Lmr 400 cable

LMR 400 is a low-loss coaxial cable designed for high-performance RF applications. You must verify the Center Conductor material, which should be Solid BCCAI (Bonded Copper Clad Aluminum) for standard LMR 400, or Solid Copper for ultra-low loss variants. Ensure the Dielectric is made of Gas-injected Closed Cell Polyethylene foam to maintain impedance stability. The Shielding must be a double-layer system consisting of an Aluminum Tape outer conductor and a Tinned Copper Braid to provide >90 dB shielding effectiveness. Finally, check the Jacket material; PE (Polyethylene) is required for outdoor UV resistance, while LSZH (Low Smoke Zero Halogen) is mandatory for indoor fire safety compliance.

Request a VNA (Vector Network Analyzer) test report from the supplier. The Impedance must be strictly 50 Ohms. For LMR 400, the Attenuation (Signal Loss) should not exceed approximately 12.8 dB per 100 meters at 900 MHz and 22.2 dB at 2500 MHz. Additionally, verify the VSWR (Voltage Standing Wave Ratio), which should ideally be ≤ 1.2:1 over the intended frequency range to prevent signal reflection and equipment damage.

For global trade, ensure the supplier provides RoHS and REACH certifications to confirm the absence of hazardous substances. If the cables are for the North American market, UL or ETL listings (such as CMR or CMP ratings) are critical for building code compliance. For European markets, look for the CE mark and CPR (Construction Products Regulation) classification, typically Class Eca or higher, to ensure fire safety standards are met.

LMR 400 is the industry standard for Wireless Communication Systems, including WLAN, WLL, GPS, and Cellular installations. It is the preferred choice for antenna feeders where a balance between flexibility and low loss is required. It serves as a superior replacement for RG-8/9913 air-dielectric type cables, offering better durability and easier installation in base station deployments and industrial RF links.

The most common risk is the use of low-grade recycled plastic or insufficient braid coverage. To mitigate this, source from Audited Suppliers on Made-in-China.com who have undergone third-party on-site inspections. Always request a pre-shipment sample and perform a 'strip test' to verify the density of the tinned copper braid and the bonding of the aluminum foil to the dielectric.

LMR 400 pricing is heavily influenced by global copper and aluminum commodity prices. When negotiating, ask for a price breakdown based on raw material indices. For bulk orders exceeding 5,000 meters, you can typically negotiate a 10-15% discount. If you are a small buyer, look for suppliers offering MOQs as low as 100-500 meters but be prepared to pay a premium for custom printing or specific jacket colors.

Coaxial cables are sensitive to crushing and kinking, which can permanently alter their impedance. Ensure the supplier uses sturdy wooden reels or high-strength plastic spools rather than simple coils. For sea freight, specify waterproof pallet wrapping to prevent moisture ingress into the cable ends, which can cause oxidation. Ensure all cable ends are heat-sealed or capped before dispatch.

Utilize Secured Payment services provided by reputable B2B platforms to ensure funds are only released upon proof of shipment. In the event of a quality dispute, a third-party inspection report (e.g., SGS or Intertek) is your strongest leverage. Ensure your Proforma Invoice (PI) explicitly states the required attenuation limits and jacket markings to provide a legal basis for claims if the delivered goods do not match the specifications.