Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[NewtronStar]

Only just come across this thread.

I can say quite categorically, with just one wire connected (be that A or B wire), the phone will not work at all. The Broadband will work, but will be very slow compared to it's usual speed.

May be you could tell me why my phone worked and no sync to modem with A connected to A and B connected to Earth on the BT80b 

[Black Sheep]

The only reason would be a short-circuit between the 'Earth' and the 'B' terminal of the BT80b. Either via a physical wire, a faulty soldering track, or dampness.

[Dray]

May be you could tell me why my phone worked and no sync to modem with A connected to A and B connected to Earth on the BT80b 

One wire connected to earth is still both wires connected.

[roseway]

B*cat explained it several messages ago.

[NewtronStar]

May be you could tell me why my phone worked and no sync to modem with A connected to A and B connected to Earth on the BT80b 

One wire connected to earth is still both wires connected.

I suppose if I look at this way incoming pair A wire connected to A terminal and B wire connected to Earth terminal on BT80b and then the A wire from BT80b then goes into the A terminal of the NTE5/A and the B wire which is earth from BT80b then goes into NTE5/A B terminal

So A and Earth (B) connected made the phone work but not the broadband.

[burakkucat]

I suppose if I look at this way incoming pair A wire connected to A terminal and B wire connected to Earth terminal on BT80b and then the A wire from BT80b then goes into the A terminal of the NTE5/A and the B wire which is earth from BT80b then goes into NTE5/A B terminal

So A and Earth (B) connected made the phone work but not the broadband.

I thought I had explained what had happened, back whenever, and only posted a brief recap, above.

Let's start at the beginning.

A BT80B RF3 has six terminals, three screw and three IDC. If one views the RF3 in a portrait orientation, there are three terminals in the top right-hand corner and three terminals in the bottom left-hand corner. Please see the picture and the description in this forum post.

The terminal marked A in the top right-hand corner cluster is connected to the terminal marked A in the bottom left-hand corner cluster via one winding of a common-mode choke on a shared core. The terminal marked B in the top right-hand corner cluster is connected to the terminal marked B in the bottom left-hand corner cluster via the second winding of a common-mode choke on a shared core. The terminal marked E (or Earth) in the top right-hand corner cluster is connected directly to the terminal marked E (or Earth) in the bottom left-hand corner cluster.

When N*Star experienced his wiring mishap, he had made use of the A and E (Earth) terminals from each terminal cluster. One leg of the circuit was directly connected, the second leg passed through an inductor. In that case there was DC continuity (and adequate AC continuity in the 300 Hz to 3400 Hz band, as used by the telephone service) for the telephone to operate. However the AC continuity and balance of the circuit was grossly perturbed at VDSL2 frequencies, so much so that the CPE (modem) failed to synchronise with the cabinet DSLAM.

[Black Sheep]

Aha ...... now we're talking. For the first time in the thread it's been mentioned that it is a BT80B RF3. It has only ever been referred to as a BT80B, which does NOT have the inductor in place, and therefore would not complete the PSTN part of the circuit.

Thank you B*Cat, although I had a sneaky suspicion this is what was being alluded to all along. 

[NewtronStar]

Aha ...... now we're talking. For the first time in the thread it's been mentioned that it is a BT80B RF3. It has only ever been referred to as a BT80B, which does NOT have the inductor in place, and therefore would not complete the PSTN part of the circuit.

Thank you B*Cat, although I had a sneaky suspicion this is what was being alluded to all along. 

Their is only one type of BT80b and they all have the RF3 or inductor
http://www.run-it-direct.co.uk/BT80BRF3.html

[Black Sheep]

Aha ...... now we're talking. For the first time in the thread it's been mentioned that it is a BT80B RF3. It has only ever been referred to as a BT80B, which does NOT have the inductor in place, and therefore would not complete the PSTN part of the circuit.

Thank you B*Cat, although I had a sneaky suspicion this is what was being alluded to all along. 

Their is only one type of BT80b and they all have the RF3 or inductor
http://www.run-it-direct.co.uk/BT80BRF3.html

You really wouldn't want to put money on that, NS mi' old mate. 

We have the bog-standard BT80B (inductor-free) and BT80B RF3 (with inductor) ...... plus a BT85 with nothing in it's just a basic junction-box for crimping wires through.
Below is a 'Cut & Paste' from our e-Assistant library .............

Note: The BT 80B lid will look like the BTs 80BRF3 and 85, therefore you will need to open the block terminal to confirm type..

To add to  the mix, we also have a BT78A, which again is very similar in look to the others, but comprises of a bank of Krone terminals inside.

All by-the-by though, as again to reiterate and for understanding for others looking in ....... with just one-leg of the two-leg circuit connected, the phone WILL NOT work at all. The DSL will, but very slowly.
Knowing now that you had connected both legs (one through the Earth of the BT80B RF3 and NOT a standard BT80B) makes it easier to grasp why you had the situation you did. 

Of course, with B*Cats concise explanation as well. 

[NewtronStar]

You really wouldn't want to put money on that, NS mi' old mate. 

 I would have lost the bet again 

[Black Sheep]

I wouldn't have taken the sixpence off you.