8 Sept aurora and "above the MUF" propagation with FT8, JT9 and JT65

Olli, DQ8BHA, whose blog is listed on the sidebar, writes some very interesting material. His description of the 8 September aurora is worth reading (remember to use the back arrow to return here!).

http://www.dh8bqa.de/major-x9-solar-flare-aurora-all-around/

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Thanks to David, GM4JJJ, for alerting me to an article by Carl, K9LA, in October 2017 QST magazine entitled "Understanding Propagation with JT65, JT9 and FT8".

This article brought me to one of those "D'oh!" moments. Suddenly things which should have been obvious fit into place and I realise that I should have worked this out myself.

The article explains that the ability of the slow WSJT-X modes to receive signals "below the noise level" means that we can work stations using these modes when the bands are closed. Now that was sweeping statement by me. SOMETIMES. Let us think about why this can happen.

It is well know that these modes (and WSPR) can successfully decode signals which are below the level of noise in our receivers. In fact, so can good CW operators using their ears. The seemingly odd outcome arises both from the fact that the superb modes devised by Joe Taylor and his merry band can makes sense of extremely weak signals in this nether region, but also the way we define noise is rather arbitrary.

When your WSJT-X software shows that you have decoded a signal at -20dB, that relates to the noise factor for the SSB filter, and in reality it is not 20dB below what you can hear. However, make no mistake, it is a lot below what you can hear, just not quite 20dB. Let us take, for the sake of argument 10dB below what you can hear. Imagine that. Think of a signal that needs to be 10 times louder for you even to hear it, and then imagine decoding the weak version. Pretty impressive.

The fact is that the minimum signal to noise ratio required for reception of SSB is higher than that required for CW, which in turn is higher than that required for, say, JT65.

You may think of it this way. You are working a nice distant dx station just as the band closes as the MUF falls. In other words, rather than being below the "maximum usable frequency" (MUF), you now find yourself operating above the MUF. Whilst on SSB the signal would have faded into the noise, and you can no longer hear it on the loudspeaker, on FT8 or JT9 you are still about to complete the QSO. Magic. Except that it happens all the time if you use FT8 or JT9 (or JT65 or WSPR). You just keep completing QSOs where you cannot hear the other station in your loudspeaker.

However, there is another way to look at this. For an SSB operator the band has closed. They cannot make a QSO as the MUF has fallen and "the band has closed". But you, as a data mode operator can still work people. What you are doing is using what is called "above the MUF" propagation.

In effect, using these data modes has made an otherwise closed band stay open for longer.

Let us have yet another take on this. When I started on data modes back in the 1970s I used RTTY. I might be appalled by that mode these days, but it was cutting edge then when nobody had a PC. RTTY was (should be past tense) a mode which basically replaced the microphone with a bulky, oil-spewing, unreliable, clattering electro-mechanical beast. You did not get any extra performance out of this contraption, it just meant that your QSO got printed out instead of spoken. Unlike RTTY, WSJT-X slow modes are not just a text-based replacement for voice or CW. They out-perform SSB by being able to be used successfully in conditions where phone, RTTY and CW would not work at all.

In the 1970s, during any opening, my RTTY success directly mirrored by SSB success. If the band was "open" I could use SSB or RTTY. If the band was "closed" then both stopped working. But the WSJT-X slow modes continue to work. So how does that happen? Surely the F-layer (or the E-layer) is either bending the signals back to earth, or it isn't. How can using different mode make a band open?

Let us go back to basics. The diagrams are my own (copyright!) handiwork, not to scale and can be enlarged by clicking on them. The QST article is based on 28MHz and F-layer propagation, but there is no reason why the same principles would not apply to other bands or E-layer propagation. For this purpose though I will stick to the same example as the article.

When the band is "open" the ionosphere bends (some of) the signal back down to Earth in the well known way. The classic diagram shows band open ...

... (above) where you would expect to find propagation between A and B, and (below) closed, when you would expect nothing to happen between A and B ...

If this was all there was to it, everything would be as we expect. But once again the simplistic diagrams we all used to learn radio theory let us down.

The diagrams above show the F-layer as if it is a thin line which either reflects (band open) or refracts (band closed) the radio signal. In reality we would have no propagation at all if that was the case. The F-layer could never reflect radio signals at the angles we transmit them. The F-layer is not a mirror, it is a layer of ionised gas which has a structure of steadily varying density. This variation in density results in a very large number of small refractions of the signal, gradually bending it down until it is almost horizontal, and only at that angle is there one, small, reflection which returns the signal via a whole series more of refractions.

So almost all the work of returning our signals to Earth is done by a large number of refractions. Let us look at a diagram of how the F-layer would look - and this is definitely not to scale - when the band is open ...

The signal follows the green line inside the F-layer. It starts to bend as soon as it enters the F-layer, refracted by the changing density it passes through. It is almost as though the F-layer was made up of a series of very thin layers on top of each other, each with a different density.

What nobody told us in radio school was that every time one of those refractions takes place, there is also a reflection. This has been known for hundreds of years in optics, and light is just a different wavelength of electro-magnetic energy from radio, so the same principles apply. The Fresnel equations can calculate the relative strengths of the reflection and the refraction. The other basic optical principles apply too - so the angle of the diffraction will depend on the relative difference in density, but the angle of the reflection will still be the same as the angle of incidence. Which means that actually we get something like this ...

Why did nobody tell us about this? In the real world of radio the many reflections are small in relation to the strength of the eventual main signal. Not only are they low in relative strength, they are directed slightly differently and sometimes out of phase. So  in the world of 20 metre band SSB you often never notice them. They do reach Earth, but they are weak enough to have been considered irrelevant.

In fact, given the noise handling ability of your radio you might never hear them. But JT65 can.

And JT9, FT8 and WSPR can hear them too. WSJT-X slow modes can successfully decode signals well below what we can hear. You might correctly take that to mean that they can hear weaker stations when the band is open, but it can also mean you can work stations when otherwise the band is closed and you can hear nothing but noise on the loudspeaker.

Moving on from the time the band is open until when it is closed we would get this diagram for the ionosphere ...

This is what we knew: it explains why we hear nothing when the band is closed. But the weaker reflected signals are still directed towards Earth, as shown below...

These weaker signals will pass through the F-layer, though they may be bent a bit in the process, and some will reach the ground. If they are WSJT-X slow modes they can be detected down to much lower levels than would be possible for voice signals.

