50 Ohm vs. 75 Ohm Coaxial Cable: What Is the Difference?

Coaxial cable is widely used for signal transmission in wireless communication, RF systems, broadband networks, CATV, CCTV, and video applications. Among the most common types are 50 ohm and 75 ohm coaxial cables. Although they have a similar basic structure, they are designed for different system requirements. Understanding the difference between them can help engineers and buyers select the right cable for their applications.

What Does Coaxial Cable Impedance Mean?

The impedance of a coaxial cable is its characteristic impedance, measured in ohms (Ω). It is mainly determined by the relationship between the center conductor, dielectric material, and outer conductor.

The two most widely used impedance values are 50 ohms and 75 ohms. Neither is universally better than the other. The appropriate choice depends on the equipment and transmission system.

50 Ohm Coaxial Cable

50 ohm coaxial cable is commonly used in RF and wireless communication systems. Typical applications include cellular base stations, DAS (Distributed Antenna Systems), antenna feeder systems, radio communication, RF equipment, and other high-frequency applications.

Common 50 ohm cable types include LMR200, LMR400, LMR600, and RF feeder cables. These cables are designed to provide reliable RF signal transmission and can be selected according to frequency, attenuation, power handling, and installation requirements.

In an RF system, maintaining a consistent 50 ohm impedance between the equipment, cable, connectors, and antenna helps reduce signal reflection and improve transmission efficiency.

75 Ohm Coaxial Cable

75 ohm coaxial cable is widely used for video, television, broadband, and signal distribution applications. Typical applications include CATV, MATV, CCTV, satellite TV, broadband networks, and HFC (Hybrid Fiber-Coaxial) systems.

Common types include RG59, RG6, RG7, and RG11. RG6 is widely used in residential and commercial video and broadband networks, while RG11 is often selected for longer cable runs because its larger conductor and structure can provide lower attenuation.

50 Ohm vs. 75 Ohm: Which One Should You Choose?

The key difference is the system for which the cable is designed. 50 ohm coaxial cable is generally preferred for RF and wireless communication, while 75 ohm coaxial cable is commonly used for video, CATV, and broadband transmission.

When selecting a coaxial cable, impedance should match the system requirements. Using an unsuitable impedance can result in signal reflections, higher VSWR, and reduced transmission performance.

In addition to impedance, buyers should also consider attenuation, operating frequency, shielding effectiveness, power handling, bending radius, jacket material, and environmental conditions.

Conclusion

Choosing between 50 ohm and 75 ohm coaxial cable depends on the application and equipment specifications. 50 ohm cables are widely used in RF and wireless communication systems, while 75 ohm cables are common in CATV, broadband, CCTV, and video applications.

United Wiring provides a range of 50 ohm and 75 ohm coaxial cables, including RF cables, LMR series cables, RG series cables, and customized cable assemblies. Cable construction and specifications can be customized according to different transmission and installation requirements.