CSR50-D is a UHF receiver module for desktop or 19”/1U rack use, operating in 400–550 MHz with 16 switchable channels within a 7 MHz window. It features FM modulation with configurable deviation, a CTCSS sub-audio tone decoder, and a transformer-balanced, floating XLR audio output. Power input is 10.5–16 VDC. Front indicators show Receiver On, Squelch, and CTCSS status. It is user-programmable via the UPK100 kit and supports NR processing.