Antennas, Antenna Cables, Wireless Products: Technical Articles
RG-174 compared to LMR-100 Coax : Shielding and Signal Loss
Table of Contents
LMR-100 and RG174 Coaxial Cable Comparison
Overview
RG174 and LMR-100 are both 50‑ohm coaxial cables commonly used with Wi‑Fi, Cellular, GPS, and IoT wireless applications. While they share a similar diameter and connector compatibility, they differ significantly in shielding, attenuation, durability, and outdoor suitability.
LMR-100 is double‑shielded and suitable for indoor and outdoor use.
RG174 uses a single shield, is highly flexible, and is best suited for short indoor runs.
Attenuation (Signal Loss)
Lower values indicate better performance
| 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 |
Source: Data Alliance coaxial cable specifications
Key takeaway: LMR‑100 consistently exhibits lower attenuation, making it more suitable for longer cable runs and higher‑frequency applications.
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 make it an ideal choice for a wide range of contemporary and consumer applications, including:
- Security and access control
- Automation and IoT networking
- GPS
- Wireless networking such as LAN/WAN:
- For Wi-Fi: Most typically RP-SMA, cables
- For LTE: SMA cables or N-Type cables
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. The dielectric diameter is 1.55mm (0.06 inches)
- Outer shielding: A single layer of tinned copper with coverage between 88% and 90%, depending on the 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
- Impedance: 50 ohms
- Maximum Conductor Resistance: 142.4 ohms/km
- Dielectric Resistance: ≥ 1000 ohms
- Maximum Frequency: Up to 6 GHz
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 & Construction
RG174
Center conductor: Copper‑clad steel or silver‑plated copper (varies by manufacturer)
Dielectric: Solid polyethylene
Shield: Single tinned copper braid
Jacket: PVC
LMR‑100
Center conductor: Solid or stranded copper (often silver‑plated)
Dielectric: Gas‑injected foam polyethylene
Shielding Dual shield (aluminum foil + tinned copper braid)
Jacket: Polyethylene (UV‑ and moisture‑resistant)
Cable Variants
Both RG174 and LMR‑100 are available in multiple configurations, including:
Standard
Ultra‑flexible
UV‑resistant / outdoor‑rated versions
Associated Wireless Technologies:
RG174
Wi‑Fi antennas
GPS receivers
Bluetooth and short‑range radios
Low‑power cellular connections (very short distances)
LMR‑100
2G / 3G / 4G LTE
Wi‑Fi and WLAN
RFID systems
IoT gateways and remote sensors
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 indoor and outdoor IoT deployments, particularly where longer cable runs are involved. If you're looking at IoT applications such as outdoor weather stations, smart agriculture, or city-wide sensor deployments, LMR-100 stands out as the preferred choice.
Conclusion:
Coaxial cables 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 Internet of Things (IoT) domain. 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, LMR-100, with its enhanced performance metrics, is the superior option for more extensive and demanding scenarios, especially outdoors. As the landscape of IoT continues to evolve, ensuring you're equipped with a suitable coaxial cable can be the difference between seamless connectivity and unwanted transmission losses.
FAQs
What is the main difference between LMR-100 and RG174 coaxial cables?
The main difference lies in shielding and signal loss. LMR-100 is double-shielded, offering lower attenuation and better outdoor performance, while RG174 has a single shield, higher loss, and is best suited for short indoor cable runs.
Which cable is better for outdoor wireless or IoT applications?
LMR-100 is the better choice for outdoor installations due to its dual shielding, UV-resistant jacket, and reduced signal loss over long distances. RG174 should only be used indoors for short, low-power connections.
What wireless technologies are compatible with RG174 and LMR-100 cables?
Both cables support Wi-Fi, Cellular (2G–5G), GPS, and IoT applications. RG174 is ideal for short-range Wi-Fi or GPS use, while LMR-100 suits extended-range cellular, RFID, and outdoor IoT deployments.
How much signal loss do LMR-100 and RG174 have at 2400 MHz (Wi-Fi frequency)?
At 2400 MHz, RG174 has a signal loss of approximately 0.75 dB/ft, while LMR-100 offers a much lower loss of about 0.39 dB/ft, making it more efficient for longer cable runs.
What are the typical physical and electrical characteristics of RG174 cable?
RG174 has a 2.79 mm diameter, 50-ohm impedance, stranded copper-clad steel core, LDPE dielectric, single copper shield, and PVC jacket. It operates from –40 °C to +80 °C and supports frequencies up to 6 GHz.