to ground the pulse generator 44 further includes an inverter 131 i1 74aco4 whose input is connected to the range delay generator 53 and whose output is connected in series to the base of the transistor 126 via a resistor 133 r 22 ohms and a capacitor 134 c 10 picofarads the range delay generator 53 has its first input terminal 139 connected to one end of a resistor 140 r 4 7 kilohms the other end of the resistor 140 is connected to the 5 v power supply bus via a resistor 142 r 10 kilohms to the ramp generator 77 via a resistor 144 r 4 7 kilohms to a variable shunt capacitor 146 c ranges between 2 to 6 picofarads which is connected to ground and to the input of a first inverter 150 i1 74aco4 this simple rc delay circuit 144 146 provides an exponential delay function with respect to control range delay voltage supplied thereto the output of this first inverter 150 is connected to the input of a second inverter 151 i1 74aco4 which in turn is connected to the input of the inverter 131 via a potentiometer 149 the output of the resistor 149 is connected to a shunt capacitor 155 c 4 7 picofarads to ground the ramp generator 77 includes a capacitor 153 c 0 1 microfarad that is connected at one end to the output of the 40 hz scan oscillator 78 and at its other end to the base of a transistor 154 2n2222 via a resistor 152 r 1 kilohm the.