SO239 and PL259 UHF Connectors

SO239 and PL259 UHF Connectors

Even though they are often called UHF connectors, SO239 and PL259 are used for HF and VHF work as well. They are also called coaxial connectors. PL259 is the plug and SO239 the socket. The numbers are their original military part numbers. These connectors have threaded coupling which prevents accidental removal. Threads can be tightened to give a good low resistance connection. Good quality connectors can handle over one kilowatt power. UHF connectors are seen on most amateur radio base stations.

Soldering the PL259 connector needs a little bit of skill. Poor soldering can result in an open circuit. Central copper of the coaxial cable is tinned first before inserting into the connector. A more powerful soldering iron of at least 75 watts is desirable. Please remember that the connector will be hot for quite some time after soldering! Only the excellent quality connectors can work in the UHF range. Lesser quality ones may work only up to 100 MHz. Expensive ones may have gold plating over the PL259 pin.