R10 AM Radio Shortwave Receiver DIY Kit

1.Overview

This R10 Shortwave PLL Receiver Kit is designed for receiving ordinary short-wave broadcast signals. It has undergone several optimizations to provide an enhanced user experience. The hardware described in this manual is version V8.0, with the main PCB labeled "HM00ABRA_8".

2. Specifikationer

• Forsyning Voltage: 12V (Linear regulated power supply or battery recommended)
• Strøm: 110mA
• Tuning rækkevidde: 3-23 MHz
• Mode: AM
• Trin: 1KHz / 10KHz / 100KHz

3. Kit Contents (Parts List)

The R10 Shortwave PLL Receiver Kit includes the following components. Please verify all parts are present before beginning assembly.

3.1. 1/4W 5% Resistors

3.2. Beads, Inductors, Transformers

3.3. Chip Capacitance

3.4. Electrolytic Capacitance

3.5. Transistors

3.6. ICs

3.7. Crystals and Filters

3.8. Other Components

The display board includes a circuit board, a 3mm LED, a digital LED display, and an encoder.

4. Monteringsvejledning

4.1. Component Selection

All capacitors less than 1000pF should be high-frequency ceramics. Capacitors greater than 1uF are aluminum electrolytic capacitors. All resistors are 1/4W 5% fixed resistors.

4.2. Soldering Reminder

The display board must be soldered with the digital LED and connector plug-in by yourself. After installation, the assembled display board will look like the image below.

4.3. General Assembly and Adjustment

1. Test all transistors, resistors, and capacitors with a multimeter before installing them.
2. Install all components according to the circuit diagram and the markings on the PCB board.
3. Generally, follow the low-to-high order of installation for components.
4. Install a socket for the integrated circuits (U1, U2, U3) to avoid direct soldering of the core integrated circuits.
5. Once all components are in place, check and connect the power supply. Ensure the positive and negative polarity of the power supply are connected correctly.
6. Plug a walkman headset into the headphone socket. You should hear white noise when powered on.
7. Attach a flexible wire (approximately 3 meters) to the antenna. The noise should significantly increase, indicating that the RF channel is functioning correctly.

4.4. Chassis Mounting

This circuit board can be conveniently placed in a standard aluminum profile case with dimensions of 76mm x 35mm x 100mm. Please note that the case is not included in this kit and must be purchased separately if desired.

5. Initial Setup (Without Instruments)

1. Connect a 3-meter cable to the antenna socket and power on the receiver.
2. The digital display should show a frequency (e.g., 9.810). Gently adjust the encoder to tune into an AM broadcasting station.
3. Once a broadcast sound is heard, adjust T1 to achieve the highest signal and lowest noise.

Vigtig: Do not screw the core into T1. It is recommended to use a non-inductive or plastic driver for adjustment.

5.1. Power Plug Requirements

The power plug (5.5/2.1) requires inner positive and outer negative polarity.

6. Betjeningsvejledning

1. Upon first power-on, the receiver defaults to frequency adjustment mode. The digital LED displays the frequency value. Turn the encoder to adjust the frequency.
2. Short press the encoder: Changes the step value (e.g., 1KHz, 10KHz, 100KHz). If the digitizer turns black, it is not in use.
3. Long press the encoder: Initiates station searching.

6.1. Configuration Mode (SET Button)

To enter configuration mode, connect the antenna and press the SET button. "C1_15" will be displayed. Continue pressing the button to cycle through settings. Exit configuration mode when "C4_68" is displayed to return to working mode.

De tilgængelige indstillinger er:

• C1 (Sound setting): Default 15. Adjustable from 0 to 25. Higher values result in louder sound.
• C2 (Search threshold setting): Default 15. Adjustable from 0 to 25. Higher values mean a stronger signal is required for detection.
• C3 (IF frequency setting): Default 50 (unit: 200Hz). Adjustable from 0 to 99. This indicates the IF frequency is 10690000 Hz + (value * 200Hz).
• C4 (25MHz Clock offset): Default 68 (unit: 100Hz). The default frequency is 25,000,000Hz + (value * 100Hz). If there is drift in the receiving frequency, the 25MHz clock frequency on the PLL small board can be measured with a frequency meter, and this offset can be adjusted accordingly.

Note: C3 and C4 settings should only be adjusted with instruments and experience. Modified values do not take effect immediately; you must exit configuration mode and adjust the working frequency for changes to apply.

Forsigtighed: Configuring the EEPROM in the MCU takes time. Do not power off the device during configuration to prevent misoperation.

7. Brugertips

• Always double-check component polarity, especially for electrolytic capacitors and diodes, before soldering to prevent damage.
• When troubleshooting, refer to the circuit diagrams and component identification guides provided in this manual.
• For optimal reception, experiment with different antenna lengths and orientations.

8. Fejlfinding

8.1. Generelle problemstillinger

• No white noise after power-on: Recheck power supply connections (polarity), headphone connection, and ensure the RF channel is properly assembled.
• No broadcast sound: Ensure antenna is connected, try adjusting T1 as described in "Initial Setup", and verify frequency tuning.
• Incorrect configuration: If you make a mistake during configuration, do not panic. Hold down the SET key and re-power on the device. This will restore the machine to its default settings based on the SET key state.

9. Circuit Description

Refer to the circuit diagrams provided in this document for a visual representation.

The signal received by the antenna first passes through a filter network. The bandpass filter ensures that only the 3-23MHz signal enters the source pole circuit (composed of J310), while other signals are attenuated. This signal is then fed into the TA2003, which contains a mixer that combines the received signal with the PLL local oscillator signal.

The intermediate frequency (IF) is 10.7MHz. The signal from the TA2003 is sent to a 10.7MHz ceramic filter, which removes irrelevant signals generated during mixing. After filtering, the signal is amplified by a 2N2222 transistor before being sent to the TA7613 for further IF amplification, detection, and audio amplification. The TA7613 handles AM signal detection and includes an internal audio power amplifier capable of directly driving speakers.

10. Komponentidentifikation

10.1. Resistor Color Codes and Ceramic Capacitor Identification

Resistors are marked with colored bands. Most are 5% accuracy (four bands), while less common 1% accuracy resistors have five color rings. Ceramic capacitors are generally denoted in pF (picoFarads). Some are directly labeled (e.g., 1000p, 220p). Many are labeled exponentially (e.g., "102" means 10 with two zeros, or 1000pF; "221" means 22 with one zero, or 220pF).

10.2. Polarity of Electrolytic Capacitors

Electrolytic capacitors are polarized. Ensure that the positive and negative pins correspond correctly to the PCB markings when inserting these components.

10.3. IC Identification

Integrated circuits (ICs) often have a notch or dot indicating pin 1. Pin numbering typically proceeds counter-clockwise from pin 1.

10.4. Transistor and Diode Identification

Transistors (e.g., TO-92 package) and diodes have specific pin arrangements and polarity markings that must be observed during assembly.

11. Ledningsdiagrammer

For detailed circuit schematics and PCB assembly drawings, refer to the images below and the external PDF document.

External Schematic Diagram Link: R10.pdf

11.1. R10 Shortwave PLL Receiver Circuit Diagram (V8.0)

11.2. PCB Assembly Drawing

12. Garanti og support

For any questions, technical support, or warranty inquiries regarding your R10 Shortwave PLL Receiver DIY Kit, please contact the seller directly through the platform where you purchased the product. Please retain your purchase records for reference.