I believe that this is the unit that uses the coax to send the voltage to
the relay. What you are reading must simply be saying that you don't have
to have seperate voltage wires going from your control box out to the relay
at your antenna. Your antenna coax carries this voltage to the relay.

Ameritron does make a unit that requires voltage wiring to be run to the
relay.

Does this help ?

73 de jim K4PYT