50 Ohm U.FL Panel-Mount Receptacle — Hirose UM-QR(40)
The Hirose UM-QR(40) is a 50 Ohm U.FL (UMCC) receptacle with a male pin contact, designed for panel-mount RF interconnect applications up to 1 GHz. This is the bulkhead-mount side of the UM series — the connector body passes through the panel and is secured with the included lockwasher and nut, making it a fixed entry point for a coaxial signal path. The snap-on fastening gives quick mate and unmate, and the 1000 mating cycles mean this receptacle holds up in test setups or field-service scenarios where the cable gets disconnected regularly.
Panel Installation and What Ships in the Box
This is a bulkhead-mount receptacle with front-side nut retention — the connector body pushes through the panel from the outside, and the nut tightens from behind. The package includes three pieces: the connector body, the lockwasher, and the nut. The lockwasher sits between the nut and the panel to prevent loosening under vibration. The solder cup termination on the centre pin accepts a tinned wire or a pre-tinned centre conductor from a coaxial cable — you tin the wire, insert it into the cup, and flow solder.
Mating and Compatibility — What It Connects To
The UM-QR(40) is the receptacle half of the U.FL (UMCC) interface. It mates with a standard U.FL plug — typically a crimp-on or solder-on plug on the end of a coaxial cable. The snap-on fastening means the plug pushes onto the receptacle's centre pin and the outer shell snaps into the receptacle's body. This is not compatible with SMA, BNC, or any larger RF connector — the U.FL form factor is much smaller, designed for internal RF interconnects where space is tight. The 50 Ohm impedance is standard across the U.FL family, so any U.FL plug rated for 50 Ohm will match.