Hey Charley,

You're more than welcome to donate money (or time) if that's more up your alley. Also, if you want to donate UTP cat6, we'll take that as well. We use a bunch of ethernet cable both at the omni and for other installations, so we can always use more. If you're feeling really generous, we can really use shielded outdoor cat5 and cat6 for installing antennas. Don't worry - no matter what kind of ethernet cabling you feel like donating, we can almost certainly find a use for it :)

As for the questions you've outlined:

First thing: shielded cable

This isn't actually an ethernet run. It's dsl lines + phone lines running over cat copper wires. As such, it's my understanding that it's more sensitive to EMI disturbance. Additionally, it's much better to err on the safe side as we'll only want to string this once and the entire network communications infrastructure depends on the dsl signal that passes through this line. As for needing shielded mating jacks, we have plenty of grounded rj-45 connectors and with whatever other scenarios, it's pretty easy to ensure that they're grounded. We're not talking about our entire network infrastructure, we're just talking about this one cable run.

Second thing: hand termination

We're using an EZ RJ-45 crimper, which makes the process fairly straightforward. We have spools of other types of ethernet cables and have done runs throughout the building. Also - we'll be breaking out these pairs anyhow, so most of this is fairly non standard types of termination which are much easier than rj-45 disconnects.

Daniel, let us know if I missed anything here?

Max

On Tue, Aug 25, 2015 at 2:01 AM, Charley Sheets <rcsheets@acm.org> wrote:

Hey Daniel,

I am interested in helping out, but I have to admit I'm fairly
skeptical of two elements of this request, so I'd like to get some
clarification if possible.

First thing: shielded cable. My understanding is that most of the noise
rejection comes from the twists, not the shielding, and that shielded
cable is only useful in high-EMI environments. Am I mistaken about the
application, or are we perhaps in a high-EMI environment? The standard
example of high EMI is something like a factory floor. Shielding also
only works as intended if the mating connectors (jacks and whatnot) are
also shielded. Does that apply here? My inclination is to donate
standard (UTP) cat6 cable. Please help me understand why I should
donate shielded cable instead.

Here is some information (could be biased -- it's from a cable
supplier) about the differences as they apply to cat6a:
http://mirapath.com/blog/item/cat6a-shielded-or-unshielded

Second thing: hand termination. You've stated a preference for a box of
several hundred feet of cable. To me that implies that you'd prefer to
hand terminate the cable rather than having pre-terminated cables. I
certainly won't make any claims about your personal ability to
terminate cables, but most people are not especially skilled at this,
and many hand terminated cables I've seen in the field are visibly not
well made. I've terminated cat5 and cat5e cable, and it's always been
very fiddly and challenging for me to minimize the untwisted distance,
and to ensure there are no open pins. Pre-terminated cable is
available with strain relief boots and is often certified to be
complaint with the relevant cabling standard. What do you see as the
advantage of spools of cable? Why not buy pre-terminated cable?

I hope this doesn't come across as overly critical. Sorry if it does. I
really just want to make sure we get exactly what we need.
--
Charley Sheets

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