  Examining cables using many conductor transmission line theory has shed light
on the modes supported by various cable types. However, so far the theory
disregards the fundamental surface wave mode whose lateral confinement
increases with frequency and hence is expected to play an important role in
high frequency applications. To address this issue, we propose an extension to
the theory which incorporates surface waves on uncoated, cylindrical wires.
Crucially, this requires new definitions of the per unit length transmission
line parameters which are derived using the single wire surface wave solution.
By closely examining a two wire and three wire system, we show that these new
parameters can predict surface waves as well as modes found using conventional
many conductor transmission line theory. Furthermore, all calculated modes are
validated experimentally by diagonalization of a measured channel transfer
matrix. Additionally, the theoretically predicted propagation constants for the
modes are validated against full numerical simulation for the two wire case and
good agreement is observed when proximity effects can be neglected.
