Short answer: Distance statistics show how far each contest QSO went. The longest QSOs are the highlights, but the average distance per band and the spread of distances through the hours tell you much more about your station and about the propagation of that weekend. Read them together with the continents and the beam heading, compare the same contest between years and remember that a long average is not always a good sign: it can also mean that you missed the nearby stations.
What the numbers measure
For every QSO in the log, the distance between your station and the other station can be calculated if the location of both is known. The location of the other station is usually estimated from its country or its prefix, because the log does not contain the exact position. This means that the distances are approximate. For a statistic of a whole contest, the approximation is good enough: a mistake of a few hundred kilometres for some QSOs does not change the picture.
The result is a set of figures. The most simple is the longest QSO, and others include the average distance of all QSOs, the average on each band, the distribution in classes such as near, medium and far, and the change of the average through the hours. Together they describe the reach of your station in that contest.
The longest QSOs
The longest QSO is the one that most people remember, and it is pleasant to see it in the report. It is also the least reliable figure, because it depends on one contact. A single QSO to the other side of the world can be the result of a lucky opening, a strong station at the other end or a favourable path at a particular minute. The value of the longest QSO is more interesting when it is part of a list: the ten or twenty longest QSOs, with their bands and times.
Look at the list and ask a few simple questions. On which bands do the long QSOs appear? At what time of the day? With which continents? If the longest QSOs are all on one band, for example, the antenna on that band is probably a strong point of your station. If they are all at the same time, you have found a good opening, and it may repeat in the next contest. The distance has a meaning that depends on the band and on the part of the cycle of solar activity; see the article on solar flux and contest results for more about this.
Average distance per band
The average distance on each band shows the character of the band at your location. On the low bands, the average is usually shorter, because the signals travel mainly at night and over shorter paths. On the higher bands, the average is longer when the band is open, and shorter when it is not. These patterns are normal, and the point is to compare your own bands with each other and with your previous results.
- A high average on a high band often means that the band was open to distant places and that you worked them.
- A low average on a high band can mean that the band was open only for short skip, or that you stayed on it too long without long paths.
- A very low average overall may indicate a contest in which many nearby stations are active, or a station with limited antennas for long distances.
- A change in the average on one band from year to year may be due to an antenna change, but also to propagation. See judging an antenna change with your contest statistics.
Distance by hour
The average distance through the hours of the contest can be even more interesting than the totals. Early in the contest, on a band like 20 metres, you may work Europe and then, as the band changes, North America or Asia. The average distance rises and falls with the openings. A graph of average distance by hour often shows peaks that correspond to the openings, and valleys in the hours when only nearby stations were available.
If you compare this with your table of QSOs by hour, you can see when the long paths were open and whether you were on the right band at that time. The article on band strategy by hour explains how to use the information to plan the next contest.
Combine distance with continents and heading
A distance figure alone does not tell you the direction. Put it beside the continent breakdown and the beam heading, and it becomes a complete picture. A long average that comes from many QSOs with one distant continent is different from a long average that comes from several. A high number of QSOs at one heading may show that your antenna was pointing in one direction for most of the contest. The articles on the continent breakdown of a contest log and beam heading and distance statistics describe the two other parts of the picture.
Another figure that goes with distance is the share of DX QSOs and of same-continent QSOs, which is explained in DX versus same-continent QSOs. A station with a long average distance and many DX QSOs is working a different contest from a station with a short average and mostly local QSOs, even if the scores are similar.
Reading the numbers wisely
- Long is not always better. In many contests, the points depend on distance or on continents, but the rate also matters. A long average may come with a lower rate.
- Beware of the approximation. The location of the other station is estimated, so the figures are approximate, particularly for stations in large countries.
- Compare similar things. Compare the same contest and the same band. A comparison between two different contests is of little value.
- Look at the distribution. The average can hide a lot. Look at how many QSOs are near, medium and far.
- Remember propagation. A good or poor year for the bands changes the distances regardless of what you do at the station.
Getting the figures from your log
You do not need to calculate the distances by hand. Contest Analyzer gives full statistics, with rates, QSOs by hour and band, countries, continents, CQ and ITU zones, WPX prefixes, distance, beam heading, breaks and off time and callsign length and structure. It checks every callsign and every zone against official license databases and several independent reference sources and shows only the few QSOs worth a second look, so that your distance figures are not distorted by wrongly logged calls. You can edit calls or zones in the report, download a corrected Cabrillo and compare with your own logs from earlier years. It works with Cabrillo from N1MM Logger+, DXLog and Win-Test and supports 22 contests, which the contests page lists. Serial numbers are not checked and dupes are not errors.
A busted call is a good example of how a wrong entry distorts the numbers. A call that is wrong in one letter may be assigned to a country on another continent, and the QSO appears in the statistics as a very long one. After the review, such QSOs disappear, and the longest QSO that remains is real. This is a reason to correct the log before you draw conclusions or post a claim about your best DX.
A small worked comparison
Imagine two years of the same contest. In the first year, your average distance on 20 metres was moderate, and most of the long QSOs came during one short opening in the afternoon. In the second year, you see a similar average, but the long QSOs are spread over several hours, and the list of the ten longest QSOs includes more continents. At the same time, your QSOs on 40 metres show a lower average than before. What can you conclude? The most careful reading is that conditions on 20 metres were more stable in the second year, or that your antenna on that band was used better, and that on 40 metres there were fewer long openings or that you spent less time there at the best hours.
To decide between the explanations, look at other numbers: the hours you spent on each band, the solar flux in the two weekends and any changes at the station. If the figures for the other bands moved in the same way, propagation is the likely cause. If only the band you modified changed, the antenna is a better candidate. This habit of asking what else could explain a change is the main skill in reading statistics, and distance is a good place to practise it, because the numbers are easy to understand.
It is also worth looking at the other end of the scale. The shortest QSOs, those with stations in your own country or on your own continent, often make up a large part of the log. They give points and multipliers, and in some contests they are essential, but they also give a lower average. If you see that the average fell because you worked many more nearby stations, it does not mean that your station was weaker. It may simply mean that you chose to run on a band that favoured nearby stations during the hours in which the long paths were closed.
Using the figures for planning
Once you have the figures from a few contests, they become a tool for planning. If the average distance is low on a band where you would like it to be higher, think about the antenna: the height, the pattern or the direction. If the long QSOs concentrate in a short period, think about how to be on the right band at that time. If the proportion of far QSOs is small, consider how much of your time goes to nearby stations and whether a different strategy of searching could change it. Use the numbers to ask questions, and then to test the answers in the next contest. The article on setting realistic goals from last year’s statistics shows how to turn these questions into targets.
Related reading
- Beam heading and distance statistics
- Continent breakdown of a contest log
- DX versus same-continent QSOs
The bottom line
The longest QSO is a nice memory, but the distance statistics are most valuable when you read them as a whole: by band, by hour and together with the continents and the heading. Clean the log first, compare the same contest year by year and use the figures to ask where your station reaches well and where it does not.
FAQ
How is the distance of a QSO calculated?
From your location and an estimated location of the other station, usually based on its country or prefix, so the values are approximate.
Is a longer average distance always better?
Not necessarily. It depends on the points system, the rate and the propagation. Look at the whole picture.
Can I compare distance between two different contests?
It is better to compare the same contest and the same band from different years.
Why does a busted call affect distance?
A wrong call may be assigned to a distant country, which makes a QSO look longer than it was. Review the log first.
Which figures go well with distance?
Continents, beam heading and QSOs by hour and band.
