Coaxial Switch Receptacle — 2.80 mm Plug Diameter
The Hirose MS-166 is a coaxial switch receptacle with a 2.80 mm plug diameter, designed as a female socket for surface-mount RF applications. It sits in the MS-166 series and carries an internal switch feature — the switching function allows signal routing or test-point isolation without an external relay.
50 Mating Cycles — Built for Low-Reconnect Duty
Rated for 50 mating cycles, this connector is intended for applications where the connection is made a limited number of times — think internal antenna switching, test-point access, or factory calibration ports. The gold-on-gold contact interface (centre contact and body finish both gold) keeps contact resistance stable over those cycles, but the 50-cycle ceiling means it is not suited for frequent field reconnection. The snap-on fastening type reinforces this: quick to mate, not designed for repeated unmate-remate cycles in service.
SMT Termination and Reel Packaging
Both the shield and centre contact terminate by solder — surface-mount pads on the PCB, no through-hole posts. The Tape & Reel packaging confirms this part was designed for automated pick-and-place lines.
Obsolete — Sourcing via Independent Distribution
The MS-166 is marked obsolete by Hirose. If the BOM can accept a substitute, a parametric search for a 50 Ohm SMT coaxial switch receptacle with a 2.80 mm plug interface and internal switching is the next step; no pin-compatible drop-in is documented.