The result of this is that before the bands open, and after they close, the weak signal modes should be able to decode signals we cannot hear above the noise. We need to re-think our existing assumptions. Most MUF predictions are made on the basis of a conventional SSB radio with about 100W and a dipole or small beam. The QST article suggests that a path of almost 3,000km, a single F-layer hop, would be open for an SSB contact at 28MHz (obviously) with the MUF of 28MHz. In fact this could be done on low power, with 100mW of CW doing the trick. But of course once the MUF falls below 28MHz this path is lost and the band is considered to be closed.

The article goes on to suggest that CW using a narrow filter could keep the path open at 28MHz at 10W even if the MUF falls to 25MHz. So, operators are already using "above the MUF" propagation. However, using FT8, JT65 or JT9  this path would be open with the MUF of around 23MHz. So the ten metre band would sound dead, SSB would be possible on fifteen metres, but data operators could operate on the otherwise "closed" ten metres. CW operators might get away with the WARC band on twelve metres.

The significance of this is that the MUF rises to 23 MHz far more often than it reaches 28MHz.

The fact that WSJT-X data operators are making stacks of contacts when the band is open is already clearly demonstrated. But this other fact shows what some of us had already noticed - these modes can make contacts possible on an otherwise "closed" band.

It could be said that there is confusion over our own figure "maximum usable frequency". For practical reasons we have set this figure by taking the measured critical frequency using near vertical incidence reflections and multiplying it by a constant which produces a figure which works for SSB and the receivers we all normally use. However, the better sensitivity of these WSJT-X modes alters the constant to be applied. What we call "MUF" is really the "Maximum workable frequency for easy SSB contacts".

In a sense it is silly to talk about "above the MUF" contacts as F-layer propagation should be impossible above the MUF by definition if it is really the maximum usable frequency. However, I bet that the term MUF will continue in use to mean the frequency at which those easy F-layer QSOs start happening.

I avoid the easy contacts and go for the difficult ones. But you knew that already.

So what happens if the MUF is much lower, and the F-layer basically disappears? Does this "above the MUF" propagation disappear? Not totally. At that point although reflection more or less stops, even at a very low level, scattering from the atmospheric molecules will still occur and produce just the sort of weak signals which JT modes love. Ionoscatter has been known for years too, but it usually requires high power as it produces weak signals - something which JT modes are ready to help with.

I should have seen this coming. I knew that these modes can receive much weaker signals than the human ear. What I had not thought about was that they could in effect outwit the conventional calculation of "maximum" usable frequency. None of this is new - Isaac Newton (1642-?1726) knew about reflections during refraction in light. The people who made my camera or my glasses spend a lot of time trying to minimise the effect by applying coatings to the lenses. However, our radio educators thought fit not to remind us about it. As so often, the standard diagram in the radio text books is over simplified. Oh yes, it was over simplified on this blog too ... mea culpa.

When I started using WSPR I told some old timers about the results I was getting. Their immediate reaction was that it is was impossible and somehow WSPR must be using the internet rather than radio. When I assured them that WSPR was all radio over the whole route from my antenna to the other station's antenna they were very sceptical. Now I know what was happening. More recently as WSJT-X modes became more popular on 6m, several of us have been finding paths open when the band is otherwise "closed".

As always, more investigation is required.

This is my stumbling attempt to explain this. I encourage you to look up the much clearer explanation by K9LA in QST if you can. I hope to put it to more use soon.

And thanks again to GM4JJJ for putting me on to this. It explains a lot of what I have been experiencing but not understanding.

I wonder how often stations turn on, listen to the band, hear nothing, and switch off. What would happen if they tried calling CQ on FT8?

73

Jim
GM4FVM

Did I miss an aurora?

I have been in Blankenberge which, as is well known, is in Belgium. It is customary in this blog to show the means of transport I used at the end of my trip (how did that come about?). Anyway here is a tram at De Panne, which was as far as we got before heading back to Blankenberge...

Tram at De Panne 09 September 2017

We did use trains which were more comfortable and rather faster to reach Belgium in the first instance.

The journey back from De Panne was, at 115 minutes, the longest time I have ever travelled in one tram. We broke the journey on the way out, but as we were tired on the return we decided to do the whole thing in one trip. Result - seriously numb bums. Almost as bad as the plastic seats on Euskotren from Bilbao to Irun via Donostia.

Anyway, it was clear to me that all my recent talk of the "end of season wind-down", and me decamping to Belgium, doesn't stop auroras happening. If I learned anything in statistics class (did I learn anything in statistics class?) it was that anything with a distinct probability, however small the probability, will happen sometime if you wait long enough. Like motorcycle accidents and unexpected pregnancies, if the basic requirements keep being met, then eventually even an unlikely outcome will occur, given enough time. So we shouldn't be surprised, and that also explains the scars on my leg, my broken upper jaw, and other things like me being here in the first place.

I have gone on about this before. The "Carrington Event", the most violent solar storm seen and recorded (so far), occurred in 1859. When I was at school we were told it was a "once in a hundred years" event, so we have better expect it soon. Now we are told that it was a "once in 400 years" event. We shall see. "Once in a hundred years" floods seem fairly common these days.

The aurora on 8 September was a good one. Not in the Carrington Event category, as one of those would threaten power systems and satellite communications, but good all the same. As we have not had a good aurora for some time, and as I missed it (boooh-hoooh), I am lucky to be able to draw on the reports of others to describe what it was like. Mike, GM3PPE is about 30km South West of me in IO85, David GM4JJJ is about 90km North-West of me in IO86, and both gave me accounts of the event. Thank you to both of them for allowing me to quote from their reports.

The basic plan for aurora is to be on alert for anything untoward happening. Mike was able to send me this email on 6 September which was very accurate in predicting the events of the 8th.
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"I was on 15 meters this morning working stations on FT8 when suddenly at 0910Z all signals disappeared.  The same on the other HF bands.  I thought my rig had broken, or the antenna fallen down!  Then 30 minutes later all signals back.  A massive event on the sun.  Middle of the day another total radio blackout.  Apparently the biggest solar X class solar flare for several years.  It looks like there was an accompanying CME in our direction, which augurs well for a big Au event over the next 24 to 36 hours."

