Monday, 28 May 2018

WSJT-X audio, tx period, timing plus a long 4m QSO

From time to time I get queries about WSJT-X and here are a few that came in recently:-

Why has my audio suddenly failed?

David GM4JJJ provided the solution to this one. I was away in Greece at the time so it had not caught up with me yet. Now that I am back and have installed the recent Windows 10 update my audio streams stopped working too. Thankfully I had David's advice - go to Settings, Privacy and select "Microphone" from the left bar. Turn "allow apps to access microphone" on, and then you might want to turn off all the other apps. WSJT-X is not listed but it is accessible if you turn the overall button "on".

Maybe it is just me. Although I write a blog I do like to keep some things private. I turn off the microphone because there isn't one on this PC anyway. I do it as routine on my laptop and tablet because I try to avoid giving anything to the collectors of "big data". So if this does not affect you then you are not as nutty as I am and you had your microphone turned on in the first place.

What does the selection Tx even/1st mean?

This is not really very clear in WSJT-X. It looks a bit like the choice is either even or first. What it actually means is that the choice is for or against even and first (versus odd and second).  Even and first are two ways of describing the same thing.
WSJT-X showing the period selection at the top
 To many people none of this matters at all. In FT8 clicking on a station calling will set it automatically. However, it is crucial to meteor scatter operators as it shows the direction the operator is seeking contacts. Also, it is common round here for local stations to use second period simply to stop us overloading each other's receivers. We can still reply to somebody by transmitting on first but we usually call CQ on second.

I am not about to go into the background about all this, which has its roots in meteor scatter and EME. Suffice to say that the labelling on WSJT-X is confusing some people. Choosing first (itself an odd number) means selecting the even period, whereas choosing second (obviously an even number) chooses the odd periods. The two terms made some sense when the periods were a minute long, but now that they are sometimes 15 second long it is all getting confusing.

This is one area which MSHV makes perfectly clear with a simple choice between two options....
MSHV showing a clear choice of period.
 Why am I seeing traces but nothing is decoding?

Could be many things, but almost certainly because your timing is wrong.

Data modes depend on accurate timing. The timing regime as supplied as standard with Windows is not accurate enough for this purpose. Most people use Dimension 4 or Meinberg to upgrade their timing to the necessary standard. See the link to Meinberg on the sidebar.

Not that these are totally foolproof. I have had quite a bit of trouble with Meinberg. I discovered it because I was using a different computer for 10m WSPR. The two PCs showed different times, even though both had Meinberg. I added the Meinberg monitor and what I expect to see is this - some yellow time sources found (suitable), one green one (the best one which Meinberg is using) and maybe a red one (not suitable). Then some will be white ("a survivor" but not one chosen) :-
Meinberg Time Server Monitor. One time source (green) is synchronised with 2 in reserve (yellow)
But many times none of the listed sources were synchronising and some were simply marked as survivors, meaning that Meinberg did not look for a replacement. If all six were like that the whole thing was stuck. This showed up as a several second difference between the two computers. I coloured those (otherwise white) sources purple to make them easier for me to see.
All sources unsuitable - this stayed like this for hours.
Another failure is if Meinberg software simply fails to start. I know of no way of testing for this other than by installing and using the monitor. Fortunately this fault often causes the time to default to the last time you turned the computer off, so it shows up fairly easily.

Either way, restarting the computer seems to be the only way to free these situations up as user starting and stopping of the software is turned off in the standard version of Meinberg.

Anyway, in my experience, just because I have installed Meinberg does not make everything certain.
Great QSO on 4m FT8 with Olli, DH8BQA, today (link to DH8BQA's blog on the sidebar). So much for 1 minute QSOs on FT8, this one took 40 minutes.

For the first 30 minutes or so I could not get a good bearing on a station which was showing up as a faint trace. Data modes don't help here, as unlike CW or SSB you cannot catch a bit of a callsign. I knew it was somewhere between 150 and 80 degrees, but that was as close as it got. It was very steady but very weak with occasional meteor pings and blips of Es. Eventually I worked out that it must be Olli. Only then did I occur to me to look and find that he had posted that he was hearing me on the cluster. He must have PSK Reporter logging turned off.

