True 75Ω BNC Connector
A 75-ohm BNC connector is designed for a 75-ohm transmission-line interface.
This is characteristic impedance at signal frequencies, not a claim that a resistance meter will read 75 ohms between the connector contacts. BNC fittings also exist for other impedance systems.
True 75Ω BNC Connector — BNC Cable
On a digital coaxial cable, a 75-ohm BNC termination supports matching to an intended 75-ohm signal path. The connector and cable construction both contribute to maintaining the impedance through the connection.
Compare the connector’s stated impedance with the cable and equipment requirements. A BNC shape alone does not distinguish every electrical variant or establish that the complete assembly is correctly matched. Do not treat “75 ohm” as a sound-quality ranking; it identifies the transmission-line compatibility required by the interface.