Mike Speed wrote:
The braided shield will be substantially lossier than a solid wire or
tube of the same diameter.

Why?

Two factors. One is surface roughness. The other is caused by the
current having to continually move from one group of wires to another as
it travels. I'm just now doing some research on how significant these
effects are, but so far I've found out they're very noticeable. It's one
of the reasons the loss of typical coax is substantially greater than
predicted with idealized programs or calculations that fail to take
these factors into effect.

And the relatively poor quality dielectric
used for the outside of the cable will also reduce the Q somewhat.

The sheath is easy to strip.

True enough, but my guess is that the resulting water and crud you'll be
getting among the fine wires will be worse than the insulation.

But hey, you don't have to believe me. Make up some coils and measure
their Q -- it's not hard at all. Then stick them outside for a while and
measure them again. Or do like most amateurs do -- make the coils,
discover that you can talk to far away places "barefoot", and declare
that they "work".

Roy Lewallen, W7EL