I was determined to complete this one as it was obviously not your normal 5/9+ Es QSO. At the time there was no Es QSO going on on 6m, and nothing on 10m WSPR so it was unlikely to be Es on 4m, or at least not entirely. The presence of a constant, weak, signal at about 1100km range suggests to me some underlying scatter mode, tropo- or iono- scatter. The meteor pings probably just served to spoil the FT8 decoding, but there were also occasional weak Es period superimposed on the weak trace. This weak Es was never long enough to allow a decode, so I had to wait for the weak steady signal to get through.

The QSO was easy enough once I knew exactly where to point the beam. I then mis-posted it as Tropo but I think it was a steady scatter mode, with a bit of assistance from Es and tropo, plus a wee bit of meteor scatter to mess it up.

I like that type of thing. Having spent hours on single meteor scatter QSO in the past, 40 minutes is not much time to spend on an interesting outcome.

I suspect that marginal paths like this are possible a lot of the time.
Finally, it has been a BRILLIANT Giro d'Italia. Quite the best bike race I have followed for 20 years or so. OK, so Dumoulin did not win this time, but the mountain climbing, the break aways, even the sprinting, had me on the edge of the seat every day. Wonderful.



Saturday, 26 May 2018

Back from SV4 and the FTdx101D shows Yaesu are awake at last.

I am back from another trip away - to Skiathos in Greece where I was operating as SV4/G4FVM. As per usual I got eQSL and coverage ready and indeed I exchanged an eQSL with IW4AOT almost immediately after the first QSO ...
Blank eQSL - I took the photo on my phone at Koukounaries
I would like to work square KM19 myself.

I was using the FT-817. It was not meant to be like this as I had planned a listening only trip with the Fun Cube Dongle but other things got in the way of that. Then I suddenly discovered that the cabin baggage weight limit for the flight was only 6Kg, so I had to jettison almost everything I had intended to bring.

Anyway, once I got there HF was impossible to use due to a very high noise level. I could use 10m WSPR and stations could hear me, but I could not hear anything. So I resorted to 6m and did moderately well. 6m WSPR delivered a few but I heard dozens of stations on 6m FT8 (I must add the total up). Anyway, best dx heard was Sweden. I worked five stations, not bad as the 817 could only be persuaded to produce about 2 watts and the antenna was terrible due to other unforeseen problems.

These overseas operations are always tricky for me. They take place during a family holiday so operation is patchy. There are limits to the amount of equipment I can carry, and how much I am willing to invest on gear for a week or two's trip each year. This last point is important as the radio element developed when the holidays took place during better HF conditions. Now I generally only have 6m and 10m and even then only during the period May to August.

At the same time my FT-817, which is fine here, is not ideal for carting about. On the weight front, by the time I have added the data interface the 817 station is almost as heavy as my IC-7100, a vastly more capable radio. The 817 arrived back having mysteriously lost all its memories and at the same time it had taken on new settings. Fortunately the original ones are backed up here.

Anyway, I learned a lot, including how to deal with the almost total lack of small plugs, ferrites and wires that I discovered I needed. If I do this again I need to be better prepared.

I say that every time.
When I lambasted Yaesu for releasing the FT-818 (here), which is just the ancient FT-817 design with a few largely irrelevant tweaks, I was thinking that Yaesu are really losing the plot these days. Radios like the FT-991 and the FT891 are, in my view, backward-looking and rather outdated. Compare that with, say, the IC-7100 or any of the other recent SDRs.

Now, at last, we hear of the FTdx-101D - here

We do not have many details yet, but the 101 is clearly an up-market SDR. This model makes sense from a marketing point of view as it will allow Yaesu to recoup some of their development costs. By this I mean that most up-market radios selling at three times the price of a basic rig do not cost three times the amount to design or make, so expensive radios are big money earners. The £1000 market makes almost nothing, whereas the £3000 market funds everything else (the £8000 market is ... unprintable).
Early photo of the Yaesu FTdx-101D from the Martin Lynch site

The FTdx-101D looks like a competitor for the IC-7610 (which is actually £3500). I usually pour scorn on that sector of the market preferring 3.5 radios at £1000 to one radio at £3500. The IC-7610 will not do the job of two radios for me, but the FTdx-101D just might if it does indeed include two separate receivers, 70MHz, and the switching and audio connections I would need. I doubt very much if it will meet my needs, and anyway I already have two perfectly good radios.

