75 Ohm BNC HD Plug Rated to 18 GHz
The 034-1025-12G: This is not a standard 50 Ohm BNC — the 75 Ohm characteristic impedance is built into the dielectric geometry and centre contact dimensions, so it mates correctly only with 75 Ohm BNC jacks and receptacles. The connector is rated to 18 GHz, an unusually high frequency ceiling for a 75 Ohm BNC, making it suitable for HD-SDI, broadcast video routers, and test equipment that pushes beyond the typical 3-4 GHz limit of standard 75 Ohm BNCs. The kit includes three pieces: the plug body with a gold-plated phosphor bronze centre pin, a crimp ferrule for the cable braid shield, and the centre contact.
Cable Group and Crimp Termination
This plug is listed for AT&T 734, AT&T 734A, and Belden 1505A cable. The cable group determines the correct crimp tool and die set: the centre contact must crimp onto the centre conductor, and the ferrule must compress the braid against the cable jacket. Using a cable outside this group risks impedance mismatch or poor shield termination, which will degrade the VSWR above 1 GHz. The shield is terminated by crimping the included ferrule over the braid. The centre contact is also crimped. Both operations require the specified tooling; Amphenol RF recommends their crimp tool set for this series.
50 Ohm vs 75 Ohm: Not Interchangeable
The 034-1025-12G is a 75 Ohm plug. The visually similar 034-1025-11G is a 50 Ohm version. The centre pin diameter and dielectric dimensions differ between the two impedance variants — they are not mechanically interchangeable. A 75 Ohm plug mated to a 50 Ohm jack will have an impedance discontinuity that increases VSWR and reduces signal integrity above a few hundred MHz. The 75 Ohm version is correct for video and broadcast systems; the 50 Ohm version is for RF test and telecom.