[Antennas] Need a bit of wire advice

[Mark]

Actually, I seem to remember .. back in my wire antenna heyday, years ago,
that the difference .. if any ... had to do with "radiation resistance" ---
Note, I have used WAY CHEAP steel electric fence wire with great results for
"real" longwires, and TFDF aerials, etc....radiation resistance reduces "Q",
which broadbands the antenna .. to a degree, n'est-ce-pas? --- And, in fact
we use stainless steel for our whips, and lots of marine applications do so
also.... I concur with George, the "crud" doesn't really affect the antenna,
but I might point out that in a high icing condition, and a little wind ..
SNAP!  My copperweld antennas always crudded up when here on the Pacific
Coast .. but worked fine.  Using the multi strand copper antennas ...
another story .. more from a durability standpoint, rather than radiation
problems.  My 2wo bitz..
73 -- Mark .. AA6DX
----- Original Message -----
From: "George, W5YR" <w5yr@att.net>
To: <n8de@thepoint.net>
Cc: "Lefczik, Larry D" <larry.d.lefczik@lmco.com>; "David W Sher"
<davew9lya@juno.com>; <IamSF5@aol.com>; <antennas@mailman.qth.net>
Sent: Thursday, February 07, 2002 12:49 PM
Subject: Re: [Antennas] Need a bit of wire advice


> Interesting . . .
>
> 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.
>
> I suspect that a negligible amount of r-f current would try to make its
way
> through the poorly conducting copper oxide. So, its higher resistance is
> immaterial. I seriously doubt that any measurable difference in
> driving-point impedance can be seen between a shiny new copper antenna
when
> it is first erected and a few weeks or months later when it has built up
> its layer of crud.
>
> 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.
>
> 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 . . .
> >
> > 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