This DIY kit (HU-017A) is a wireless FM radio receiver with a 4-digit 7-segment display. It operates within the global FM receiving frequency band of 87.0-108.0 MHz, making it suitable for use in any country or region. The kit offers two power supply modes, allowing you to use it both at home and outdoors. This DIY electronic product will help you understand circuits and improve your soldering skills. Features 87.0-108.0 MHz FM Radio: Built-in RDA5807 FM data processor with a standard FM receiving frequency band. The FM frequency can be adjusted using the F+ and F- buttons. Adjustable Volume: Two volume adjustment methods – button and potentiometer. There are 15 volume levels. Active & Passive Audio Output: The kit has a built-in 0.5 W power amplifier to drive 8 Ω speakers directly. It also outputs audio signals to headsets or loudspeakers with AUX interfaces, allowing personal listening and sharing of FM audio. Configured with a 25 cm dedicated FM antenna and a (red) 4-digit 7-segment display for real-time display of FM radio frequency. The transparent acrylic shell protects the internal circuit board. It supports dual power supply methods – 5 V USB and 2x 1.5 V (AA) batteries. DIY Hand Soldering: The kit comes with various components that need to be installed manually. It helps exercise and improve soldering skills, making it suitable for electronics hobbyists, beginners, and educational purposes. Specifications Operating voltage DC 3 V/5 V Output impedance 8 Ω Output power 0.5 W Output channel Mono Receiver frequency 87.0 MHz~108.0 MHz Frequency accuracy 0.1 MHz Operating temperature −40°C to +85°C Operating humidity 5% to 95% RH Dimensions 107 x 70 x 23 mm IMPORTANT: Remove the batteries when powering the radio over to USB. Included 1x PCB 1x RDA5807M FM Receiver 1x STC15W404AS MCU 1x IC Socket 1x 74HC595D Register 1x TDA2822M Amplifier 1x IC Socket 1x AMS1117-3.3 V Voltage Converter 18x Metal Film Resistor 1x Potentiometer 4x Ceramic Capacitor 5x Electrolytic Capacitor 4x S8550 Transistor 1x Red LED 1x 4-digit 7-segment Display 1x Toggle Switch 1x SMD Micro USB Socket 1x Radio Antenna 1x AUX Audio Socket 4x Black Button 4x Button Cap 1x 0.5 W/8 Ω Speaker 1x Red/Black Wire 2x Double-sided adhesive 1x AA Battery Box 1x USB cable 6x Acrylic Board 4x Nylon Column Screw 4x M3 Screw 4x M3 Nut 4x M2x22 mm Screw 1x M2x6 mm Screw 5x M2 Nut