After the aurora Mike sent this report "6 meters started buzzing at lunchtime and closed to Au contacts mid evening. Kp went up to 7 and the geomagnetic records went purple.  I have never seen that happen with previous events.

I worked about 40 stations all over the UK and Europe, with some even on SSB.  Signals were very strong with some peaking 59A on my K3.  Towards the end of the event some signals start going Es, with hardly any Au buzz at all.  LA8HGA was particularly noticeable for this effect."
" ... the Au opening ended quite abruptly for me at about 1830Z - as you say, quite early.  In terms of DXCC countries, I worked G, GM, GW, EI, ON, LY, SM, F, DJ, PA and LA, making a total of 21 squares.  Not a bad haul for one day on 6 meters!"
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Quite right Mike, and well done on that. 21 squares on 6m is remarkable and once again it proves what can be done on VHF.

SSB can be useful during auroras, even if the distortion makes it difficult to use voice. There is a large band of amateurs who never use CW, and during an aurora they can only be reached on phone. If I need the square I can use almost any mode I need to, however difficult that might be.

Mike sent me a link to the British Geological Survey site:-

http://www.geomag.bgs.ac.uk/education/current_activity.html

This certainly shows the 8 August event in context (and shows the purple bar graph which was a new one on me too) ...

BGS "Current Geomagnetic Activity" chart for Lerwick taken on 14 September 2017

Click to enlarge if necessary (as always).

Note too that geomagnetic activity had another smaller peak later in the week and there may be some more action to come. The fact that you often see possible warnings of auroral events when nothing actually appears is part of the joy and the frustration of the hobby. This time who knows?


David, GM4JJJ sent me these useful illustrations of his operations:- 
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2m Aurora Map showing worked squares with 500km intervals in red

4m Aurora showing worked squares with 500 km intervals in red

OH SLICE meteor Radar showing the solar flare attenuation at 36.9 MHz on the day before Aurora at around Noon. 

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Thanks and congratulations David, well done.

It takes a fair amount of determination to work stations on 2m during an aurora. The Doppler shift is greater as the frequency increases. This makes life harder.

Clearly 8 August 2017 was a "big" aurora in every way. 

I am sorry I missed it. I used to work in Belgium and I always enjoy practising my rusty Vlaams (and indeed Dutch and French, if I can admit to that too). 

En waarom niet? Een fles Kwak voor GM4FVM!

Thanks for all the information and let us see if there is another aurora round the corner.

73

Jim
GM4FVM

31 August Es and the end of the season wind down

Here, as I gaze over my estates from the lofty heights of the old stone tower at the end of the West Wing, I see the workers toiling in the fields to save the wheat crop ...

Harvesting the wheat as seen from GM4FVM's QTH on 27 August 2017

Actually, there does not seem to be too much toil involved sitting up there in the cab of the harvester watching the machinery doing its work.

If I really did have a West Wing with a stone tower on it, I would have attached another antenna to it long before now. Especially if it had lofty heights.

No, this week I have been watching the field behind the house being sucked clean of all its produce, then straw baling being completed. The straw bales have already been removed and no doubt ploughing and drilling will be complete within days. Who knows what crop will be pushing up next year?

When it comes to harvest time I start thinking of Autumn, and the end of the Es season. Time for me to review the Summer and then batten down the hatches for Winter.

This year I feel that I have overdone things over the Summer. I think that it is time for a break from operating and use the opportunity to spend a bit more time with my other projects.

Most of my amateur radio life has been marked by upsurges and downswings in activity. I am not an operator with just a rig and a bit of wire, but nor am I someone who invests all his time and money in this hobby. I move around the middle ground, sometimes getting too much involved and having to step back a bit. So this is time for a step back.

The Es season is over, the Christmas VHF Contests are over the horizon. Time for a measured reaction. The Autumn promises more Es, more aurora, more meteor scatter, and more tropo. So bring it on, as I am not going hunting for it.
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 31 August produced a nice Es opening.

I knew it was coming towards the end of the week because the RSGB VHF propagation report said there wasn't going to be one then, but "at the head of the week" and it would "struggle" due to "weak Jet Streams".

So, of course with this promise I reckoned that if they say it will happen weakly at the beginning of the week I should start looking for a strong one at the end of the week. I find that is the best way of treating these reports, and it has always worked for me.

I am not saying that Jet Streams have nothing to do with Es (though that is what I think, but it is hard to prove a negative), but what I can say with fair certainty is that using them for prediction does not work. Relying on the predicted Jet Stream to base an Es prediction is always wrong here.

Jet Streams might be implicated in Es (I doubt it) but if this is the track record of making predictions based on them, what I have seen over the last year or so makes the predictions look laughable.

Es as reported by DXMaps at 21:18 on 31 August 2017.

I had a number of nice contacts, including I6FLD, IK4ISR, IZ8IBC, SP7QJF and SP8NR on 50MHz, and returning regulars DD3SP and OK2BRD on 70MHz.

Actually Sandro, DD3SP was an interesting one on 4m as I worked him first with meteor scatter on MSK144 at 13:16. I guessed that would be my last German station on 4m for this year, as their temporary authorisation ended on 31 August. But then I worked him again on SSB on Es at 20:32. I also worked Jiri, OK2BRD twice, both on Es. First by FT8 at  20:37, then again on SSB at 20:45.

It is notable that the last QSO was at 22:55 and I only stopped because I needed some sleep. This bout of Es was generated by a geomagnetic storm caused by a coronal hole. There was no widespread aurora, though I did hear the usual Northern Ireland beacons over the previous day or so. I often see this Es pattern repeat itself during positive polarity coronal hole disturbances. Perhaps today we will get some negative polarity material from the Sun too, and maybe an aurora.

10m Es was pretty good as well...

10m Es on WSPR, 31/8/17. Presumably Mauritius was F layer, but you never know!

A great day of Es to round off the season, so to speak. I will miss the German stations on 70MHz even though, due to conditions, they have not been as prevalent as previous years. I already miss Italian stations who we have not heard on 4m for several years.
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It definitely has been a busy Summer and I am in need of a bit of a break. Never mind the radio, a brilliant Tour de France (Rigobero Uran was brilliant) was star of the season. Now the battling of Contador, Nibali and Aru are keeping me welded to the television and La Vuelta Ciclista a Espana. Not just cycling, but cricket has been superb too, plus of course Masterchef Australia. What a Summer.

