Re: CAT5e cable

On Sun, 20 Apr 2025 15:56:08 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

On 4/20/2025 2:15 PM, Joe Gwinn wrote:

My concern is mainly to know how to specify the type of cable
that should be used in future installations (in which I won't
likely be involved).  Other than naming a specific vendor
and model number (whose manufacture could also change, over
time)

>

As I suspect "paid help" would be less meticulous than I, it
would be wise to specify materials that they would be less
likely to abuse.  <frown>

 
The simplest way I know of is to get samples and cut them open for
detail inspection.

>
That only works for the samples you have in your hands.
I don't see any criteria that is *specified* for the
cables that highlights the differences that I am seeing.

True.  You can specify such things, but dream on - the vendors won't
notice of care. 

The only things you can specify are  the overall system-driven
requirements like max attenuation versus frequency and distance,
shielding effectiveness, and the like.

And buying sight unseen is almost guaranteed to end in tears.

If I specify "Belden xyz" or "Southwire abc", there's no
guarantee that they won't change how they are manufactured.
Or, the aspect that I'm concerned with.
>
Or, simply stop making it.

Yep.

Life's like that.

Joe

So, I'm looking for a way of specifying the criteria that
are important -- and, ideally, of extracting it from a
manufacturer's datasheet.
>

Without destructive inspection, there are a few tests.   First, mass
per length - heavier is better.

>
Weight is likely something that can be easily determined -- even
without actual samples in your hands.  And, holding the wire gauge
constant, you'd have to assume any weight differences were due to
changes in insulation and/or jacket.
>
Unless, of course, they also include the weight of the packaging...
>

 Second is DC resistance of each
conductor per length - smaller is better.  For shielded twisted pair,
the shield quality can be measured, but this requires special tools.
 
Joe Gwinn

>