SMB Receptacle for 50 Ohm RF Signal Paths
The Molex 0734042300 is a 50 Ohm SMB receptacle in the 73404 series, carrying a male pin contact inside a snap-on mating receptacle body. It is a through-hole, solder-terminated RF interconnect rated to 4 GHz with a typical insertion loss of 0.2 dB — sized for board-level coaxial signal routing in communications, test equipment, and instrumentation where the SMB bayonet-style quick mate is preferred over a threaded interface. The gold-plated brass body and gold centre contact plating support the 500-cycle mating life, and the PTFE dielectric keeps the impedance stable across the -55°C to 155°C operating range.
RF Performance and Signal Integrity
The 4 GHz upper frequency limit with 0.2 dB insertion loss makes this connector suitable for baseband and low-microwave signal paths where the SMB interface's 50 Ohm controlled impedance and snap-on retention are sufficient — no need for the torque-controlled SMA or N-type threads. The 500-cycle mating rating reflects the gold-on-gold contact interface; the snap-on coupling wears the detent spring over repeated connects, so plan for periodic replacement in high-cycle test applications.
The brass body and centre contact are gold-plated; the PTFE dielectric is pre-loaded in the housing. No crimp tooling required, but the solder joints need a controlled-profile iron or selective wave to avoid melting the PTFE. The snap-on fastening engages with a mating SMB plug; no coupling nut torque spec to track.