Hi You could simply immerse all the cables in a swimming pool full of mercury … :) (bonus points for a link to the prior discussion of that topic ..).
Bob > On Apr 2, 2017, at 11:05 PM, Bruce Griffiths <[email protected]> > wrote: > > For even more fun you could try to detect the PTFE phase change at around > 20C using a cable with PTFE dielectric. > > A pulse source with somewhat more pulse to pulse jitter may be more useful in > that averaging will occur over a wider range of fine interpolator codes. > > Bruce > >> >> On 03 April 2017 at 05:34 Mark Sims <[email protected]> wrote: >> >> I implemented the channel offset compensation feature specifically to >> make measuring cable delays more accurate. I wanted to measure my TDR >> calibration cable and another very precision delay line. I used Heather to >> null out the channel/connector delays and then replaced one of the "T" >> cables with the TDR cable. >> >> My test setup / TICC was coming up with a -306 ps channel offset error. >> The test signal was the 1PPS output of a FTS4060 cesium. Connecting / >> reconnecting one of the test setup cables and re-doing the offset test (I >> was averaging for 1800 seconds) could produce compensation values that >> varied from -300 ps to -325 ps. Just de-doing the offset test without >> messing with the cables produced values around -300 to -310 ps. >> >> BNC connectors aren't the best for precision timing. I need to re-run the >> test with SMA cables / T adapter and the precision HP connector torque >> wrench and see what that looks like. It would also be fun to lay a coax >> outdoors and see how the delay changes over a day as it heats/cools. >> >> -------------------- >> >>>> >>> Some “cables” have very long delay numbers. >>> >>> _______________________________________________ >>> 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. _______________________________________________ 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.
