Remove duplicate QSOs from a ham radio log
Drop the log — or several logs at once — and every QSO that is in it twice is listed: the same call on the same band and mode within the minutes you choose. Merging leaves one QSO of each, and nothing from the copies is thrown away.
Where duplicates come from
A log imported twice; a log merged with one from another computer or from QRZ, Club Log or eQSL; an LoTW download added on top of your own log. The copies are rarely identical: one has the time without seconds, another the band in capitals, one has the grid and the other the confirmation.
What counts as the same QSO
The same callsign (in any case), the same band — from the BAND field, or from the frequency when there is none — and the same mode, within the window: the same minute, 2, 10 or 30 minutes. USB and LSB count as SSB, and a general name like DATA, as LoTW writes it, matches any digital mode. But FT8 and FT4 five minutes apart are two QSOs, not one.
What merging keeps
The fullest copy is the base. Every field it lacks is taken from the others — a grid, a name, a comment, a POTA reference. QSL statuses take the strongest value (received beats requested, requested beats no), together with its date. Where two copies disagree, the base keeps its value and the page tells you which fields differed.
Questions
- Are duplicates in a contest log removed too?
- Only if you merge them. For a contest you submit, leave duplicates in: the robot scores a duplicate as zero, and deleting one can cost the other station that QSO. This page is for your everyday logbook.
- Which window should I pick?
- 10 minutes catches copies with rounded or shifted times without joining two real QSOs. Pick 30 minutes for an LoTW download — that is how far apart LoTW itself lets two logs be — and “the same minute” when you only want exact copies.
- Is the log uploaded?
- No. The file is read in your browser and the new one is made there; nothing is sent anywhere.