bt line problem.

[tauran]

hi,
i am getting a lot of interference on my BT line. i can hear crackling as soon as i pick up the receiver. this is not a problem at BT's end as i removed the front panel from the main line box and plugged in a phone and it sounds crystal clear. i have 4 extensions from the line box, all have crackling on them, i have checked and all are wired correctly.
this crackling is also causing problems with my broadband, i lose the connection intermittently and have now noticed the only way to get the connection back is if i make or receive a phone call.

please can anyone help, this has been doing my head in for 4 months now.

thanks for any help.

[phcjpp]

I had exactly the same problem recently - it turned out to be due to dodgy internal wiring(I had done!). The wiring, although it worked was acting like an aerial and picking up 'crap' - I had even used cat5 twisted pairs.

I would suggest removing all internal wiring and adding it back one bit at a time to find out which bit is the issue.

The noise could also be due to a phone appliance so you had better remove those.

You are very fortunate that the line is clear at the BT side. This should really be fairly easy to solve through a process of trial and error.

Also note that crappy broadband appliances can introduce noise on the line - you will want to remove that when you are investigating - especially if youa re using an internal adsl card - you would not beleive the crap that comes out of pcs in the form of electrical noise.




Chris

[katman]

hi,
i am getting a lot of interference on my BT line. i can hear crackling as soon as i pick up the receiver. this is not a problem at BT's end as i removed the front panel from the main line box and plugged in a phone and it sounds crystal clear.

OK. So the incoming line appears to be clear which means the problem is inside the house

i have 4 extensions from the line box, all have crackling on them, i have checked and all are wired correctly.

Is the crackling present if you only have a phone connected to any one of the sockets ?

With your internal wiring connected but nothing plugged in, is the line still noisy if you plug into the socket on the front of the NTE5 facepate rather than the one behind the faceplate ?

How are your sockets wired ?

All individually run back to the NTE5 or daischained from one to the next.

Is your wiring plugged into the NTE5 or hardwired to the removeable faceplate?

Have you used the correct pairing of the cable ?

BLUE/White 2
ORANGE/White 3
WHITE/Orange 4
WHITE/Blue 5

Incorrect pairing can introduce noise as the line becomes unbalanced.

this crackling is also causing problems with my broadband, i lose the connection intermittently and have now noticed the only way to get the connection back is if i make or receive a phone call.

Does the line hang up properly after you have made a call.
ie If you pick up straight after a call do you get dial tone?

Does the line ring properly on an incoming call or does the ringing trip after a couple of rings ?

You may have a damaged cable that has got damp and is either earthing on one wire or has gone partial short circuit across two or more wires.

It may also be one of your sockets or could even be damage to the removable faceplate of the NTE5.

IDC connectors should have a maximum of two wires punched down into them otherwise intermittant connections can occur.

You need to disconnect EVERYTHING and starting with the closest bit to the BT line start reconnecting and test at every stage until you find the problem.

Hope that helps

Keith

[tauran]

all wiring is correct, although you state there must be 4 wires. i have only connected 2,3 and 5.

the line hangs up properly,
the phone rings correctly on incoming call.
all the wiring comes back to the nte5 individually rather than daisy chaining.
i have 1 wire coming out of the nte5 into a junction box which then connects all the extensions.
i will disconnect all the connections this weekend and reconnect 1 by 1 to see if it is a particular connection.

1 thing i should mention is, my dad changed the line box a few months ago, this meant everything was working superbly/perfectly for a total of 1 day before the noise came back. this to me suggests a problem with one of the extensions.

[katman]

all wiring is correct, although you state there must be 4 wires. i have only connected 2,3 and 5.

WHITE/Orange on 4 isnt used. Just added for completeness

i have 1 wire coming out of the nte5 into a junction box which then connects all the extensions.
i will disconnect all the connections this weekend and reconnect 1 by 1 to see if it is a particular connection.

1 thing i should mention is, my dad changed the line box a few months ago, this meant everything was working superbly/perfectly for a total of 1 day before the noise came back. this to me suggests a problem with one of the extensions.

OK. Sounds like it is wired OK and having individual cables means you can abandon the offending one until you can replace it.

If they were daisy chained, sods law says it would be the first leg of the cable rendering everything out of action.

Regards

Keith

[tauran]

one thing i noticed the other day was, the telephone seocket in my bedroom (where PC is) was a master socket (1 with yellow capacitor type thingy) i replaced it with a normal one but this did not change anything. i suspect that i may have master sockets elsewhere in the house, would changing these make a difference???

[katman]

Additional master wont cause noise but may affect ADSL.

No need to change them, just snip the capacitor and resistor out.

Leave the lightnign arrestor in there, the more protection the better.

Keith

[tauran]

how should the "a" and "b" connectors on the line box be wired up, i know i've got a white/orange and orange/white going there but not sure which way round this should be.

[tauran]

also would this be a cheap and easy way to route my cables outwards from the line box.

http://www.maplin.co.uk/Module.aspx?...ges&doy=search

[katman]

With the line idle, the most negative wire should be on the B terminal but in reality is doesnt really matter and even if you do put it the "right way" round it may mysteriously reverse itself (polarity wise) due to people working on external cables.

The maplin website never ceases to annoy me. It is tne most unfreindly website ever needing lots of scrolling to see the item you are intereseted in yet the rest of the screen is filled with crap.

I also cant believe that they are charging £4 for that connector and only have two of them!!!!

Take a look at this
http://cpc.farnell.com/jsp/endecaSea...=TE00770&N=411

These are the type that BT use. They have 6 terminals rather than 4, there is also a BT78A but very few places stock that. It has 8 terminals so can fully connect all the pairs in a CAT5 cable.

Regards

Keith