I may have posted this link before. It is on topic, even though I was using coax cable: http://ko4bb.com/Test_Equipment/CoaxCableMatching.php
It would be easy to do the same experiment with cat-5 cable. I would expect the pictures to look somewhat similar. Didier KO4BB Tom Van Baak <[email protected]> wrote: >> Pulse quality of single-ended RS232 over unbalanced twisted pair is >going >> to be pretty bad beyond a few feet. If you want to transport the 1pps >over >> twisted pair there are a couple of options: > >Hi Brian, > >I suspect this is true at one level, but what would be helpful to to >*quantify* it. What is "pretty bad"? What is "few" feet? You are >implying that 1PPS timing is dependent in cable quality and cable >length. I would agree. But please provide some numbers, even rough >numbers, because what is important for modern T&F applications >(picoseconds and nanoseconds) can be irrelevant for NTP, which still >lives in the millisecond and microsecond world. > >What I'd like to see, and what would be educational for the group, is >if you could take some 'scope traces at a few inches, at a "few feet", >and at a few meters or tens of feet to graphically demonstrate your >pont. > >My gut tells me 1 ns or 10 ns or 100 ns or 1 us or 10 us makes no >measureable difference to the quality of NTP/PC timekeeping. > >/tvb > > >_______________________________________________ >time-nuts mailing list -- [email protected] >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
