Red GPO 741 Wall Telephone - for all domestic VoIP services. BT Digital Voice, EE, Sky etc.
Supplied with our own inDAT Pulse to Tone converter to give you tone dialling and, if you require, 'Star', 'Hash', 'Last Number Redial' and up to seven stored numbers. These options are switchable so the telephone can quickly be customised to your needs.
Developed with Geoff Peters, the inDAT is an internal pulse to tone converter that is near silent in operation. It is designed to function on traditional copper telephone lines, all domestic VoIP lines (BT Digital Voice, EE, Sky etc) and external ATA's. It is not suitable for use on Digital Business lines without an external ATA.
About the telephone
The Telephone 741 was first introduced in 1968 to replace the 711. Originally only available in Black, Grey and Ivory, this telephone is recased in Red.
This 741 is fitted with an excellent 'aftermarket' fixing bracket which is a significant improvement over the original, utilising keyhole fixing slots. As a result the bracket does not need to be removed from the telephone to hang it. We will also include a template to make it easy to mark the fixing positions.
Of course it has the quintessential twin bell 'ring ring', a No.21 numeric dial and an electret transmitter unit for high quality speech. It also comes complete with our own reproduction paper furniture on which we can print your exchange and telephone number.
About our inDAT
This is another product we produced because we were not happy with the performance of other similar products on the market.
Because we know a lot of our customers like vintage telephones to be kept as original as possible, our inDAT can operate in one of three modes.
1) Pulse to tone conversion only – dialling 0-9.
2) Pulse to tone conversion, 'Star' & 'Hash'.
3) Pulse to tone conversion, 'Star & Hash', 'Last Number Redial' & Stored Numbers.
Our inDAT is fitted internally. It is a single unit and requires no addition components.
Technical Notes
The inDAT has full bridge rectification to protect against reverse line polarity. It needs 24mA to operate which is matched or exceeded by all common VOIP services.
It has a balancing circuit to work with most types of microphone - carbon or electronic.
Once a dialled digit has been detected, the circuit will send out a corresponding tone burst to line using DTMF4 encoding. To solve the noise issue we have a muting device to attenuate the tone to an almost inaudible level.
Because of the current draw, the inDAT cannot be used in a circuit that has a Dial-A-Tone before it in the circuit. Rearranging the order of connection will resolve the issue.
Note: Because of variance across the new VOIP market, we supply all inDAT installations with a BT to BT ring capacitor adaptor. This will allow telephones to ring in all VoIP connections that do not have a ring capacitor, but should not be used unless required. Please contact us and we will explain – it’s very straightforward!
