Cat5e and phone wiring

[mark88]

If I were to flood a house with cat5e and have RJ45 sockets in each room. All cat5e cable going to a central point with a patch panel.

Now I wish to be able to use a patch panel to decide what RJ45 sockets in the house become phone sockets. The house has 1 telephone cable coming into it from outside which terminates at the BT master socket.

My question is this, if I connect the 1 telephone line to a patch panel just how many RJ45 sockets in the house can become telephone sockets? Just 1? I don't get how 1 incoming telephone cable can enable say 4 RJ45 sockets to be phone sockets.

Secondly, do you always need a master socket or could you go straight into a patch panel?

[PeterNav]

Telephone extension sockets are wired in parallel with the master. If there's nothing plugged in to them they present no load. When devices are plugged in to the extension sockets they present a load defined by their "REN" or ringer equivalence number. Different devices have a different REN but a typical BT line can support up to 4 REN. So the limit isn't "how many sockets" but the total REN of the devices plugged in to the sockets. It is also possible to buy REN boosters. e.g. http://www.maplin.co.uk/Module.aspx?...C=SO&U=strat15

The BT master socket includes a component to protect against high voltage spikes, a resistor and a "ring capacitor" that is necessary to make UK phones ring. Extension sockets don't have those components so a master socket is necessary to make the system work.

[FF99]

Just want to revive this with a related question. I have acquired an Orchid PBX to use as the hub of the Cat 5 wiring that I am installing. I want to use a large phone extension bell (BT 80D or somesuch) to connect up as an extension that the front door push button calls up through the PBX. However, the PBX does not seem to generate enough current to get anything other than a low buzz out of the bell unit. Will a REN booster improve this or is there anything else to be done ?

[beerhunter]

Originally Posted by PeterNav

The BT master socket includes a component to protect against high voltage spikes, a resistor and a "ring capacitor" that is necessary to make UK phones ring. Extension sockets don't have those components so a master socket is necessary to make the system work.

UK phones haven't needed any special ring circuitry for donkeys years. That is a hang-over from the days when we transitioned from hard-wired phones to the 'new' and exciting (it was then) sockets and was done so that existing phone types on extensions didn't 'tinkle'. Current UK phones are the same as any others the world over and run quite happily with out special circuitry of any kind.

Try it - I did.

However one does have to have a BT Master Socket because that is the BT/Subscriber 'Demarcation Point' and, in theory, provides some protection for the PSTN. Any extensions must be wired from that Master Socket.