Duplicate QSOs Submitted to LoTW

by Wayne Mills, N7NG

After uploading a log to LoTW, have you noticed that your activity record shows many recorded QSOs and QSLs, but many fewer new QSOs and/or QSLs listed in the count at the top of your user page? This is usually the result of submitting duplicate QSO records.

Submitting a few duplicate QSO isn’t a problem for LoTW. A duplicate QSO record is one that has the exact same time, date, band, mode, and callsign as a previously submitted record. When a duplicate record is submitted, the new record replaces the old record. The only noticeable difference is that the replacement QSL record has a new match date.

This process actually has an advantage. While the QSO data can not and will not change, your location data can be changed. (In fact, even your country can change.) If you have made an error with your county, IOTA number, CQ Zone number, etc. the error can be fixed by simply resubmitting the log file with edited location information. That’s a good thing.

A bad thing is that many log duplicates are submitted for no reason at all. What seems to be happening is that people are submitting cumulative logs. That is, a log is submitted to LoTW, after which QSOs are added to the file over some period of time, and the WHOLE LOG is submitted again. In fact, the whole log is submitted time after time. The log becomes larger and larger and each time, many additional dupes are submitted. Maybe only one or two QSO records have been added, but the whole log is submitted again. For Logbook, this is a waste of time. Processing duplicate QSO records uses system resources that could be put to better use.

Sometimes, people resubmit a file because they are in doubt about whether a log has been received. This is usually not necessary, but it isn’t really a problem. If an exact copy of a log file is submitted, Logbook recognizes the file as an exact duplicate and terminates processing. A notice is then delivered to the user. (To be sure that your file has been received and will be processed, check for the message “File [n7ng].tq8 queued for processing.” This message will appear above the“File to Upload:” box after uploading and should assure the user that the file has been received and will be processed.)

If any change has been made to a previously submitted log file, such as adding one QSO record, or even changing the QSO time by one second, the file will be processed. This isn’t an exact duplicate file, but it may contain many duplicates. This file unnecessarily uses system resources.

There is a simple solution for those who find it convenient to submit cumulative logs – one which was designed for this purpose. When using the TQSL signing program, an available option allows you to assign “not before” and/or “not after” dates in a window that appears as you are setting up the signing process. These settings tell the signing program to sign only those QSO records between the start and stop dates. If you have a cumulative log, and you wish to submit only those QSO records beginning on a certain date, all you need to do is set the Start Date equal to the date on which you wish to begin the submission. If you use logging software with embedded LoTW log preparation, look into how your software handles selecting QSO records for submission. It is very likely that your software allows you to select only the QSOs you wish to submit.

This week’s hint is to determine if you are inadvertently submitting duplicate QSO records and take steps to minimize their submission. If you have questions, email me at n7ng@arrl.net.

(c) 2012, Wayne Mills, N7NG