GPO 746 VOIP setup

[ro55mo]

Hello

This is my first post and first attempt at making a setup like this work so please be gentle. 

I have recently purchased an old(ish) GPO 746 model rotary telephone built in 1978. The aim is to make it work over VOIP. See picture. The adapater unit is a Cisco SPA112. See

http://www.cisco.com/en/US/prod/collateral/voicesw/ps6790/gatecont/ps10024/ps10029/datasheet_C78-691106.html.

Currently I can place calls to the number I have for it through http://sipgate.co.uk but the bell does not ring. I have what I understand to be the correct voltage (75) and hertz (25) settings configured under the regional settings section of the device but no luck currently.

As a testing unit I have a modern tone phone. A very generic BT Converse 2100. This can place outgoing calls with no problem but also does not ring when an incoming call is placed although its incoming call light does flash.

I am aware I will need a pulse tone conversion unit of some type to allow the 746 to make outgoing calls but I want to solve the ringer issue first.

Any tips gratefully received.

Ro55mo

[twocvbloke]

The problem I'm guessing will be that the RJ11 to BT socket adaptor you're using there has no ringer capacitor, and is 2-wire operation only, and BT & converted GPO phones need that capacitor, which is normally housed in the Master socket, in there on the bell wire to ring...

One solution is to take an ADSL broadband filter (so long as it has an RJ11 socket on it's Line input, which you can replace with an RJ11-RJ11 cable) and connect it to the VOIP adaptor's RJ11 socket, this will in effect give you a master socket which will generate your ringing signal properly...

This sort of filter is what you need:
http://www.ebay.co.uk/itm/251198803623

I use a similar one myself on my Panasonic phone system to act as a mini master socket...