1. Introduction
This manual provides detailed instructions for assembling, operating, and maintaining your DIY FM Radio Kit. This kit is designed for enthusiasts to build a functional FM radio from individual components, offering a hands-on learning experience in electronics.
The assembled radio features an 87-108MHz frequency range, an STC15W chip, RDA5807S FM module, and a TDA2822 amplifier, all housed within a transparent acrylic case. It supports dual power options: USB 5V or two AA batteries.
Figure 1.1: Assembled DIY FM Radio Kit with transparent acrylic case.
2. Safety Information
WARNING:
- This kit requires soldering. Always use appropriate safety gear, including eye protection, and ensure good ventilation when soldering.
- Handle electronic components with care. Some components can be sensitive to static electricity.
- Ensure the power supply is disconnected before making any changes or repairs to the circuit.
- Do not short-circuit the battery terminals or power supply.
- Keep out of reach of small children due to small parts and potential choking hazards.
3. Package Contents
Before beginning assembly, please verify that all components listed below are present in your kit:
- Circuit Board (PCB)
- Acrylic Case (multiple pieces)
- USB Cable
- Various Assembly Components (resistors, capacitors, ICs, speaker, antenna, buttons, battery holder, screws, etc.)
Figure 3.1: All components included in the DIY FM Radio Kit.
Note: You will need to provide your own soldering iron, solder, wire cutters, and a small screwdriver for assembly.
4. Assembly Instructions
This kit requires careful assembly and soldering. Follow these steps in order for successful construction.
Figure 4.1: The product is provided as a kit and requires self-assembly.
4.1. Component Identification and Placement
Familiarize yourself with the PCB layout and component values. The PCB is clearly labeled to guide component placement.
Figure 4.2: Printed Circuit Board (PCB) layout diagram.
4.2. Soldering Components
- Resistors: Solder all resistors according to their marked values and positions on the PCB. Resistors are not polarized.
- Capacitors: Solder ceramic capacitors (small, non-polarized) and electrolytic capacitors (larger, polarized - ensure correct polarity, usually marked with a stripe for negative).
- Diodes/LEDs: Solder diodes and LEDs, paying close attention to polarity (anode and cathode markings).
- Integrated Circuits (ICs): Carefully insert ICs into their respective sockets or solder directly if no socket is provided, aligning the notch on the IC with the notch on the PCB silkscreen.
- Buttons and Jacks: Solder the push buttons, 3.5mm headphone jack, and USB power interface.
- Speaker: Connect the speaker wires to the designated pads on the PCB.
- Antenna: Solder the telescopic antenna base to its designated spot.
- Battery Holder: Solder the battery holder wires to the appropriate positive and negative terminals on the PCB.
Figure 4.3: Detailed view of various electronic components for assembly.
4.3. Case Assembly
Once all electronic components are soldered and verified, assemble the transparent acrylic case around the PCB. Use the provided screws and standoffs to secure the PCB within the case and fasten the case panels together.
5. Operation
5.1. Powering On the Radio
The radio supports dual power options:
- USB 5V: Connect the provided USB cable to the micro-USB port on the radio and a 5V USB power source (e.g., phone charger, power bank, computer USB port).
- AA Batteries: Insert two AA batteries into the battery holder, ensuring correct polarity.
Choose only one power method at a time. After connecting power, turn on the radio switch. The digital display will light up.
Figure 5.1: Power options (USB or AA batteries) and 3.5mm headphone jack.
Video 5.1: Demonstrating powering on the radio and initial tuning.
5.2. Controls and Functions
Figure 5.2: Key components and controls of the FM Radio Kit.
- Antenna: Extend the telescopic antenna for optimal FM signal reception.
- Digital Display Screen: Shows the current frequency.
- Volume Adjustment: Use the rotary potentiometer (or designated buttons) to adjust the audio output volume.
- Frequency Adjustment: Use the 'F+' and 'F-' buttons to change the radio frequency. A long press may enable faster tuning.
- 3.5mm Headphone Jack: Connect headphones or external audio devices for private listening or amplified output.
5.3. Power Saving Mode
The radio features a power-saving mode for the digital display.
- To activate power saving mode, press the V+ and V- buttons simultaneously. The digital display will show 'L' and turn off after approximately 15 seconds.
- To return to normal mode, the display will show 'H'. This is the default operating mode.
Figure 5.3: Digital display indicating Power Saving Mode (L) and Normal Mode (H).
6. Maintenance
- Cleaning: Use a soft, dry cloth to clean the acrylic case. Avoid abrasive cleaners or solvents that may damage the plastic.
- Battery Replacement: If using batteries, replace them when the audio quality degrades or the radio fails to power on. Always use fresh AA batteries.
- Storage: Store the radio in a cool, dry place away from direct sunlight and extreme temperatures. If storing for extended periods, remove the batteries.
- Component Check: Periodically inspect soldered joints for any signs of corrosion or loose connections, especially if the radio is exposed to vibrations or frequent handling.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Radio does not power on. | No power supply; incorrect battery polarity; loose power connection; faulty switch. | Ensure USB cable is properly connected or batteries are correctly inserted and charged. Check all power-related solder joints and the power switch. |
| No sound or very low sound. | Volume too low; speaker not connected; faulty speaker; amplifier circuit issue; loose headphone jack connection. | Increase volume. Check speaker connections and ensure it's functional. Verify solder joints for the TDA2822 amplifier and headphone jack. |
| Poor reception or static. | Antenna not extended; weak signal; interference; faulty RDA5807S module; loose antenna connection. | Fully extend the antenna. Try moving the radio to a different location. Check antenna solder joint and RDA5807S module connections. |
| Digital display not working. | Loose connection to display; faulty display; power saving mode active. | Check connections to the digital display. Press V+ and V- to exit power saving mode. |
| Buttons not responding. | Loose button connections; faulty buttons. | Inspect and re-solder button connections if necessary. |
8. Specifications
| Feature | Detail |
|---|---|
| Model Number | Zy-syj-141 |
| Frequency Range | FM 87-108 MHz |
| Main Chip | STC15W |
| FM Module | RDA5807S |
| Audio Amplifier | TDA2822 |
| Power Supply | USB 5V or 2 x AA Batteries (not included) |
| Dimensions (L x W x H) | 4.21" x 2.76" x 0.91" (10.7 cm x 7.0 cm x 2.3 cm) |
| Case Material | Transparent Acrylic |
| Special Features | Noise cancellation, soft mute, bass enhancement, high sensitivity, low noise, strong anti-interference. |
9. Warranty and Support
As a DIY kit, the warranty typically covers manufacturing defects of individual components at the time of purchase. Due to the nature of self-assembly, issues arising from incorrect assembly or soldering are not covered.
For technical support or inquiries regarding missing/defective components, please contact the seller through the platform where the kit was purchased. Provide your order number and a detailed description of the issue for prompt assistance.
