Master phone sockets.

[Bob Eager]

Only that you appeared to be correcting a statement that wasn't wrong.

[Owain]

LJUs were not supposed to be used on party lines. The bell wiring was different, as well as needing a fleeting earth to seize the linefinder.

I think we're confusing master sockets and lineboxes, folks.

Owain

[Kaiser]

I know they were not intended to be used for party lines, but in several cases they were. The problem being there was still party lines around when the LJU's came out and the old type jacks were discontinued. The old type of phones could have the bell circuits modified from series to parallel by re arranging the links and fitting a new lead.

[John Rumm]

Note that I said "input" - there are two screw terminals on the back of the socket for the A & B lines from the exchange, there are then a further 6 IDC terminals for the outgoing line with wires as you descibe.

Piccie here (half way down):-

[Dave Liquorice]

an NTE it had three screw terminals A B amd Earth connected to the center of the center tapped surge arrestor. But I guess there are variants in use.

[Andrew Gabriel]

Yes, I have a few old BT ones here. About half of them have an earth terminal, about half of them have a surge arrestor plugged in (not related to weather they have an earth terminal or not), but none have a center tapped surge arrestor, from which I assume none actually had an earth connection when in use.

[Bob Eager]

I think that's the variant! The more usual one is this:

the surge suppressor *isn't* centre tapped, and there is no earth terminal.

[John Rumm]

I get the imporession they call it a PBX-NTE5 on the gorunds that is the only legit place and end user could install one ;-)

That looks exactly the same as the one in the solwise piccie (the NTE5 that is rather than the plain "master")... or am I missing something?

[Bob Eager]

I'm no telecoms engineer, but I'd hazard a guess that > 99% of domestic master sockets are of this particular type/variant. (but I don't quite understand the parenthesised part of your reply)

[Kaiser]

My apologies. I can see what you are referring to now, I was referring to the original LJ1/1A as in this pic.

[Bob Eager]

Ah, I see. You'll understand that I was making the same point!

I remember 'illegally' fitting one of those, to a sunken wall box, in our last house. It'd only been there a few weeks and BT decided to replace the pole and all the drop cables. But the guy said my work was fine, so he left it...

[Kaiser]

I don't think BT engineers are too bothered if you fit your own sockets as long as they are wired correctly.

I was just looking at our master socket and I never noticed before that it is one of those NTE5 sockets with the removable lower front plate. Saying that, I've really not had a need to investigate before as there was a slave socket in virtually every room when we moved in 5 years ago.

[Bob Eager]

The nice thing about those is that it's easy to fit the 'proper' ADSL filter to them - either the original or the modified version. As luck would have it, our NTE5 is two feet from the router rack...

[John Rumm]

I was refering to the fact that the page link has two master sockets shown - the NTE5 (with removable faceplate section that lets you connect /disconnect the secondary side of the phone wiring by simply unplugging it), and the older master socket that it a one piece face plate.

The NTE5 shown on both sites is the same - two (screw) terminals in, six (IDC) out, no earth connection.

[Andy Wade]

The IDC-input version of the NTE5 is called a CTE5. If the N stands for network, what does C stand for?

[Bob Eager]

Customer? By definition, a non-IDC input wouldn't be much good for connecting directly to typical network wiring.

[John Rumm]

If you look at the manufacturer's site:

suggest the CTE5 might be used on CATV cable drops...

[Andy Wade]

"Cable" - methinks you've cracked it: the CTE5 version was, perhaps, introduced for the cable industry.

also tends to support that view.