What Is RG402 Coaxial Cable?

RG402 is a specialty coax cable used for radio frequency and microwave applications. It has a 50-ohm characteristic impedance. RG402 coax cable has a solid silver-coated copper clad steel inner conductor surrounded by a solid polytetrafluoroethylene (PTFE) dielectric. Allied Wire and Cable's RG402 coaxial cable's outer shield is a solid copper tube that provides excellent shielding and protection, allowing users to bury this coaxial cable directly in the ground. Another benefit of a semi-rigid construction is that the solid tube provides better RF isolation from electromagnetic interference (EMI). RG402 cable has a maximum voltage rating of 2,500 volts, a maximum temperature rating of 100 degrees Celsius, and exceptional high-frequency shielding capabilities.

1 items

  • RG 402
    $0.00 / 1000 FT
    • Approx LBS/MFT: 0.00
    • Cond. Material: Silver-Coated Copper Clad Steel
    • Conductor Stranding: solid
    Add to List

RG402 Coaxial Cable Structure


The inner conductor is a solid steel wire that's silver coated and copper clad. The steel core provides strength, while the low resistance of the silver coating improves the conductor's skin effect, improving high-frequency performance.


RG402 uses a solid PTFE dielectric with a relatively low dielectric constant of 2.0. The solid dielectric helps keep the conductor centered when bending the coax cable and limits variations in the voltage standing wave ratio (VSWR).

Shield and Outer Conductor

The outer shield is a solid copper tube that protects the cable and permits its use outdoors and for underground burial. The solid shield provides 100% radio frequency shielding. The outer diameter of RG402 cable is 0.141 inches or 3.6 millimeters.

RG402 Coaxial Cable Applications

You can use RG402 coax cable for any application requiring a characteristic impedance of 50 ohms. It's suitable for use in radio frequency communications in the gigahertz range, microwave circuits, and radar. The solid outer conductor provides extremely effective shielding against signal loss and EMI.

Alternative Coaxial Cables

Alternatives to 50-ohm RG402 cables include military specification RG402, LMR low loss, and TCOM low loss coaxial cables. Note that outside diameters vary and only RG402 has a semi-rigid solid copper shield.

Military Specification RG402

This coaxial cable is identical in many respects to standard RG402, except that it meets the stringent requirements of the M17 military specification. These include a guaranteed 20GHz sweep frequency, a temperature range of 125 C to minus 40 C, and a slightly lower maximum voltage of 1,900 volts.

LMR Low Loss

LMR low loss cables from Time Microwave have similar shielding capabilities of 90 decibels (dB) thanks to a closely braided outer shield and an aluminum tape inner shield. The outer diameter varies depending on the cable voltage and specification, with smaller sizes coming in at 0.11 inches.

TCOM Low Loss

You can use TCOM cables for up to 10 GHz applications. These cables have a 20-year outdoor rating, but a lower RF frequency shielding capability than the RG402 of 60 dB.

RG402 Specifications

  • Conductor: Silver-plated, copper clad, solid steel conductor
  • Dielectric: Solid PTFE with an outside diameter of 0.119 inches
  • Shield: Solid copper tube with an outside diameter of 0.141 inches and a wall thickness of 0.01 inches
  • Characteristic impedance: 50 ohms
  • Nominal capacitance: 29.4 picofarads per foot
  • Peak voltage: 2,500 volts
  • Temperature range: From 100°C to -40°C
Find out more about coaxial cables through the Allied University FAQs or contact our technical team for further information on RG402 cables and our specialty coaxial cables.