Saturday, 11 April 2015

WSPR Update number 2 - yippee, "dead" band!!!


(Edit - this picture of no activity seems to have disappeared.!!!)


Who'd have thought it?

10m WSPR, at lunchtime on a Saturday in mid-April, zero activity worldwide.

Two medium geomagnetic storms in the early hours of 10 and 11 April 2015 have reduced the ionosphere to a quivering wreck. Long spells of negative Bz - in other words the magnetic field of the particles arriving from the Sun are in the right direction for maximum effect on the Earth's magnetic field) can trigger an aurora and so forth. But on this occasion, the particles are not energetic enough, nor travelling fast enough, to trigger an aurora. So we have have had two days of particles raining into the Earth's ionosphere and ruining the radio conditions for DX. "Radio Blackout" as it was called in the days when long distance radio was the communications medium of the world.

Give it a day or two and it will recover and normal service will be resumed. The Solar Flux Index is currently 115, a pretty poor number for this stage in the 11-year solar cycle. This is a very poor cycle for solar flux levels, and their related sun spot numbers. Sure, we can still have solar activity which can affect our radio conditions (e.g. today's blackout and the 17 March aurora), but so few sunspots deliver while they are pointed right at us, simply because there are so few sunspots in this cycle.

Since I last addressed this issue, my WSPR performance has not been too bad. Not on 50MHz which has not got me out of the British Isles, and Sporadic E has not yet arrived at 50MHz around here, yet. But on 28MHz it has not been too bad.

Being heard in VK on 100mW is quite good for me


2015-04-07 11:40  GM4FVM  28.126088  -26  -1  IO85wu  +20  0.100  VK6YS  OF77xt  14638  9096 

... which works out at 146380 km/watt

Being heard in the US on 10mW is also interesting

15-03-25 17:54  GM4FVM  28.126082  -18  0  IO85wu  +10  0.010  WG2Z  FN21oa  5335  3315 

... just 533500 km/W. And with a signal like -18dB, I could hopefully have gone down to 1mW and still have got a copy (5,000,000 km/W).

But it did not happen at 1mW. Dropping the power in both cases lost the stations so I need to try again. I have done over 2,000,000 km/W on 10m Sporadic E. Doing that kind of thing on normal F layer DX propagation to another continent is hard. Getting a two-way WSPR confirmation is even harder given that so many WSPR-ers are content to just run 5 watts and use their time to investigate inefficient antennas instead.

Whatever emerges, WSPR contacts do not count as QSOs for me. For a QSO to count in my book you have to convey the Callsigns and Signal Reports and confirm receipt. WSPR does not convey signal reports so it is a beacon mode. A very interesting beacon mode, but that is it.

WSPR is also a "inverse beacon" mode. You can transmit and then get reports back via the internet as to how you are received by distant stations. That makes it very useful for antenna and propagation monitoring.

Perhaps even more useful for me is that is shows which paths I can use for QSOs. If someone can hear me on 1 watt on WSPR, I can usually work that area on, say, 20 watts of JT65. That is how many of my contacts into VK have resulted. I didn't know there was a path most days on 10m into VK at about 11:00 in Spring and Autumn, WSPR showed me that.

As I have never worked ZL, this interested me:-
2015-04-09 11:08  ZL3DMH  28.126079  -26  -2  RE66im  +37  5.012  GM4FVM  IO85wu  18591  11552 
I heard him, but he did not hear me. At the time I was only running 20mW. He was very weak at -26dB, but could a JT65 contact work?

This is "a possibility". I love possibilities. A target to reach, or maybe just strive towards.

If I just wanted to work people I could go on 20m, buy a kilowatt linear, or use an internet linking VOIP system. What is the point of that for me? What would I learn? It is fine for those who need to fill their log book, or work someone every day. But the spectrum I use (10m and VHF) does not provide goodies every day. Sometimes we got nothing on the map, as above. It makes the good days more interesting. And, KEY POINT, a "dead" band makes us try harder. Try new modes, try smart operations, do more, think, think, think. Learn.

I believe this hobby is here for us so that we can learn about radio. If I do not learn, what is the point (for me). OK, if you just want to chat, you do that. I am not stopping you. But for me, if I do not learn about wiring things up, using them, or learn about the wonderful world of propagation and Earth Science, then I would rather not bother at all.

A "dead" band is an interesting band. Because, unlike humans, they won't stay dead for ever.

In fact, 10m and VHF never produces dead bands. Just sleeping ones. They all wake up eventually.

73

Jim
GM4FVM

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