atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Static on POTS lines

I will also take the "black box" approach to this problem. If a ground works...then it works.

In California (and I don't know how everything is rigged at the telco), I get a far FAR clearer connection with my test set when I simply hold a finger on the tip (usually) or ring side of the circuit. I don't know what it is, don't care, and only know that it temporarily solves the problem of hearing the other end.

That said, for me it's nothing close to a surprise that some kind of grounding--or re-grounding--has "fixed" a chronic noise problem on a POTS line.

Out here, shoving a rod in the ground would make you look like a nutcase as our grounds are ordinarily top-notch. But I cannot argue with success.

As Ronald Regan said, "Facts are stubborn things".

...What?

Basically, here's how it is at my friend's house:
The electrical service panel (meter panel) is at the back of the house, the breaker panel is next to it. (also outside). the bare copper ground wire coming from the meter box is inside a conduit. that wire is connected directly to the ground rod and a cold water spigot. the cable tv and telephone demarc grounds are clamped to the #8 copper lead with split bolt connectors.

Other than the wire being connected to the water spigot, it probably met code back when the house was built or whenever the service was upgraded, so it's grandfathered. I would leave it alone though I don't like the connection to the water spigot. It should be connected directly to the water line inside the house where it comes in. If the meter is inside, the wire should be long enough to run through clamps on both sides of the meter.

And Ufer grounds are only for new construction obviously. For existing service upgrades the requirement is still two ground rods.

I get a far FAR clearer connection with my test set when I simply hold a finger on the tip (usually) or ring side of the circuit. I don't know what it is, don't care, and only know that it temporarily solves the problem of hearing the other end.

Huh??? Maybe it's time for a new butt set?

-Hal

Thanks guys for the helpful info! I learned more about grounding than I knew existed, and I'm sure that just scratches the surface.

Could the static have been caused by power line noise that wasn't being dissipated effectively?

Is the Ufer ground what they do on new construction where they use a thermite weld to attach a grounding conductor to a piece of the foundation rebar?

I know at antenna towers, they bury a copper wire in a circle around the base of the tower with a ground rod at each corner of the tower. I'm sure this is solely for lightning protection, as the one I saw was about 4 foot deep and made of pretty heavy wire. probably helps the "ground plane" for the antennas too. (I'm somewhat of an RF geek)

Talking about butt sets, mine is a blue Bell System rotary one and still works perfectly! Gotta love western electric engineering!

<all caps rage>
IF YOUR TEST SET WORKS PERFECTLY WHY WOULD YOU NOT TEST THE JACK BEFORE YOU WENT TO ALL THE WORK.
</all caps rage>

Oh my. All of this wasted chatter about ground rods, etc. Grounding is only associated with telephone circuits for lightning or power cross (personnel and property) protection. That's all, nothing else. It has absolutely nothing to do with the proper operation of a typical telephone line loop whatsoever.

(OK. Maybe a good ground with regard to ground-start trunks).

What is your question? A ground rod will affect a power influence measurement, but I have not seen it affect a circuit noise measurement, as measured across the pair.

Exactly. And not only that this isn't even a copper circuit anymore it's coax into a cable modem. It's virtually impossible for the same problem to continue to occur with two so completely different technologies and be the fault of grounding.

My thought here is that we have the usual situation where the customer's description of a problem bears no resemblance to actuality. Listening to the customer is bound to get you running around in circles. A good tech will never take a customer's word for anything and will personally confirm the alleged problem then decide on a course of troubleshooting based on his findings.

-Hal

...a ground will effect the measurement, because a good ground is needed to run the test.

However, I actually originally thought you were suggesting that static was created from a T1/VDSL/etc "circuit". And, had nothing to do with the line quality.

Power influence has more to do with BONDING, and grounding that. Not actually grounding the pairs with a protector.

When you get a bad power influence reading you generally get a hum on your line, not to be mistaken with the sound you get when you've got a R or T ground. That test -aswell as longitudinal balance- generally only apply when working out in the country where our OSP is running parallel to high voltage/frequency lines.

"circuit noise" or noise metallic as I'm use to hearing it is definitely influenced by the state of your ground - however this is purely to run the test. Circuit noise is like putting a Vu meter on the end of some speaker wire. It confirms if there is noise but from there its up to the technician to figure out why.


From my experience static almost always proves to the BSW where its coming out of the ground to the house, entrance wire, or an outside wirerun.

However since this is a cable system, almost none of those tests are useful, unless using something like an exfo that can measure pairs under 300ft

Can we post this in every forum?
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