1. Product Overview
This document provides instructions for the 3-28Mhz 45W SSB AM Linear Power Amplifier, designed for use with transceivers, HF radio, and HAM applications. It functions as a power amplifier for SSB, AM, CW, and FM signals, offering basic signal amplification.
Video: Overview of the assembled SSB Linear Power Amplifier.
2. Package Contents
The amplifier is available in two versions: 'DIY KITS' and 'Finished'.
- DIY KITS Version: Includes all necessary electronic components and a bare PCB for self-assembly. A heat sink is NOT included and must be sourced separately.
- Finished Version: Includes a fully assembled amplifier board, typically with a heat sink attached.
Image: Components included in the DIY KITS version.
Image: Top view of the finished amplifier board.
3. Setup and Assembly (DIY KITS)
For the DIY KITS version, assembly is required. Users should have experience with soldering and electronic component assembly. A heat sink is essential for proper operation and must be provided by the user.
- Component Identification: Carefully identify all components provided in the kit using the PCB markings.
- Soldering: Solder all components onto the PCB according to the circuit design. Pay close attention to component orientation (e.g., polarized capacitors, diodes, ICs).
- Heat Sink Attachment: Securely attach a suitable heat sink to the power transistors. The heat sink should be capable of dissipating heat for outputs up to 57W.
- Input/Output Connections: Connect the input and output signals using standard SMA interfaces. The board features external thread holes for these connections.
- Power Connection: Connect a DC 13.8V power supply (10A or higher) to the VCC_PA and GND terminals.
Image: Example of a DIY KITS version assembled with basic wiring and a heat sink.
4. Operating Instructions
The amplifier is designed for linear amplification of SSB, AM, CW, and FM signals within the HF frequency range.
- Power Supply: Ensure the amplifier is connected to a stable DC 13.8V power supply capable of providing 10A or more.
- Input Signal: Apply an input signal with a power level between 1-5mW to the RF_IN (J1) SMA connector.
- Output Connection: Connect the RF_OUT (J2) SMA connector to your antenna or subsequent RF stage. The output impedance is 50 ohms but can be adjusted between 10-200 ohms if needed.
- Frequency Range: The amplifier operates across the 3M-30MHz HF channel.
- Monitoring: It is recommended to monitor the output power and temperature during operation, especially when operating at higher power levels.
Image: Example of a test setup for monitoring amplifier performance.
5. Maintenance and Safety
Proper maintenance ensures longevity and safe operation of the amplifier.
- Heat Dissipation: Adequate heat dissipation is critical. If operating at maximum power (45W or up to 57W), a large heat sink capable of handling over 200W is required. Insufficient cooling can lead to damage or unsafe conditions.
- Power Supply: Always use a stable and correctly rated power supply. Over-voltage or under-current can damage the unit.
- Connections: Ensure all connections (power, input, output) are secure and correctly polarized before applying power.
- Environmental Conditions: Operate the amplifier in a dry, well-ventilated area, away from direct sunlight and extreme temperatures.
6. Troubleshooting
No specific troubleshooting steps are provided. For issues, verify all connections, power supply, and input signal levels. Ensure adequate heat dissipation is in place.
7. Specifications
| Feature | Specification |
|---|---|
| Input Power | 1-5mW |
| Output Power (Max.) | 45W (typical), 57W (without cooling fin, with sufficient heat sink) |
| Input Voltage | DC 13.8V (10A or higher) |
| Output Impedance | 50 ohm (adjustable between 10-200 ohm) |
| Input Frequency Range | 3M-30MHz (HF channel) |
| Input/Output Interface | Standard SMA interface, external thread hole |
| PCB Size | 60 x 100 mm |
| Located Hole Diameter | 3mm |
| Color | Green |
| Package Weight | 58g / 2.07oz |
7.1. Output Power vs. Frequency (Test Data)
| Frequency | Output Power |
|---|---|
| 3.500MHz | 54W |
| 7.050MHz | 56W |
| 10.000MHz | 57W |
| 14.270MHz | 55W |
| 21.400MHz | 41W |
| 24.000MHz | 37W |
| 28.100MHz | 25W |
| 29.600MHz | 20W |
Note: Output power may vary based on specific operating conditions and heat dissipation.
8. User Tips
- Heat Sink is Crucial: For sustained high-power operation, especially above 45W, ensure you have a robust heat sink. The manufacturer notes that the maximum output of 57W was measured with a heat sink capable of withstanding over 200W. Do not operate at high power without adequate cooling.
- AM Band Compatibility: This amplifier is suitable for use in the commercial AM band as a linear power amplifier.
- DIY Enthusiast Friendly: The DIY KITS version is designed for enthusiasts who enjoy assembling their own electronics. It offers a low-noise and high-performance solution once correctly assembled.
- Frequency Performance: While usable across the entire 3-30MHz HF range, expect slightly lower output power in the 3-5MHz range due to lower frequency and small inductance, which can lead to some gain loss.
9. Warranty and Support
Specific warranty information is not provided. For technical support or inquiries, please refer to the seller or manufacturer's contact information available at the point of purchase.
