[geeks] debugging house phones

[Charles Shannon Hendrix]

Fri, 27 Aug 2004 @ 22:36 -0400, Porkchop said:

> It really sounds like there is an electrical fault somewhere on the 
> line. I'm as much an ee as I am a trapeze artist, but my advice 
> (since you haven't fixed this since you posted tuesday) is:

On the inside or outside wiring?

> Option 1: Get the insurance plan... most telephone companies have the 
> option of you paying an extra (extremely reasonable fee) to support 
> your house wiring. Then you can call them and they'll deal with it no 
> matter what.

Not my house.  I've presented that option to them though.  I was just
trying to help them out.

> Option 2: Keep trying it yourself.

I'm going to look at it again this weekend some time.

> I'd hook up all three phones directly to the mod jack in the NID. If
> it dosnt work there, call the phone co and lie to the automated
> computer. Explain it to the linemen when he comes out.

This part is physically difficult.

> You say that each jack in the house has a dedicated pair going to the 
> basement... is it a clean junction box? Are any of the runs excessive?

What's excessive?  The phone company installs longer lines than I would
myself, so I've never really known for sure what the maximum length is.

> You say the modem on B hangs up when A gets a ring. If I remember my 
> telco tech well enough, a ring is generated by a voltage spike... 
> 90VAC at 20hz or something like (voice is tiny voltage compared). 

I think it's 80V, but yeah, that's the idea.

> If there is any sort of galvanic connection across the pairs, it may
> cause your hangup... and bring the voltage available to the ringers on
> those three phones down. 

That's what I was thinking about.

> You may be able to test this by disconnecting both lines at the NID,
> then testing for continuanty/resistance in the basement (or perhaps at
> the NID if you have customer-side contacts you can touch).

Heh... this is Tidewater Virginia... no such thing as a basement.
It's not even dry *above* the ground.

I can touch both customer and telco side contacts.  All I have is a
multimeter though.

I did a quick test across pairs on the internal wiring, with phones
disconnected, and I got no current across them.  I did a few quick tests
on alternate pairs too.  Same thing.

What about across the telco pairs?

One test I am trying to get the equipment to do: Run lines directly to
the telco side from the modem and a single phone.  If I call line A and
line B hangs up then, I'd say it is definitely on the telco side.

> If you notice a difference on wet verses dry days (or think you do), 
> there can easily be a problem on the telco side.

They told me that every time it rains, this problem is worse.  After a
storm, they often lose phone service.  Disconnecting all the phones and
then reconnecting them fixes the problem.

Thanks for the notes.

-- 
shannon "AT" widomaker.com -- ["There is no such thing as security.  Life
is either bold adventure, or it is nothing -- Helen Keller"]