modem - dial-up line noise

[Peterclan2]

Can there be line noise outside the audible range that results in my ISP's server dropping the connection, and applying a continuous tone, as soon as the handshake has been completed?

Background: I typically connect at 46.7-48.0 kbps. REN on the line is <4. I had to call out the telco repair guy when 60 Hz noise suddenly appeared on the line and my connection speed dropped as the noise got louder.
When "fixed" by the telco all the 60 Hz noise had gone, but a low-intensity low frequency continuous hum had appeared. It might be a harmonic of a signal I can't otherwise hear. From that moment my ISP drops me as soon as I connect, without even attempting to shuffle down through the speeds.
The telco denies all responsibility. I'm going nuts. A little Radio Shack "noise eliminator" does nothing.
What do I do next?
BTW two computers with different configurations and modems are behaving in this manner, and I have connected directly at the consumer interface, thereby disconnecting all phone wiring in the house, in case it was acting as an antenna. And yes, the low hum is definitely incoming.

[bookbox]

FWIW here is a link to my server with some of their excuses for dropped connections: http://help.pacifier.com also includes some tests you can try to sort it out.

GL

[WyllyWylly]

It doesn't necessarily have to be line noise. A poorly terminated phone jack can cause the same problem, or a pinched wire - any number of conditions.

If it's consistent, it's probably a wiring problem. If it's not, you may be picking up interference in the line from an external source.

Unfortunately I can't do a thing about your telco. The local carrier in my area offers a "wirecare" service which has paid for itself time and again - it was they who once found that a crappy connection in an unused phone jack was causing my poor connections. The best suggestion I can offer is to keep after them; if you've circumvented the house wiring, I don't see how it could not be their responsibility.

Good luck.

[DocWatson]

"if you've circumvented the house wiring, I don't see how it could not be their responsibility." Mark

I agree 100% with Mark on this one. The problem is in their lines and not your house since you've connected directly at the consumer interface (which I assume is the jack on the outside of the house where the phone line comes in). INSIST that your phone co. send out another tech and request that they send someone who understands in line noise problems. These things can be real ######s, so you may have to keep after them about this until they get it right. <img src=/S/argue.gif border=0 alt=argue width=50 height=25> Once you show them that the problem is external (evidenced by your connection) they should have a difficult time denying responsibility.

[DaveA]

Remember that the most home owners are NOT paying for a clean line. If you want a clean line for data, you are going to have pay for it. All you are paying for is a VOICE line, and they must good for 9800 baud and that is all. Check with you local phone company and see what they have to say. I complained that I could here noise while using the voice line and ended up getting a good clean line. Then some one down the street complained and they (The phone company) switched my line for theirs and ened up with a another dirty line. About that time I when to cable.

[DocWatson]

Of course you're right, that we are not paying for a "clean" line, but we certainly have every right to insist that they provide the best service possible. The squeaky wheel etc, etc... As you pointed out, you complained and got what you asked for. For a little while anyway <img src=/S/compute.gif border=0 alt=compute width=40 height=20> How much complaining should relate directly to your options. <img src=/S/aflame.gif border=0 alt=aflame width=15 height=15> For some cable is not an option <img src=/S/frown.gif border=0 alt=frown width=15 height=15>

[DaveA]

I agree with what you said. It is just the the phone companies DO NOT have to provide a clean line unless you are paying for one. This is how some are pushing DSL, when you call to complain you are told about DSL.

[Peterclan2]

<P ID="edit" class=small>Edited by WyllyWylly on 24-May-02 21:58.</P>Thanks to all who offered comment. I had to do a lot more digging, and I've come up with news both good and bad.
1) http://www.modemsite.com offers a wealth of comment, troubleshooting methods, and advice -- well worth your bookmark.
2) My telco is adamant that their only contractual obligation is to provide a dial tone and voice connection.
3) There are many excellent technical reasons why general voice system upgrades and capacity extension results in changes that make lines dedicated to voice service unsuitable for modems.

Yes, I suspect that my telco is happily using degrading of voice lines by A/D and D/A converters as a way to promote its DSL sales, but I feel fairly sure that they are not deliberately impairing the use of lines by modems just to promote DSL sales.

In short, I think that the day of the modem in metro areas is just about over.