Having a coax connector that doesn’t match a coaxial cable’s characteristic impedance can lead to reflections, attenuation, and other signal problems. Since many coaxial connectors come in 50 & 75 ohm versions, many manufactures list the RG cable rating individual connectors are compatible with. Matching the RG cable rating will ensure that not only will the impedance match but the connector’s physical size will match the cable as well.
