Homemade cat5 cable using existing phone line fails.

yes, i have looked at it, i have maintain the machines and worked with the management that are involved in getting the twinning machines set up to run this product. they are all twisted the same rate. the only difference is when the pairs get bunched together, we have a process to make sure they are coupled together at offset points. it must work because it passes all test our engineering department put on it along with QC.

That why I *always* snip the cable in half - ethernet, phone cord, handset cord....

Jamie hath wroth:

I didn't know that anyone made teflon CAT5. PTFE has a higher dielectric constant than polyethylene. That means the outside diameter of each pair is smaller for PTFE than for polyethylene. With a smaller diameter, it would be possible to twist all 4 pairs in the opposite direction as the twisted pairs, and have a fairly small number of points of contact. Also, the smaller diameter insures that it will not bloat beyond the 0.250" O.D. limit. However, I see a potential problem making CAT6, where the wires in each pair have to bonded or solvent welded together. PTFE doesn't that too well.

well then you should notify our engineering staff because they obviously have something wrong. i have seen our competitors wire and they do have their pairs slightly staged in twist. we don't do that , we group the pairs in a special order when bundling them. this grouping apparently gives the same results. in fact while i am composing this, i have open up a cat5 teflon cable made by us and i can say the twist are no more than maybe an 1/8 of inch difference between each other and this is most likely due to the consistency of our twinning machines. i remember years ago when we were optimizing the process it was a big deal on how the pairs were bundled together. the offset position of how these pairs laid together were very important for cross talk issues for tightly bunched cables. we did the same thing when we developed the IBM 590 super cable that had the 12 conductors, that had twisted pairs on the outside of a shielded twin pairs of foam. cross talk was a big issue on that also. actually we did the 590 project first then the CAT5 process was after that.. we were also the first ones in the business to develop the cross linking polyrads for wire! , i wasn't there with them at that time how ever. oh well.

i can concur with you there, i do remember it was a problem getting things to stay in track, but we end up using a following idler system that would rack the wheel which control a cam following system to shift the angle a bit as the pairs came together.. this works perfectly and allows us to run at a high rate of speed. at the time we came up with this, we have some of the smartest engineers in the business. now adays, a lot of that is going by the waste side.

On Mon, 10 Jul 2006 00:15:38 GMT, in message , DecaturTxCowboy scribed:

Yes, I remember that trick, from long ago in my technician days. It's good practice. We would also do things like smash the legs on bad IC's, things like that. Make sure the bad component *stays* bad.

This somehow brought back forgotten memories of weird set of my first wife's relatives, from very old (pre-Gold Rush) San Francisco family: bunch of strange, reclusive brothers and sisters all living in big old brown-shingle mansion on Sixth Avenue, up against the Presidio wall. Only 2 out of 7 siblings ever married or left the house, and one of those soon returned to the nest.

Took our small children up to visit them one Christmas. Somehow, a really old electric light bulb was discovered on the top shelf of a kitchen cabinet, with a tag attached by some ancient string bearing two scrawled notes:

"October 14, 1937 -- No good"

and then below this, in different ink:

"August 7, 1943 -- still no good"

So, was it still no good?