A device for switching antennas from transmit to receive
A device for voice activated switching from receive to transmit
A device that assists in manual sending of Morse code✓Correct answer
An interlock to prevent unauthorized use of a radio
Explanation
An electronic keyer generates properly timed dots and dashes with the correct spacing when the operator moves a paddle, so the operator still sends manually but the machine enforces the timing. It is not an antenna switch, a voice-operated switch or a security lock.