The GB7ZP Duplexer for our UHF DStar repeater consists of a Procom DPF70/6-Cavity set, supplemented by a Procom BPF70/3 bandpass filter on the 439.4875 MHz transmitter output. The original set up was integrated into the rear of a Icom ID-RP4000 UHF D-Star Repeater, along with a Microset PR430A preamp. In 2024 when ZP moved to the newer Icom ID-RP4010 repeater model, the duplexer and filter was extracted and re-packaged in a new 1U case. Rear knockout positions in the case were exploited for N-SMA bulkhead adaptors, to facilitate highly screened coax. This was done in such a way that the Tx and Rx ports aligned with the new repeater and care was taken to optimise isolation. A professional vector network anslyser was used to measure the high isolation levels achieved. Duplexer internals and Performance summary - click for Summary and Full test results