Observers will note that 75 ohm BNC connectors have different diameter pins than 50 ohm BNC connectors, yet the RG5000-HD Receiver Guard claims that it works with both.
Here's why:
Although the BNC connectors used on the RG5000-HD are 50 ohm, constant impedance connectors are not required at (or very near) the HF receiver input -- which is the typical position of the DXE-RG5000HD in the system.
The center pins of 50 ohm BNC connectors are slightly larger than the center pins of 75 ohm BNC connectors. 75-ohm connectors will still work with 50-ohm connectors, but 50-ohm male connectors placed in 75-ohm female connectors may cause them to permanently expand, creating unreliable connections. That's why the RG-5000-HD and many other amateur radio products use 50 ohm connectors.
Almost always used on HF, the RG5000HD is an impedance-tolerant device that can handle 50-75-ohm-range connectors.
BNC male to F female adapters may also be used if required.