21. Detecting phase difference is very important in many applications, such as servo mechanisms, and demodulators . 22. This signal is mixed with the IF before the receiver's second detector ( demodulator ). 23. The only extra stage needed for AF ( other than the loudspeaker ) is an FM demodulator . 24. The mystery unravels a bit when you consider a modem's full name : MOdulator / DEModulator . 25. Some audio electronics manufacturers included the CD-4 demodulator as a built in feature of other equipment. 26. A four-channel audio receiver unit might contain the demodulator along with FM radio and amplifier circuitry. 27. A product detector is a type of demodulator used for filtered out from the output of the product detector. 28. These terms are traditionally used in connection with radio receivers, but many other systems use many kinds of demodulators . 29. There were even superheterodyne designs, which used the regenerative receiver as a combined IF and demodulator with fixed regeneration. 30. Generally, FM demodulators are not affected by amplitude variations, since the baseband is contained in the frequency deviations.
