Stereodekoder (für FM-Empfänger)

This design is intended to meet the requirement for an FM tuner of outstanding performance that is easy for the home constructor to build and align. For optimum stability of tuning the circuit employs permeability tuning instead of the more popular but somewhat capricious varicap. Use of a variometer also reduces the number of `home-brew` coils. The first part of the article covers the design of the front-end and a simple i.f. strip and demodulator suitable for mono reception. A more advanced double- conversion i. f. strip suitable for stereo reception, and the stereo decoder are described in part two.