[Xitami] FW: Website using Xitami
Paul Reid
xitami@lists.xitami.org
Fri, 11 Jan 2002 11:09:24 -0500
> Simple test is pick up your phone receiver and listen to it. If you here static, then U have a bad ground.
It could be a lot of things. In any case, in the USA, phone grounding is the
PHONE COMPANY'S job, not the customer's job. If you hear hum or static, bypass
your inside wiring by plugging into the box where the phone line comes into
the house. (If you don't have the modern kind of telco entrance box, call the
phone company and demand one: they are very much better than the old carbon
block protectors, and easier to diagnose.) If you have hum inside but not at
the box, fix (preferably re-run) your inside wires. If you have hum at the
outside box, MAKE the telco fix it. There may be larger safety issues.
> There should be at least 3 feet of 3/8 inch copper rod driven into the ground for your telephone
A dirt rod, especially a little 3-foot, is almost worthless in most US soils.
It has a resistance as high as the phone line. A dirt rod is no longer allowed
to be a home's only power ground, and it isn't allowed for power and phone to
"share" a dirt rod (that becomes exceptionally dangerous in lightning or when
a 13,000/240 power transformer shorts).
If that fixed your problems, I guess you better leave it alone. But I wouldn't
like it, my phone company would be upset, and the electrical inspector
probably should be consulted. Home grounding has become complex lately; the
best rule is "it is usually done wrong".
> If it's connected to a cold water pipe, or something similar it can cause all kinds of comm problems.
Until plastic pipe became common, the water system was the same as a dirt rod
(it goes through the same dirt!) except VERY much better, being miles long and
typically wet from seepage in the mains. In my area, the telco always
connected to a metal water pipe: even had a standard clamp and "WARNING" tag
for the purpose. That should do no harm; though with modern plastic pipe it
may do no good. (My inside pipe is copper but I discovered that it turns to
plastic a foot outside the cellar, so I get no benefit from the water mains
system.)
"Your" side of the telco entrance point should be UNgrounded. The wires
"should" be correctly grounded (through protector blocks which don't ground
the normal signals) by the telco. Most telcos are pretty good about this: if a
home phone is improperly grounded, THEIR workers are in danger.
If you have static, call and complain. Many telcos don't want to hear about
modems, and may have lax standards for voice quality. But if you say you hear
static AND your fax machine prints garbage and drops the connection, they will
often do something about it.
-PRR