li...@rtty.us said: > If you are trying to set up say a 1 us delay, you will get ~ 50 ps per > degree C in your delay. That's a lot .....
A while ago, t...@leapsecond.com said: > A long delay cable is fine too. If these are timing receivers you probably > don't need more than 100 ns of delay, once you figure out which receiver is > ahead of the other. The cable tempco is low enough not to worry about. 100 ns is 50-100 feet. That's a reasonable length to work with. But I was curious about the temperature coefficient. Google found this: http://www.hepl.hiroshima-u.ac.jp/phx/notes/cable/cable.html which says: # Belden 8240 (solid) shows a temperature coefficient of around -0.252ps/m/deg in a temperature range between -20 and 30 deg. The coefficient becomes steeper beyond 30 deg. # Belden 8219 (foam) shows a larger temperature coefficient of around -0.352 ps/m/deg than that of 8240 in the similar temperature range. The coefficient becomes steeper beyond 30 deg, but less steeper than that of 8240. # Fujikura RG58-A/U shows the smallest temperature coefficient of around -0.152 ps/m/deg, but in a narrow temperature range between -10 and 20 deg. The coefficient beyond 20 deg is much steeper than the others. To pick round numbers, 30 meters and 3 C and 0.25 ps/m/C gives 25 ps. -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.