The DE6491 is a CMX649-based wireless voice link demonstration kit that demonstrates CMX649 ADM Codec IC operation in a low-power, cordless headset application. Operating as a short range RF device in the 863 865 MHz European licence-exempt band, this demonstration kit consists of two separate stand-alone PCBs each with the following sections: CMX649-based audio, RF transceiver and control. The basic design may be user adapted to other RF frequencies. Full-duplex voice operation at up to 20 metres range is provided via a single RF channel Time Division Duplex (TDD) link. With the supplied headsets a user can investigate two-way voice-audio transfer between units. Each PCB can be powered, standalone, from a choice of AAA batteries or a bench power supply. Intelligent power saving reduces supply current when not communicating. Each terminal draws between 17 25.5 mA when communicating or 850A, typical, when powersaved. Each on-board Controller's FLASH memory comes programmed with the latest version of operating firmware. If desired, a user may reprogram and in-circuit debug the Controller themselves, using a proprietary programmer (not included).