What is this phone connection called?

[TheManFromIT]

I've been told that multiple phones around the school need longer extensions. Unfortunatley they plug into old BT phone sockets, about which I know very little.

 

One end is an RJ45 with connects to the phone, the BT plug end has 4 pins, but every cable I've ordered has them in the wrong layout. What should I be searching for?

 

[Steve21]

Do you know if it's a digital phone system? rather than analogue, as it's unlikely to be using RJ45 on the other side if it's not linked to a PBX normally

 

The standard ones would be with 4 gold in middle, so just wondering if it's connected to an on-site system first and it's using cat5 to split multiple phones across a patch

 

Steve

Edited September 21, 2023 by Steve21

[MatthewL]

It's a line jack unit (https://telephonesuk.org.uk/line-jacks/)

 

You can plug RJ11 (the small end that goes into the phone) into normal network points it will work. Analogue phones only require 2 wires to work.

 

You can also get these https://www.comms-express.com/categories/voice-converters-line-adapters/ which convert the LJU to RJ45.

 

A telephone extension lead like https://www.comms-express.com/products/telephone-extension-lead/ will allow you to extend.

[phil0569]

If its a 4 wire one it is a 431A if it has six wires it is a 631A connector. Long time ago Telewest, which is now virgin, did exactly the same ones but the retaining clip was on the opposite side which made more confusion, they were the 430A and 630A. It should have an RJ11 on the other end to connect it to the phone.

[TheManFromIT]

Your right it is RJ11 at the phone end. Just looked up the phone model, they are ancient Inter-Tel 8520 digital phones.

 

Still can't find the correct cable. 431A wiring is gap, 4 wires, gap. The ones I need are 2 wires, 2 gaps, 2 wires. I've considered trying 631A, but can't find anywhere that sells 5m.

[phil0569]

If it's 2 gap 2 then theoretically a 6 wire one should work, unless there are any cross overs. If you check Comms Warehouse you can get the whole phone for around £20 inc VAT

 

Intertel 8520 £20.13 | 551.852 | Business Phones, Digital Phone | Buy Online (commswarehouse.co.uk) would that be cheaper and easier

[TheManFromIT]

I've dropped them an email. Here's hoping...