[Tfug] Copper Clad Aluminum CAT-5e wire outdoor/waterproof

[Kramer Lee]

Tinned copper wire has a higher loss at GB LAN frequencies than shiny
non-oxidized copper, because tin is not as good a conductor as copper
or aluminum, and at that high frequency  the tin is where most the
current is.

The ohm meter is probably measuring at DC, 0 Hz.  Aluminum is about 3x
the resistivity of copper, so it makes sense to measure more
resistance of the copper clad aluminum than plain copper with a DC ohm
meter.

The diameter of #24 wire is about 0.5mm, but the skin depth of copper
at 100 MHz (in the range of 100Mbps) is close to .007mm.  For GB it is
closer to .002mm.  I am not going to check these numbers, they are
coming from websites.  This is free. They seem reasonable.

However the CCA will perform as well, signal wise, as the plain copper
at Ethernet frequencies.

It will break from less flexing than copper, but even copper won't
last forever when subjected to constant flexing.  I know of instances
of aluminum shielded twisted pair, #24 wiring in use in some medium
vibration environments so it must not be that breakable.

On 7/2/14, Louis Taber <ltaber at gmail.com> wrote:
> Hi Adrian,
>
> The wire is not steel.  I tried a magnet.  Scraped off the copper color and
> is looks like aluminium.  But, yes, it is small hand hard to tell.  It is
> certainly not copper in the center.
>
> I haven´t come up with a way to measure the gauge her in Pennsylvania.
>
> There is lots of (sometime conflicting) information about CCA Cat-5 if you
> do a Google search.  For example:
> http://www.fia-online.co.uk/pdf/Whites/wp-IAN002-01.pdf.  And from a seller
> of CCA http://sewelldirect.com/articles/cca-facts.aspx  At least Seawell is
> up front about what they are selling.  My vendor did not provide a clue,
> even when asked.
>
>   - Louis
>
>
> On Wed, Jul 2, 2014 at 1:35 PM, Adrian <choprboy at dakotacom.net> wrote:
>
>> On Wednesday 02 July 2014 12:16:21 Louis Taber wrote:
>> > Hi All,
>> >
>> > I purchased some Aurum CAT-5e wire off of eBay.  No mention of the
>> > Copper
>> > Clad Aluminum in the description -- or on the box.  The only reason I
>> > noticed it was I checked the resistance, looking to see if I had been
>> > shorted, for example less than 500 feet.
>> >
>> > The resistance measured 3 times what I was expecting.   300 Ohms for
>> > 500
>> > feet end-to-end on all 8 conductors in series vs calculated for copper
>> > at
>> > about 120 Ohms.
>> >
>> > Has any one on the list used/purchased CCA intentionally or
>> > unintentionally?  Any problems with it?  Data rate?  Electrical
>> > connectivity at the terminations?  How out-of-spec is it for the data
>> > communications spec?  I have no personal interest or plans at this time
>> in
>> > doing POE with it.
>> >
>> >   - Louis
>> >
>> > http://www.ebay.com/itm/161314178639
>> >
>>
>>
>> I have never heard of copper clad aluminum being used for network cable
>> (Cat5/6). Tinned copper, yes. Copper-clad steel wire used as fake copper
>> wire,
>> yes. Undersized copper wire used in cheap/knock-off cable, yes (should be
>> 22 or
>> 24ga, some cheaper cable is 26ga, knock-off is sometimes 28 or even
>> 30ga).
>> No
>> direct experience, but it seems to me aluminum wire that small would be
>> pretty
>> fragile and subject to fracture under bending.
>>
>>
>> Adrian
>>
>>
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>