Quabbin Wire & Cable Co., Inc. has broadened its offering of double-shielded coaxial cables designed for DS-3 digital signaling. These new bundled and jacketed groups of coaxial cables have application within ISP facilities, complex wide-area-networks, and Telco central offices.These DS-3 bundles contain up to 24 individual Type 735A coaxial components, each capable of transmitting 672 channels with a bandwidth of 44.7 MHz. The cables may be used as a system with Quabbin's previously developed DS-1 (T-1) paired cable and DS-3 single coaxials, providing an integrated copper cabling solution for handling time-division multiplexed (TDM) digital signals.
Applications include facilities where high bandwidth or multiple DS-1 circuits are employed such as Central Office or cellular antenna environments interconnecting routers, bridges, or switches. Pictured is a 24 component bundle and a dissected coax which illustrates the dual shielding. The coaxial components may be terminated using readily available BNC type connectors. The DS-3 family now includes single coaxials, 3/C, 6/C, 12/C, 24/C, a 2/C zip cord version, and a zip cord with a tracer.
These coaxials comply with Bellcore GR-139-CORE requirements for central office coaxial cable. They use an efficient high-density foamed insulation that provides high velocity of propagation, combined with low signal distortion. A double shield consisting of 100% coverage aluminum/polyester tape and 90% coverage braid provides both signal return path and EMI isolation. A flame-retardant PVC jacket over each component and over the entire bundle, gives the cables excellent mechanical protection, a 75-degree C temperature rating and NEC/CEC CMR fire resistant listing.
Electrically, they provide a mutual capacitance of 17.5 pF per foot combined with 75% velocity of propagation. The characteristic impedance is 75 Ohms with 30 dB minimum return loss through 90 MHz. The attenuation at 50 MHz is typically 3.47 dB per 100 foot.