RCA Plug and Jack

A one conductor plus ground plug and jack connector introduced by Radio Corporation of America, now Thomson Electronics. The jack is a metal stud a little larger around than a pencil (about 3/8 inch) with a center hole that a small lollipop stick would fit (about 1/8 inch). The matching plug has one fat (1/8 inch) center pin that represents the live conductor, and a shell that presses onto the jack stud and that is almost always grounded. Normally the center pin is connected to the center conductor of a coaxial cable and the shell is connected to the shell or shield of the cable.