frequency for what was an excellent test of the new Wimo antenna. For over a hour I collected signals from Germany. Thanks Chris, and thanks also for spotting me on the DX cluster.

Now, have I got the social side of this hobby wrong? Can I leave that image of boring meetings behind me? I can see that lots of people are contacting me and we are developing new ideas and plans.

This posting is all about people. The image of amateur radio is not all about Tony Hancock types in isolation. It is about working together and supporting each other, either in person or by "other means".

Thanks folks.

73

Jim
GM4FVM