More distance stats

Back to statistics. This time, I've just looked at the distance. This looks pretty Poisson-like, and I need to think why.

(Click the chart to make it bigger) Each column is a 1000km slice. There are obvious reasons for the steps in it. The second column being bigger than the first is skip. Sub-1000km QSOs are rarer because of skip. The first step at 5000 km is the Eastern seaboard of the United States coming in. To the left of that, there's a gentle fall off as we progress over Europe (bear in mind I've popped all the bands into one pot here).

The second step is as we cross the relatively barren and difficult lands of India and China to Japan, thence to Australia and New Zealand, who lurk off on the right hand end. 20,000 km is about as far as you can do until SETI makes some discoveries.

So, clearly it gets more difficult with increasing distance (no surprises there). But it's also influenced by the difficulty of working DX in certain countries because of the lack of amateur activity there. There are, for example, only an estimated 800 hams in PR China - whereas there are 1.3 million in Japan.

But then, 800 is more than the total number of us involved in WSPR (about 500).

Sources:

• http://www.nationmaster.com/graph/lif_ama_rad_ope-lifestyle-amateur-radio-operators
• http://wsprnet.org/drupal/wsprnet/stats

Footnote - where is Australia on that data about ham operators? New Zealand? Anyone know a better source?

Log Analysis

What to do on a quiet day, but look at your logs. I have been meaning to do this for some time. I extracted the last 1000 or so QSOs from my log (kept in HRD) and I've analysed distance, by band. I was convinced that I was getting the "best" results out of my kit on 17 metres. It appears that this may not be the case!

The graphic isn't very clear (click on it) but I poured the exported data into "R"(a stats package) and got it to process it for me. The distance is in km. It's worth saying that virtually none of these contacts are SSB or FM - I am almost exclusively digital or CW

20m appears to have provided me with my best DX(a ZL), so it retains its label as a DX workhorse of the bands. followed by 10m, 15m and then 17m. I'd say 12m was underperforming - probably my antenna. I don't spend much time on 30m. I find 40m crowded. I don't stay on 80 or 160m long enough in the evening to pick up real DX.

What is interesting is that the median distance - half the contacts are above, half below - (indicated by the bold line in the middle) on 20m is way down on the median distance on 17m - I think this is caused by heavy local (i.e. European) QRM drowning out the DX, hence my impression that 17m at M0DEV is more DX-y. If you have a very high presence of european stations, then you won't hear the DX - even though it is there. Indeed, 17m at M0DEV has the highest Median. Of course, I am probably skewing this by going after DX contacts calling CQ, and ignoring the locals. The 20m distribution (and 15m and 40m) is classic positive skew, bunched up at the bottom end. The 17m distribution looks more "interesting".

It would be interesting to take this further, and try to tease out factors which are caused by my equipment, and factors which are really "there".

So what does it all add up to? Very litte!