[TCML] keeping primary copper tubing nice and shiny

[jimlux]

G Hunter wrote:
> Gary, you are correct.  Pure silver is a much better conductor than silver oxide according to this ham radio site:
> 
> http://hamwaves.com/antennas/coils.html
> 
> Quote:
> 
> "At a temperature of 20°C (293.15K), silver (Ag) has a resistivity of 1.58·10-8Ωm, which is the lowest of all metals, and a temperature coefficient of 0.0038K-1. Silver[I] oxide (Ag2O) at this temperature has a 500 times higher resistivity of 8·10-6Ωm and a temperature coefficient of 0.004620K-1 [3]. Nonetheless it is still considered to be a conductor, whereas both copper[I] oxide (Cu2O) and copper[II] oxide (CuO) are semiconductors at room temperature."
> 
> Close quote.
> 
> Nuf said,
> 
> Greg
> 


Even better, that page cited a source for the Ag2O resistivity (the 
paper by Chatterjee) which I'll have to look up at work.

But, also, bear in mind that at TC frequencies, the skin depth is so 
large compared to plating thickness that it's not like a HF loading 
coil.  And even in a HF coil, the value of silver plating is dubious, at 
least from a loss standpoint.  Low resistivity connections is a better 
reason (e.g. Silver oxide is a whole lot better than Copper oxide).

Also, what's the resistivity of silver sulfide (the usual tarnish)??