[Amps] Silver Strap

[Steve Thompson]

> Folks,
> 
> I used to think silver plating was a big deal until I ran a bunch of 
> tests.  See http://www.bnk.com/W0QE/inductor_Q_tests.html  for the 
> results.  Silver is only 7% better than copper and with reduced 
> resistance comes reduced skin depth resulting in only about a net 
> difference of 4%.  Lore has it that the corrosion on copper increases 
> the resistance but my tests did not show that to be true for copper I 
> oxide (reddish brown), copper II oxide (black), and copper carbonate 
> (blue green).

Many years ago there was an article in RF Design magazine that 
looked at this - the analysis was that if the tarnished surface is 
higher resistivity than the underlying metal, than the current 
tends to to concentrate in the lower resistance area under the 
corrosion so the effect on Q/loss etc is less than you might 
expect from appearance.

Steve