Monday, 19 December 2016

It's meteor scatter time ...

I have once again been distracted by other things. Things like crimping and soldering fork connectors onto DC leads, and fixing the TV rotator.

Actually, there wasn't much to do with the TV rotator. Careful jiggling around re-engaged the gears. I took it apart and it turned out to be a superior type of TV rotator, with nice metal gears and bushed bearings, though the bearing rested on nylon-type discs. Anyway, a bearing is one thing, but when it is open on one side save for a casting on the body to hold it in place, then it is going to tilt and the gears are going to separate, if the rotator has a strong sideways force.

I guess the makers of these cheap items are not too familiar with tilt-over masts. They expect the TV antenna to be dropped into the rotator from above, rather than attached with the whole thing leaning sideways, only then to be tipped upwards to the vertical. So I suppose it is hardly surprising that after I put it on the tilting mast it jammed on being turned vertical.

Anyway, it works again in that cranky half sensible way those things do. If you do not mind having a fairly inaccurate indication of direction and keep the load light (and don't tilt it) it is fine. For portable operation in some unspecified situation yet to be defined. I have only been portable twice in my career where a rotator would have been any use, so I am not sure when this is really needed. But you never know.

No, you never know. The Perseids meteor shower in August did almost nothing here, for the second year running. So I was not sure about the Geminids in December. As it turned out things went pretty well.
 GM4FVM VHF Meteor Scatter contacts by locator squares from 1 to 18/12/16 with 500km circles.

I am a regular meteor scatter operator. This means that the showers come and go while I just plod along. Other operators turn up for a day's frenzied operations on the peak night, which gives them about 5 reasonable days operation each year. Not everybody devotes the time to it that I do, which is fair enough.

So for me, given that the peak for the Geminids this year was predicted to be 13 December, I started taking an interest on 1 December. In it for the long term, I am. 10 days of white noise beckoned. Except you never know.

Here is the table of stations worked before 13 December.
As usual click to enlarge if necessary.

The red squares are new ones.

First of all it shows that there is no need to wait for the peak day to work stations.

Secondly it shows how I can be busy only working MSK144 on 4m and 6m.

Thirdly, and sadly, it shows that JT6M is still around. Stations who worked on MSK144 during the rest of the time use JT6M for the Nordic Activity Contest on 8 December. Strange.

Fourthly, I seemed to do very well at various times of the day. Certainly, contacts are likely to be weaker and take longer away from the early morning peak, but there are still lot of people around at different times.

I have tried to encourage people to use the latest modes but it seems that they are reluctant to do it. I even tried diverting people onto the bandplan frequencies. I also tried to encourage some of them to move  away from the established calling frequencies during contests. However I have decided that this is a waste of time - they seem to need to go wherever they please and my efforts were in vain. So I will have to content myself with following the crowd.

For the 13th itself I decided to try harder to make some 2m band contacts.
Most stations on 2m were using FSK441 mode, and all the ones I worked were using this older mode.

Six new squares would always be worth the effort in my book.

Most stations send 73 to confirm the contact, some do not. I always do, and I either send 73 briefly in return to a 73 as well, or call CQ. If you do this you can be certain that you have completed the contact. If, as in one of these contacts, you get no response to your RRR message you are left high and dry. This time I claimed it.

So clearly it is worth coming on during the peak day. After that things cool down a lot. This seems to me to be a waste as there are often good contacts to be made.
In fact, there are some minor showers between the Geminids shower around 13 December and the Quadrantids during the first few days in January. These Ursids showers are weak by comparison but still useful in making a bridge between the two main peaks.

I feel that too many operators turn off their rigs between the showers and do not try during these periods. To counteract the reduced meteor action you can operate closer to the daily peak (around 06:00 local time). The only period I find it difficult to make contacts is mid-January until around the end of March.

One contact in this later group which specially pleased me was Rudi, DK7OM. We tried two days earlier, but although we exchanged reports we could not complete a QSO. I asked him for a sked and the result was a good QSO.

I have noticed that MSHV was out-performing WSJT-X on MSK144 reception. I could see and hear signals on 6m but WSJT-X was not decoding them, whereas MSHV was decoding them. In fact, the final QSO in the list with PeO, SM5EPO, was a test to see what was happening. I quickly noted that opening out the frequency tolerance on WSJT-X helped, but that also over-strained my computer processor.

Checking everything carefully I discovered that the  audio rx frequency (showing as Rx 1400 Hz) was at its default position of 1400 rather than the recommended 1500. I must have updated WSJT-X so many times over the past few months that I forgot to update that parameter this time. When I corrected it I could reduce the frequency tolerance back to 100 and still receive all the signals. Silly mistake. I wonder how many others make it too.

MSK144 is normally used, by convention, with 15 second tx/rx sectors. This is unlike FSK (30 seconds), JT65 (60 seconds) and WSPR (120 seconds). Some operators were turning up over the past few days using MSK and 30 second sectors. This still works, but it is slow, wasteful of spectrum and frustrating for other operators.

On one occasion I switched to 30 seconds to work a station. Then I saw him later still using 30 seconds and struggling to complete a QSO. So I sent him "pse change to 15sec", which he did. I then worked him again and felt that I had done us all a good job. As soon as I had finished, a German station called him on 30 seconds, he went back to 30 seconds, and that effort was wasted.

There are only certain things I can change, so the I will just have to accept the other things.

So I think that was a good meteor shower.

MSK144 is very good when it comes to working those stations who want to use it. Why it is not tested more on 2m is a mystery to me. I suppose that may be because WSJT-X is still marketed as a trial version, so some people are reluctant to try it. That's the clue in the name - trial versions are meant to be tried.

This warning every time you start it will put some people off ...
However, as I pointed out before, MSHV is available without such a warning.

Until it is launched on the official WSJT site, WSJT-X v1.7.0 will remain slightly beyond the average amateur's line of sight. Let us hope it soon progresses into general usage.

Then, hopefully, we can say goodbye to JT6M and FSK441.

73

Jim
GM4FVM

1 comment:

  1. WSJT-X v1.7.0 now appears to be officialy released.

    73

    Stephen

    ReplyDelete