2 Pin Phone Cord Views

Electronics

Plugs and jacks of this type are often called modular connectors, which originally distinguished them from older telephone connectors, which were very bulky or wired directly to the wall and therefore not accommodating of modular systems. A common nomenclature for modular connectors is (e.g., 6P to indicate a six-position modular plug or jack). Sometimes the nomenclature is expanded to indicate the number of positions that contain conductors. For example, a six-position modular plug with conductors in the middle two positions and the other four positions unused is called a 6P2C. RJ11 uses a 6P plug; furthermore, it often uses a 6P2C. (The connectors could be supplied with more pins, but if more pins are actually wired, the interface is no longer an RJ11.)

In the powered version, Pins 2 and 5 (black and yellow) may carry low voltage AC or DC power. While the phone line itself (tip and ring) supplies enough power for most telephone terminals, old telephone terminals with incandescent lights in them (such as the classic Western Electric Princess and Trimline telephones) need more power than the phone line can supply. Typically, the power on Pins 2 and 5 comes from a transformer plugged into a wall near one jack, supplying power to all of the jacks in the house. Trimline and Princess phone dial lights are rated at 6.3 volts and the transformer output is typically around 5 volts, providing a long service life for the incandescent lamps.

RJ21 is a registered jack standard for a modular connector using 50 conductors, usually used to implement a 25-line (or less) telephone connection such as that used in the 1A2 key telephone system. It is also known as a 50-pin telco connector, CHAMP(AMP) or an Amphenol connector. (The latter is a genericized trademark, as Amphenol was the largest manufacturer of these at one time.)

Hi, you can check if you're using the correct type of phone cord by referring to my first post in this thread with an image of the 2-wire phone cord. If you are using 4-wire phone cord, and cannot find a 2-wire phone cord in any local store, you can get the Two-to-four wire phone cord adaptor from the HP Parts Store. Search for the part number Q3093-80004.