Between-Series Adapter: BNC to D.FL, 75 Ohm
The BNC(75)J-D.FL75J-BPA is a between-series adapter from Amphenol RF that converts a BNC jack interface to a D.FL jack interface. Both ends are female sockets, making this a jack-to-jack straight adapter for free-hanging (in-line) applications. This adapter is specified for 75 Ohm systems — the impedance is not negotiable. Using it in a 50 Ohm path creates a mismatch that degrades return loss across the band. The 12 GHz max frequency covers HD-SDI (up to 12G-SDI), broadband video, and instrumentation links where the signal stays within the 75 Ohm reference. Fastening combines a bayonet lock on the BNC side and a threaded lock on the D.FL side — the adapter stays mated under cable strain without additional support.
Rated for 20 mating cycles, this adapter is intended for semi-permanent installation — think rack-mounted patch panels, broadcast camera CCUs, or test equipment bulkheads where the connection is made once and left. It is not designed for daily reconnection in a field-test kit; the D.FL threaded interface and BNC bayonet both wear with each mate, and the 20-cycle rating reflects the practical limit before contact resistance begins to rise.
The PTFE dielectric maintains stable impedance across the full range — no dielectric constant shift that would detune the signal path at temperature extremes.