L-400, sometimes referred to as LMR-400, is a low loss coaxial cable with a 10.16 mm outer diameter. Supporting frequencies beyond 6 GHz it's a popular choice for entry- to intermediate-level wireless communications systems. Due to its braided outer conductor the cable cannot be used for PIM sensitive applications such as distributed antenna systems.

This cable type is sometimes preferred over its smaller diameter compatriots when connection over the upper 4G LTE bands is sought, such as over B3 (1800 MHz), and B7 (2600 MHz). The downside is the large outer diameter which dramatically increases cost and difficulty of installation.

L-400 is classed as a Flexible cable as it uses a double outer conductor comprising aluminium tape and tinned copper braiding. This double shielded outer conductor provides exceptional RF shielding exceeding 90 dB, and PE jacket for a service life in excess of 20 years.

Terminating L-400 coaxial connectors requires a 10.89 mm (.429") hex die.

LMR400 coaxial cable layers

RF Specification

Min. Frequency
0 GHz
Max. Frequency
16.2 GHz
Shielding Effectiveness
> 90 dB
Capacitance
78.4 pF/m
Impedance
50 Ω
Velocity
85%
RF Operating Voltage
8000 Vrms

Frequency Test Data

Frequency Attenuation
1000 MHz
0.14 dB/m

Physical Specification

Colour
Black
Min. Bend Radius Static
25.4 mm
Min. Bend Radius Dynamic
101.6 mm
Min. Operating Temperature
-40 °C
Max. Operating Temperature
85 °C
Weight (g/m)
100 g

Cable Layers

Layer Diameter Materials
Inner Conductor
2.74 mm
Dielectric
7.24 mm
Outer Conductor
7.39 mm
Outer Conductor
8.13 mm
Outer Jacket
10.29 mm

Manufacturer Variations

Illustration Manufacturer Series Description
LMR400 coaxial cable layers
Powertec PTL-400

Powertec’s PTL-400 is an L-400 class low loss coaxial cable with a 10.29 mm outer diameter. Supporting frequencies beyond 6 GHz, it is a popular choice for entry- to intermediate-level wireless communications systems.

PTL-400 is classed as a Flexible cable as it uses a double outer conductor ...