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| | Radio-frequency coaxial cables similar to military specifications. SPECIFICATIONS 1. Center Conductors Center cable conductor may be solid or stranded wire or, in some cases, a tube. Selection is made on the mechanical and electrical properties desired. Solid wires result in lowest cable attenuation. Stranding permits increased cable flexibility but also increases attenuation. Bare, tinned, or silverplated copper wire is usually used for center conductors. Other materials are Copperweld, cadmium bronze, aluminum, nichrome and Karma. 2. Dielectrics (Cable) Extruded Polyethylene. Low cost, flexibility, ease of application, high dielectric strength and low dielectric constant make it well suited for RF applications. It is the most commonly used lowtemperature cable dielectric. Foam Core (Cellular Polyethylene). An excellent low-temperature dielectric formed by expanding polyethylene with millions of bubbles of an inert gas. Its low dielectric constant of 1.5, compared with 2.26 for solid polyethylene, permits the design of lower attenuation and low capacity cables. Teflon. Teflon will withstand high temperature applications. It has high dielectric strength and a very low dielectric constant. Its ability to withstand exposure to gases and liquids makes it the dielectric selected where other materials would be inadequate. 3. Outer Conductors Shield (Armor) or Braid. The outer conductor is usually made of a metal braid but it can be a solid tube. The braid is used where flexibility is a vital factor. Tubular construction is used where a high degree of shielding is required. Tubular construction also provides lower cable attenuation. Two adjacent braids offer better shielding action than one braid. Braids are generally made of copper, tinned copper or silver-plated copper. 4. Operating Temperature Limits Type I (black PVC jacket): –40°C to 80°C Type II (grey PVC jacket): –25°C to 80°C Type IIa (black or grey PVC jacket): Under 1/4˝ O.D. –55°C to 90°C. Over 1/4˝ O.D. –40°C to 90°C. Type IIIa (black polyethylene jacket): –55°C to 85°C Type IV (black synthetic rubber jacket): Under 1/2˝ O.D. –55°C to 80°C. Over 1/2˝ O.D. –40°C to 80°C. Type V (fiberglass braid jacket): –55°C to 250°C Type VI (Silicon-rubber dacron braid jacket): –55°C to 175°C Type VII (PTFE Teflon jacket): –55°C to 250°C Type VIII (synthetic rubber jacket): –55°C to 75°C Type IX (FEP Teflon jacket): –55°C to 200°C 5. Jacket Types Type 1, black polyvinyl chloride. Excellent weathering and abrasion properties, but is of contaminating type and will cause cable attenuation to increase with age. Can be used for direct burial. Type II, grey polyvinyl chloride. A seminoncontaminating jacket. Type IIA, black or grey polyvinyl chloride. Noncontaminating. Good weathering and abrasion-resistant properties. Can be used for direct burial. Type IIIA, black polyethylene. Moisture-resistant, abrasion-resistant, defies ultraviolet damage. Noncontaminating. Recommended for direct burial. Type IV, black synthetic rubber. Used only on highvoltage pulse cables. The basic material is polymerized chloroprene. Type V, fiberglass braid. Impregnated with silicone varnish to provide abrasion resistance and a moisture seal. Type VI, silicone rubber dacron braid. Two wraps of silicone rubber-impregnated fiberglass tape, fused into a homogeneous layer. A dacron braid is applied, followed by a high-temperature fluorocarbon lacquer. Type VII, polytetrafluoroethylene Teflon. Either extruded to tape wrapped. Withstands high temperatures, chemically inert, insoluble in liquids and gases. Type VIII, synthetic rubber. A polychloroprene compound, used with only a few pulse cables, primarily as a jacket material for multiconductor cables. Type IX, fluorinated ethylene propylene Teflon. Excellent weathering properties, chemically inert. |
