The PCM-23 is a lightweight (2.2 lbs), compact, portable VF PCM Tester designed to characterize analog interfaces of PCM equipment and analog transmission equipment. Level, loss, stability, frequency response, gain/level response, crosstalk, idle channel noise, and total distortion measurements of voice frequencies can be easily accomplished using the transmitter and receiver features. The PCM-23 can operate up to eight hours from two 9V alkaline batteries. A choice of protective cases and an ac charger for use with NiMH batteries are optionally available.