I am not going QRT, just taking a bit easier. There is plenty more for this blog, or so I hope anyway.

73

Jim

GM4FVM

2017 Es season - not that bad? Aurora springs to the rescue.

I wrote this over the past few days. It started off being a piece complaining about poor Sporadic E conditions. As the piece developed, it turned out that things were not as bad as they had seemed.

What was bugging me was that on the 70MHz band (4 metre band), I had only had one Es QSO so far in August. Normally I would have had many more, and I can often work up to 8 DXCC in August, whereas of course in 2017 it was just one. I moaned about this in my last posting, and I went off and got the figures out of the logs to prove it.

Of course, it was probably just random variation (and not the weather and definitely not the jet stream). As I was finishing off my blog there was a small opening on 4m. I worked two stations in 4m, both in EA. One was on SSB and the other on FT8. That was followed the next day by a short opening into OH with two stations worked. For a while, the OIRT interference made it look like the "good old days" of Radio Gdansk...

OIRT broadcast stations at GM4FVM on 27 August 2017

So I have decided to re-write my downbeat piece as a review of the good things that have happened recently. And why not?


I can hardly complain about the 2017 Es season as a whole, even if August has been relatively poor. Six trans-Atlantic contacts on six metres on six different days so far this year. These cross Atlantic paths are (we believe) multiple hop Sporadic E. Ron, WB3LHD, went so far as to send a very striking QSL card direct ...

QSL Card received direct from Ron for 6m FT8 QSO on 29 July 2017

We do have sea eagles not far from here, plus kites and buzzards overhead, but that is quite a bird. Even the slightest squeak from any large bird sends Katy out of the garden and into the shack for shelter, so I have kept Ron's card out of her very sharp cat vision.

However, none of those NA QSOs were in August.

I suppose in this respect I am "old school". I really like receiving an unexpected QSL card through the post. After I sent the card back (direct) Ron sent me a screenshot of what the QSO looked like from his end. Unfortunately I did not take a screenshot at my end.

Nor can I complain about working 7K2KF in Algeria recently. I view this as a new continent. Sure, I have worked Madeira and the Canary Islands on 6m, which count as Africa, and had many 2-way spots with CN8LI on WSPR, but I have never before had an actual QSO with a station on the African continental mainland itself.

7K2KF on 6m at GM4FVM on 25 August 2017

I am not sure why this has taken me so long as the CN8LI spots prove that the path is open quite often. 2162km to 7X2KF is not far in 6m terms. It seems that the "FVM equations" are the problem, with Egypt, Tunisia, Libya, Algeria and Morocco all within easy range but not very active. The issue here is not about the level of Es, but more about the level of activity. Or so I suspect.

It also depends how the weekends fall in the month. Conditions are always better at the weekend. Of course, this is not true, but it seems to be. There are more stations around, they make more noise when the bands open, and that gets others involved.

I have also had a few QSOs into France - which is a great place for me to find new squares on 6m. France was late to release the 6m band, and then at first only part was opened up. Now it is easy to work French stations but they are still few and far between. Given the size of France, just about everybody starting up is in a new square for me.

However good things have been on 6m, 4m has not been good for weeks. I have to conclude that it is probably just normal statistical variation. Up here at 56 degrees North I am towards the edge of the strong Es. Stations in the Mediterranean get much more, and the further North you go the less we benefit from it. So it might reach us here on 6m, but the ionisation might just be too weak to work at 4m from here. A few days like that and it makes all the difference.
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If Es levels may be down (and reading the above, they probably are not down), auroral activity is definitely down.

I wrote a long piece about auroras to illustrate them, but I still have not posted it.

There were more auroras over the last couple of years, and fewer recently. ("Please, no more figures Jim", they cry). That is probably due to the well established pattern the auroras peak in the two years after a sunspot maximum.

Like meteors, auroras do not go away just because it is not a maximum period for them. The various sites suggested that a coronal hole might have been active for the previous two days, but nothing exciting was predicted for 23 August. Suddenly my 10m WSPR monitor showed a blast of noise which filled the waterfall right across the screen. It must have been fairly wideband but I did not see it on the higher bands...

Wideband noise burst on 10m before the aurora on 23 August 2017

This was followed by me hearing the beacons on 2m in Northern Ireland, plus the 4m beacons on  Syke and in Northern Ireland. Interestingly the 4m NI beacon is now running PI-RX mode and I could compare the signal direct and via aurora, depending on which way I turned my beam antenna.

GB3CFG beacon near Carrickfergus while beaming directly at it (tropo)

GB3CFG beacon while beaming North (aurora). PI-RX is decoding despite the Doppler distortion

I must say something more soon on this blog about PI-RX beacons. Let us say now that unlike almost every other data mode, PI-RX works during an aurora. Looking at the comparison above, between direct and via aurora, it is amazing that PI-RX can make anything out of it at all.

Beacons were all very well, but what actual stations could I hear. As usual, not many.

I managed to work one station each on 4m and 6m. They were both LA9BM. Leif and I seem to find ourselves in this position quite often - the band is open but there is nobody else to work. Not quite though, he worked a few more, including OH0CO. I had heard OH0CO over the past few days via meteor scatter but he did not hear me, and I did not hear him on aurora. Aland Island would have been a new DXCC on 4m and 6m, but not a new square.

Anyway, I worked LA9BM on 4m and 6m using CW, and not even using my pre-programmed QSOs using the keyer memory. All done old style with a keyer and brain power. I did hear a couple of other stations but their CW was far too fast for me to try to work. Why does anyone use fast CW during an aurora when signals can be distorted and hard to copy?

I like a good aurora. Even if I only got to work one station on two bands, this one was better than nothing.
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73

Jim

GM4FVM

Amateur radio rotator rant

OK, I have been fed up about this for ages and it is time for a full-frontal whinge.

There certainly is a thing called "buyer's regret". That happens when you buy something and then wish you had bought something else. This is not the case here, I think.

I think that none of the rotators on the market meets my needs, for reasons I will explain.

The thing about rotators is that the market for them is not very big. In my career I have had three rotators, the first two bought second hand. So in my first 40 years of radio I spent less than £100 on the first two. Then I gave the first one away about 10 years ago (a Ham M dating from the 1960s). It went to a needy new amateur. The second one, a Yaesu G-600, which must be 20 years old now, is still in use.