With such sparse detail it may be that the FTdx-101D is actually aimed even higher up the market. Until we know the full specification and price we cannot be sure. It looks to me rather like the discontinued FTdx5000, which might put it in the £3500 to £4000 class.

I don't have a vacancy for a radio like that. Yes sure it would be nice to reduce the radio count by having one which did two jobs, but a second IC-7100 (for 6m, with the one I already have on 4m) would give me all that and two nice displays. OK, not quite the same specification, but very nice all the same.

My need is to listen on two bands at once, not actually transmit on both those bands simultaneously. So a radio with the ability to receive on two bands at once would, you would think, save money by only having one PA stage. Oddly, such radios actually cost three times more (plus, plus ...). 

I reckon that the Icom marketing department got the launch of the IC-7100 totally wrong. The normal method is to introduce the expensive version first, then bring along the cheaper ones later, gradually making cheaper ones after you have stung the enthusiasts for the premium price launch models. I know that I personally would have paid 50% more for what is a fine piece of equipment. So as if to compensate, the 7610 is hugely more expensive. No doubt the 101 will be pricey too. I would have thought that an SDR would cost a lot less to make than a complex multi-band superhet ...

Luckily, I do not need to do anything. If any item here was to be sidelined it would be the FT-817. The present alternatives to it are either unsuitable or far too expensive for my WSPR/drag to Greece radio.

Having pondered over the few details we have of the FTdx101D's technology, I soon expect to see down-market SDR replacements for Yaesu's ageing FT-857 and FT-450. Could it be that the FT-818 is just a short-term stopgap before a capable Yaesu portable SDR arrives to replace the FT-818 too? Oh I hope so.

As I always say, it is the conditions that make radio fascinating for me, not the equipment. But you do want to have something that gives you the best start.
The apartment in Greece had a television which had a German sports channel. On that I could watch the Eurosport highlights from the Giro d'Italia. Wow! What a wonderful race this year so far. Blistering every day now for three weeks and we still have the final two stages to come.

At least that took my mind off the cricket and the mysterious RF feedback problems.



Monday, 14 May 2018

Back from a trip, Deep Search and review of small boxes.

I am back from one of my jaunts. As usual it was a rail journey. Strikes on the French railway system put me off my planned route, so it had to be closer to home. It is my belief that you cannot appreciate the world if you do not know your own country so it was time to take a week off and visit The Scottish Highlands.

At this point I usually show a shot of me standing in front of a sign taken in South East Italy, or Belgium, or some similar far-flung place. However, the two shots of me proudly standing below the sign "Welcome to Wick" are both horribly out of focus. D'oh. So I will just have to rely on a photo taken on my phone out the train window ...
Lough Awe captured from the window of the Glasgow to Oban train
OK, I took better photos than this, but it seems to capture the moment better than the others. With trees flashing past as we sped along there was little I can do about the composition.

Having visited Oban, and Mallaig on the West Coast, plus Thurso, and Wick in the "Far North", all in short order, staying in Crianlarich and Dingwall along the way, I can confirm that the Highlands are high. I even took the hand portable and heard ... nothing.
Back here and I received an email from Joe, K1JT. Joe makes two good points about Deep Search. Some of you may recall my long and rambling posting on the subject here.

Firstly Joe has explained that most JT65 EME QSOs do not rely on Deep Search. "The fraction of QSOs (and decodes) that require DS is small for nearly all stations -- and certainly for those qualifying for, say, DXCC. Careful operators use DS to make QSOs faster when signals are marginal, because subsequent messages (after a full decode) are less likely to require repeats". That certainly agrees with my limited experience.

Joe also goes on to make another interesting point - "Recent versions of WSJT-X offer "a priori" (AP) decoding for the modes QRA64, JT65, and FT8.  This feature makes no use of an accumulated callsign database; instead, it makes use of information accumulated during a QSO.  It's very powerful, and works well; it's described in somewhat more detail in the WSJT-X User Guide"

Yes, though I have mentioned here before that not everybody reads the WSJT-X User Guide. They should.

