Hi All,

As a EE, I just couldn’t resist commenting on this thread.

Copper oxidation is an obvious (and observable) phenomenon with non-plated copper wire.

But it’s possible effects, in any area other than connection interfaces, would have to be extremely limited.

1 The oxidation layer would be rather thin. Unless you want to overplay the possible interactions with (RF) skin effects, it’s effects on the overall transmission efficiency (resistance) of a cable would have to be (IMO) almost nonexistent.

I am not talking about hazardous (vaporous) environments, this is another discussion altogether. (UL Salt Spray Test anyone?)

2 At the connection points, however copper oxide is an issue that is dealt with by gold (and other metals) plating/tinning. This is especially true in “dry circuit” applications as current flow over a few milliamps (or perhaps microamps) will also keep contact point oxidation at bay.

I have observed RF coaxial cables that have been in outdoor environments for many years and they continue to function just fine as long as the connectors are properly maintained.

Changes (hardening & cracking) of PVC insulation due to UV/ozone exposure may cause a cable to fail in time.

With coaxial cables, there can be small, long term changes in the dielectric characteristics, (characteristic impedance and velocity factor) and perhaps this could, potentially cause some “observable” changes.

Regards,

Scott

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The definition of an expert is a washed up drip under pressure

[This message has been edited by SPasse (edited April 01, 2004).]