The DS26502 is reportedly the market's first 64 kHz composite-clock transceiver. The device is a building-integrated, timing-supply (BITS) clock-recovery element that supports standard frequencies ...

the Pentek Inc. Model 7140-420 dual digital transceiver with wideband digital downconverter (DDC) and interpolation filter handles input and output signal bandwidths from 4.8 kHz to 40 MHz.