What signals are used in a computer-radio interface for digital mode operation?
Receive and transmit mode, status, and location
Antenna and RF power
Receive audio, transmit audio, and transmitter keying✓الإجابة الصحيحة
NMEA GPS location and DC power
الشرح
A digital-mode interface has to carry the radio's received audio into the computer, the computer's generated audio out to the transmitter, and a keying signal that puts the radio into transmit at the right moment. Antenna, RF power and GPS lines are not part of that interface.