The Amphenol RF 919-107J-51SX is a 50 Ohm MCX jack (female socket) in a snap-on fastening style, built for free-hanging in-line cable termination. The PTFE dielectric keeps insertion loss to 0.1 dB across the band up to 6 GHz.
This jack is designed for RG-174, RG-188, RG-188A, RG-316, LMR-100, and M17/119-RG174 cables. The included ferrule compresses over the cable jacket during the crimp stroke; the contact solder joint handles the signal path. The cable group listed covers the common 0.100-inch-diameter flexible coax family, so if you're terminating LMR-100 or RG-174, this is the right jack.
Why the 6 GHz Ceiling and 500-Cycle Rating Matter
The 6 GHz maximum frequency covers the full L-band, S-band, and most of C-band — enough for Wi-Fi 6E, GPS/GNSS, cellular backhaul, and ISM-band radios. The 0.1 dB insertion loss is tight for an MCX interface; you won't lose signal budget to the connector itself. The 500 mating cycles come from the gold-on-gold contact interface — this jack can live on a test cable or a field-swappable antenna lead without wearing out early.