[TowerTalk] Copper grounding bus bar

[Jim Lux]

Terry wrote:
> I'm looking at copper sheet on these sites to be used as a SPG plate 
> about 16" x 16".  What would be the minimum thickness to be 
> "self-supporting" as opposed to laminating it on some substrate as 
> Polyphaser does?
> 
> 73 de Terry KK6T
> 
unless you want to solder directly to the plate, why not use aluminum. 
It's a lot cheaper, much easier to work with (drilling thick copper is a 
chore, tapping even more so, prepare to buy many spare taps and use lots 
of lube.. soldering to a big sheet of thick copper would require a 
fairly high output torch, too).  I'd find it hard to believe that the 
conductivity difference would be significant (for DC & line frequency, 
the thickness of the aluminum helps, for RF, it's a big flat surface 
either way).  A wide variety of lugs are available, and a nice tapped 
hole in the aluminum will make fairly good contact.

If you feel that the copper is important, slap a big piece of copperclad 
  PC board material on top of the aluminum, or stick copper flashing on. 
  You could also put copper foil tape on the aluminum in places where 
you think it's important. 3M makes a kind with conductive adhesive.