Then eventually I had need of another one (maybe I should not have given away the HamM). I bought the third one for (I cannot recall how much now) but it would now cost £376.75 for the rotator, plugs and bottom clamp.

£376.75 for the most basic rotator on the market (the Yaesu FT-450)!!!

That does not include postage or the cables. Nobody is likely to use less than 30m of cable. 40m supplied by Yaesu and complete with the plugs costs £100. You can do it for less, but with the plugs costing almost £30, not much. You can find the plugs on eBay for a few £££ and get your soldering iron going. As for the cable, at one point in one of my runs the rotator cables is two parallel runs of old mains flex (total cost for that bit £0).

If you buy the long cable and the bottom clamp that brings it to £480.

You can, for sure, do these things to get the price down. Once you do so, you are departing from the CE approval which is needed to sell appliances in the EU. This is meant to protect you. If you do something like use old mains flex and then your house burns down, your insurer may take a dim view of you departing from the CE marked "official" Yaesu cable with its pre-fitted plugs.

I looked fairly carefully at the small rotator market at the time. The Yaesu was not my immediate choice. I would have preferred a worm-drive mechanism, which the SPID rotator has, but even the lightest SPID appears to be much heavier than the Yaesu and claims only to take 50mm diameter masts (mine are 52mm).

Also on the market seem to be:-

The equivalent Hy-Gain rotator, the venerable AR-40X sells for £449.95.

You could get a Create RC5-1 for about £500 (+ £££ bottom clamp) or the Spid RAU is £480.

Now if you take a step above the entry level there is much more choice. However, these are choices not available to me. My mast is light weight and not able to accept anything much heavier. Anyway, if you pay enough for a rotator you can get anything you want, which is not the point for anyone on a budget. It is a bit like me remarking on my £1000 rigs and then getting emails from people saying that a £4000 Elecraft radio and matching Elecraft linear is better. Yeah, sure, and a new Rolls Royce would be better than my 8 year old Volkswagen. I keep making points like this but the Elecraft "my wallet is bigger than yours" brigade keep writing to rub my nose in the dirt of my limited budget.

My gripe is not so much that the Yaesu rotator I settled for is not really very good. Well, it is not very good at all really, but then for a motor, some gears and a housing, what do I expect?

My gripe is that at least some of the cost of the Yaesu, (and the Hy-Gain and Create) rotator must go on providing me with the mechanical indicator. When you think about it, this is a masterpiece of electro-mechanical engineering. However, I don't need it, I don't want it, and I cannot see why they persist on selling it.

Controller for my Yaesu G-450 complete with clock-face indicator and no digital control

Going back to my old Ham M, it had a nice simple single slider control on the front. Sprung to centre off, and a slight pressure either side released the electro-mechanical lock on the rotator. Any further pressure on the slider moved the antenna. You could stop turning it and keep the slight pressure on so that it coasted to a halt before allowing the lock to engage. And the display was a simple meter calibrated from South to South via North - it just read the voltage coming down from the resistor in the rotator.

Then moving on to the Yaesu 600, its control box had two buttons, left and right, plus some dorky wiring to stop you trying to turn the antenna both directions at once. It also has a lock, but you cannot control it separately. And it had this amazing clock-face 360 degree indicator, which the Create and the Hi-Gain have too. This a great thing, but does it really tell me much more than the old meter did? They used to sell the meter version alongside the clock-face ones, and the meter version was cheaper (of course). Now you have to shell out on the fancy display.

None of this would matter had my display on the G-600 not failed. Maybe after 20 years that is not so surprising. But whilst a meter could have been fixed, this marvel of all that clockwork complexity was beyond me. So I bought an EA4TX digital control box, reviewed here. Now this is a great device but it costs almost as much as the Yaesu G-450, once you have added the tax and carriage, and you have a lot of tinkering to get it to work. It was a simple choice when I was faced with the G-600's indicator failure to buy one, and it has kept that rotator in business for another couple of years, but it is a lot of money and work to go to if I want to replace my G-450 indicator.

Let us just consider this. I have one rotator under computer control, the G-600. I had to re-wire the G-600 controller to extract the motor voltage and organise the new EA4TX box. It worked out fine in the end. Now I would like to have the G-450 under computer control and the sums just do not add up. I need to delve into a perfectly good controller to get the motor supply out, and then spend as much as the original rotator on a control box. Crazy.

So why don't Yaesu just sell a controller with two switches and digital readout showing azimuth? Or even a small LCD screen with a pointer on it? And, crucially, a nice USB socket allowing connection to a computer? After all, this is what SPID do for the RAU. And high end, larger, heavier, more expensive rotators do allow easy hooking up to a PC.

I think that the problem for Yaesu and the other manufacturers (except SPID!) must be that any investment in updating the rotator control box must be a very doubtful proposition when they only sell most amateurs one or two rotators in their entire career (in my case, one every 20 years). You need to sell a lot to recoup the cost of re-tooling your production.

Set against that, most electronic devices now have been redesigned in this way. Moving parts are minimised. Even a single humble meter can be the cause of a re-design, to be replaced with a digital readout. Transverters have been redesigned to replace a meter with a numerical display or an LED strip display, and transverters are very low volume products. So surely the cost of making those mechanical clock-face displays must justify a change of direction (ahem!).

The EA4TX shows how simple it is to include PC connectivity and stand-alone back up.

From what I can see SPID do a display with a simple three figure azimuth read-out in degrees. This has a USB output for the PC. You can use this "stand alone" without a computer using the display, or with the computer using the USB socket.

You can add on interfaces for some Yaesu rotators but you have to buy the unwanted display first and the interfaces are expensive and do not work with the G-450 anyway.

What I would really like to see would be Yaesu making a modern controller for the G-450 (and I suspect the G-650) with a built-in power supply and a socket for their standard rotator plug. This would be a straight replacement for the existing rotator control and it would feature a USB socket. As well as being available with the new rotator (and surely cheaper than the exiting controller) it would also be sold as a replacement for people like me ... or those whose mechanical readout has inevitably failed.

But, you say, there already is such a device. Yes, believe it or not, Hy-Gain sell just such a thing for Yaesu rotators - the YRC-3X. Weird. They sell a device to fix their competitor's rotators. This is exactly what I want. Downside? It costs £449.95, just for the controller. In other words, I could just about buy a brand new SPID and its perfectly suitable controller, for the price of the Hy-Gain replacement box.

