1960s two-way radio remote control consoles used direct current loops. Users would run ordinary telephone wiring from the remote consoles to the radio base station chassis. In some cases, the base station was located at the same address as the control console. In other cases, the base station was located at a distant site. For distant sites, a dry pair of telephone wires called a "DC loop", "private line-" or "RTO circuit" (Radio Telephone Operation) was leased from the telephone company. Older burglar alarms used the same type of DC wiring from subscriber location to the alarm office.