Extend phone cable with Cat5?

[dave.81]

I've just got back from a few weeks paternity leave to find that the main reception has been ripped out and redesigned, thanks for the warning...

I now have a phone cable lying around that needs extending, i seem to remember that you can extend it with cat5 cable.

Can i just connect the cables together and it'll work or should i be using some sort of adaptor? Best bit is they have removed them from the wall boxes and i have no idea what cable plugs in where...

[powdarrmonkey]

If the cable to be extended is also cat 5, you can just jumper it but make sure it's pin to pin. If it's two pair, you just need to be more careful and don't connect all strands. If you're not sure, don't try.

[tom_newton]

Have done this a few times. As powdarrmonkey says, it is easiest if you just have 2 wires.

Personally going from a standard master socket to a phone, I found it easier to order a ethernet-plug-to-phone-socket lark, but I did the "phone socket to ethernet cable" bit myself by disecting a cable wot i stole from a phone, and patching it into a piece of hacksawed patch panel. You may be able to buy the whole shooting match. Depends where your socket is (if it is near an existing patch panel, that may be an easy option) etc.

There's no problem with just patching around til you get the right wires, but there are diagrams out there. If need be I can go and fish out one of my creations and check. Think they're all mothballed now, as we have started putting the faxes (our only PSTN phoines) on VoIP using linksys ATAs.

[_Adam_]

Cat5 is better quality than phone cable, and I have used it for a while now without problems (if there are problems let me know).

I would always recommend a junction box for joins, whether you're terminating plugs or bare wire. To echo the others, just be careful you do not cross wires.

[dave.81]

The cable it's using at the moment seems to be 3 pairs but it's only using 1 pair so as long as i patch just 2 cables and dont cross them all should be fine i hope.

They are now talking about wanting the fax relocated to so looks like i'll have plenty of practice to get this right.

[powdarrmonkey]

The cable it's using at the moment seems to be 3 pairs but it's only using 1 pair so as long as i patch just 2 cables and dont cross them all should be fine i hope.

Then it sounds like analogue or digital phone trunk cable - just keep the pairs correct and you can jumper cat5 onto them.

[maniac]

My phone cable here is extended using Cat5 - I found an old modem lead which I crimped a cat5 plug onto the other end of, then into a piece of normal cat5 via a connector, then I changed the plug on the end of the normal phone cable for another cat5 one which connects onto this with another connector - I can extend my phone cable as much as I need to just by changing the interlinking patch lead for another one.

At my previous school, all the phone distribution was over cat5. Each cabinet had a telephone patch panel in with 20 pairs connected back to a massive array of patch panels next to the telephone switchboard. That way we could move extensions around the building just by patching the relevant telephone extension through to whatever wall outlet we wanted. Little bit cumbersome to make mass changes to, and the patching was a total mess after years and years of patching and re-patching, but it worked well.

[smiths75]

Looking ahead you could have had all phones on Cat5 then used any connection for phone (dependant on how you patch in your patch panels).
E.g. all odd numbered ports patched for telephones all even number ports patched for PCs don’t have to have a full VoIP system

The use of a Secondary or Master Balun is required at the telephone end

Westlake Communications Ltd BALUN / MODTAP

This is only a brief explanation slightly more involved.

[smiths75]

Westlake Communications Ltd BALUN / MODTAP

Telephone adaptor for converting BT telephone lead to Cat 5 socket (known as secondary baluns or modtap) - commonly used with digital or proprietary system telephones.

MASTER BALUN / MOD TAP

These adapters allow analogue telephones / modems to be connected to Ethernet (Cat 5) wall sockets or UTP networks, with a view to running a phone system over Cat 5 structured cabling.

[timzim]

Don't waste money on connectors - you can solder the wires together easy enough. Just insulate them from each other and don't untwist the pairs too much. Or you could use the standard BT practice of twisting the wires together and plopping a scrappy bit of sticky tape on top. (If anyone from BT thinks that's libellous they're welcome to come and inspect our 50 year old phone cabling).

[ahuxham]

Don't waste money on connectors - you can solder the wires together easy enough. Just insulate them from each other and don't untwist the pairs too much. Or you could use the standard BT practice of twisting the wires together and plopping a scrappy bit of sticky tape on top. (If anyone from BT thinks that's libellous they're welcome to come and inspect our 50 year old phone cabling).

Surely standards have improved in the modern era?

[powdarrmonkey]

Don't waste money on connectors - you can solder the wires together easy enough. Just insulate them from each other and don't untwist the pairs too much. Or you could use the standard BT practice of twisting the wires together and plopping a scrappy bit of sticky tape on top. (If anyone from BT thinks that's libellous they're welcome to come and inspect our 50 year old phone cabling).

Bad Idea™. In a year's time you don't want to be redoing it because the solder joint has dried out; at least use junction block if not a proper connector. An IDC connector is the best solution.

[timzim]

Bad Idea™. In a year's time you don't want to be redoing it because the solder joint has dried out

Solder? Dried out? What are you soldering with???

[powdarrmonkey]

Solder? Dried out? What are you soldering with???

A dry joint is one which has not properly formed during soldering, and increases the resistance of the electrical path. If they are allowed to wear, the whole joint can disintegrate. Why do you think Cat5 doesn't include any soldered joints in the specification?

[timzim]

A dry joint is one which has not properly formed during soldering, and increases the resistance of the electrical path. If they are allowed to wear, the whole joint can disintegrate. Why do you think Cat5 doesn't include any soldered joints in the specification?

Thanks for the lecture however, if you solder properly your joints shouldn't be dry. Why would I recommend soldering if I was going to bodge the job and do rubbish soldering?? And where/how exactly is this cable going to wear since it's most likely going to be in a conduit?

Anyway, we're not talking about using the cat5 for high quality data, are we? In this case it's just for ordinary analogue phones, in which case soldering the cable is fine.

Ok, to eliminate the risk of dry joints I'll add the proviso: don't solder the cable if you're a one-handed monkey who can't handle a cup of tea without spilling it.