2. 306 With zero signal into the bridge bring the ground level recorder to zero by adjusting R=-3 (See Fig. 16) Calibration The calibration of the telepulse coding unit should be done in the following order: 1) bridge, 2) converter, 3) comparator. Figure 16 shows the positions of the controls. 30601 Bridge: 1. With zero input, the bridge is balanced (R-3) to produce a zero reading on the recorder. 2. A negative one volt signal is applied to the input and the sensitivity control (R=-5) adjusted for full scele on the recorders 3. The marker push button is closed and the recorder brought to full scale by adjusting R-9. lh. The duration of the marker is set by adjusting timer T-1, 3.6.2 The minimum period should be five seconds. Converter: 1. With zero signal input, the bias of V=3 is adjusted to -1.45 volts. The amplitude of the converter output pulses, appearing across R-10, should be approximately 16 volta. 2. With 1.4 volts applied to the input of V-3, the amplitude of the pulses across R-10 should be approximately 30 volts. 3.603 Comparator: 1. Resistor 2-5 in the comparator unit is adjusted so that the univibrator (V~-13) is triggered reliably by ten volt input pulses. @ 35