Description
Marine VHF Antenna CX4b Overview
The Marine VHF Antenna CX4b from AC Antennas is a professional 1.26m black fibreglass antenna designed for marine and land-based VHF communication systems. Covering 146.0–162.5 MHz, the antenna provides 3dB marine gain, 150W power handling, a UHF female connector and IP68 waterproof protection.
The CX4b features a rugged coaxial dipole design with omnidirectional coverage, making it suitable for commercial vessels, workboats, pilot boats, patrol craft, RIBs and modern recreational vessels where a discreet black antenna finish is preferred.
Manufactured using premium materials to help prevent galvanic corrosion, the antenna uses brass radiating elements and AC Antennas crimping technology, producing a significantly stronger internal construction for demanding marine environments.
Marine VHF Antenna CX4b Applications
- Marine VHF radio systems
- Commercial vessels and workboats
- Patrol craft and pilot boats
- RIBs and rescue vessels
- Fishing vessels
- Harbour and marina communications
- Land-based VHF communication systems
- Professional marine electronics installations
Black Fibreglass Marine VHF Antenna
The CX4b combines reliable VHF communication performance with a durable black RAL9005 fibreglass finish. This low-visibility appearance makes it popular on modern vessels where traditional white antennas may not suit the overall vessel design.
The fibreglass radome provides excellent environmental protection while maintaining reliable RF performance across the entire operating frequency range.
Marine VHF Antenna Height and Range
Marine VHF communication range is strongly affected by antenna height, installation position, cable quality and surrounding obstructions. Mounting the antenna as high and clear as practical will generally improve line-of-sight communication performance.
For more information, read our VHF Antenna Height vs Range Guide and Marine VHF Antenna Range Guide.
Dual Thread Mounting System
The CX4b features a versatile dual-thread mounting arrangement consisting of a 1″ 14TPI male thread and an ISO 228/1-G1 female thread. This provides excellent compatibility with a wide range of marine antenna mounting systems.
An N239F mounting nut is included, making installation straightforward on compatible marine mounts and brackets.
Technical Specifications
- Product: CX4b
- Part Number: 100022-T
- Product Group: VHF
- Design: Coaxial Dipole
- Pattern: Omnidirectional
- Frequency Range: 146.0–162.5 MHz
- Bandwidth: 16.5 MHz
- Nominal Impedance: 50 Ohm
- Maximum Input Power: 150W
- Gain: 0 dBd / 2.15 dBi / 3dB Marine Gain
- VSWR: < 1.5:1
- Polarisation: Vertical
- DC Shorted: Yes
- DC Grounded: Yes
- Connector: UHF Female
- Length: 1.26m / 4.14ft
- Sections: 1
- Weight: 0.50kg / 1.10lbs
- Survival Wind Speed: 200 km/h / 55 m/s / 124 mph
- Wind Area: 0.0186m² / 0.2002ft²
- Wind Load @ 160 km/h: 27N
- Material: Fibreglass
- Colour: Black (RAL9005)
- Operating Temperature Range: -55°C to +70°C
- Ingress Protection: IP68
- Thread: 1″ 14TPI Male / ISO 228/1-G1 Female
- Mounting: N239F Mounting Nut Included
Mounting Compatibility
The CX4b is compatible with a wide range of marine antenna mounting systems using standard marine antenna thread formats.
For more information, see our Marine Antenna Thread Sizes Guide and Marine Antenna Mount Compatibility Guide.
Marine VHF Antenna Installation
For optimum performance, install the CX4b vertically and position it as high as practical to maximise VHF communication range. Avoid mounting close to radar scanners, large metal structures or other equipment that may affect antenna performance.
- Mount vertically for correct polarisation
- Use marine-grade coaxial cable
- Protect cable runs from damage
- Seal external RF connections correctly
- Inspect the antenna and mount periodically
- Ensure all mounting hardware remains secure
For more installation advice, see our Marine VHF Antenna Mounting Guide.
Recommended Marine VHF Antenna Cable
Correct cable selection is critical to maintaining VHF communication performance. Poor cable quality, water ingress or incorrect connector installation can significantly reduce system performance.
Read our Marine VHF Antenna Cable Guide for more information.
CX4b vs CX4b-6
| Model | Connector | Mounting | Colour | Gain |
|---|---|---|---|---|
| CX4b | UHF Female | Dual Thread + N239F Included | Black | 3dB Marine Gain |
| CX4b-6 | N Female | 1″ 14TPI Male | Black | 3dB Marine Gain |
Related Marine Communication Guides
- Marine VHF Antenna Information Guide
- 3dB vs 6dB Marine VHF Antennas
- Marine VHF Antenna Range
- VHF Antenna Height vs Range
- Marine VHF Antenna Cable Guide
- Marine VHF Antenna Mounting Guide
- Marine Antennas Explained
Downloads
Frequently Asked Questions
What frequency range does the CX4b cover?
The CX4b operates across 146.0–162.5 MHz, making it suitable for marine and professional VHF communication systems.
What connector does the CX4b use?
The antenna is fitted with a UHF Female connector.
What gain does the CX4b provide?
The CX4b provides 0 dBd / 2.15 dBi gain, commonly referred to as 3dB Marine Gain.
Is the CX4b waterproof?
Yes. The antenna is rated IP68 for protection against water ingress in demanding marine environments.
What mounting thread does the CX4b use?
The antenna uses a 1″ 14TPI male thread and an ISO 228/1-G1 female thread.
Is a mounting nut supplied?
Yes. An N239F mounting nut is included with the antenna.
What is the difference between the CX4b and CX4b-6?
The CX4b uses a UHF Female connector and includes a dual-thread mounting system with an N239F mounting nut, while the CX4b-6 uses an N Female connector.
Manufacturer Information
Manufactured by AC Antennas.
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