In article S7Gpb.99545$HS4.838304@attbi_s01,
"Cliff Curry" wrote:

Lawrence:

Find out the frequency that the LCR meter uses to measure with.
Use a piece of cable -much- shorter than a wavelength of this frequency.
Measure the capacitance of an open circuited piece
Measure the inductance of a short circuted piece.
divide by the length of the piece to get cap per unit length
and inductance per unit length.

Note:

characteristic impedance is sqrt(l/c)
propagation constant is sqrt(l*c)

Those approximations are not in general true below a few hundred
kilohertz or so. In the audio range, there is no "characteristic
impedance"; instead, at each frequency there is an impedance for *that
frequency only*. The same goes for propagation, which is
frequency-dependent. The way those parameters vary with frequency is
critically dependent upon the physical construction of the line.

For example, as frequency drops without limit, the propagation velocity
also drops *without limit*. Find out why early long-distance telephone
lines needed "loading coils". Then find out why they all were removed.

See the wonderful Schaum's Outline book on Transmission Lines for more
information on this.

More accurate measurements can be made taking into account the actual length
of the piece of cable.

Better still is to avoid the need for measurements at all.

Theoretical calculations will get you fairly close, for cables of any
length useful for speakers -- under a hundred feet, say; do it for a few
different sets of materials and different constructions if you like.
Learning enough to understand whether values anywhere near the ones you
calculated could have any possible effect on audible frequencies being
supplied by a decent, real-world amplifier to any rational set of
speakers will get you the rest of the way to true enlightenment.

Isaac