LMR-400 is a high-performance, 50-ohm coaxial cable designed to provide ultra-low signal loss, making it a standard choice for long-distance antenna runs and high-frequency RF systems. It was originally developed by Times Microwave Systems as a superior, low-loss alternative to legacy cables like RG-8.
Key Features
Ultra-Low Attenuation: Offers some of the lowest signal loss in the "400-class" category, which is critical for maintaining signal integrity over long distances.
Superior Shielding: Features a double-shielded design (bonded aluminum foil and tinned copper braid) that provides over 90 dB of RF shielding, effectively eliminating interference.
Weather Resistance: The standard version comes with a UV-resistant polyethylene (PE) jacket, rated for an outdoor service life of up to 20 years.
High Power Handling: Capable of handling significant power levels, reaching a peak power rating of 16 kW.
Technical Specifications
Electrical Property
Value
Impedance
50 Ohms
Velocity of Propagation
85%
Capacitance
23.9 pF/ft (78.4 pF/m)
Max Frequency
16.2 GHz (Cutoff)
Shielding Effectiveness
>90 dB
Voltage Withstand
2,500 VDC
Mechanical Property
Value
Outer Diameter
0.405 inches (10.29 mm)
Center Conductor
0.108" Solid Bare Copper Clad Aluminum
Dielectric
Gas-injected Foam Polyethylene
Min. Bend Radius (Installation)
1.0 inch (25.4 mm)
Operating Temperature
-40°C to +85°C
Attenuation & Power Rating (at 25°C)
As frequency increases, signal loss (attenuation) increases and power handling capability decreases.
