ASHATA SWR 120 Digital Power Standing Meter Instruction Manual

1. Introduction

The ASHATA SWR 120 Digital Power Standing Meter is a compact and portable device designed for amateur radio enthusiasts. It provides direct digital display of forward power, reflected power, antenna power, antenna efficiency, standing wave ratio (SWR), and battery voltage. Featuring a built-in rechargeable battery, it operates without the need for an external power supply, making it ideal for field use.

Figure 1: ASHATA SWR 120 Digital Power Standing Meter with power range indication.

2. Product Features

• No External Power Supply: Built-in rechargeable battery (1000mAh Polymer Lithium-ion) for portable operation.
• Digital Display: Clearly shows forward power, reflected power, antenna power, antenna efficiency, SWR, and battery voltage.
• Indicator Lights: Visual feedback for charging status and SWR levels (green for good, yellow for warning, red for high SWR).
• High Accuracy: Designed to meet the precision requirements of amateur radio operators.
• Power Range: Supports 0.5W-120W (up to 200W peak, long-term testing recommended below 120W for FM, AM, CW modes; SSB mode optional).
• Frequency Range: 1.8MHz-50MHz (with reference value for V band).
• Alarm Function: Audible buzzer for high SWR and battery undervoltage.
• Mode Switching: One-touch display and mode switching functionality.

3. Specifications

4. Components Overview

Familiarize yourself with the main components of your SWR 120 meter:

• Power Switch: Located on the front panel, used to turn the device ON/OFF.
• ANT Port (SO239): For connecting your antenna.
• TX Port (SO239): For connecting your radio transmitter.
• Type-C Charging Port: For charging the internal battery.
• Digital Display: Shows measurement values and status.
• Control Buttons (UP/DOWN/M/U): For navigation and mode selection.
• Indicator Lights (ALERT/FULL/CHARGE): Provide visual status.

Figure 2: Front panel showing Power switch and ANT port.

Figure 3: Side panel showing TX port and Type-C charging port.

5. Setup and Connections

To set up your SWR 120 meter for use:

1. Ensure the device is fully charged before first use (refer to Section 8: Charging the Device).
2. Connect your antenna to the ANT (Antenna) port on the SWR meter.
3. Connect your radio transmitter to the TX (Transmitter) port on the SWR meter.
4. Turn on the SWR meter using the POWER switch.

6. Basic Operation

Once connected and powered on, the SWR 120 meter will display real-time measurements on its digital screen.

Figure 4: Digital display showing forward power (FWD) and SWR readings.

• Power On: Flip the red POWER switch to the ON position. The digital display will illuminate.
• Reading Measurements: The display will show forward power (FWD W) and SWR (SWR) values. It also indicates battery voltage (BAT).
• Mode Switching: Use the M/U button to cycle through different display modes or measurement parameters if available.
• Adjusting Settings: The UP and DOWN buttons may be used for adjusting certain settings or navigating menus, if applicable to the current mode.

7. Indicator Lights and Alarms

The SWR 120 meter provides visual and audible feedback for various operational states:

• VSWR Indicator Lights:
  • Green Light: On when VSWR is less than 1.5 (optimal).
  • Yellow Light (ALERT): On when VSWR is greater than 1.5 and less than 2.5 (warning).
  • Red Light: On when VSWR is greater than 2.5 (critical).
• VSWR Buzzer Alarm:
  • If VSWR is greater than 2.5 and less than 3, the buzzer will alarm intermittently.
  • If VSWR is greater than 3, the buzzer will alarm continuously.
  • The buzzer can be turned off with one key press (M/U button).
• Battery Undervoltage Alarm:
  • If the battery voltage is low, the buzzer will continuously prompt, and the yellow indicator light will be on.

8. Charging the Device

The SWR 120 meter features a built-in rechargeable battery. To charge the device:

1. Connect a standard Type-C USB charging cable to the 5V/1A Type-C port on the side of the meter.
2. Connect the other end of the cable to a compatible USB power source (e.g., wall adapter, computer USB port).
3. Charging Indicator:
   • The red light (CHARGE) is displayed when charging while the device is powered on.
   • The green light (FULL) is displayed when the battery is fully charged.
4. Allow sufficient time for the battery to fully charge for optimal performance.

9. Maintenance

To ensure the longevity and proper functioning of your ASHATA SWR 120 meter:

• Keep the device clean and free from dust and moisture. Use a soft, dry cloth for cleaning.
• Avoid exposing the device to extreme temperatures or direct sunlight.
• Do not attempt to open the casing or modify the internal components, as this will void any potential warranty and may damage the device.
• Store the device in a safe place when not in use to prevent physical damage.

10. Troubleshooting

If you encounter issues with your SWR 120 meter, consider the following common problems and solutions:

• Device does not power on:
  • Ensure the battery is charged. Connect the device to a power source using the Type-C cable.
  • Verify the power switch is in the ON position.
• No readings on display:
  • Check all cable connections (antenna to ANT, radio to TX) are secure.
  • Ensure the radio is transmitting power.
• High SWR readings:
  • Inspect your antenna system for proper tuning and condition.
  • Check antenna connections for shorts or open circuits.
  • Ensure the operating frequency is within the antenna's designed range.
• Buzzer alarm sounds continuously:
  • This indicates very high SWR (greater than 3) or low battery voltage. Address the SWR issue or charge the battery.
  • Press the M/U button to temporarily silence the buzzer.
• Battery undervoltage alarm:
  • Charge the device immediately using the Type-C port.

11. Warranty and Support Information

For warranty claims or technical support, please refer to the retailer or manufacturer's official website. Keep your purchase receipt as proof of purchase. Specific warranty terms and conditions may vary.