Refer to the diagram below. Place the dial on 20mA and plug the multimeter’s black probe into the negative side of the battery and the red probe to the cathode of the LED. Like when measuring voltage, switching probes won’t harm the meter and displays the magnitude with a negative sign. . CW Key Paddle Parts All Parts December 16, 2017 March 29, 2021 Administración bencher , bencher key , Bencher Parts , bencher streight key , cw , electronics , key , parts , vibroplex. The mode A keyer completes the element being sent when the paddles are released. In the late 1800s, Morse code was used for radio communication. Touch and hold both paddles.