Wednesday 21 June 2017

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


Sunday 18 June 2017

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.
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"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

Thursday 8 June 2017

A bit of an Es opening.

"Somehow we have so far avoided those ear-bending days on 4m where your head is spinning after working seven or eight DXCC in half-hour whirlwind of broadcast interference and huge signals. Yes, we have had the broadcast stations, but not a full opening. Not so far. Not here."


Was it only yesterday morning I wrote that on this very blog (check below if you want to read it all)?

There was a bit of an Es opening here yesterday.

Somebody somewhere was listening to my pleas. Must be "The Es Fairy".

It says something that I have not quite assimilated everything yet and only the 2m band contacts have really stuck in my mind. I still have to work out exactly what new squares and so forth I have worked. There are now 40 cards waiting in my in-box at eQSL and I have not had the time to look at them.

Firstly was this opening was on 6m, which I largely avoided due to local QRM. I did a little bit of 6m WSPR to inform me what was going on....
6m WSPR at GM4FVM on 07/06/17
That was nice enough but eventually, late in the evening, the local QRM had gone to bed and I went back on JT65...
6m JT65 contacts at GM4FVM 22:40 to 23:00 on 07/06/17
There were lots of stateside stations on but I was having a bit of a problem with the linear, plus, to be honest, I was not operating at my peak. Past my bedtime.

Most operating was done, as so often here, on 70MHz (4m band).
4m SSB contacts at GM4FVM on 07/06/17
I was pleased to work at least 2 new squares in Germany but I need to analyse it all further. I tried my
"doing the treble" trick (see here). Honestly, I forgot to do it, but a German station was complaining that he heard no 2m opening, so that reminded me!

This worked 100% on this occasion. Moving up from 6m, 4m was open and I knew which way to beam. Coming back down to 4m when 2m had closed, though a technical success, came at a time when I was exhausted. "Brain fade" I think is the modern term. Anyway, I had a pile-up to work through and ended up trying to work a Polish station twice.

Meanwhile, when I was on 2m ....
2m SSB contacts at GM4FVM on 07/06/17
Now this did make me sit up and pay attention. Nine contacts. Four new countries, Ukraine, Czech, Slovakia and Hungary, plus a new square in Poland.

2m Es is different from 4m, and totally different from 6m. It is hectic. Your best hope is exchanging callsign, report and locator as quickly and clearly as you can once. Any hanging about and the other station has faded away. The area covered is small and moves about quickly. Plus, we usually only get an hour or so of it on two or three days in any year. Before I worked out the "treble" approach I almost always missed it. So you have to make it count if you happen to find it. No wonder I was knackered after all this.

It would be easy to relax now and just analyse it all but we are off again today. 4m and 6m have been open into Europe. I spent a long time listening to Japanese stations on 6m. I worked some stations on 6m JT9 and then SSB on 4m. It seems that no recovery time is possible.
VHF contacts at GM4FVM up to 13:30 on 08/06/17
Several of you have sent me your experiences of the 7 June opening. This one from Mike GM3PPE seemed to hit the nail on the head for me ...

I have just had the most amazing opening ever on 6 meters.  Between 1827Z and 1857Z I worked WP2B, WP4JCF, VP2ETE, NP2J and PJ4NX - all about 56, giving me an average of 55.  Just astonishing.  The VP2 was calling CQ and getting no replies.  WP2B peaked a genuine 59 and worked a number of GMs!  I keep saying - just astonishing.  I missed FG4NN who was only about 44 with me and had a massive Eu pile-up calling him.  ...  I see now why they call it the "magic" band!

It just goes to show what can be done with modest equipment and a certain thirst for knowledge. Curiosity, is what I would call it, and it is well repaid when it all goes right.

Well, I guess that today's situation will be different from yesterday's. That is what makes it interesting. That is why I am curious.

73

Jim

GM4FVM (going to lie down and rest)