The oscillator coil shown in the figure can have 14 to 40 turns with a socket in the middle of the winding. This coil is wound with wire 28 in a ferrite core approximately 1 cm in diameter. The variable capacitor can have values in the range of 80 to 220 pF and the signal can be taken from the collector of the transistor or from a second coil wound along with L1.
