Introduction
This manual provides detailed instructions for the proper assembly, installation, operation, and maintenance of your HYS Dual-Band NMO Antenna, Model TC-CST-144/430V-N1. This antenna is designed for optimal performance with VHF (144 MHz) and UHF (430 MHz) mobile radio systems. Please read this manual thoroughly before use to ensure safe and efficient operation.
Product Features
- Dual-Band Operation: Supports VHF 144/430 MHz (136-174MHz and 400-470Mhz) with a VSWR of less than 1.5.
- High Gain: Features vertical polarization with a gain of VHF 3dBi / UHF 5dBi for enhanced transmission and reception.
- Power Handling: Capable of handling a maximum input power of 100W, suitable for various 2-meter and 70-centimeter mobile radios.
- Durable Construction: Constructed from stainless steel NMO for long-lasting durability.
- Wide Compatibility: Compatible with mobile radios from brands such as Motorola, Kenwood, Icom, Vertex, Blackbox, HYT, and Hytera.
Setup and Installation
Proper assembly and installation are crucial for the antenna's performance. Follow these steps carefully:
- Unpack Components: Carefully remove all components from the packaging. You should have the NMO base, the stainless steel whip, and a hex key.
- Whip Installation: Insert the stainless steel whip into the NMO base. Ensure it is fully seated.
- Secure Whip: Use the provided hex key to tighten the set screws on the NMO base, securing the whip firmly in place. Do not overtighten.

Image: Antenna components (NMO base, whip, hex key).

Image: Securing the antenna whip with the hex key.
- Mounting the Antenna: Attach the NMO base to a suitable NMO mount on your vehicle or desired location. Ensure the mount provides a good ground plane for optimal performance.
- SWR Tuning (if necessary): While the antenna is pre-tuned for 144/430 MHz, minor adjustments may be required for specific frequencies or installations. Refer to the provided SWR chart and cutting guidelines for precise tuning. A low SWR (Standing Wave Ratio) is essential for efficient power transfer and to prevent damage to your radio.

Image: HYS Dual-Band NMO Antenna with SWR performance chart.

Image: Stainless steel whip cutting chart for frequency adjustment.
Installation Videos
Video: HYS Dual Band NMO 144Mhz/430Mhz Antenna assembly guide. This video demonstrates the process of assembling the antenna components.
Video: HYS Dual-Band NMO 20 inch Antenna overview. This video provides a brief look at the antenna and its features.
Video: HYS VHF UHF NMO Antenna (magnetic base not included). This video illustrates the antenna's design and potential applications.
Operating Instructions
Once the HYS Dual-Band NMO Antenna is correctly installed and tuned, connect it to your compatible mobile radio. Ensure all connections are secure. The antenna is designed for reliable communication across its specified frequency bands. For optimal performance, operate your radio within the antenna's rated power limits.
Maintenance
To ensure the longevity and consistent performance of your HYS Dual-Band NMO Antenna, consider the following maintenance tips:
- Regular Inspection: Periodically check the antenna whip and NMO base for any signs of damage, corrosion, or loose connections.
- Cleaning: Clean the antenna with a soft, damp cloth to remove dirt and debris. Avoid using harsh chemicals or abrasive materials.
- Connection Integrity: Ensure the coaxial cable connection to the NMO base and your radio remains tight and free from moisture.
- SWR Check: If you experience a decrease in performance, re-check the SWR to ensure it remains within acceptable limits.
Troubleshooting
If you encounter issues with your HYS Dual-Band NMO Antenna, consider these common troubleshooting steps:
- Poor Reception/Transmission:
- Check all cable connections for tightness and proper seating.
- Verify the antenna is correctly installed on a suitable ground plane.
- Perform an SWR check. High SWR can indicate a problem with the antenna, cable, or tuning.
- Ensure the antenna whip is not bent or damaged.
- High SWR Readings:
- Confirm the antenna whip length matches the desired frequency using the cutting chart.
- Inspect the NMO mount and coaxial cable for damage or shorts.
- Ensure the NMO mount has a solid electrical connection to the vehicle's metal surface (ground plane).
Specifications
| Feature | Detail |
|---|---|
| Model Number | TC-CST-144/430V-N1 |
| Frequency Range | VHF 144/430 MHz (136-174MHz and 400-470Mhz) |
| VSWR | < 1.5 |
| Gain | VHF 3dBi / UHF 5dBi |
| Polarization | Vertical |
| Maximum Input Power | 100W |
| Antenna Length | 20.0 inches |
| Material | Stainless Steel NMO |
| Impedance | 50 Ohms |
| Item Weight | 6.4 ounces |
| Product Dimensions | 8 x 0.9 x 0.9 inches (packaging) / 20.08"L x 20.08"W x 20.08"H (assembled) |
Warranty Information
HYS products are manufactured to high-quality standards. For specific warranty details, including coverage period and terms, please refer to the product packaging or contact HYS customer support directly. Keep your purchase receipt as proof of purchase.
Customer Support
If you have any questions, require technical assistance, or need to report an issue with your HYS Dual-Band NMO Antenna, please contact HYS customer support through the retailer where the product was purchased or visit the official HYS website for contact information.