The 9018 is a high-frequency, low-power NPN transistor made from silicon. It has a characteristic frequency (fT) of up to 1.1 GHz, making it ideal for use as an FM transmitter. This transistor is commonly used in simple radio circuits due to its performance and availability.
The following diagram shows a single-transistor FM transmission circuit using the 9018. This design is very straightforward, making it perfect for hobbyists and beginners who want to experiment or create temporary broadcasting solutions. As seen in the schematic, it's a classic three-point capacitor oscillator configuration. However, it's important to note that the 9018 is not a dedicated emitter follower transistor. As a result, some frequency drift may occur during operation. The higher the operating current, the more pronounced this drift becomes.
To build the circuit, a coil is wound with 6 to 8 turns of 1mm enameled wire around a 32mm drill bit. This setup allows the circuit to cover the standard FM broadcast band of 88-108 MHz, which is ideal for receiving FM radio signals. Adjusting the tightness of the coil helps fine-tune the transmission frequency. In open areas, the circuit can transmit up to approximately 100 meters using a dipole antenna. This makes it a great project for learning about RF circuits and basic wireless communication.
Pattern Braided Sleeve,Wire Sleeving,Expandable Braided Sleeving,Cable Wrap Sleeve
Shenzhen Huiyunhai Tech.Co., Ltd. , https://www.cablesleevefactory.com