"Telamon" wrote in message
...
I'm not confused. Coax and waveguide are the same regarding conductor
spacing.

Waveguide has no 'conductor'. It's basically a pipe with the proper internal
diameter for a given wavelength. It does, therefor, indeed, get smaller for
higher frequencies.

The same is not true for coax. Skin effect is the most significant factor in
coax as frequency goes higher: there needs to be more surface area as the
frequency goes up.