The dreaded warning of being changed by BT for a callout

[Rik]

How about no phones?

[klipp]

I can't try that right now, I don't have a mobile but I'll get someone to call me tomorrow.

[Rik]

If you want to PM me your number, I'll do it now.

[klipp]

OK Well that was interesting.  I have just done the following:

1. Before doing anything.
result: n/m 6.5db

2. Disconnected the phone, leaving only the router connected to the test socket.
result: n/m 16db, eventually settles at 12db about a minute later.

3. Got my sister to call on her mobile.
result: n/m drops to 1.5db for a few seconds then jumps up to 16db.

4. Phone call ends.
result: n/m drops over a few seconds, before levelling at 12db.

5. Telephone is reconnected to test socket filter + router.
result: n/m returns to pre-test level of 6.5db.

[Steve]

Not sure of the explanation but I think if you didn't have a phone on that line you would get your sync back.

[klipp]

Well that is impractical due to the phone being required.  However a second phone line specifically for b/b is beginning to seem like a realistic idea, leaving my current line for the phone.

I assume a second phone line would not be degraded like my current one is?

[Niall]

Well that is impractical due to the phone being required.  However a second phone line specifically for b/b is beginning to seem like a realistic idea, leaving my current line for the phone.

I assume a second phone line would not be degraded like my current one is?

It depends. At my house, the main line is an absolute mess according to BT, and my line to my bedroom where I have my phone line with DSL is fine. It also depends if it's two lines or two lines spliced from one cable (for want of a better term).

[klipp]

There are currently 2 lines running to my house.  One used to be a second line and is currently disconnected.

[Simon]

Could it be the phone itself, I wonder?

[klipp]

Could it be the phone itself, I wonder?

Don't think so.  That recent screenshot was taken during a test with no phones connected at all.  Seems I get the rise to 15 or 16db when someone calls me, regardless of whether a phone is connected or not.

The curious thing about that test was that my regular noise margin is 12db with no phone connected, but 6.5db when the phone is connected.  Very odd.

[Technical Ben]

[Complete random speculation] Could the old wire be acting as an antenna and causing interference?
Could you try 2 filters? Hmm, but with no phone connected in the test, that would not help anyway. 

[Rik]

The curious thing about that test was that my regular noise margin is 12db with no phone connected, but 6.5db when the phone is connected.  Very odd.

The rise in noise margin is an improvement, eventually BT would reduce the target back to 6db and you'd get higher speeds. The fact it goes even higher when someone phones suggests a bad joint to me. The ringing current is improving the circuit for a short while.

[klipp]

bad joint

What's a bad joint?  Sounds like something you should avoid at Glastonbury.

[Rik]

That as well. BT cables run in segments between subscriber and exchange. There are several different kinds of joints employed, depending on the cable run, but your line will have several to many joints along its length. If one of them corrodes or gets a bit loose, it can cause problems.

[Steve]

I suppose the extra load of a phone in that situation just tips it over the edge.

[klipp]

Ah, so a second line might not make a shred of difference if the problem exists elsewhere.

[Rik]

It's impossible to know, unfortunately. However, if you order the line specifically for ADSL, you stand a good chance of improvement. First, though, follow through the changes the phone situation makes with support.

[klipp]

Thanks Rik.

I've been chatting with Brian from support this afternoon via email.  See what (if anything) can be done.  Interestingly he revealed his records show I have disconnected 11 times this week so far lol.

[Rik]

I'm not surprised.