This sensitive FM radio tuner is the right circuit for hobbyists who want to build their own tuners instead of buying a “plug-n-play” finished product. The fm tuner circuit is designed with only 3 transistors. The amplification is around 40 dB. The first transistor works as an RF amplifier. The second transistor is the mixer.
The incoming signal is introduced into the base and the oscillator signal is coupled to the emitter. The third transistor is the oscillator. The coils are wind around 6 mm coil formers with a ferrite core. The best material for the coils is a silver coated copper wire since it is very easy to be tapped. The distance between the windings must be 0.8 mm.