BBC Single Point Chart Recorder BBC Single Point Chart Recorder Instructions This program uses the BBC A/D converterand printer to emulate a four channel dotting recorder. The analogue input voltage range is 0v to +1.8v Each channel is plotted as a different symbol and a description of each input signal can be printed next to the symbolused for that channel. The number of channels to be used can be selected, between 1 and 4. A minimum delay of 5 seconds between samples is recommended when using all four channels Selecting a gain of greater than unity decreases the analogue input voltage required to give full scale deflection.