Figure 1 shows the block diagram for the NTE789. The input signal form the detector is amplified by a lowdistortion
preamplifier and simultaneously applied to both signal, generated by a local voltagecontrolled oscillator
(VCO), is counted down by two frequency dividers to a 38kHz signal and to two 19kHz pilottone supplied
by the FM detector is compared to the locally generated 19kHz signal in a synchronous detector.
NTE789 Stereo Multiplex Decoder
The resultant signal controls the voltage controlled oscillator (VC)) so that it produces an output signal to
phaselock the stereo decoder with the pilot tone. A second sychronous detector compares the locally generated
19kHz signal with