To properly tune and operate your SWAN VHF-150 2-meter amplifier for SSB, CW, and FM modes, adhere to these steps, typically found within the user manual.
Amplifier Tuning:
- Connections: First, connect the amplifier to your antenna or a dummy load. Connect the relay control cable from your transceiver (e.g., Swan FM-2X) to the RELAY CONTROL jack on the amplifier's rear. Then, connect your transceiver's output to the INPUT connector on the VHF-150.
- Power Up: Connect the power cable to the appropriate AC voltage (117V or 230V, or 12VDC for mobile use). Turn the PWR ON switch to the "ON" position and allow about two minutes for warm-up.
- Mode Selection & Bias: Set the BYPASS TUNE-CW-FM SSB switch to SSB. Adjust the P.A. BIAS control until the meter indicates 60 mA of cathode current.
- Plate Tuning: Tune the PLATE control for a "DIP" reading on the meter. Then, adjust both GRID and PLATE controls to find the maximum and minimum meter readings, respectively.
- Load Adjustment: Fine-tune the LOAD and PLATE controls for the highest meter readings, ensuring you stay within recommended levels.
- Final Check: Verify plate tuning for a "DIP" in the CATHODE CURRENT reading.
Operation:
- Drive Control: Set the DRIVE control based on the requirements of your radio equipment.
- Mode Selection: Choose the correct operating mode (SSB, CW, or FM) on your transceiver.
- SSB Operation: For SSB, ensure the BYPASS TUNE-CW-FM SSB switch is set to the SSB position for linear amplification.
- CW Operation: For CW, set the 5894B tube bias to cutoff for Class C operation.
Maintenance:
- Tube Life: The 5894B tube is designed for extensive service life when operated correctly.
- Monitoring: Regularly check the idling and plate current for any changes that might signal tube degradation.
- Component Longevity: The amplifier's other components are designed for long-term reliability.
- Safety: Always follow safety precautions when performing any maintenance to avoid high-voltage hazards. Following these guidelines, you can ensure effective and reliable operation of your SWAN VHF-150 amplifier across different modes.