Figure 2, AC Voltage Circuit of RCA WV77. The common input jack goes to meter circuit common. The common jack goes to chassis through the parallel combination of a 1 meg ohm resistor and a 0.001 u f capacitor. The AC OHMS jack connects to the rotor of switch S2E. The switch is shown in the AC position. The AC stator connects to one end of a 0.047 u f capacitor. The other end connects to 5 of the stators of switch S1D, range switch. These are, 1.5 v, 5 v, 15 v, 50 v, and 150 v. the 150 v stator connects through a 900 k ohm resistor to the 500 v stator. The 500 v stator connects through a 320 k ohm resistor to the 1500 v stator. The 1500 v stator connects through a 138 k ohm resistor to circuit common. This is the prerectifier divider which prevents voltages higher than 150 volts from being applied to the rectifier. The rotor is shown in the 500 v position. The rotor connects to one end of a 0.02 u f capacitor. The other end connects to the rectifier tube. The tube contains two independent diodes. The capacitor connects to the anode of diode 1 and the cathode of diode 2. The cathode of diode 1 is connected to common. The anode of diode 2 goes to common through another 0.02 u f capacitor. The anode also goes through a 20 meg ohm resistor to the AC stator of mode switch S2D. This point goes through a 91 meg ohm resistor to the wiper of the AC BAL, a c balance pot in the power supply. The rotor of S2D goes to the 1.5 v stator of S1B, range switch. The 1.5 volt stator of S1B goes through a 7 meg ohm resistor to the 5 v stator. The 5 v stator goes through a 2 meg ohm resistor to the 15 v stator. The 15 v stator goes through a 700 k ohm resistor to 50 v stator. The 50 v stator goes through a 200 k ohm resistor to the 150 v stator. The 150 v, 500 v, and 1500 v stators are all tied together. This is the post rectifier voltage divider. The three stators connect through a 70 k ohm resistor, then a 20 k ohm resistor, then a 10 k ohm resistor to common. Three separate resistors are used because they also connect to the DC voltage divider switch that is shown in cyan. The rotor of S1B connects to the AC position of S2F. The rotor of S2F connects to the 3.3 meg ohm resistor which connects to the left hand grid of the meter amplifier tube. This completes the verbal description of the AC measurement portion of the meter.
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