Intercom & doorbell 2 stations

This circuit device is a mini communication tool, to be used at home, with a microphone which is connected to a loudspeaker to another room.

Technical specifications:
- power supply : 6-12VDC.
- consumption : 40mA (talking), 182mA (push SW tone)
- there is calling tone.
- max. length of shielded cable : 50m.
- PCB dimensions : 2.73 x 2.03 inches. (big board) 1.15 x 0.76 inches. (small board)