Water pipe is very impure copper..it does not need to be 99% or even near, just a copper colour will do to sell it..
Copper is copper..it costs x? per ton.. so if it¡¯s cheap there is a reason.
Air con tubing for instance has full spec, which can be downloaded to see purity, can¡¯t do that with b and q water pipe..
And since air con tubing is not that expensive compared to water pipe( 2x?if bought on the reel, and not on ebay) it makes sense to use as spec¡¯s can be seen.
Re heliax..yes its corrigated..so one needs less length to make same loop..
Also it¡¯s typically of good quality due to nature of its requirements..so more R is not true as less Length is needed.( corrigated) ie same r.
However my preferred copper of choice is air con from a uk/ euro source..( as annealed and in a coil..)
Ie my 160-80 mag loop will be again this winter chatting to usa ssb on 160m..proof is in the eating as they say.(might av got that saying wrong.)
Simon g0zen