If only I knew for sure if the SPID does fit my masts or not. 50mm - do they mean that as an exact measurement? And as for the weight quoted for the SPID, are those shipping weights for the whole kit, or just the weight of the rotator? I am fairly sceptical about the level of detail you get for these things, after all, the torque and wind loading figures given are not comparable between makers either.

You can see that if I could sort out the details I would rather sell the Yaesu G-450 and buy the SPID than spend the same amount of money buying the Hy-Gain box to convert the Yaesu. Not that there is anything wrong with the G-450, just that I am irritated by paying twice to get it working the way a  modern rotator should.

Anyway, Yaesu continue to sell an outmoded and no doubt expensive to make controller and give no option for purchasers but to buy it. I bought one. The rotator is OK, as far as cheap rotators go. It meets my needs in the sense that it has not broken down yet - though the first Yaesu G-450 which was supplied to me was seized solid and it took weeks to get a replacement. If the wind causes the gears to strip then I will know that it is not good enough mechanically. I already know that it is not good enough when it comes to the controller.

I suppose that the manufacturers are stuck with small volumes of sales. If Yaesu think that selling the G-450 with no computer connectivity will force people to buy heavier and more expensive rotators then they are wrong, as they would be too heavy for me. I cannot blame Hy-Gain charging a high sum for their replacement Yaesu controller as the market must be small. So, come on Yaesu, get that controller modernised and start selling replacements.

Where is the Chinese manufacturing industry when you need them? A rotator is a 30volt-ish motor, a bearing or two, a couple of gears and some castings. A controller is two switches, a display, a circuit board with a couple of relays, PSU and USB socket. Surely that could be done for less than £380? In radio terms the volume may be small, but someone could corner the market with a well-priced rotator. If the existing manufacturers cannot modernise and innovate (with the exception of SPID who do try), then can newcomers come in and shake it all up?

Where is Adam Smith's hidden hand? (Note: obscure reference to the Father of Economics, who also resided in IO85 square).

Rant over.

73

Jim

GM4FVM

Es and broadcast QRM, the Wouxun 950PL, and 2 computers with PstRotator

Sometimes with amateur radio you just have to wait and watch...

Katy, 2nd operator at GM4FVM waiting patiently

At other times you let your guard down. You go off duty, you get slack, you relax. You know, you have waited for ages and nothing showed up, so you took it that nothing was going to happen.

Katy has slackened off She is in there as her tail shows

It was when we were slacking, two days ago, that we missed Moldova on 2 metres. That would have been a new country and a new square. I saw something happening on EsSense, but I went out and cranked the antenna up and poured myself a Ribena, then I came into the shack and heard somebody else working Moldova and then the opening was over. Grrrr.

You win some, and you lose some.

Often, when Es is at its strongest, there is simply nothing to work. On 6m here the band is full of Russian (and general Eastern from here) TV signals. On 4m there are lots of OIRT broadcast signals. The noise gets so high that the rig overloads. Curtains. I might as well climb into Katy's bed (no tail to show, honestly; I am not The Devil).

Here is such a day (18 June). Although a bit short of overload, the radio was full of OIRT on 4m and no further progress could be made. I have got used to sitting this type of thing out. I might be able to hear an SSB signal in there, but there is no chance of being able to understand it. Not with my ears anyway.

You might be able to see, just between two peaks of FM broadcast, a faint line which is indeed an amateur signal. Right in the passband of the receiver on 70.176

That line is indeed DG0KW. I had just worked DF5VAE (accidentally I was on 70.170, but he still found me). Apparently JO64 is new square for me though I was surprised by that.

It certainly looks as if you can squeeze a JT65 signal between the sidebands of the FM broadcast signals. In fact, DF5VAE was more of less on top of an FM signal, yet he was easy to decode.

I am beginning to get the impression that JT65 works quite well in the face of heavy FM interference. I suppose CW might work too, but JT65 takes the agony out of listening to the terrible raspy noises. I could never have worked either of them on SSB, and indeed I would not even have tried.

Just a word of explanation about OIRT for those of you outside Europe. The Organisation Internationale de Radiodiffusion et de Télévision is (or was) a group set up after World War 2 to establish TV and FM broadcast radio standards in Europe. The FM radio band they proposed was around 70MHz (now 65.8 to 74MHz). Western European nations left OIRT in the 1950s once 88 to 108MHz became their preferred band and OIRT was left to cover Eastern Europe, or in reality the former USSR and its affiliates.

In the past radio amateurs had to deal with broadcast stations in the 70MHz band from many countries in Central Europe. Gradually former "Warsaw Pact" countries abandoned OIRT frequencies and opted to go with 88 to 108MHz.

As far as I know OIRT as an organisation no longer exists, but the term "OIRT" is used to describe stations still operating on those frequencies. Typically, I hear stations in Russia (especially Kaliningrad), Ukraine, and Belarus, but other countries further East still seem to be operating too.

I believe that most OIRT stations are now just duplicates of stations in the 88 to 108 MHz band. It must cost a lot to keep them running as they certainly must rack up quite an electricity bill.

Wide band FM at considerable power is just one of the snags to get over when trying to work Es on 4m. It just shows how good the propagation is on that band. They do not make it impossible to operate, you just have to find ways to work round the commerical stations, as we used to do on 160 and 80 metres in the good old days.

Imagine my puny JT65 signal successfully battling through that wall of RF.
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To be frank, I never really expected the Wouxun KG-UV950PL to become my shack FM radio.

I had intended it to be a mobile radio and I still think it would be great for that. However, it never made it past the shack where it replaced two separate rigs.

There is a good review of it here ... if the link is broken it is this ...
http://www.g3zpf.raota.org/articles/wouxunKG-UV950pl.pdf.

In my experience so far this review says almost all you need.

The 950 is really is two radios in one box, and one of them only covers part of the range. This is odd and hard to get your head around. I have one set up to cover 50 and 70 MHz, and the other for 144 and 432 MHz. Strange. Luckily mine came with the programming cable thrown in so I can tame it that way. I would hate trying to set it up manually as it took about 10 days to figure out how it works. At least with all the memory frequencies in place I could adapt to it and learn as I went along.

I had looked at the 950 as a possibility before, but it seemed too expensive. Adding the programming cable tipped the balance.

