Feature: 1. PURPOSE: 17F is an FM stereo transmitter chip, this machine is mainly used in wireless headphones. Package includes antenna x1, screw package x1, sound cable x1, easy to install. 2. WIDE TRANSMITTING DISTANCE: This kit has strong stereo sound, stable frequency, only need to solder without any debugging, transmitting distance is better than 100 meters. 3. STEREO MODULATOR: Stereo modulator generates a composite signal consisting of the main, sub and pilot frequency signals of the 38kHz oscillator. FM transmitter by modulating the carrier signal with the composite signal. 4. MAIN COMPONENTS: The transmitter by the power supply, pull code frequency control, phase locked circuit, the main frequency amplifier circuit. 5. SUGGESTIONS FOR USE: As a result of high frequency modulation circuit, although there is a better power filtering design, you should still choose a premium power supply to reduce the radio due to power modulation interference. Specification: Item Type: FM Radio Transmitter Module Material: PCB Color: Atrovirens Machine Main Technical Indicators: (1) Power Supply Voltage 9V 2A, It Is Preferable to Use a Switching Power Supply with Small Ripple to Reduce the Noise of High Frequency Modulation. Power Supply Voltage Should Not Exceed 9V, More Than May Be Due to Heat Generation and Burned Transistors and Chips. (2) Machine Current: About 60mA (3) High Frequency Power: About 300mW (4) Tested with a Spectrum Analyzer Waveform Integrity, Harmonic Components of Small (8) Self Setting Frequency: 87.7 87.9 88.1 88.4 88.5 88.7 88.9 106.7 106.9 107.1 107.3 107.5 107.7 107.9. Package List: 1 x FM Radio Transmitter Module 1 x Antenna 1 x Screw Pack 1 x Sound Cable 1 x User Manual Note: Should not use more than 9V power supply, more than 9V power supply will burn the chip, power tube.