KMR400 Coaxial Cable 50ft 50 Ohm Low Loss - Reliable Long Run

In this review the KMR400 Coaxial Cable 50ft is evaluated as a practical, low-loss feedline for 50 ohm RF systems. The single biggest reason to buy is its combination of ultra low loss over a 50 ft run and robust weatherproof construction, which makes it a straightforward choice when signal retention across distance matters. The review focuses on performance, construction quality and compatibility so buyers can decide if this 50 ft KMR400 cable is right for their antenna, booster or radio setup.

Key Features

• Ultra low loss: At 900 MHz the 50 ft cable reports less than 1.8 dB loss and an SWR around 1.15, which preserves more signal compared with higher-loss alternatives.
• 50 ohm compatibility: Works with any 50 ohm RF system so it is suitable for cell phone signal boosters, WiFi repeaters, ham radio and CB installations.
• Equivalent standard: KMR400 is specified as equivalent to LMR400 and RG8U, making it easy to substitute into common coax runs without redesigning the system.
• Durable construction: The centre conductor of copper clad aluminum plus aluminium foil and aluminium-magnesium braid provides mechanical protection and consistent shielding over long runs.
• Weatherproof jacket: A PVC outer jacket allows indoor or outdoor routing and helps the cable withstand harsh environments without immediate degradation.
• Connector flexibility: The cable is compatible with UHF, SMA, BNC, TNC, N and TS9 style connectors for a wide range of radio and antenna hardware.

Who It's For

This cable is a good fit for radio hobbyists, home cellular booster installers and small network operators who need a dependable 50 ft feedline with low insertion loss and solid shielding. It suits installations where runs are moderate in length and maintaining signal level is important, such as rooftop antennas to indoor equipment or boosters to outdoor panels.

Those who need a factory-terminated cable or a very flexible, ultra-small-diameter coax for tight indoor routing should look elsewhere; KMR400 is a mid-size coax built for lower loss and durability rather than extreme flexibility or pre-terminated convenience.

Pros & Cons

Pros

• Consistently low loss across higher frequencies helps preserve signal over a 50 ft run.
• Robust shielding and copper clad aluminium conductor provide a balance of conductivity and strength.
• Weatherproof PVC jacket makes outdoor deployment straightforward without extra protection.

Cons

• Ships without the wooden spool shown in some images, so handling during installation requires care to avoid kinks.
• Not as flexible as smaller coax types, which can make tight bends more difficult.

Specifications

Length	50 ft
Impedance	50 ohm
Loss at 900 MHz	< 1.8 dB
SWR	Approximately 1.15
Conductor	Copper clad aluminium (inner)
Outer shielding	Aluminium foil and aluminium-magnesium braid
Jacket	Weatherproof PVC

Our Verdict

The KMR400 Coaxial Cable 50 ft is a practical, value-oriented choice for anyone who needs a reliable 50 ohm run with low insertion loss and weather resistance. It is especially worth buying when replacing generic RG8 or upgrading older, higher-loss coax because it keeps more signal through the run and accepts common RF connectors, delivering solid performance for antenna and booster installations.

Frequently Asked Questions

Is this cable suitable for outdoor antenna runs?
Yes. The PVC jacket is weatherproof and the aluminium-magnesium braid helps protect signal integrity in outdoor installations.

Can I use this with my cell phone signal booster?
Yes. It is a 50 ohm cable and is compatible with typical cell phone boosters and WiFi repeaters that require 50 ohm feedlines.

Does the cable come pre-terminated with connectors?
No. The package includes the 50 ft KMR400 cable only and does not include pre-attached connectors or the wooden spool sometimes shown in images.