Telephone Question...

Sounds ok... I think I would be tempted to fit a new style (NTE5) master socket to both lines before they get to the PBX. That way the PBX will be protected (a little) by the lightening arrester built into the master sockets.

It is probably just a phone without the audio bits ;-) hence should behave like a phone in terms of how it is connected.

Most PBXs use "PBX master" sockets at each extension. These are cut down masters with no lightening arrester - but they still contain the ringing capacitor. Hence they only need a single pair when wiring - so you can connect 4 extensions to 1 cat5 if you want - each connected to a different pair. If you have lots of normal secondary sockets you can convert them to PBX masters simply by adding a bell capacitor. I used

So I'd daisy chain from an NTE5 to the PBX would I?

I've still not worked out which cables i need to bring to my cellar setup, need to open up that box tommorow and check it out... the 4 pairs i have on the cat5 should be enough whatever though, and I picked up some nice IDC Punchdown terminal boxes to connect it to...

Cunning, ta, any idea which of the terminals I should be connecting it to? They're numbered 1 thru 6, and number 3 isn't connected at the pbx, so each extension is 5 wires.

Not on this PBX (see above) it's got 5 wires to each socket, presumably for systemphones.

This any help ?

The (usual) 6 core cable colours of the house wiring, are as follows:-

1. Green with White markings Unused in domestic phones.
2. Blue with White markings B wire (or A wire)
3. Orange with White markings Ring current wire (bell wire)
4. White with Orange markings Signalling earth (normally unused)
5. White with Blue markings A wire (or B wire)
6. White with Green markings Unused in domestic phones

The five wires will be for the internal extension system if the PBX is self powered I would think. If it is powered from the external lines and only switches between them if one line becomes engaged, then I think it would only have the three wires to the extensions like normal domestic phones.

I have the install manual for this, so if you have any particular qs, just ask. How much was it , out of interest, I might ebay the one I have. I only stopped using it as it did not transmit the caller id.

mrcheerful

PABX 'extensions' are normally just on a two wire system, so to add an extension to one - as your bell - use a normal master socket and slave, using three wires to the slave.

Until (or if) a line is connected into an NTE box you should not be messing with the NTE (other than the small front panel) or the wiring leading up to it. This might give you problems as your first line appears to be hard wired and have a bell box. The bell box may well be a low impedance bell rather than todays high impedance.

The use of CAT5 for this would be a big indicator to BT that someone has been messing with their wiring. If/when they find out you will be charged to have it corrected. Also as one line appears to be hardwired BT has records of lines that don't have NTEs fitted so even if you fitted your own you could still get lumbered with a "regularisation of illicit master socket" fee.

Probably best to get BT out to move/fit NTEs where you want them.

I'd give it its own extension you can then configure assuming the programming of the PBX allows, when it rings. For all external calls, on either line, perhaps ring differently between the two lines.

Although installing the bell on its own extension is advantageous, as it won't ring on a internal call/transfer to the phone on the extension it shares. I'm assuming the PABX is set to ring all extensions on an incoming call.

Christian.

I think I have the install manual actually, so that's not the problem ;)

I'm after a SystemPhone, and this is only the standard version of the 2+

Yep, it's setup as a Key System...

pah, the phone wiring in this house dates back to GPO days ;) The first line we have doesn't even have an NTE. I might pop over to RS later and grab a pair of CTE5's (The IDC Version of the NTE5) and extend the bt lines to those, then to the PBX...

yep, loads of help, i'll take a look at the incoming box and try to find out what they've done for our 2 lines.

the pbx is obviously internally powered, although it will switch thru to ext 20 for line1 and ext21 for line2 in the case of power failure.

Sorry, but no system phones. I'll have a check which one mine is, I expect it is the standard one, did enhanced have music on hold ? if so mine is standard. However at that price I'll stick it on ebay.

mrcheerful

yep, it did...

And BT will have a record of this, so when you call 'em out for a fault and the records don't match you stand a chance getting lumbered with the =A325 + VAT fee as detailed at the bottom of:

Provided your work is done to standard ie BTs side of the NTE is in CW1308 rather than CAT5 I doubt they'll notice... But don't say you didn't know. B-)

Oh and make sure the NTEs easy to get at, the engineers that visit are human and don't like having to work at arms length lying down in the under stairs cupboard only just able to see the sockets...roof spaces are a no no as well.

At £25+vat per line, i think i'll take the risk ;) Besides, i've already regularised the lines, by putting an NTE on one of them, and replacing the NTE on the other...

Although i'm going to reconnect the NTE on the newer line tommorow, as I found I actually need to keep that one working... oops! (My Tivo can't dial out...)

I'll take some pics tommorow when i've finished. BTW, are there any dangers in putting 2 NTE's on a line?

I might do an FAQ actually, there doesn't seem to be anything on diyfaq.org (which I used to host actually, and would be happy to do so again without bandwidth restrictions BTW), with a bit of specific info on PBX's, as it's something that interests me...

Hell, i'm so bored i'm going to go off and write something for Telephone/Data Wiring I think...

Why do you want a PBX? A DECT multi-phone cordless system is one in its own right. has all the features you want from one, and available from Argos cheap too.

Tiny handsets and buttons. Loads of features and menus you'll never need but have to use a magnifying glass to check. Give me a nice simple corded phone any day - unless you really need a cordless.

Because they are cheap, and they work, and have other facilities like door phones.

And the Mirror doesn't listen in to your private converstaions.

And the wirees work through foil lined plasterboard.

And you can drive modems through them.

And they are not recommended by IMM, and are therefore provbably good technology.

Being able to run multiple device types through it, such as fax, modem, computer/telephony integration etc. is one obvious one.

A simple DECT phone in front of a PBX as an extension may be useful. I do this in front of my ISDN one, but the latter is also supporting a whole bunch of other capabilities such as MSNs, call routing, forwarding and logging etc.

.andy

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