I have been studying for my C-7 Low Voltage contractors License here in Calif. The school I have been going through provides practice tests and a study guide for this license and they are well known and trustworthy.
One part in the study guide and several test question cover telephone cables, but I have never seen the function associated with the colors of a standard 6 wire cable using GRN, RED, YEL, BLK, WHT, and BLU colors like they are using them.
Here is the color to function that is being used in the state test.
GRN TIP/+
RED Ring/-
YEL GND
BLK Used for lighted handset dial
YEL & BLK Used for an accessory like a lighted dial, via a 6-v step down transformer, or as a second line
WHT & BlU Used for optional function such as security signals, speakerphones, automatic dialers, background music, etc
The YEL & BLK as a second like I know, but I never heard of the rest of the stuff.
How old is this and is any of it still used today?