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| | RG TYPE PREMIUM GRADE COAX ABBREVIATIONS DIELECTRIC CEL PE . . . . . . . . . . . . . .Cellular Polyethylene FEP . . . . . . . . . . . . . . . . . .Fluorinated Ethylene Propylene (Solid) PE . . . . . . . . . . . . . . . . . . .Polyethylene (Solid) PIB . . . . . . . . . . . . . . . . . .Polyisobutylene, Type B, per MIL-C-17D PS . . . . . . . . . . . . . . . . . . .Polystyrene PTFE . . . . . . . . . . . . . . . .Polytetrafluoroethylene (Solid) Rubber . . . . . . . . . . . . . . .per MIL-C-17 CONDUCTORS & BRAID MATERIALS AL . . . . . . . . . . . . . . . . . . .Aluminum BC . . . . . . . . . . . . . . . . . . .Bare copper BCCS . . . . . . . . . . . . . . . .Bare copper covered steel BerC . . . . . . . . . . . . . . . . .Beryllium-Copper Alloy CCA . . . . . . . . . . . . . . . . .Copper covered aluminum CCS . . . . . . . . . . . . . . . . .Copper covered steel GS . . . . . . . . . . . . . . . . . .Galvanized steel HR . . . . . . . . . . . . . . . . . .High resistance wire MY . . . . . . . . . . . . . . . . . .Mylar NC . . . . . . . . . . . . . . . . . .Nickel coated copper SC . . . . . . . . . . . . . . . . . . .Silver covered copper SCBerC . . . . . . . . . . . . . .Silver covered Beryllium-Copper Alloy SCCadBr . . . . . . . . . . . . .Silver covered cadmium bronze SCCAl . . . . . . . . . . . . . . . .Silver coated copper covered aluminum SCCS . . . . . . . . . . . . . . . .Silver covered copper covered steel SSC . . . . . . . . . . . . . . . . .Silver covered strip TC . . . . . . . . . . . . . . . . . . .Tinned copper TCCS . . . . . . . . . . . . . . . .Tinned copper covered steel JACKET MATERIAL CLP . . . . . . . . . . . . . . . . . .Cross-linked polyethylene E-CTFE-XI . . . . . . . . . . . .Ethylene/Chlorotrifluoroethylene Copolymer ETFE-X . . . . . . . . . . . . . . .Ethylene/Tetrafluoroethylene Copolymer FEP-IX . . . . . . . . . . . . . . .Fluorinated Ethylene Propylene, Type IX, per MIL-C-17 FG Braid-V . . . . . . . . . . . .Fiberglass, impregnated, Type V, per MIL-C-17 HDPE . . . . . . . . . . . . . . . .High density polyethylene KEL-F . . . . . . . . . . . . . . . .Old fluorocarbon material prior to Teflon™ PE-III . . . . . . . . . . . . . . . . .Clear polyethylene PE-IIIA . . . . . . . . . . . . . . .High molecular weight, black polyethylene, Type IIIA, per MIL-C-17 PFA-XIII . . . . . . . . . . . . . .Perfluoroalkoxy, per MIL-C-17 PTFE . . . . . . . . . . . . . . . .Polytetrafluoroethylene, per MIL-C-17 PUR . . . . . . . . . . . . . . . . .Polyurethane, Black specific compounds PVC-I . . . . . . . . . . . . . . . .Black polyvinyl chloride, contaminating, Type I, per MIL-C-17D PVC-II . . . . . . . . . . . . . . . .Grey polyvinyl chloride, noncontaminating, Type II, per MIL-C-17D PVC-IIA . . . . . . . . . . . . . . .Black polyvinyl chloride, noncontaminating, Type IIA, per MIL-C-17 Rubber . . . . . . . . . . . . . . .Per MIL-C-17 Sil/DAC-VI . . . . . . . . . . . .Dacron braid over silicon rubber, Type VI, per MIL-C-17 TPE . . . . . . . . . . . . . . . . . .Thermo-plastic Elastomer |
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