Can any one help me show that the o 1

[kennair1]

Can any one help me show that the outer exposed aluminium on the CATV trunk cable is less corrosive than copper.

thanks

 

[kenvlach]

Aluminum can be quite corrosion resistant in the right environment. I imagine you are talking about its use as a sheathing for buried cable in soil. It should be OK as long as there is not a lot of chloride in the soil. It also depends upon the alloy, but you can be pretty sure that the cable or telephone company selected a pretty corrosion-resistant one (no Cu or Zn, low Fe) was chosen.
The aluminum is cheaper than copper and more resistant to rodents gnawing than lead.