Re: question about "Network Interface" phone jack

"wylbur37" <wylbur37nospam@xxxxxxxxx> wrote:
> Network Interface
> *Caution
> Disconnect plug from this jack during installation and repair
> of wiring.
> *Testing
> Plug working phone directly into this jack. If phone operates,
> fault is in wiring. If phone does not operate, call repair
> service.

This is the telephone network interface (or demark box), which
demarcates the place where the phone company's responsibility for
phone line problems ends and yours begins. Plugging a known working
phone into this jack will help you determine who gets billed for the
service call.

>When I opened the case, I noticed that the red and green wires
>(the only ones that will be actually used by the telephone itself)
>are also connected to a little circuit board whose most conspicuous
>component is a yellow cylinder-shaped object (about 3/4" long and
>about 3/8" diameter) with the following markings ...
>
> 250V
> TI
> 0.47 MFD
> +/- 10%

Could be some cheap surge supressor, but more likely an RF supressor
of some kind. Try removing it and see if you get radio stations on
your phone. [You may need to remove it if you want DSL, for
instance.]

There should also be lightning arresters on each line. Modern ones
look like little grey boxes bolted to the ground wire.

>Also, when I looked inside the jack itself
>(the hole where you would plug the phone into),
>I noticed there's some strange-looking gunk inside.
>It's clear-colored and has the consistency of rubber cement.

It's a waterproofing compound that's inside the incoming cable.

.