I've seen recently that some companies such as andrews etc are now
offering different coax and hardline with al outer shielding

they advertise lower cost, and lighter weight then copper , ok i
get that

but then they say the rf spec's are 'the same' so i ponder how do
they do that i would think copper would have better spec's ?
obviously i am missing something obvious


Actually, the loss characteristics of solid jacket heliax depends much
more on the dielectric material, physical diameter, and the size of the
center conductor, than it does on the jacket material. Also, aluminum is
a pretty good conductor anyway.


Ed K7AAT