RG400 RF Coax Cable 40 ft - Double Shielded RG400 Coaxial Cable

In this review the RG400 RF Coax Cable 40 ft is examined for users needing a durable, high-performance coax run for RF and antenna work. The bottom line: this cable is a practical choice for installers and hobbyists who need a flexible, heat-resistant 50 ohm cable with strong shielding and reliable signal transmission; the most compelling reason to buy is its double silver-plated copper braid and PTFE construction, which together deliver consistent conductivity and excellent insulating properties.

Key Features

• Double shielding: The silver plated copper double braid provides superior shielding performance to reduce interference on RF signals.
• High temperature jacket: The FEP jacket resists heat and environmental stress, making the cable suitable for demanding installations.
• Low loss conductor: The silver plated copper inner conductor and PTFE insulator support good conductivity and stable signal transmission.
• Wide frequency support: Rated to a maximum operating frequency of 12400MHz, the cable handles a broad range of radio and RF applications.
• Standard impedance: A 50 ohm impedance ensures compatibility with most RF equipment and antennas without complex matching.
• Long length: The 40 ft package gives flexibility for runs between equipment, repeaters, or antennas without splicing.

Who It's For

The RG400 40 ft cable is well suited for radio amateurs, RF technicians, and AV installers who need a reliable 50 ohm coax with strong shielding and a heat-resistant jacket. Its flexibility compared with heavier LMR400-style cables makes it easier to route and coil in tight spaces while still providing solid performance.

It is less appropriate for users who require factory-terminated connectors or a lighter consumer coax for simple TV hookups; those users should look for pre-terminated cables or lower-spec consumer RG types. Also, if an ultra-low-loss, very heavy duty trunk is required for long outdoor runs, consider specialist low-loss trunk cables instead.

Pros & Cons

Pros

• Excellent shielding from the double silver plated braid reduces RF interference in noisy environments.
• PTFE insulation and silver plated conductor deliver reliable conductivity and strong insulating properties under load.
• FEP jacket and construction offer high-temperature resistance and durability for installation flexibility.
• 40 ft length provides convenience for many antenna and equipment placements without splices.

Cons

• Sold as a bulk cable without factory connectors, so users will need to terminate ends for many applications.
• Heavier and stiffer than thinner consumer coax types, which may be overkill for very short, low-power runs.

Specifications

Cable Type	RG400 RF double shielded coax
Length	40 ft
Impedance	50 ohm
Max Operating Frequency	12400MHz
Inner Conductor	Silver plated copper (19 x 0.203mm)
Insulator	PTFE (2.95mm)
Outer Conductor / Shielding	Silver plated copper double braid (3.95mm)
Jacket	FEP (4.95mm)

Our Verdict

The RG400 40 ft coax is a solid, value-minded choice for radio and RF work where strong shielding, heat resistance, and reliable conductivity matter. Installers and hobbyists who can terminate their own ends will appreciate its flexibility and insulating properties, making it a practical option for medium-length antenna and equipment runs.

Frequently Asked Questions

Does this cable come with connectors?
No, the package includes 1x 40 ft RG400 cable only; connectors must be attached separately.

Is this cable suitable for outdoor use?
The FEP jacket is heat resistant and durable, but for exposed outdoor long-term burial you should use cable rated specifically for direct burial or add protective conduit.

Can it handle high power RF?
Yes, customers report it suits high-powered jumpers and RF applications thanks to the silver plated conductor and robust shielding, but verify power handling for your specific transmitter.