This Design Idea applies a noveltopology to an oscillator. It usesa series-connected LC (inductive-capacitive)tank circuit to give the circuita higher tuning range than circuitsthat use a parallel-LC ...

The wire descending from the antenna goes to the parallel LC resonant circuit consisting of a coil and a variable capacitor, CV. Together they tune in to the desired frequency.

This novel LC resonant tank amplifies the magnetic coil current by 2X while generating a high-frequency magnetic field.

This is a common emitter Colpitts oscillator. R1 and R2 form a voltage divider to provide base bias. the emitter resistor R3 also provides some bias. R4 is the collector resisotr across which the any ...