[Antennas] Need a bit of wire advice

[Don Havlicek]

George,
Actually, we agree .. 
I said:

> The 'built-up crud' is oxidation.
> Copper Oxide and/or copper sulfate [IF sulfur is absorbed from the
> atmosphere], are both corrosive and have higher resistance to electron
> flow .. at DC or RF.  Connections with 'crud' will be higher resistance
> .. affecting the impedance of the antenna.
> Don
> N8DE

You said:

>Seems to me, and I think that Mother Nature concurs, that the layer of bad
>crud would be no different than a layer of insulation (good crud) on the
>wire. The current flow will always be on the surface of the lower
>resistance conducting path which will be the uncorroded copper beneath the
>crud. 

Remember .. that the higher the frequency, the more the RF flows on the
OUTER surface of the conductor.. that's where the 'crud' is.  Yes, I
agree that the 'path of least resistance' will be within the conductor,
but there will be some flow in the 'higher resistance region'.

You then wrote:

>Connections, IF made through the crud, would have higher resistance, of
>course. But all r-f connections to the antenna will sensibly be made to
>clean copper with solder so that there is intimate contact between the
>feeder copper and the antenna copper, even though both may acquire a layer of crud over time.

In my statement, I never mentioned SOLDER.  As you and I both know,
that's the key to a good connection!

You then wrote:

>As to corrosion, many copper wires - antennas and otherwise - have managed
>to stay up for years without succumbing to deterioration from copper oxide.
>My limited understanding is that the oxide layer actually does insulate the
>wire from further corrosion by other agents and acts as a protective layer.
>And, that once the oxide layer is formed, its chemical reaction with the
>copper stops and no further crud develops.

>Don, I guess we just don't agree on this one . . .

You are correct in saying that 'no further crud develops' ... Provided
the wire is not abraded.
As I said above ... we agree much more than we disagree .. unless that
DX station doesn't come back to one of us!
Don N8DE