Joe's efforts on behalf of amateurs have brought us very important extra resources for our research. In particular my knowledge of propagation has been vastly helped first by WSJT modes and then those brought together in the WSJT-X suite. I have passed along my thanks for his efforts.
It was nice to have a 2 metre QSO with Jeremy, M0XVF, yesterday. We have broadly similar stations but the terrain between us has always made the 133km path between us marginal. This was my first SSB contact on my revised 2m set-up, and so my first with my low noise amplifier. As it turned out, Jeremy has also installed an LNA and a sequencer. The result was that we had an easy contact peaking above S9 at times.

That little box on my mast is proving it's worth.
Several readers were somewhat surprised to hear that I had bought a small transverter for 70MHz portable use. It isn't really a quality item but it works. When I bought it I had a dim recollection that somewhere in the "general radio bits" box (an Ikea children's toy box re-purposed for this use) was a small box marked by me "70MHz bandpass filter ex-PMR, 10W max".
"Bandpass filter" plus 20 pence piece for scale
I cannot recall now where this came from. I will need to test it and make sure it is indeed bang on 70MHz, as if it came from a Low Band PMR radio it might need some tweaking. Still, I have a larger box with the right sockets to put it in and it should be just what I need to clean up the Ukrainian transverter's output.

I usually remember what is in the bits boxes because I often have to trawl through all of them looking for something which should be in "Computer Bags" box (yes, some of it is bagged and tagged within a box!) but turns out to be mis-filed in "Microphones" (where all the mics are loose in the box). But that is where the memory usually stops - where it came from and how I got it is often lost in the mists of time. But at some stage I must have thought this trifle was worth keeping for some unknown future project.
Speaking of transverters, the big brother box ME2HT on 2 metres now has a temperature controlled fan on top and a temperature sensing probe inside it.

The PA module is fine, but the mixer box starts with ambient at switch on and climbs relentlessly on receive from 20 to well over 30C. Then it wobbles all over the place. A bit of transmitting takes it beyond 35C at which point I feel the need of the fan.

The sensor turns on the fan at 30C or off at 29C. Net result is that the normal range of temperature fluctuation is now down to 2 degrees.

It's still a lash-up. To get the fan blowing on the right module I have fitted the top panel back to front. If I decide I need to fit it there permanently I will need to turn the panel back and drill ventilation holes through it. I'll try putting the top panel back and blowing the air from the back. Never drill holes if you don't really need to.

I am also toying with the idea of a small heatsink on the mixer module box. As that would still be inside the case I would still need the fan.

The benefit now is that the frequency quoted on FT8 is the same after I have completed a QSO as it was before. It is only a tiny benefit, but I would still rather have it.
Another small box useful during various tests has been my rarely used Trimble Thunderbolt GPS frequency standard. Once locked onto GPS it produces 10MHz with high stability, plus copious harmonics right up to 150MHz. It also has a 1 pulse per second output. It has a parallel connection to the computer. The original software has long ceased to work with modern Windows operating systems but "Lady Heather" software by KE5FX works well.
GPS Antenna, Trimble Thunderbolt and PSU
The Trimble can "discipline" the PC clock allowing accurate timing for data modes without an internet connection. I bought it on eBay and it is ex-equipment (the give-away is the sicker marked "used", surely an understatement). This is old tech these days. Much more compact and cheaper GPS standards are available now. It works though.

The PSU is in fact the new generic noisy one supplied by the eBay seller mounted in an ex-PC PSU box.
David, GM4JJJ kindly sent me a Mini-Circuits splitter for the receive path for my transverters.
Top - Rx Splitter, Bottom - FCD, Right - Fan Controller
Here it is linked to the Fun Cube Dongle, which can provide a panoramic view of the 2 metre band or, for example, the ability to listen on the SSB calling frequency while working on FT8. During testing with the GPS standard the FCD proved very frequency stable.

Sharing the same space for now is the lashed-up temperature control for the ME2HT fan. I see we are on 29.4C and the fan is running.
I live in the land of little boxes.




