FLDIGI Training Workshop Fldigi (short for Fast light digital) is a free and open-source program which allows an ordinary computer’s sound card to be used as a simple two-way data modem. The software is mostly used by amateur radio operators who connect the microphone and headphone-connections of an amateur radio SSB or FM transceiver to the computer’s headphone and microphone connections. Fldigi is useful for passing traffic between two or more operators where voice … Continue reading FLDigi Training Workshop