> > When the cable is 4 wire, it is likely that there are 2 twisted pairs > > in it. If the landlord used 2 wires from different pairs the balance > > will be bad. Look at the cable and see whether there is used one > > twisted pair. When u have luck this can save u the digging! > > > > Regards, Harry > > AFAIK, the 4 wire is flat. There are different kinds of 4 wire cable. I think Harry is thinking of two twisted pairs, and Declan is thinking about flat ribbon.
Another kind that we used a lot is called "JK" or "JKT" and is used a lot for internal house wiring. It has the four wires together in a slow spiral. A cross section looks like a square, and the whole thing just spirals together. The red/green pair are the opposite corners of the square, and yellow/black are the other opposite corners. As long as you use the pairs right (and don't mix up the colors), and keep the circuits balanced, it can have excellent crosstalk rejection, because all coupling is pure common-mode, which telephones can't see. Andy -- Author: Ingraham, Andrew INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
