RadioBanter - View Single Post - copper transmission lines with polumer insulator

Jim Lux · July 11th 08, 09:45 PM posted to rec.radio.amateur.antenna

wrote:
Hi all,

I am working on an application of transmission lines for use in
magnetic resonance. I know I have seen in the past pre-made
transmission line that has an inner conductor surrounded by a white
insulator ( I think it is Kel-F, it may be teflon) and a copper layer
on the outside. It is quite stiff, and comes in long pieces that can
be bent with a little effort. Does anyone know where I can pick some
of this up? I have been through about 200 google pages with no luck.

Thanks

What you are looking for is generally called semi-rigid coax. There are
3 relatively common sizes (outside diameter): 0.141", 0.085" or 0.086",
and 0.047", as well as other sizes.

There's a lot of different dielectrics and metals available, other than
the usual PTFE and copper. For instance, foamed PTFE for low loss, a
sort of sintered silica, etc. Silver plated stainless steel is used in
cryogenic applications. Aluminum is used in weight sensitive applications.

Vendors are companies like MicroCoax, Haverhill, UniformTube, etc.

googling semirigid coax turns up a lot of hits.