[TowerTalk] solid THHN vs jacketed copperweld

[Lux, Jim]

On 9/27/22 2:22 PM, Steve Maki wrote:
> I seem to recall ordering Copperweld wire, but it was a long time ago.
>
> Just a quick note that after replacing the (insulated) #12 THHN with 
> the same length insulated #12 "copper clad steel tracer wire", we 
> could see no change in resonant frequency, so there seems to be enough 
> copper cladding for my purpose at 3.5 MHZ.
>
> There will only be an inch or so of wire exposed to the air at the 
> center insulators, so that will be easy to monitor for corrosion over 
> time (such as it is :-) Or I may coat the exposed wire with liquid tape.
>
> 73, Steve K8LX


Skin depth in copper at 4 MHz is 1.3 mils, 32 microns.


Copperweld

https://www.copperweld.com/application/files/4915/3833/2604/Welded_Copper-covered_Steel_CCS_21.pdf


21% CCS AWG 12 has 0.0808" diamter (2.05mm) with a nominal thickness of 
0.0616 mm ( so about 2 skin depths at 4 MHz)


https://www.copperweld.com/application/files/7115/3833/2604/Welded_Copper-covered_Steel_CCS_40.pdf

40% CCS  has copper that is 0.2052 mm thick ( 6 skin depths)



>
>
>
> On 9/21/2022 2:07 PM, Donald Chester wrote:
>> Steve Maki lists at oakcom.org Tue Sep 20 15:19:37 EDT 2022 wrote:
>>
>>> I had sworn off copperweld many years ago after noting that the copper
>>> plating did not last forever.
>>
>> Was that real copperweld, or was it copper-plated steel with only a 
>> minuscule layer of copper deposited on the surface, like the stuff 
>> used for electric fence wire?
>>
>> Real copperweld has a thick copper jacket that is practically 
>> indestructible.  I use #10, salvaged from an abandoned railway 
>> telegraph line of yesteryear, scored free for the taking many decades 
>> ago.  You can beat it with a hammer or leave it buried in the soil 
>> (as ground radials) for years and the jacket won't come off unless 
>> it's deliberately removed with a file or grinding wheel.
>>
>> That copper-plated junk begins to rust through in only a couple of 
>> years.  The copper is so thin that it probably has negligible 
>> benefit  from the skin effect; you are effectively using plain old 
>> steel wire.
>>
>> Don k4kyv
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