R&S®FKDL FM Monitoring Demodulator
The RF section of the FM Monitoring Demodulator includes a variable-frequency oscillator whose frequency can be modulated and which is synchronized to the frequency of the transmitter to be measured. A 5-LED array indicates the tuning with respect to carrier midpoint. The AC component of the correction voltage is proportional to the AF modulation voltage of the received signal and used after peak-rectification for indication of the FM deviation. The stereo decoder module working on the time-division-multiplex principle decodes the multiplex signal. The AF levels of the right and the left channel are indicated on LED arrays after A/D conversion. The stereo decoder module automatically switches over to mono operation if the pilot tone is absent.
