FM Receiver with a Single Transistor

Figure 1 

This project contains a very unique one transistor FM receiver accompanied by homemade air-core coils and a homemade fixed capacitor.

The component count on this project was minimized to 12 without compromising or sacrificing the audio output, selectivity, and sensitivity. A small source coil was re-designed for the receiver which stands no taller than ½ inch and 8mm in diameter. The 30 gauge enamel coated magnet wire took 26 wraps and was soldered onto the PCB. The drain coil is also placed in the PCB without altering the spacing of the newly made coil since it is from this set form along with the tuning capacitor that the right FM band can be attained.

The variable/tuning capacitor may come from a salvaged AM/FM tunable radio for as long as it still has the turning knob on its shaft. There are typically 6 leads coming from the sides of the tuning capacitor with three leads on each side. Only two terminals will be needed to locate the frequencies from 87MHz to 107MHz and with the center terminal as the ground. Also created for this receiver are the drain/source capacitor and the drain capacitor.

Click here to see the rest of the project.