Monday, 24 April 2017

Height, propagation 3 ways in one day, and the Sliced Bread Theory.

After thinking about the conundrum of several receptions of a station while the mast was lowered, I tried to work someone reasonably close on meteor scatter with the antenna deliberately lowered - 5m elevation rather than 10m. I do this even though I suspect it was just random chance.

It was not a perfect test and on its own it means nothing. I would need to run a series of tests to prove anything. But the theory as I understand it goes that lowering the antenna will tend to raise the angle of radiation. So with this in mind I worked OZ3ZW in lightening quick time on 20 April. It is a short 867km path and the software suggests an 11 degree elevation is necessary.

I would need to do a lot of tests to make any headway on whether this really makes much difference from my QTH. The first example of this for me was on 2m, whereas this test was on 4m. So the proximity to the ground in wavelength terms would be different. Also, OZ3ZW is handily placed in a direction where I have no other obstructions - using a 5m mast beaming south would be pointing direct into the roof of the house. So how practical it might be to use lower antenna elevation is a bit doubtful.

Also, I have a bit of a nagging distrust of ground gain calculations. The ground here is always dry, and is exceedingly dry just now. We get terribly bad RF earths. That does not seem to be a great foundation to achieve much. But lets see.
23 April was a busy day.

With the Lyrids peak scheduled for the weekend of 22 and 23 April I had hoped to exceed my results on the previous weekend.

Not a bit of it.

22/23 April seemed like a normal period for MS, save that it was more annoying than usual. I am referring to the odd conditions where you get isolated, strong, reflections. Usually at a peak you get long enough periods of ionisation to conduct a QSO quickly and easily, at least on 6m.

With the isolated strong peaks conditions you get very strong CQs from all sorts of interesting places, in this case particularly from Italy, and then nothing more. If you reply to the CQ you spend 10 minutes transmitting in vain. Bah!

Always the optimist I planned an early start on 23 April and this splendid attention to duty returned a 6m QSO with PA0TCA in JO21 square. Nice as this is, it hardly justified me stirring from my scratcher at 05:00 to get this at 05:55. Eventually at 08:24 I made a scratchy 4m QSO with Jurek SP9HWY who is in JO90 square. The intervening two and half hours produced nothing at all. For an acknowledged shower peak period that was disappointing.

The previous day was a washout and the more sceptical amongst us might have concluded that the Lyrids came a week early. However, old Isaac Newton was pretty good at his physics and these things depend on solar system gravitational forces and they are very predictable events.

I wonder a bit whether some of our old familiar meteor showers are becoming exhausted and are basically not a good as they were. Perhaps new comets and similar bodies will heave into view and leave us new trails. This process happens over a long time period, but I was not expecting it now. Another effect is the relative angles of the showers, which is also predictable and which modulates the intensity of the shower over the years. Perhaps we have just been unlucky recently.

Leaving that aside, there was nice Es opening on 23 April.
10m Es WSPR at GM4FVM on 23 April 2017
This looked like a proper Summer Es type event. Gianfranco, IU1DZZ was a good signal over a two hour period. Later I even heard EA8, though that seemed to be part of a very weak F layer event.

I count the start of the Summer Es season from the first 6m (or 4m if it is first) contact. I did not get one on 23 April, though other GM stations did. Just the luck of the draw really, or my lossy co-ax?

So with Meteor Scatter and Es during the day, I was able to complete an Aurora contact too, in the evening. I heard Clive GM4VVX calling "CQ A" with serious AU distortion on his signal so I had to have a go. I could not manage to plug in the key, but I proceeded with the CW memory in the TS-590. I had a simple QSO programmed in, so it was slightly formal but it worked. So all three propagation methods produced a QSO on that day.
As I write this on 24 April there has been another Es opening.
10m Es WSPR at GM4FVM on 24 April 2017
Once again I had no success working anyone on 6m though other GM stations did. Personally I blame the white sliced loaf. Since bread production went industrial nothing has been the same.

Mrs FVM has taken up home baking and our bread has improved no end, but she cannot change the world single handedly.

Sorry about that, it was another attempt on my part to match the crazy ideas others have about radio propagation. They never seem to need a reason for good propagation (apart from their own operating excellence), but they can always be relied on for something bonkers when they turn on and there is nothing but white noise.

I (of course) am above such things.

The Es area showing on DXMaps on both days was over the North Sea and too close for 6m propagation from here, though GM stations further north and west did better. This is an alternative explanation, but I am sticking to the bread idea.

Lets hope all three aspects of VHF propagation improve further.





    Bonkers or what?

  2. I also wrote these VHF DX tips many years ago, some may still apply. The first one is slightly bonkers but is generally works in my QTH!