Thread: al coax
View Single Post
  #2   Report Post  
Old March 25th 07, 02:44 PM posted to rec.radio.amateur.antenna
[email protected] jimlux@earthlink.net is offline
external usenet poster
 
First recorded activity by RadioBanter: Jan 2007
Posts: 61
Default al coax

On Mar 25, 4:19 am, ml wrote:
hi

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



Skin effect means that the RF current is only being carried in a very,
very thin layer, so one can silver plate the inside of the aluminum
shield and the outside of the center conductor. At 100 MHz skin depth
for copper or silver is a bit more than 6 microns (0.25 mil), so it
doesn't take a very thick layer.