Tone remote

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.

[1][2][3] A tone remote may be a stand-alone desktop device in a telephone housing with a speaker where the dial would have been located.

Users would run ordinary telephone wiring from the remote consoles to the radio base station chassis.

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.

Audio levels set too low may cause the transmitter to drop out when speech peaks occur.

If everything is set ideally, a notch filter at the base station blocks the steady 2,175 Hz tone from going out on the air.

[8] This is desirable because persons calling on the radio who are whispering or yelling would ideally be intelligible and be presented to the console user at roughly the same volume.

It also helps the console user talk on the telephone without loud sounds coming from the remote control speaker.

This allows the dispatcher to shift her attention between the radio and the phone without continually adjusting volume controls during a conversation.

In the case of 2,175 Hz, the steady tone leaking from a receiver phone line, or from the output of the voting comparator, may cause the transmitter to lock on.

The simplest tone remote system uses a two-wire audio circuit to operate a simplex base station.

Some systems where transmitter steering is employed may also require a separate audio path for transmit and receive, (four-wire circuits).