RG-174 compared to LMR-100 Coax : Shielding and Signal Loss

LMR-100 and RG174 Coaxial Cable Comparison

  • RG174 and LMR-100 Both are compatible with Wi-Fi, Cellular, and most IoT wireless applications.
  • LMR-100 is double-shielded and suitable for outdoor as well as indoor use. 
  • RG174 has a single shield and is not suitable for long-term outdoors use.
ATTENUATION Signal Loss: dB/ft. Signal Loss: dB/ft.
Frequency (Mhz) RG174 LMR-100
100 0.088 0.038
200 0.140 0.100
400 0.220 0.146
500 0.159
900 0.300 0.228
1000 0.320
1500 0.301
2400 0.750 0.390

RG174 is a small, flexible, coax for antenna cables, with an American Wire Gauge of 26. Its diameter is 2.79mm (0.11 inches). Its relatively small diameter, flexibility, high speed and efficient data transfer makes it an ideal choice for  a wide range of contemporary and consumer applications including:

RG174 Physical Characteristics:

RG174's structure is typical of coaxial cables and is comprised of the following layers and materials:

  • Central conductor: 7 strands of stranded copper clad steel (CCS), with a diameter of 0.483mm (0.019 inches).
  • Dielectric: Low Density Polyethylene (LDPE) which contributes water resistance and flexibility to the cable. Dielectric diameter is 1.55mm (0.06 inches)
  • Outer shielding: A single layer of tinned copper with coverage of between 88% and 90% depending on manufacturer.
  • Jacket: Polyvinyl Chloride (PVC) a flexible weather resistant coating, with good flame resistance. Due to its material composition (plastics), the operating temperature of this cable is between -40 and 80 degrees Celsius (-40 degrees to 176 degrees Fahrenheit).

Electrical profile of RG174

The impedance of RG174 is typically 50 Ohm. The conductor resistance is a maximum of 142.4 Ohm and dielectric resistance is at least 1000 Ohm. The maximum  frequency transmitted this cable is 6GHz.

Comparison of RG174 and LMR-100 coax cable

Key Features:

  • RG174:
    • Diameter: Typically around 2.79mm.
    • Impedance: Standard 50 ohms.
    • Velocity of Propagation: Approximately 66%.
    • Attenuation: Higher than LMR-100, especially over longer distances.
  • LMR-100:
    • Diameter: Roughly 2.79mm, similar to RG174.
    • Impedance: Maintains the 50 ohms industry standard.
    • Velocity of Propagation: Slightly higher than RG174 at around 70%.
    • Attenuation: Provides better performance with lower loss over extended distances.

Materials Composition:

  • RG174: RG174 coaxial cables often consist of a silver-plated copper center conductor, surrounded by a dielectric insulator, typically made from solid polyethylene. This assembly is then covered by a shield, usually made from tinned copper, followed by an external PVC jacket.
  • LMR-100: This cable features a copper center conductor, often silver-plated, and a gas-injected foam polyethylene dielectric core. LMR-100 is recognized for its dual shielding, with the inner layer being aluminum and the outer layer made from tinned copper braid, all enveloped in a durable polyethylene jacket.


Both RG174 and LMR-100 come in various versions, especially designed for specific environments. You can find these cables in their regular form, or as ultra-flexible versions, or even with UV resistance for outdoors installations.

Associated Wireless Technologies:

  • RG174: Due to its higher Attenuation, RG174 is commonly employed in low-power short-distance applications, such as Wi-Fi antennas, GPS systems, and certain mobile communications.
  • LMR-100: LMR-100, with its superior Attenuation performance, finds its applications in a broader range of wireless technologies. This includes 2G/ 3G/4G cellular, WLAN, RFID, and more.

Applications & Suitability for Specific IoT Applications:

IoT revolves around connectivity, requiring reliable transmission lines.

  • RG174: Suitable for indoor IoT applications where the cable run is short. Ideal for connecting Wi-Fi-based IoT devices, short-range sensors, and indoor antennas.
  • LMR-100: Given its low loss characteristics, LMR-100 is more appropriate for both indoor and outdoors IoT deployments, particularly where longer cable runs are involved. If you're looking at IoT applications such as outdoors weather stations, smart agriculture, or city-wide sensor deployments, LMR-100 stands out as the preferred choice.


Coaxial cable have been at the forefront of telecommunication and radio-frequency transmissions for decades. As technology advances, the requirements for more efficient coax cables grow, especially in the domain of the Internet of Things (IoT). Two significant contenders in this arena are the RG174 and LMR-100 cables.

When comparing RG174 and LMR-100 coax cables, understanding their key features and associated applications is essential. For short-distance, indoor IoT applications, RG174 may suffice. However, for more extensive and demanding scenarios, especially outdoors, LMR-100 with its enhanced performance metrics is the superior option. As the landscape of IoT continues to evolve, ensuring you're equipped with the right coaxial cable can be the difference between seamless connectivity and unwanted transmission losses.

Posted by George Hardesty on 17th Nov 2023

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