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What is this phone line device for? |
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#1 |
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Forum Member
Join Date: May 2004
Posts: 10
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What is this phone line device for?
A friend of mine has an unknown device fitted to the BT wiring outside his house, and wants to know what it does. It's a long cylinder shape and is made by 3M corporation. Image linked below:
http://www.peterbaran.com/misc/device.jpg |
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#2 |
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Forum Member
Join Date: Sep 2004
Location: Essex
Posts: 712
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it just seals the join in the cable and keeps water out
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#3 |
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Forum Member
Join Date: May 2004
Posts: 10
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Interesting. Why is it so large if that's all it does?
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#4 |
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Forum Member
Join Date: Jun 2001
Location: Dorset
Posts: 1,709
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I think it's a joint for a larger number of lines than the normal line that goes to a property. This is the sort of thing that you would expect to see in a block of flats or the like, though I have seen it linking up a row of houses where the cable runs along the building from one end to the other rather than all coming off a pole.
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#5 |
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Forum Member
Join Date: Jul 2010
Posts: 24,092
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Yep! Waterproof junction box, as said.
Standard phone wiring uses 6 wires, There are 6 pins on the rj11 jack, 2 currently not used, 4 used for distributed wiring ......... http://www.wppltd.demon.co.uk/WPP/Wi...telephone.html |
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#6 |
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Forum Member
Join Date: Mar 2006
Location: Hampshire, England
Posts: 7,172
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Quote:
Yep! Waterproof junction box, as said.
Standard phone wiring uses 6 wires, There are 6 pins on the rj11 jack, 2 currently not used, 4 used for distributed wiring ......... http://www.wppltd.demon.co.uk/WPP/Wi...telephone.html BTW, even Internal wiring only needs one pair. The ring circuit hasn't actually been needed for donkey's years and the other three wires have never been used. |
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#7 |
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Forum Member
Join Date: Jul 2010
Posts: 24,092
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Only a sinlge pair from exchange. No recall. We don;t now have party lines (listening to neighbours used to be fun).
I believe any BT installed extensions after the master socket still use all 6 wires. |
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#8 |
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Forum Member
Join Date: Mar 2006
Location: Hampshire, England
Posts: 7,172
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Quote:
I believe any BT installed extensions after the master socket still use all 6 wires.
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#9 |
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Forum Member
Join Date: May 2004
Location: Reading
Posts: 27,900
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Quote:
Nope. Not that I have ever seen. 2, 3 & 5 are usually connected even though 3 is unnecessary. Some say that BT have connected 4 for neatness in the past but I haven't come cross it. The only time I have found all six connected was when the work was carried out by the householder or sparkies and the like. ('Cos it's wrong.)
I have also seen systems which use 1 and 6. These would be specialised systems that have clever extension phones with loads of non-standard features. The extra pair is used for data signalling back to the PABX unit. |
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#10 |
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Forum Member
Join Date: Jul 2010
Posts: 24,092
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"Although pin 4 has no function in a domestic installation it is usually connected for the sake of neatness. The quality of wiring carried out by many older BT wiremen is often approaching art in its perfection."
http://www.wppltd.demon.co.uk/WPP/Wi...telephone.html Phone cable is 6 core. You're adding an rj connector, Y not all 6 wires? |
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#11 |
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Forum Member
Join Date: Mar 2006
Location: Hampshire, England
Posts: 7,172
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I know about that statement on that site and I do not agree with it. Posting something on a web sites doesn't make it true.
I'm not sure what you mean by: "Phone cable is 6 core. You're adding an rj connector, Y not all 6 wires?" |
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