Short answer: Every QSO in your log is a small piece of evidence that a band was open to a continent at a certain time. When you list, for each band and continent, the time of the first QSO, the last QSO and the busiest hours, you get a map of the openings that is based on your own station and your own contest. Used over several years, it is one of the best tools for planning which band to be on and when, but it must be read with care: a missing QSO does not always mean a closed band.
What an opening looks like in a log
A band is open to a continent when signals from that continent can be heard and worked. In a contest, you know this only because you made QSOs: if you worked three stations from Asia on 15 metres between 07:00 and 09:00 UTC, you have evidence that the band was open to Asia at that time. If you worked none, the band may have been closed, or you may not have been listening on it, or you were busy elsewhere.
The log therefore shows the openings that you used. It gives a partial picture, but a useful one, because your decisions were based on what you heard. If the contest was long and you moved between bands regularly, the picture is fuller. If you stayed on one band, the picture of the others is thin.
First and last QSO per continent and band
The simplest way to read openings is to list, for each band, the first and the last QSO with each continent. The list shows when each continent became available to you and when it disappeared. For example, you might see that North America on 20 metres starts in the early evening and continues for several hours, while Asia on the same band appears in the morning and fades by noon. Those times are not exact limits of propagation, but they are a good approximation of when it was worth being on the band.
- The first QSO shows when you noticed the opening, which is often a little after it began.
- The last QSO shows when the opening ended or when you left the band, which may be earlier than the real end.
- The busiest hours show when the opening was strongest, and most useful for rate.
- Gaps in the middle may be fading, or a decision to work another band.
With this information, you can build a small table, with the bands in the rows, the continents in the columns and the times in the cells. A few years of such tables give you a map of what the bands do in your contest.
Opening windows and the rate
An opening is only useful if there are stations to work, and stations to work are the key to the rate. When an opening is both open and busy, the rate climbs. When it is open but quiet, you may have a few QSOs and many calls in vain. The numbers of QSOs by hour for each continent show which type you had. Combine them with your rate: the article on contest rates and QSOs per hour explains how to read the figures, and hour-by-hour analysis of a contest log shows how gaps and peaks appear in the sheet view.
It is also worth separating the openings that served your run from those that you found by search and pounce. A continent that came in by itself while you were running gave a good rate. A continent that you had to search for gave multipliers but a slow rate. Both are valuable, but they have different roles in the plan. See run versus search and pounce.
Compare years, not only hours
One contest is an example. Several contests are a pattern. If the opening to Asia on 15 metres appears around the same time every year, you can plan to be there at that time. If it moves, it may be because of the season, the solar cycle or the date of the contest. The solar conditions change the structure of the openings, and the article on solar flux and K index explains how to take them into account when you compare years.
A practical method is to keep a simple record for each contest: for every band, the continents you worked, the time of the first and the last QSO and the number of QSOs. After two or three years, the typical windows become clear, as do the exceptions. You can then plan your hours and your breaks around the windows. The article on comparing contest results between years gives other figures to add to your record.
What the log cannot tell you
It is important to remember the limits. The log shows only what you worked. It does not show openings that you did not hear, or that you heard but did not use. It also depends on the activity of the stations on the other side: a continent with few active stations will give a short list of QSOs even when the band is open. And your own antenna influences the result, because an antenna that is weak in a direction hides openings in that direction.
- Do not treat the last QSO as the end of the opening. You may have left the band earlier.
- Do not treat a missing continent as a closed path. Perhaps you were not there at the right time.
- Remember the activity of the other side. Quiet stations do not mean a closed band.
- Remember your own antennas. The picture is limited by the pattern of your station.
- Check the log for errors. A wrongly logged call can place a QSO in the wrong continent and change the time of the first or the last QSO.
Cleaning the data first
The last point is easy to forget. If a busted call has been assigned to a country on another continent, your table will show a QSO with Oceania at a time when no such path existed, and the first or last QSO of that continent will be wrong. The review is therefore a good first step. Contest Analyzer 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. After you correct them, the report 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. 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, shown on the contests page. Serial numbers are not checked and dupes are not errors.
When the data is clean, the table of continents by band and hour gives a faithful picture of the openings that you used, and you can read the first and the last QSOs with some confidence.
An example of reading the table
Suppose that your table for 20 metres shows Europe from the first hour to the last, North America from the early evening to the early morning, Asia in two short windows and nothing from Oceania except one QSO. The simplest reading is that 20 metres served you as a general-purpose band, with Europe all the time and North America at night. The two windows from Asia suggest that you were on the band at the right time to catch the openings, and the single QSO from Oceania suggests that the path was either rare or that you did not look for it. Next time, you could try to be on 20 metres at a time when Oceania is more likely to appear, and see whether more QSOs come.
Now compare this with 15 metres, where the table shows Asia for a long window in the morning and almost nothing else. This suggests that 15 metres was open in a narrow direction for several hours but was not a band for general work. The plan could be to use 15 metres in the morning for Asia and then move to another band when the opening closes, without waiting for a return. These readings are not certain, but they give a starting point that is based on your own contest, and every new year makes the picture more reliable.
From the table to a plan
The table is useful only if it changes what you do. A few examples show the idea. If the opening to a continent that is important for multipliers regularly ends earlier than you expect, plan to work it first. If a band fades in a direction at a time when you used to stay on it, move to another band earlier. If two bands are open to the same continent at the same time, choose the one on which your antenna is stronger, and use the other for multipliers. Write these decisions down and test them in the next contest. If the changes work, keep them. If not, the next table will show why.
The same table can also help you with breaks. The hours in which no continent is open on any band that you can use are the best hours for rest, if the rules allow it. The article on off time and breaks explains how breaks count in the contests where they matter.
Related reading
The bottom line
Your log is a record of the openings that you used. By listing the first and the last QSO with each continent on each band, together with the busiest hours, you can build a map for your own station that gets better with every contest. Read it with care, clean the log first and let it guide your choice of band and of rest.
FAQ
Does the first QSO show when a band opened?
Not exactly. It shows when you first worked that continent, which is usually a little after the opening began.
Can I rely on one year of data?
Use it as a guide. Several years give a much clearer pattern, especially if you note the solar conditions.
What if I stayed on one band for a long time?
Then your data for other bands is thin. Use it only for the band that you actually worked.
Do errors in the log matter here?
Yes. A wrong call can place a QSO in the wrong continent. Review the log before you read the table.
How can I use the table in the next contest?
Plan the bands and the rest around the typical windows, and test the plan against the new numbers.
