Abstract: An economical yet versatile dual spring actuator switch assembly providing an excellent tactile impression includes a planar switch closure assembly having domed protrusions extending from a surface thereof to provide switch closure when depressed and a switch actuator assembly.

Abstract: A highly flexible and economical dual tone multiple frequency (DTMF) communication system includes a data input source such as a keyboard; a repertory dialer or electronic memory; an integratable digital encoder which includes a digital sine wave synthesizer; and a transmission unit such as a radio or a connection to a standard utility telephone system. The digital encoder provides a DTMF output signal at standard telephone frequencies in response to input data and includes a predial delay circuit which allows for dial tone delay or transmitter start up after receipt of data and before generation of an output signal, a two second delay circuit providing a two second output signal which may be utilized to prevent shut down between successive number entries and to lock out noise from a microphone or to a speaker and an automatic number insertion (ANI) circuit.