sw wire oxidation

[ridgescan]

my 100' wire is of #12 solid copper and has a thick coat of bluegreen oxidation on it-should I be cleaning this stuff off occasionally or is it not affecting its max performance at all? I like its performance but can this stuff actually hinder reception?

 

[ridgescan]

I did some digging and found a sensible answer by kb2vxa which I am satisfied with-thanks Warren. Here's what he said
"What you may not know is the more copper weathers (to a point) the better it's protected FROM weather. That point is at least 10-15 years down the road when the green oxide patina forms, then it's nearly bulletproof. You've probably seen power lines, copper roofs, sheathing, leaders and gutters up for more that 50 years all a lovely green yet having no signs of deterioration and never given it a second thought... until now."

Quoted from this thread
http://forums.radioreference.com/scanner-receiver-antennas/125604-copper-versus-jacketed.html

good to know

 

[SCPD]

Hmm, I no chemist or materials expert but long ago, when I had a 65ft-ish bare copper wire for my SW antenna... it degraded after six months or so. I replace it with a fresh bare copper wire. It sure seemed to make a difference to me!

I eventually got smart and went with #14ga Flexweave which is UV insulated. This stuff is great. You could leave this up for years and not have any signs of weathering, cracking, etc.

It's more expensive but it will last forever. I also preferred the black insulation since it's virtually invisible outdoors (at least around trees.)

From thewireman.com:

544 FLEXWEAVE™ 14 AWG with Black, Army Green, or Clear ultra violet resistant, very flexible PVC jacket. Break strength 143 lbs. 0.30/ft

545 FLEXWEAVE™ 12 AWG with Black, Army Green, or Clear ultra violet resistant, very flexible PVC jacket. Break strength 196 lbs. 0.50/ft

 

[SCPD]

Found this from a landscaping forum:

Oxidative corrosion of copper and its effect on conductivity. Electrical conductivity is a measure of a materials ability to carry an electrical current. Copper is an excellent conductor making it ideal in all electrical applications. However, in the presence of air and moisture its surface oxidizes forming a layer of copper oxides that conduct electricity very poorly. This layer is not initially a problem since the layer is very thin and actually serves to protect the underlying copper.

In an outdoor corrosive environment, however, the oxide layer progressively extends deeper into the copper strand and eventually oxidizes the entire thickness. The resultant decrease in conductivity severely compromises the lighting system. Landscape lighting wire is especially prone to this severe corrosion because it is a stranded wire with very thin strands. Lighting installers often see the devastation of this effect when they pull old wire from the ground and see the strands completely blackened and brittle.

 

[E-Man]

I do not know if that is true with solid cooper wire, stranded perhaps? And it will not take that long in SF for your green oxidation to turn into a brownish thick coating. PG&E has designated salt spray areas within SF, all salt spray areas only use cooper wire, SS transformers, and switches. I dont think the jacketed #12 at your home improvement store would make much difference as it is not designed for weather protection. If you know someone at PG&E's Line Dept. they could hook you up with some covered #6, but the jacket on that stuff is pretty thick, not sure how that would effect reception?

 

[ridgescan]

Thanks for the comebacks-luckily I got the thick #12-I ran up there and took steel wool to a 6' section and the coat came off right away to expose fresh bright copper again so it's holding up well after a year of that salty air. I mainly wondered if the coating would block some of the reception.Silly I suppose. Just wondering if it's an excercise in futility going up there every couple months to steel wool it-my disability really makes it hard .

 

[SCPD]

Thanks for the comebacks-luckily I got the thick #12-I ran up there and took steel wool to a 6' section and the coat came off right away to expose fresh bright copper again so it's holding up well after a year of that salty air. I mainly wondered if the coating would block some of the reception.Silly I suppose. Just wondering if it's an excercise in futility going up there every couple months to steel wool it-my disability really makes it hard .

Or you could just swap out your bare copper for the above Flexweave #12 above and never have to worry about it again.

 

[RadioDaze]

...found a sensible answer by kb2vxa which I am satisfied with...

I think THAT'S the real story here!

jk, Warren!

 

[SCPD]

I do not know if that is true with solid cooper wire, stranded perhaps? And it will not take that long in SF for your green oxidation to turn into a brownish thick coating. PG&E has designated salt spray areas within SF, all salt spray areas only use cooper wire, SS transformers, and switches. I dont think the jacketed #12 at your home improvement store would make much difference as it is not designed for weather protection. If you know someone at PG&E's Line Dept. they could hook you up with some covered #6, but the jacket on that stuff is pretty thick, not sure how that would effect reception?

Like the quote says, the outer layer will get oxidized first. Stranded is probably worse (long term) since the strands are fairly thin compared to a solid copper 12ga wire and will affected quicker.

Either way, that outer layer's resistance gets built up over time and will probably affect your overall sensitivity.

I suppose an easy test would be to let a copper wire oxidize over a period of time and then test its resistance from one end to another with an multimeter. You'd probably see a measurable difference.

 

[ridgescan]

Or you could just swap out your bare copper for the above Flexweave #12 above and never have to worry about it again.

That is what I will do then thank you sir. Can I get it handily at like Home Depot?

 

[edjanowetch]

wire oxidation

old hams use to polish their antennas...go figure it..

 

[ridgescan]

old hams use to polish their antennas...go figure it..

true!

 

[E-Man]

Like the quote says, the outer layer will get oxidized first. Stranded is probably worse (long term) since the strands are fairly thin compared to a solid copper 12ga wire and will affected quicker

I did not see your post until I posted. I was responding to warrens comment about the oxidation protecting the cooper wire. I do not see how the oxidation protects solid cooper, but I could see that it could protect stranded wire, if it completely covers it, and no longer allows moisture to make contact with the strands. But I am no expert, purely guessing.

 

[ridgescan]

I dug around Nick-looks like I can only get that Flexweave online-called HRO in Oakland too and they went "huh?" cool-I will try Wireman. Thanks for all the help!

 

[ridgescan]

Funny how your answers come to you from left field-I'm in "the wireman.com" site and in one of the antenna wire pitches it said this:

"Jacket has minimal effect on performance - less than that of a year's accumulation of oxidation product on bare wire, with less noise".

So according to that quote, oxidation not only affects performance, it also allows more noise. There it is

 

[SCPD]

TheWireMan.com is a good site and they are good people. Give them a call if you have any questions, etc.

 

[w2xq]

I think the only "cleaning" that might need to be periodically done might be at the connection point between the copper wire and the feedline to the receiver. An antenna coating material could be used at the joint to increase the interval of attending to the connection.

 

[ridgescan]

I think the only "cleaning" that might need to be periodically done might be at the connection point between the copper wire and the feedline to the receiver. An antenna coating material could be used at the joint to increase the interval of attending to the connection.

Hey Tom-got it covered-literally. My 50 ohm connect point is a modded d130j and the wire is connected at the base of the whip with lockwashers for bite andd weatherproofed with silicone sealer. Which I will have to redo when I get Nick's "flexweave"

 

[majoco]

My antenna is made from insulated 7-strand copper (30thou strands) and the joints at the ends are covered in heatshrink. In my years at sea with looong wire antennae, they were made of 7 strand hard drawn naked copper - they just went green in the sea air and never broke unless provoked. You should never solder an antenna wire as you will make a sharp transition from flexible to stiff where the strands will break at the end of the solder.

 

[KMG54]

I did it the cheap and easy way.17 gauge galvanizied electric fence wire, a 1/4 mile spool 19 dollars at tractor supply.