RJ9
From Wikipedia, the free encyclopedia
The connector incorrectly known as RJ9 is the unofficial industry standard for wired telephone handsets. It is used to provide connection from the base of the telephone to the handset. "RJ" stands for Registered Jack, a family of telephone connection standards. This handset connector is actually not a Registered Jack at all, since it was never intended to connect directly to the telephone service lines. It uses the 4P4C modular connector, which has four pins or electrical connections per connector. The typical pin-out of a telephone handset's RJ9 is usually the same as the normal 4P4C provided by the phone company. This can be demonstrated by plugging the handset of a phone directly to a phone jack and getting a dial-tone. In most cases, even if more than two conductors are provided, only the inner two conductors are used.
| USOC registered jacks | |
|---|---|
| RJ9 • RJ11 • RJ12 • RJ14 • RJ21 • RJ25 • RJ45 • RJ48 • RJ50 • RJ61 |