My Wouxun KG-UV950PL - I separated the control head from the rig to install it

What can I add to the G3ZPF review? I have it mounted with the control unit in the shack shelving and the radio itself mounted at the other end of the shack - the control cable comes as standard. I took the strain off the mic cable by adding a right angle ethernet plug with a cable to an ethernet "back to back" socket. The mic plug is therefore not tugging on the rig socket when you transmit.

There may be two radios in the 950, but there is only one RF socket. I already had a Comet CF-530 duplexer doing the same job for my Wouxun handheld in the car, so I brought it in to allow me to split the 50 and 70MHz signals from the 144 and 432 MHz ones.

The review mentions the volume control issue at low volumes. This is a snag for me - I cannot get it low enough with the inboard speakers. Easy enough with outboard speakers. So I just set the speaker on the microphone as my main speaker. In a car this would not be an issue as low volumes are not needed.

It takes a bit of getting used to. I suppose that every new FM radio does. Now that I know that it takes two presses of the PTT coming off scan to work the transmit function, I can do that. I can now enter frequencies via the keypad, but the process takes some remembering. However, I use it almost entirely on memory mode.

Now that I have had it for a few weeks I can say that I thoroughly approve of the Wouxun 950. The basic 950P model covers 10, 6, 2 and 70cms, and that might be the one for you. However, the 6, 4, 2, 70cms "950PL" version is the right one for my particular purpose. Both versions are marked 950P on the front, incidentally.

Aside from the rather odd control arrangement, the radio side is fine. It is powerful (40 to 50W) and sensitive. The squelch works well. Sensitivity is similar to other single and dual bands rigs I have used, and there appears to be no performance penalty by reducing the rig count by one. It is certainly streets better than the ancient ex-commercial PMR radios still in use of 4m.

As well as looking as if the case is used as a heatsink (as on my previous VHF FM radios) the 950 is equipped with a cooling fan. This is great. I used to have radios like the Yaesu FT-1900 and 2900 which got incredibly hot. A cooling fan is very useful, and I cannot hear it.

At almost £300 it is a bit pricey for what me, but then it is better value than some other quad band rigs. Now that I have got used to the quirks, I like it.
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I have gone back to using two computers as a trial.

Despite all the comments to the contrary, I cannot get two instances of WSJT-X to run reliably. Two versions of MSK144 overload the computer (any computer I use up to my most powerful), and two versions of JT65 run for a while and then one of them get stuck in decode (but stops decoding). So I split them across to computer to see how I would get on.

So far so good. There is no detectable increase in noise, though I have not looked everywhere yet. I may add yet another display screen. I can now run two versions of WSJT-X easily, one on each computer.

I have used a "Smart KM-Link" to allow me to control both computers from one keyboard and mouse. This is a USB device, unlike the older switches which also  switched the monitor. It allows the mouse to move between the screens and automatically switch between them. Apart from some fan noise from the extra PC, the operation of the screens is exactly as before.

This works fine but I struck a problem with the rotator software driving my Yaesu G-600 rotator (the G-450 uses the standard Yaesu mechanical display). The display for my existing software prevents the mouse switching between screens. As I was using the basic software which came with the EA4TX ARS-USB rotator controller ("ARSVCOM"), it was time to switch to some more advanced software.

For some time I have been eyeing PstRotator by YO3DMU. I downloaded it and paid the very reasonable sum of €20 to register it.

PstRotator display - as always click to enlarge if necessary

It does lot more things than I will ever require. First plus is that I now have a choice of 12 presets instead of eight. Not that I can actually think of four more just now, but I have the option. I can enter a locator and the rotator will point there (useful) and even a callsign works too.

This is as far as I need to go with PstRotator for now. It provides lots of options for the future.

We will see whether I stick with two computers as time goes on. However, PstRotator seems worth having.

73

Jim

GM4FVM

A dual-band antenna, 70MHz JT65, and classic rigs

These are the days of the Es season when I change gear. I go into cruise mode.

The "new-ness" of it all has passed. I have no need to work the same station today as I worked yesterday. Others do have this need for some reason. Mostly I sit and watch them all working each other, and I wonder what they have learned since the day before.

Personally, I prefer to look for new squares and new countries. I am of course happy to answer calls if I call CQ, but then I do not spend all day calling CQ. I leave it to others to call CQ continuously. And they do that duty rather well.

True, I have had a few successes in the past few days. IK2MMB (JN45 1382km) was a nice contact on 2m on 16 June. HA/SP7VC (KN17 1866) was a new square on 4m. I really appreciate people activating these rare squares.

It was not so good with an activation from the Nordic VHF meeting in Sweden. The 4m meteor scatter station would have been a new DXCC as well as a new square but it was not to be. I heard them many times, but could not get through. I tried to email them as they did not seem to be sticking to the split they were alleged to be working, but I only got a reply after it was over, and it said that I was too late. Clearly this team put a lot of effort into this activation but sadly I could not work them. Again, for another year. I said that last year.

Also nice have been some contacts on 70MHz JT65. There is no frequency allocated for JT65 on 4m. In fact, the WSJT-X software is supplied with entirely the WRONG preset. It defaults to the WSPR frequency, and every month or two I see people who use this setting this being scolded on the cluster.

Anyway, several people have commented about 4m and I decided to try 70.176. This is not ideal as it falls inside the precious German allocation, but where else to go? I then worked G0XVF and G0MJI, both of whom have been pressing for some JT65 action. Then I was really surprised to work GM4ZMK, also on 4m JT65. This was followed eventually by DL5MCG (JN48 1113km), my first "DX" JT65 contact on 4m. It is not for me to say that 70.176 is the "right" frequency, but I hope that it (or some other one) becomes standardised.

So why do I want to see JT65 on 4m? For the same reason I like it on VHF in general. There seems to be a general lack of interest in data modes amongst some VHF operators. However, JT65 is not just a replacement for SSB or CW, it offers its own special attributes. It is particularly suited to long distance DX working. It was designed for Earth-Moon-Earth use and that is a similar steady low strength situation.

Lately we have had many stations worked from Europe on 6m, as far away as China, Japan and Korea. This, it is suggested, is "Short Path Summer Solstice Propagation" (SPSSP). How this differs from multi-hop Es is subject to discussion. For example, is the frequent path from here to the Caribbean, or the United States or even South America at this time, also SPSSP, or what? Well, in any case, JT65 is brilliant for it. CW also works, SSB is tricky and that is it.

