1. Introduction
The NISSEI Mini TX-502 is a high-quality SWR/Watt meter designed for measuring forward power, reverse power, and standing wave ratio across a wide frequency range of 1.6 to 525 MHz. It supports HF, VHF, and UHF bands with a maximum power handling of 200W. This manual provides essential information for the proper setup, operation, and maintenance of your device.
2. Package Contents
Please check the package for the following items:
- NISSEI TX-502 SWR/Watt Meter x1
- 13.8V DC Power Cable x1
- User Manual x1
3. Setup
3.1 Power Connection
The external power supply (9-14V DC, 200mA) is primarily for enabling the LED backlight function. It does not affect the measurement capabilities of the device. Ensure correct polarity when connecting the power cable:
- The black and white wires should be connected to the positive pole.
- The black wire should be connected to the negative pole.
3.2 Antenna and Transceiver Connection
The TX-502 features two sets of M-type (SO-239 female) interfaces on its rear panel, each corresponding to a specific frequency range:
- 1.6-200MHz Interface: For HF band operation.
- 125-525MHz Interface: For V/UHF band operation.
Connect your transceiver (transmitter) to the TX interface and your antenna or dummy load to the ANT interface, ensuring you use the correct frequency range ports for your application.
4. Operating Instructions
4.1 Cross Pointer Reading
The TX-502 features a cross pointer display that simultaneously shows forward power (black pointer), reverse power (blue pointer), and standing wave ratio (red pointer). No calibration is required for this feature. The SWR value is read at the intersection point of the forward and reverse power pointers.
4.2 Control Functions
The front panel of the TX-502 includes several controls for operation:
- LED ON/OFF Switch: Toggles the backlight for the meter display.
- RANGE Knob: Adjusts the power measurement range. Select between 2W, 20W, and 200W settings.
- FUNCTION Knob: Switches between Average Power (AVG) and Peak Envelope Power (PEP) measurement modes.
- HF/V/UHF Switch: Selects the operating frequency band.
5. Maintenance
To ensure the longevity and accurate performance of your NISSEI TX-502 SWR/Watt Meter, follow these general maintenance guidelines:
- Cleaning: Use a soft, dry cloth to clean the exterior of the device. Avoid using abrasive cleaners or solvents.
- Storage: Store the meter in a cool, dry place away from direct sunlight and extreme temperatures.
- Handling: Handle the device with care to prevent physical damage to the casing or internal components.
- Connections: Periodically check all cable connections for tightness and signs of wear.
6. Troubleshooting
If you encounter issues with your TX-502, consider the following basic troubleshooting steps:
- No Display/Backlight: Ensure the 9-14V DC power supply is correctly connected and the LED switch is in the 'ON' position. Check the power cable for damage.
- Inaccurate Readings: Verify that the correct frequency band interface (1.6-200MHz or 125-525MHz) is being used for your application. Ensure all connections to the transceiver and antenna are secure. Check that the RANGE knob is set appropriately for the power level being measured.
- No Readings: Confirm that your transceiver is transmitting power and that the connections are solid.
If problems persist after performing these checks, please contact customer support for further assistance.
7. Specifications
| Feature | Specification |
|---|---|
| Brand | NISSEI (Nansheng) |
| Model Number | TX-502 |
| Frequency Measurement Range | 1.6 - 525 MHz |
| Centre Calibration | 28.5 / 145 / 435 MHz |
| Power Measurement Range | 0 - 200 W |
| Power Scale | 2W / 20W / 200W |
| Maximum Power | 200 W |
| Accuracy | ±10% of full scale or higher proportion (Note: 20W/1260MHz) |
| Insertion Loss | < 1.2:1 |
| Testing Functions | Electricity Power, SWR, PEP |
| Impedance | 50 Ohms |
| Connector Type | M-type (SO-239 female) |
| Input Power (Backlight) | 9 - 14V DC, 200mA |
| Weight | 1039 g |
| Product Size (WxHxD) | 184 x 118 x 131 mm |
| Origin | Taiwan, China |
8. User Tips
- Power Range Selection: Always select a power range (2W, 20W, or 200W) that is appropriate for or higher than your transceiver's output power. Exceeding the selected power slot's limit can lead to inaccurate readings or potential damage.
- Versatile Application: The TX-502 is suitable for a wide range of radio communication setups, including shortwave radio stations, vehicle-mounted stations, and handheld walkie-talkies.
9. Warranty and Support
The NISSEI TX-502 SWR/Watt Meter comes with a 6-month warranty period from the date of purchase. This warranty covers manufacturing defects and malfunctions under normal use. Please retain your proof of purchase for warranty claims.
For technical support, troubleshooting assistance, or warranty inquiries, please contact the seller or authorized service center. Provide your product model number (TX-502) and a detailed description of the issue to facilitate prompt service.
