Hi and thanks for the reply. The SLEEVE connects to the ground of the Radio as the radio works on a resistance ladder setup. so the Tip is 3.3 volts and the sleeve is ground. The ring is also 3.3 volt as must be grounded to the sleeve to acjieve the "shift" function. The radio wired remote is "tip = 3.3 volt", the "ring = 3.3 volts" and the are all at 0.5mill amps. the 5volt input is a stable power supply