Friday, 4 May 2018

At last, Spring is here

Finally, the time of year has arrived when the evidence is here - our long Winter's days of waiting are over.

It has started!

Of course I refer to the Giro d'Italia cycle race which started its 101st iteration today in Jerusalem.

Well, not just that. The Sporadic Es season has started in the Northern Hemisphere and meteor scatter propagation has picked up again too.
28MHz WSPR spots to/from GM4FVM 24 hours up to 17:00 on 4 May
I have been rather distracted by other things, so the Lyrid meteor shower in late April and the Eta Aquariids just about now have largely passed me by. Not without some activity though
QSOs by meteor scatter at GM4FVM 15 April to 4 May 2018
Es activity has really got underway. 50MHz FT8 has been heaving:-
Snapshot of 50MHz activity in a 15 minute period on 3 May 2018 on PSK Reporter
I even managed to capture a new DXCC for me on 6m on 4 May with S01WS in Western Sahara. I had seen this station on 6m last year but never made the contact. Today they were very strong, and I also managed to double my contacts in Algeria by adding 7X2TT to last year's scalp of 7X2KF, and indeed work them both today. Together with three new squares, that was not a bad haul from 6 QSOs on 50MHz today.

With general mayhem underway in the FT8 window I have been tending to sit on the sidelines and watch.

Nothing so far on 4m Es, though with German stations active again this year during the period May to August I managed two QSOs amongst the meteor scatter list above.

On the two metre side I have been much perplexed by miniscule drift in my TS-590SG/transverter combination. Not that this would count as drift were it not for FT8 and similar data modes. Both piece of equipment are fitted with high-specification oscillators. The drift is very slight. They both drift in the same direction. This is irritating, but it never seems to be enough to affect a decode. I can see it on the FT8 waterfall. Over a period of time it amounts to perhaps 15Hz, a laughably small total in the days of yore, but it annoys me.

Both the TS590SG and the ME2HT transverter are drifting the same way, making the beacons I check against and my GPS standard appear to drift downwards.

I did open up the TS-590 to check that it had the fans fitted the correct way round (no kidding, this is a fault which many of them have) and I even removed the TCXO and inspected it. I re-soldered the TCXO joints. Nothing seems to stop the TS-590SG gradually rising in frequency as it slowly warms up.  I never noticed this on 6m and it must just be because the transverter is also moving that it came to light. However, it is a tiny amount and very slow so I think I can say that the TS-590SG is stable.

The transverter, on the other hand, can be made to gradually drift downwards by 5Hz by placing a fan on the top slots. So why not leave the fan in place? Good point. I will probably fit a fan on the top of the transverter as a permanent feature.

It does not really bother me but I had hoped that my days of fitting fans to things were over.

I used to have an FL50/FR50B combination. They drifted like plastic in the oceans, bobbing up and down. In that case it was Kilohertz, not Hertz. It never bothered anybody then, but now I expect something close to perfection. Both the transverter and the TS590 are very good on their own, it is just a pity they both move together in the same direction, adding to my delusion that this matters.

The main cause of drifting is my own self-doubt, and my new-found ability to measure tiny changes in frequency.

The transverter/TS590 combination is fine. All it needed was a fan. It took me days to sort it out and it was a frustrating business as mostly it is in my head.

Just as well I am not a perfectionist.
Speaking of the Giro d'Italia, I am hoping for another scorching race like last year's. Tom Dumoulan, the handsome Dutch powerhouse is defending his title, with my hopes - Esteban Chavez, the ever-smiling Columbian 2nd in 2016 - the combative Fabio Aru 2nd and 3rd in the past - and the outsider Simon Yates - all in the mix.

The thing about the Giro, unlike the other Grand Tours, is that it is spirited and open. Last year Dumoulan made a heroic personal challenge to beat Nairo Quintana. The Giro is unlike the Tour de France, which in my view is too easy for a strong team to manage.

They will eventually get from Israel to Italy (not by bike). The race lasts three weeks. How I will find the time to watch it is still unclear.  After four series of Masterchef Australia (3 months each) I am now wading through Masterchef USA.

There are things like this which are more important than radio you know.