home

How to Pick the Right Coax Connector


The right coaxial connector is an important element of your RF installation. A critical part of your systems cable installation is the correct low loss termination of the coax. Coaxial cables use RF connectors to terminate the electrical signals at each end of the cable. RF connectors and connections must be made correctly and high quality RF connectors should be used.

Coax connector selection can be the most confusing part of your cable install. There are at least 10 popular connector types required in Ham, CB and WiFi transmission, and selecting the best type for a particular job can be an issue. Each coaxial connector type is designed for a specific use for different cable types and characteristic impedance. The correct RF connector for a particular coaxial installation should be selected for the frequencies being used, the amount of power broadcast, and of course to fit the required coax type to prevent unanticipated loss and connector failure.

There are different quality standards for cable connectors. RF connectors for amateur radio use may use old outdated standards like WWII era PL-259s that function poorly above UHF; still there is little alternative to their use if you have to mate to the standard RF connectors on your Ham and CB equipment. For professional applications, RF connectors are often designed far better, although it is necessary to ensure that the connectors are suitable for the frequencies used. For best operational performance, avoid cheap coaxial cable connectors! Purchasing the best LMR-400 cable and installing cheap connectors will degrade your coax performance and waste money. Source your connectors from high quality suppliers. Paying for a name brand of good selectors from a supplier you trust is usually a good idea.

The correct matching of connectors to your cable type and use is one of the key parts of managing the SWR of your coax cable and antenna. This requires using coax connectors with the correct impedance. All quality RF coax connectors are designed to have low VSWR (typically 1.1:5 or better) and very low insertion loss (<0.05 typical and 0.1 dB maximum) over a very wide bandwidth with a minimum of variations. Power handling is a function of the diameter of the dielectric, the dielectric material used internally and the frequency size of the center pin. Each connector type is impedance matched to the correct coaxial cable. The thicker and better quality the coax, such as Times Microwave LMR-400, the better the signal transmission and connector performance will be. As with transmission lines, the higher the frequency, the higher the VSWR mismatch and insertion loss,the lower the effective power handling capability of the connector.

Insuring you select the proper connectors and cable to complete your radio or scanner install will allow the best signal and transmission success. With a little homework and research you can have an extremely successful install and achieve a solid setup that will last for many years. 

LINKS: