MFJ-826B Digital SWR/Wattmeter Instruction Manual

Introduction

This manual provides detailed instructions for the setup, operation, and maintenance of your MFJ-826B Digital SWR/Wattmeter. This device is designed for accurate measurement of forward and reflected power, Standing Wave Ratio (SWR), and transmit frequency on HF and 6-meter bands. Please read this manual thoroughly before operating the device to ensure proper use and to maximize its performance.

Safety Information

General Safety Precautions

• Ensure proper grounding of all connected equipment to prevent electrical shock.
• Do not operate the device in wet or damp conditions, or expose it to rain or moisture.
• Always disconnect power from the unit and any connected equipment before making or changing any connections.
• Do not exceed the maximum power rating of 1500 Watts to avoid damage to the meter and connected equipment.
• Refer all servicing and repairs to qualified service personnel. Do not attempt to open the casing or modify the internal circuitry.

Setup

Unpacking and Inspection

Upon receiving your MFJ-826B, carefully unpack all components and inspect for any signs of shipping damage. If any damage is found, contact your dealer or MFJ customer support immediately.

Image: Front view of the MFJ-826B Digital SWR/Wattmeter, showing the display and control buttons. This image illustrates the physical appearance of the device.

Power Connection

The MFJ-826B can be powered using either a 12 VDC power supply or a 110 VAC power source (via an optional AC adapter).

12 VDC Power Supply

Connect a regulated 12 VDC power supply (not included) to the DC input jack located on the rear panel of the unit. Ensure correct polarity to prevent damage to the meter.

110 VAC Power Supply

If using 110 VAC, connect a suitable AC-to-DC adapter (not included) to the DC input jack and then plug the adapter into a standard 110 VAC wall outlet. Verify the adapter provides 12 VDC output.

Antenna and Transceiver Connections

Connect your transceiver's RF output to the "TX" connector on the rear panel of the MFJ-826B. Connect your antenna system to the "ANT" connector, also on the rear panel. Use high-quality 50-ohm coaxial cables with appropriate PL-259 or SO-239 connectors for optimal performance and minimal signal loss.

Initial Power-On

After all power and RF connections are securely made, apply power to the unit. The backlit LC display should illuminate, indicating the unit is operational.

Operating Instructions

Display Modes

The MFJ-826B features a versatile 2-line LC display that can show various parameters simultaneously, offering both digital and bar graph representations.

Digital Display Mode

In this mode, the display shows precise numerical values for forward power, reflected power, Standing Wave Ratio (SWR), and the current transmit frequency. This mode is ideal for detailed analysis of your RF system's performance.

Bar Graph Display Mode

Alternatively, the unit can display transmit power and SWR as easy-to-read bar graphs. This mode provides a quick visual assessment of your RF output and SWR levels, allowing for rapid adjustments.

Measuring SWR and Power

To accurately measure SWR and power, transmit a continuous carrier signal at a low power level. Observe the readings on the display. Adjust your antenna tuner or antenna system as necessary to achieve the lowest possible SWR, ideally 1.5:1 or lower, for efficient power transfer and to protect your transceiver.

Frequency Counter

The MFJ-826B includes a built-in frequency counter that automatically detects and displays the transmit frequency when an RF signal is present. This feature is useful for verifying your operating frequency.

Maintenance

Cleaning

To clean the exterior of the unit, use a soft, dry cloth. Avoid using abrasive cleaners, solvents, or harsh chemicals, as these can damage the casing or display.

Software Updates

The MFJ-826B supports software updates via its RS232 serial interface. Periodically check the official MFJ website for available firmware updates and detailed instructions on how to perform the update process.

Storage

When the unit is not in use for extended periods, store it in a dry, dust-free environment, away from direct sunlight and extreme temperatures. Disconnect all cables before storage.

Troubleshooting

No Display

• Check Power Connections: Ensure the 12 VDC power supply or AC adapter is securely connected and providing power.
• Verify Voltage: Confirm that the DC input voltage is within the specified range (12 VDC).

Inaccurate Readings

• Cable Connections: Ensure all coaxial cable connections between the transceiver, meter, and antenna are secure and in good condition. Loose or damaged cables can cause inaccurate readings.
• Antenna System: Verify that your antenna system is properly tuned for the operating frequency.
• Test with Dummy Load: If possible, test the meter with a known good 50-ohm dummy load to confirm its basic accuracy.

No Frequency Display

• Transmit Signal: Ensure a transmit signal is present and strong enough for the meter to detect.
• Connections: Double-check all RF connections between the transceiver and the meter.

Specifications

Warranty Information

This product is covered by a limited manufacturer's warranty. The specific terms and duration of the warranty may vary. Please refer to the warranty card included with your purchase or visit the official MFJ website for detailed warranty terms, conditions, and registration information.

Customer Support

For technical assistance, troubleshooting, or service inquiries regarding your MFJ-826B Digital SWR/Wattmeter, please contact MFJ customer support. Contact information, including phone numbers and email addresses, can typically be found on the official MFJ website or in the documentation provided with your product.