40ft KMR400 PL259 Male to Male Coaxial Cable - Low Loss UHF Cable

In this review of the 40ft KMR400 PL259 male to male coaxial cable, the bottom line is simple: it is for radio operators who need a long, low loss feedline for CB, ham, VHF or portable marine setups. The reviewer found the single biggest reason to buy is the low measured loss at higher VHF/UHF frequencies, which keeps signal strength and SWR stable over distance. Build quality and a secure connector termination also stand out, making it a practical choice when a durable outdoor-capable cable is required.

Key Features

• Low loss performance: At 450 MHz the 40ft KMR400 cable shows less than 2.8 dB loss and an SWR around 1.25, helping preserve signal over long runs.
• Robust conductor design: The inner conductor is copper clad aluminum while the outer uses aluminum foil plus a tinned copper braid to protect the signal over distance.
• Durable jacket and connectors: A high-quality PVC jacket provides water resistance for outdoor use and the nickel-plated connector shells resist oxidation.
• Secure connector termination: Each UHF male connector is sealed with a 2.2 in heat shrink tube bonded with adhesive to reduce the chance of connector pull-out.
• Versatile applications: Works with CB and ham radios, SWR meters, antenna analyzers, VHF marine equipment and surge protectors in typical ham and mobile setups.

Who It's For

This cable is aimed at ham radio operators, CB users and marine VHF owners who need a long, reasonably low loss feedline without stepping up to heavier commercial hardline. It is also a good match for those connecting antenna analyzers, SWR meters and surge protectors where maintaining signal integrity matters.

Those who need a very flexible coax for frequent coil-ups, tight bends or portable backpacks should look elsewhere; customers report this KMR400 is relatively stiff. If absolute minimum loss is required for contest-grade or tower-top installations, a higher-grade or larger-diameter coax might be preferable.

Pros & Cons

Pros

• Low measured loss at VHF/UHF frequencies preserves signal strength over the 40 ft run.
• Solid build with copper clad aluminum center and tinned braid for corrosion resistance.
• Weatherproof PVC jacket and nickel-plated connector shells make outdoor use viable.
• Heat-shrink with adhesive provides a secure connector termination that resists pull-out.

Cons

• Relatively stiff cable construction reduces flexibility for tight routing or frequent handling.
• Solder quality on connectors has received mixed reports from some users.

Specifications

Length	40 ft
Cable type	KMR400 low loss coax
Connector	PL259 male to PL259 male (UHF)
Inner conductor	Copper clad aluminum
Outer conductor	Aluminum foil + tinned copper braid
Jacket	High-quality PVC, waterproof
Loss at 450 MHz	< 2.8 dB, SWR about 1.25

Our Verdict

For hobbyists and mobile operators who need a dependable 40 ft feedline, this KMR400 PL259 cable delivers strong value: low loss at VHF/UHF, sturdy weather-resistant construction and a secure connector termination. It is a sensible upgrade over generic coax for most ham and CB applications, though those prioritizing extreme flexibility or the absolute lowest loss should consider alternate cable families.

Frequently Asked Questions

Will this cable work for HF and VHF?
Yes; users report good performance across HF and VHF bands and the cable specification highlights acceptable loss at VHF/UHF frequencies.

Is the cable waterproof for outdoor use?
The PVC jacket is waterproof and the nickel-plated connector shells resist corrosion, making the cable suitable for outdoor installations with normal weather exposure.

Are the PL259 connectors securely attached?
The connectors use a 2.2 in heat shrink with adhesive for a more secure bond and reduced risk of pull-out compared with unsealed assemblies.