An upgrade for the popular CMX138, the CMX138A audio scrambler and sub-audio signaling processor is intended for use in half-duplex, analog two-way radios or family radio equipment. It particularly suits MURS, GMRS, PMR446, and FRS designs and provides a user programmable frequency inversion audio scrambler with signal processing functions, CTCSS, DCS, and in-band tones, allowing comprehensive voice processing and tone control. Enhancements include improved limiter functions, enhanced CTCSS and DCS performance, a new input AGC function, in-band tone operation enabled down to 288 Hz, and an improved audio compandor. The CMX138A is available in a 28-pin TSSOP. CML MICROCIRCUITS INC., Winston-Salem, NC. (800) 638-5577.