W7TI wrote:
Has anyone ever made their own hardline? I'm thinking 1/2 inch copper
water pipe with a center conductor supported by some plastic discs
spaced every so often. You might not get it exactly to 50 ohms but I'd
think the loss would be so low it wouldn't really matter.

Comments?

It's certainly possible - and regularly done for short quarter-wave
impedance transformers at VHF/UHF - but there are practical problems for
making long runs: difficulty of obtaining center rod in long lengths,
has to be built on-site, difficulty of splicing, standard connectors
have to be adapted... and in the longer term: internal condensation and
corrosion, difficulty of repairing...

Those are just a few problems that come to mind ,from experience with
using shorter lengths outdoors in a damp climate (though you wouldn't
think it right now in England).

Except for those special-purpose applications, it really isn't worth the
trouble. It's easier to turn detective and find surplus sources of
hardline such as 50-ohm Heliax (used at cellular sites world-wide) or
the 75-ohm hardline used in the USA for cable TV.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek