Rca1948FrequencyModu.. - The New Jersey Antique Radio Club

:RATIO DETECTOR 361Since the ratio detectors described here use the balanced phaseshift type of input circuit, the characteristics of this circuit arebriefly reviewed. Figure 3 shows the basic phase shift circuit andthe manner in which the two frequency-sensitive voltages are obtained.These voltages are combined in the ratio detector as shown in Figure4(a). The variations in the open-circuit voltages e 1 and e 2 are convenientlydescribed by Figure 4(b). The rectified voltages E x and E 2are approximately proportional to OA and OB. The phase angle