Shielded RJ-45: Internal vs External Ground?

I have seen the light and am going to replace the regular Cat5 cables on my radio links with shielded - using Ubiquiti's ToughCable Pro.

With shielded RJ-45 plugs, I see "Internal" and "External" as in Internal:

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External:

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For somebody who doesn't use that many - as in a hundred being a lifetime supply - the no-brainer would seem to be the "External" style because it can be used anywhere, not just with devices that automagically forward the ground from the shell of the connector their AC ground wire.

Does this make sense? Or am I missing something.

Ubiquiti NanoStations with POE Injectors.

Reply to
(PeteCresswell)
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I'm curious, where is this discussion taking place where they're recommending shielded cable? I wonder what's the basis for the recommendation. Yes, I'm skeptical.

Reply to
Char Jackson

Per Char Jackson:

So was I.

But the manual says that shielded cable is important. viz Page 4 of

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Self-serving promo for their house brand? That was my kneejerk reaction.... but now I know that there are several threads in the Ubiquiti fora that make it pretty clear that electrostatic discharge is a consideration. For example:

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Now I realize that I cannot afford to be skeptical because I just don't know enough. The facts are:

- Every so often 3 cams become unreachable from a remote site over a radio link.

- A fourth cam never, ever has any problems

- The 3 problem cams immediately become reachable once both ends of the radio link are re-booted.

- One of the links is attached to the top of a 15-foot windsurfer mast only about 50' from a large bay - i.e. it gets some serious weather.

Add to the above that it is starting to look like there is a correlation between the failures and high winds at the site and you see where I am....

But, like I said, I'm clueless except that I know that those three things are clearly happening.... And the pros on the Ubiquiti site are telling me that grounded/shielded cable to an outside radio is absolutely standard practice.

I have withdrawn from the discussion where this is taking place because I was starting to irritate at least one of the gurus there with my incessant beginner-type questions. The guys who matter there are mostly professionals and it is now clear to me that I was abusing the environment. There are also amateurs there, but I seem to be more verbose and less inclined to research before asking than most.

But my basic question remains: how can a radio-link problem be camera-specific?

Greater Minds Than Mine have said "No problem... see it all the time."

But I have yet to get specifics... to that end, I just pulled the trigger on a smart switch that I will swap in down at the problem site when I get down that way. Then I will be able to test the obvious suggestion that it is something to do with bandwidth (not!...but I need to prove it) and also to put WireShark on both ends of the link.

Whatever happens, I am going to come out of this knowing significantly more than when I went in.

The thread is at:

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Reply to
(PeteCresswell)

Just a pure guess, but if the wind is that bad at the remote site I wonder if the power might not be fluctuating for the same reason. With the three affected cameras being from the same brand I wonder if that brand might be more sensitive to the fluctuations.

If you have a small UPS handy you might want to plug the switch into it and see if the problem goes away since it is powering all the cameras at the site.

Reply to
GlowingBlueMist

Static buildup on metal structures is only a problem when the humidity is quite low. My guess(tm) is 20% or less. That's not a problem in the bay area, and certainly not in a wet marine environment.

Shielding does do well for EMI/RFI protection. If you're near a transmitter of any significant power level, I would use shielded cable. Even so, I doubt if it would do any good because most of the Ubiquiti radios use unshielded plastic case.

Note that there are aftermarket products that provide shielding if needed. If you're using it for cellular backhaul, it's probably a good idea.

Reply to
Jeff Liebermann

One more: Notice that the listed reasons for installing shielding do not mention precipitation static, or air friction static buildup. If you're going to shield the CAT5, might was well shield everything else (except the antenna).

Maybe try aluminum duct tape on the inside of the plastic case for cheap shielding?

Reply to
Jeff Liebermann

Per GlowingBlueMist:

I think I have disposed of the wind theory. It developed when I saw several failures in a few hours when the wind was gusting into the forties. But yesterday I had more instances when there was just normal wind.

I'll take the UPS suggestion though...

Reply to
(PeteCresswell)

X-posting to the Cabling newsgroups

Reply to
ps56k

X-posting to Cabling newsgroups

Reply to
ps56k

X-posting - for those in the Cabling world -

Reply to
ps56k

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