Trusted QSL 2.1-beta Trusted QSL keeps eQSL an open and free activity for amateur radio operators. It promotes the Digital Signature Standard (DSS). Fldigi / Flarq / Flmsg 3.22.00 Fldigi is a digital modem application for common amateur radio systems. It supports CW, PSK, MFSK, RTTY, Hell, DominoEX, Olivia, and Throb. It also helps calibrating a sound card to a time signal and perform frequency measurement tests. Flmsg is a messaging tool over digital radio, while Flarq supports ARQ file transfers.