What Is The Principle Of Intermediate Frequency Transformer And What Is Its Main Function

Intermediate frequency transformer (commonly known as mid cycle) is a unique transformer with fixed resonant circuit in superheterodyne transistor radio, but the resonant circuit can be fine tuned within certain limitations to achieve undisturbed resonant frequency (465kHZ) after being connected to the circuit. Fine tuning is accomplished by changing the relative position of the magnetic core. Its mechanism is the IF transformer in the radio. Most of them are monotonic harmonic type, with simple structure and small space. Due to the low input and output impedance of the transistor, in order to make the intermediate frequency transformer match the input and output impedance of the transistor, the primary has taps and has a small number of turns of secondary coupling coils. Dual tuning has the advantages of good selectivity and wide passband, which is often used in high-performance radios. Transistor radios usually use two-stage IF amplifiers, so three mid-range amplifiers are needed to couple and transmit the front and rear stage signals. The middle cycle in the actual circuit is usually represented by bz1, bz2 and bz3 symbols. Their positions in the circuit cannot be changed at will in use.