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

Louis Taber ltaber at gmail.com
Thu Jul 10 05:56:24 MST 2014


I did decide to keep the CCA wire.  To send back 10#(?) for $25 seemed a
waste of time and effort.  I still think:

a) It should have been clear that the wire was CCA in the description on
eBay.
b) When I asked about the 3x resistance, they might have replied back it
was CCA wire.

Oh well.

The 100BASE-TX 125 MHz symbol rate.  The third harmonic will be at 375MHz.
 Which makes the skin effect even more pronounced.

I agree for most uses it should be fine.  I would have concerns with POE.
 And, with insulation displacement connections in our Pennsylvania high
humidity environment.

Perhaps I should squeeze some Anti-Oxidant Compound in the connector prior
to punch down <grin>
 -  Louis



On Sun, Jul 6, 2014 at 11:25 PM, Kramer Lee <krameremark1 at gmail.com> wrote:

> 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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