What is a WT4 file? A WT4 file is a log file created by Win-Test, an international ham radio contest application. It contains contest configuration settings. It may also contain a log of all radio operators a user contacted during a contest. Contest coordinators can use WT4 files to verify that a contest participant's setup and submitted results were correct.

More Information Ham radio operators use Win-Test to log their setup and results for ham radio contests, in which a ham radio operator attempts to contact and log details for as many other operators as possible. Version 4 of Win-Test saves contest logs to WT4 files. Each WT4 file contains information about a participant's specific contest configuration. This includes the participant's callsign, locator, and personal information, and the contest's name category, class, and mode After finishing a contest, a participant can submit their WT4 file (or a converted version of it) to the contest's organizers. The organizers then use the participant's data to verify their setup and results were correct and truthful. NOTE: Prior to the WT4 format, Win-Test saved contest logs as .WTB files.