Remote controls are used any time a two-way radio base station is located away from the desk or office where communication originates. For example, a dispatch center for taxicabs may have an office downtown but have a base station on a distant mountain top. A Tone remote, also known as an EIA Tone remote, is a signaling system used to operate a two-way radio base station by some form of remote control. A tone remote may be a stand-alone desktop device in a telephone housing with a speaker where the dial would have been located. It may look like a desk top base station. Or, it may be an integral part of a computer-based console system with touch-screens in a dispatch center. History The first two-way radio remote controls utilized a harness of wires extending speaker, microphone, and controls for options such as channel selection or CTCSS switches. This limited a base station to being within tens to hundreds of feet from the user's workstation. Early systems often had volume unit meters, clocks, and switchboard keys. 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. As pair gain electronics and point-to-point microwave radio links came into widespread use throughout the public switched telephone network, telephone companies filed tariffs to eliminate their past responsibility of providing leased circuits with direct current continuity. If the base station were located across town in an area served by a different telephone exchange, the only available circuits reaching the distant exchange might be a single voice-grade channel in a D-4 channel bank on a DS-1 or a single microwave radio baseband channel. Tone remotes became necessary with the wide use of telephone carrier or multiplexing equipment. They require only a voice-grade audio path with roughly flat equalization from 300-3,000 Hz. A circuit that could pass audio in both directions could be used for remote control. Tone