Second, copy the matrix code to the textarea below. Before transmitting, try to input the audio frequency signal output by computer to the transmitter, and change the transmitting mode to Upper Side-band (USB). Click the "Play" button and push the PTT button of the transmitter. ⚠ Note that the default matrix code below includes the callsign of the author (BD4SUR), thus only for testing without transmitting. Please replace my callsign in the matrix below with your own callsign before transmitting, otherwise it will constitute an illegal act of fraudulent use of callsign.