50 Ohm BNC Jack for Panel-Mount RF Runs
The PTFE dielectric keeps insertion loss to 0.2 dB across the band.
Termination and Mounting: Solder Cup to the Cable, Flange to the Panel
Termination is solder cup — tin the centre conductor, flow solder into the cup, and dress the braid to the nickel-plated brass body. Panel mounting uses the flange with clearance holes for #4 screws; the bayonet lock secures the mating plug with a quarter-turn.
How the 31-203 Compares to the 31-206
The closest functional peer is the 31-206, also a 50 Ohm BNC jack with the same 4 GHz ceiling, 500 mating cycles, and 500 V rating. The 31-206 uses a clamp-style shield termination and ships as a 7-piece kit (connector, braid clamp, clamp, contact, gasket, lockwasher, nut) for bulkhead mounting with a front-side nut. The 31-203 is a simpler solder-cup, flange-mount part with no included hardware — choose the 31-206 when you need a captive-nut bulkhead install and clamp-on braid termination; choose the 31-203 when the panel has pre-tapped holes and you prefer a direct solder joint on the shield.