FM surveillance BuG Transmitter

The Circuit shown can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Frequency range is 88-108 MHz. Max current consumption is 30mA. You can power the bug with a 9Volt Battery, or you can plug a power supply to feed in 9-12 Volts. More: That bug will pick even a low whisper or even the sound of a breath well far from the microphone. Great spy equipment.

This circuit is designed as a simple FM transmitter, capable of transmitting audio signals over a frequency range of 88 to 108 MHz, which is typically allocated for FM radio broadcasting. The key components of this circuit include a microphone, an oscillator, a modulator, an RF amplifier, and an antenna.

The microphone serves as the audio input, converting sound waves into electrical signals. This signal is then fed into an oscillator circuit, which generates a carrier frequency within the specified range. The oscillator can be built using a transistor or an integrated circuit, depending on the design's complexity and desired performance.

A trimmer capacitor is included in the circuit to allow fine-tuning of the oscillator frequency. This tuning capability is essential for ensuring that the transmitter operates on a specific frequency that does not interfere with existing radio broadcasts.

The modulator combines the audio signal from the microphone with the carrier frequency. This process encodes the audio information onto the carrier wave, which is then amplified by an RF amplifier. The RF amplifier increases the power of the modulated signal, allowing it to be transmitted over longer distances.

The output of the RF amplifier is connected to an antenna, which radiates the modulated signal into the surrounding environment. The design allows for a maximum current consumption of 30mA, making it efficient for use with a 9V battery or an external power supply that can provide between 9 to 12 volts.

This FM transmitter circuit is capable of picking up even quiet sounds, such as whispers or breathing, making it suitable for covert applications. The simplicity of the circuit allows for easy assembly and integration into various projects, particularly in the realm of audio transmission and surveillance.The Circuit shown can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Frequency range is 88-108 MHz. Max current consumption is 30mA. You can power the bug with a 9Volt Battery, or you can plug a power supply to feed in 9-12 Volts.

That bug will pick even a low whisper or even the sound of a breath well far from the microphone. Great spy equipment ;)

🔗 External reference