Re: CAT5e cable

On Sun, 20 Apr 2025 03:57:28 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

I've been just picking up whatever (riser) cable is conveniently available,
in the usual 1000 ft boxes.  No real focus on manufacturer, etc.

What type of outer jacket did you buy?  CL, CM, CMG, CMR, CMP, CMX,
CMX2, CMX3, etc?

Are you dealing with any kind of fire or smoke related requirements?
Some jackets trade slow burning, so that a fire doesn't spread as
quickly, for generating toxic smoke.  If you're installing cable in a
vertical shaft that is full of potentially combustible insulation, you
want something that smolders and not burn.  However, if the cable is
being run through an air shaft (plenum), you want something that
doesn't generate much toxic smoke.

"Understanding Cable Jacket Ratings: CL, CM, CMR and CMP"
<https://www.cmple.com/learn/understanding-cable-jacket-ratings-cl-cm-cmr-and-cmp>

Incidentally, for an interesting outdoor experiment, cut about 1 meter
of each type of cable, hold the wire vertically, and use a butane or
propane gas lighter to ignite the lower end of the cable.  Note which
types of cables smolder or burst into flames, and the amount of smoke
each type produces.  Also, wear heavy gloves, use eye protection, and
have a bucket of water nearby.

But, had to run some drops in EMT recently and noticed a marked difference
it the overall durability of the different cables that were being fed.
One seemed "flimsier" than the other -- no doubt related to the jacket
composition.

Yep.  I've also seen this.  The cable was very brittle and could be
bent only a few times before it cracked.  However, it has been too
long and I can't recall what type of cable was being used.  It was in
a hospital so it probably was CMR flame retardant insulation. 

Since you're complaining about the lack of "durability" and running
cable through EMT conduit, you might want to calculate the minimum
bend radius:
<https://www.truecable.com/blogs/cable-academy/minimum-bend-radius>

I notice the cable from the (outdoor) modem has an even more duable
jacket.  But, attribute this to it being "outdoor" cable (none of the
stuff I've purchased has been thusly labeled)

Outdoor cable usually mean UV resistant.  It can also be direct burial
cable where the space between the wires and outer jacket are filled
with silicon slime.  It does a good job of keeping the water out of
the cable, but does make a mess.  If used as a cable "drop" between
the pole and a building, it should have a messenger wire to keep the
Ethernet cable from stretching.  Lots of interpretations for "outdoor
cable". 

Any tips on what to look for in a *description* to select for the "nicer"?
cable?  (I could probably look at the markings on the jackets to identify
the different brands)

Ummm... yes, it would be nice if you would disclose the maker and the
numbers on printed on the cable.

"Ethernet Cable Identification for Beginners: Reading Print Legends"
<https://www.truecable.com/blogs/cable-academy/ethernet-cable-id-for-beginners#>

Incidentally, watch out for CCA Ethernet cable.  CCA means copper clad
aluminum.  CCA is cheaper than 100% copper, but everything else about
it is horrible:
"Why You Should Stay Away from CCA Cables?"
<https://www.systoncable.com/stay-away-from-cca-cables/>

--
Jeff Liebermann                 jeffl@cruzio.com
PO Box 272      http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann      AE6KS    831-336-2558