schematicwiring.com

The following wireless microphone uses a single transistor with additional passive components. It only needs a single cell 1.5volt battery, and can work on 1.2V rechargeable battery. Here is the schematic : Transmission range is between 30-50m radius, depends on the surrounding path and obstacles. Any transistor with high frequency bandwidth and low base-emitter will [...]

This is a FM Transmitter circuit. This circuit uses logic gates. This transmitter circuit has a RF oscillator. This oscillator uses 10.7Mhz ceramic filter and inverter N2 to drive the parallel combination of N4 to N6 through N3. Here is the circuit: The output impedance will be low because these inverters are in parallel, so [...]