The following are the connections for the pyramid base of the Beocom 6000.
The wiring consists of a "T" adapter as below with three RJ11 sockets in it. Whilst RJ11 connectors can support up to 6 pins, the power and line sockets only use two pins (pins 2 & 5) and the Appliance (base) socket uses four pins (Pins 2 to 5)

The wiring for this connector is as follows:-

The mains power adapter is an unregulated unit with a loaded output voltage of 7.5 volts and rated at 0.5 amps. Below is a picture of the UK version of this power adapter:-
