The electrical length of a piece of coax does change with temp. The Gore catalog, for instance, has a graph of it. And it has a most annoying bump right around 20 to 25 C, at least for the stuff I use at work.
As to why... The length changes for one thing. I think, also, there will be a change due to the change in diameter, as well as the density of the dielectric, which will change the capacitance per unit length. On Apr 3, 2011, at 14:52, Joseph Gray <[email protected]> wrote: > That's an interesting question. Does temperature have an effect on the > dielectric that changes the VOP? I'll have to try your experiment. Is > that worth ten extra credit points? :-) > > The copper in the coax has a positive temperature coefficient, which > will contribute to an increased impedance (assuming the reactive > components don't change). But, does the impedance have any effect on > VOP? A quick Google search didn't find any information on this. AFAIK > VOP is due to the dielectric properties. > > Joe Gray > W5JG > > On Sun, Apr 3, 2011 at 3:21 PM, Bill Hawkins <[email protected]> wrote: >> For extra points, test with the same long cable at different >> temperatures. >> Say from soaking in a 150 deg F oven and a zero degree freezer. >> Bill Hawkins >> >> >> _______________________________________________ >> 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.
