~ 1ft = 1 ns for coax, but 1000-2000 us is common delay for long phone lines which is very frequency dependent, you would want unloaded circuits, loading coils would make for more problems. My experience with metallic circuits is limited to less than 10 miles at some point you would need an amplifier/repeater. I do know noise and cross talk and other impairments are common. Data modem design is quite complicated but I don't think they are very predictable as far as delay goes, except delay increases and transfer rate decreases with impairments.
Stanley ----- Original Message ---- From: J. L. Trantham <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Sent: Fri, September 10, 2010 9:09:29 PM Subject: Re: [time-nuts] Timing Distribution in Mountainous Terrain -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Stanley Reynolds Sent: Friday, September 10, 2010 7:13 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Timing Distribution in Mountainous Terrain How to keep hundreds of miles of copper stable or predict it's delay ? Stanley Would temperature changes over any consecutive 6 day period create a 30 nS change (assuming the 'central station' is indeed central)? And, if so, would that make any difference in position accuracy since all stations would have the same or similar error? Oops, there I go again thinking as a 'user' :>). Joe _______________________________________________ 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. _______________________________________________ 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.