As I write this I am still struck by a station in China who was working streams of Southern European stations on 6m, and who then posted that he was hearing the Angus beacon on 4m well over S9. The Angus beacon in China! Then the posting appeared that Haiti is now available on 4m too (is this official?) plus last year's information that at least one other South American country (was it Colombia?) is also active.

First of all - the 4m Angus beacon was heard in China when there was no 6m path for me. How often would 4m paths be available, perhaps on different trajectories, when 6m is open? How did we not know about SPSSP before a few years ago (i.e. not before JT65)? What can we do with it? Does it extend to 4m regularly, if at all?

I saw an interesing post on a Belgian amateur site. It said that this is a "scientific hobby and not just a communication hobby. In other words, it is not CB". How true. Here we have a genuine scientific discovery in SPSSP, and that beats working the same station on successive days. Well, it does for me anyway.
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I have been trying to reduce the number of poles here. Also, my cobbled together ex-dual band beam was in use on 6m, and something had to be done before it fell down in the wind. I seem to have resolved all this, though I now have another dual-band antenna, which was not in the plan to start with. Or two antennas mounted at the same height working on two different bands.

The replacement for the old 6m beam is commercial. Making it into a dual band beam is entirely an FVM invention. It is a Sirio SY50-3. This is the three element version. It is rather well made and should survive the weather here well.

The elements appear to be aluminium tubes with castings for the attachments. The attachments hold the elements using worm screws tightened with an Allen Key (Hex Key). The attachments themselves are pre-fixed to the boom at preset lengths. They are lightweight castings and look very impressive.

Attachment for the reflector on the Sirio SY50-3

The antenna is otherwise conventional, with the dimensions you might expect. The coupling to the coax is via a gamma match, and the recommended tuning settings seemed to work with a low SWR.

I am impressed by the construction. Whilst light weight, it looks sturdy. It took about 90 minutes to build (during which I built it back to front - in some ways I am still like a beginner).


The irony is that I am now about to replace the co-ax to that antenna because it was ruined by water ingress - through a Sirio vertical. Sirio antennas have generally served me well, but their 4m J-pole CX 4-68 seems to have a problem. I was warned that it lets in water, so I double wrapped the joints with self-amalgamating tape. Despite this, it filled with water, which seeped past the PL-259 and into the co-ax. The CX4-68 is a great antenna, but it has this basic flaw.

So, with the new Sirio beam up, and my Sandpiper ring base 5/8th 4m vertical above, where am I to put a 2m vertical? Why do I need a 2m vertical? Good question.

I then took my trusty old dipole, which has been in use here for many years. Over the years it has been altered to serve for 2m, 4m and 6m, horizontal and vertical, fixed and rotatable, portable ... everything. Now it is formed as a 2m dipole and fixed vertically between the driven element and the director of the Sirio 50MHz beam.

Sirio 6m SY50-3, with 2m vertical dipole and Sandpiper 4m 5/8ths vertical

This is a bit difficult to photograph. It is hard to see that the 2m antenna is vertically polarised, and the 6m horizontal. And the stand-off for the 2m antenna is exactly beside the boom on the 6m beam in the horizontal plane, but it never looks like that from the ground.

In reality, the 2m support is beside the 6m boom.

I had done this before of course. You may recall this 2m antenna briefly beside the 4m beam in the past. It may not last much longer this time. It is a lash-up. Any compromise will affect both the 6m beam and the 2m vertical. For now though it is working fine.
=======================================
"Classic" rigs have quite a following.

Myself, I can do without.

There may have been a "golden era" of amateur radio equipment. It started with commercial SSB transmitters and transceivers. Early Collins, Drake and KW rigs are in this category. Then a series of hybrid transistor/valve rigs from Yaesu and Trio/Kenwood.

However, I would say that rigs from the all-transistor era which followed are not worth resurrecting. Early transistorised rigs have output transistors which are prone to failure (they were dodgy at the time), failing switches, filters going out of alignment, capacitors leaking, resistors cooking ... in fact they are something of a liability. The older ones are similar, but worth fixing thanks to the (hard to find) valves.

Then we had the arrival of surface mount technology at which stage nothing is easily repairable. Unique displays fail and replacements are not available. The chips were discontinued years ago. The switches fall apart. Everything is tiny.

Try to put these rigs on the air and you find the problems. From my point of view drift is the big drawback. These things were designed before we had JT65 and WSPR. They cannot cope. For FM they often have the wrong spacing, the wrong deviation, no CTCSS, noisy synthesisers ...

Are there no classic rigs in the modern era? Possibly the FT-847, a rig I have never owned.

I can see the idea of buying an old VHF rig. They used to be single band, and often they were much loved in their day. There is no such thing as a VHF rig now, so the old ones appeal. In general, they do not fit into the modern shack. For all the reasons above, old rigs are a problem best avoided. The VHF ones seem to be worse as technology has advanced.

They say you appreciate your own old rigs. So it is personal. Yes, my Trio JR-599 would be a classic if I still had it. Or my FT-101s. Or the TS-530 I never had. I recall the KW2000E from the radio club at the Belfast YMCA radio club, and the FT-200 in the Queen's University club. Do I want these now? No thanks.

Key factors for me now - panoramic displays, DSP filtering, ideally SDR architecture, USB digital in/out for data modes, very good frequency stability - all things unheard of in the "good ole days".

So why do these old tubs attract so much interest? Well, the shops like taking them in as trade-ins ("part exchange") and then selling them on. Magazine articles praise them but ignore the problems. Everybody is making money selling them and writing about them, so of course they say they are great. Yes, put one on your shelf. But don't expect it to be much use these days. Turn it on and take a photo with the lights on (if you can get them to work). Then turn it off and admire it. They look great. That's about it in my book.

I can see that true pre-SMD classics are great restoration projects. The repair then is the object, rather than trying to suggest that the restored rig is comparable to anything we might use today.

If there is a classic rig worth having, it was made before 1980 in my view. After that they are just bundles of heartbreak.

They do look nice though. If I wanted to live in a radio museum I would not be working much. Luckily, I want things to work as well, so that is OK by me.

There is room in this hobby for all sorts. Sure, put your old rig on the air. It is not for me though. I will watch you drift past my waterfall. If you can get your receiver to stay put you will see my truthful reply "no decode". Sorry.

73

Jim