Technical Articles

Two Rules to Avoid Confusion About Coaxial Connectors

Rule 1: Coaxial connectors are not pipes. RF connector gender is determined by center pin, NOT by their threads.

Coaxial cable connectors have specific designations and their gender is determined by the center pin. In Amateur Radio, the PL-259 is the most popular coaxial cable connector for HF and low VHF antenna systems. The PL-259 is also known as “UHF male” in most of the world, and is an “M male” connector in Japan. It mates to the SO-239, also called UHF female. You can tell them apart because the PL-259 is the male PLug that mates with the jack or female SOcket, the SO-239 connector on equipment and antennas.

The PL-259 and SO-239 are great RF power connectors for HF systems. However, for constant impedance and lower loss, Type-N is the coaxial connector used for VHF and UHF transmitting systems, with N male typically mounted on the cable, which mates to the N female on equipment and antennas. Test equipment, metering and receiver cables often use BNC connectors. Very low power and small devices, including hand-held transceivers, use a connector called SMA. Very high power HF, VHF and UHF commercial systems use exceptional low-loss connectors called 7-16 DIN, which are now used in high-end Amateur gear. Satellite and cable TV and HF receive antenna systems use F connectors, also called Type-F. Typically, F male compression connectors installed on RG-6 type cables have a center conductor that is the center pin and the F female connectors on equipment and antennas have a center receptacle. There are many other connectors in the world of RF… too many to mention here.

Rule 2: Never ask for a cable with “end” connectors.

Knowing about Type-N connectors, you can imagine the confusion that is caused when someone refers to a cable assembly having an “end” connector.

“Was that ‘N connector’ or ‘end connector’? What kind of ‘end connector’ do you need?”

The bottom line is cable assemblies aren’t made with “end” connectors. For RF interconnections between pieces of equipment and to antennas, most coaxial cable assemblies are terminated with either PL-259 connectors or Type-N male connectors.

Be sure you know exactly which connectors you need when referring to coaxial cable assemblies. Use proper connector designations and remember that their gender is determined by the center pin.

Leave a Reply