Products & Product Reviews

Choosing the Right Coaxial Cable (Part 2): RG-400 High-Isolation Double-Shielded 50-ohm Coax

In Part 1 of our series on Choosing the Right Coaxial Cable, we looked at the benefits of DX Engineering RG-214 Double-Shielded 50-ohm Coaxial Cable—an excellent choice for outdoor applications and setups in which high RF isolation is paramount. Today, we’re highlighting another stellar performer: RG-400 High-Isolation Double-Shielded 50-ohm Coaxial Cable.

DX Engineering RG-400 brings to your RF systems the same quality and capabilities that are demanded of military and aerospace installations.


  • Very high power handling: – 2.75 kW at 30 MHz
  • Stranded silver-plated copper center conductor for extreme efficiency
  • PTFE dielectric for exceptional dimensional stability, low loss, and very high power handling
  • Silver-plated copper braided double shields for high isolation
  • Tough, waterproof fluorinated ethylene propylene MIL-C-17 jacket
  • Proper terminations on RG-400 cable assemblies provide extremely low crosstalk and low noise ingress with a double-braid shielding effectiveness that results in over 100 dB of isolation across HF frequencies


  • Ideal for critical, low signal level, low noise applications as well as high power handling for RF equipment interconnections

Notes: RG-400 is a 0.195″ diameter cable and is not related in any way to DXE-400MAX or LMR-400 cables which are 0.405″ diameter. RG-400 may be the same size as RG-58A/U, but it is an aerospace-level performance cable with dramatically improved ratings in all categories.

Availability: RG-400 High-Isolation Coaxial Cable is available by the foot (RG-400-CTL) or in assemblies of 3, 6, or 10 foot lengths with either soldered 83-ISP PL-259 or BNC male ends. All cable assemblies are hi-pot tested and heat-shrink weather-sealed for the ultimate in service longevity.

What do hams say?

Five Stars: “Replaced some 400MAX jumpers with these and it lowered my noise floor about 3 dB on 20-6M. Handles the power from my OM4000A just fine. These jumpers are very flexible in tight spaces, which is what prompted my purchase.”

Five Stars: “This is the good stuff—low loss and flexible. Wrapped a 6 foot cable around a 4 inch toroid to make an RF choke between my transceiver and antenna tuner.”

Five Stars: “I am rebuilding a linear amplifier. I chose this coax for its noise immunity and its power handling qualities.”

Whether you’re a do-it-yourselfer or prefer your coaxial ready to install right out of the package, DX Engineering offers three solutions to accommodate your preference:

Not sure what coaxial cable is right for your station? Looking for tips on maintaining and preparing your cables? Check out these OnAllBands articles:

You’ll find coaxial cable; connectors; cable prep tools and kits; cable ties, loops, and wraps; and more at

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