NETWRK@HARVARDA.BITNET (Steve Thornton) (11/23/90)
Household wire from the old days before, what, 1970 or so is quite possibly not twisted. I don't think any twisting takes place except for individual pairs-- the big cables, your hundred- or five-hundred-pair cables are just clumps of individual pairs. The cancelling of inductance only works for circuits as in individual pairs. Not a real problem in the big cables. You are far more likely to run into tuning problems at the C.O. or ancient splices giving way in the face of storms and garbage. If you ever have the opportunity to watch a spice being opened, take it. Remember the quote about not wanting to watch laws or sausage being made?
floyd@hayes.ims.alaska.edu (Floyd Davidson) (11/24/90)
In article <9011232112.AA01416@ucbvax.Berkeley.EDU> NETWRK@HARVARDA.BITNET (Steve Thornton) writes: >Household wire from the old days before, what, 1970 or so is quite >possibly not twisted. > >I don't think any twisting takes place except for individual pairs-- >the big cables, your hundred- or five-hundred-pair cables are just clumps >of individual pairs. The cancelling of inductance only works for circuits >as in individual pairs. Not a real problem in the big cables. The "real problem" with big cables is crosstalk from other pairs within the same cable. The placement of pairs within large cables is very carefully done. Pairs are bundled together, and every pair in the the bundle has a different twist. Pairs are physically located so that simular twist pairs are least likely to be close to each other. The pairs in the bundle are swirled, and the bundles have a swirl. Floyd -- Floyd L. Davidson floyd@hayes.ims.alaska.edu Salcha, AK 99714 paycheck connection to Alascom, Inc. When I speak for them, one of us will be *out* of business in a hurry.