SBCA Industry Standards Subcommittee Document: SBCA Series 6 Recommended Practices Date of Issue: Specification for 75 Ω Flexible RF Coaxial Drop Cable for Direct Broadcast Satellite (DBS) Installations
NOTICE The Satellite Broadcasting and Communications Association (SBCA) recommended practices are intended to serve the public interest by providing specifications, test methods and procedures which promote uniformity of product, interchangeability and ultimately improve the long-term reliability of digital broadcast services. These SBCA recommended practices do not endorse or encourage the use of any particular brands or any particular manufacturer s product. SBCA s recommended practices are advisory only. SBCA does not require adoption of these standards for membership in SBCA, for the National Standards and Testing Program (NSTP) certification or for any other purpose. These recommendations shall not, in any way preclude any manufacturer, distributor, retailer or installer, whether SBCA member or not from manufacturing, distributing, selling or using products not conforming to these documents, by those other than SBCA members, whether used domestically or internationally. SBCA assumes no obligations or liability whatsoever to any party who may choose to adopt the recommended practices. Such adopting party assumes all risks associated with adoption of these practices and accepts full responsibility for any damages and/or claims arising form the adoption of such practices. All Rights Reserved Published by Satellite Broadcasting and Communications Association Inc. 225 Reinekers Lane, Suite 600 Alexandria, VA 22314 USA i
TABLE OF CONTENTS INTRODUCTION... 2 1.0 SCOPE... 2 2.0 CENTER CONDUCTOR... 2 3.0 DIELECTRIC... 3 4.0 FIRST OUTER CONDUCTOR... 4 5.0 CORE (DIELECTRIC + LST)... 4 6.0 BRAID WIRE... 5 7.0 JACKET... 5 8.0 FINISHED PRODUCT TESTS... 7 1
INTRODUCTION This specification is intended to apply to general-purpose flexible Series 6 Type, 75-ohm RF coaxial drop cable used in the satellite broadcast industry. Reference to the National Electrical Code, National Electrical Safety Code and other regulations or specification should adhere to the latest document and should keep current with each document. This specification (standard) in no way should limit or restrict any manufacturer s innovation and improvement. Innovations and improvements are encouraged and this specification (standard) may be adjusted when beneficial 1.0 SCOPE 1.1 This specification applies to material, electrical and mechanical properties of Series 6 Type, 75-ohm DBS coaxial drop cables as defined herein. 1.2 75-ohm coaxial cables are used to distribute radio frequency (RF) signals. 2.0 CENTER CONDUCTOR 2.1 Material 2.2 Joints The center conductor shall be solid round copper wire intended for electrical purposes. The copper shall meet the requirements of ASTM B1. Factory joints in the finished product shall be allowed. The ultimate tensile strength in the joint area when tested per ASTM E-8 shall be 95 percent of the original unspliced wire. 2.3 Dimensions 2.3.1 Center conductor dimensions shall meet the requirements of Table 2.0 2.3.2 Center conductor tolerance shall be ± 1%. Table 2.0 Center Conductor Diameter Series 6 (inches) 0.0403 (mm) 1.02 2
2.3.3 Mechanical 2.3.3.1 Tensile strength and elongation properties of the copper conductor shall be as indicated in Table 2.1 2.4 Electrical Table 2.1 Center Conductor Minimum Mechanical Properties 0.0403 Cu minimum Tensile Strength, psi 67,000 Elongation, % 0.85 2.4.1 The center conductor electrical conductivity shall be 96.2 percent IACS, minimum, or 1.793 mω cm. 2.4.2 Maximum DC Resistance shall be measured per SCTE IPS TP008 and meet the requirements of Table 2.2. Table 2.2 Maximum Resistance in Ohms @ 68ºF (20ºC) 0.0403 Cu 6.77 Ω / kft, 22.2 Ω / km 3.0 DIELECTRIC 3.1 Material 3.1.1 Dielectric material extruded over the center conductor shall be an insulating grade virgin polyethylene and shall not contain reground, reprocessed or recycled materials. The insulation shall consist of gas injected foamed polyethylene with a closed cell structure. It shall be applied concentrically and bonded to the center conductor. The dielectric shall also contain a stabilization package to meet the requirements of section 8.1.4 Thermal Oxidative Stability (TOS). 3.1.2 Unless otherwise specified, polyethylene materials for the dielectric shall meet all applicable requirements of ASTM D 1248 and requirements of this document. 3
3.2 Mechanical 3.2.1 Nominal Dielectric Diameter (See Table 3.0) Table 3.0 Dielectric Diameter Series 6 (inches) 0.180 (mm) 4.57 4.0 FIRST OUTER CONDUCTOR 4.1 Material 4.1.1 The first outer conductor shall be a Laminated Shielding Tape (LST). The LST shall be constructed of two aluminum foils laminated to a strength member and a bonding resin on one side. (See Table 4.0). Table 4.0 LST Thickness Dimensions max Min (inch) 0.0032 0.00186 (micron) 81.28 47.24 4.1.2 The LST shall overlap the dielectric circumference by 18 percent minimum to 35 percent maximum on the finished product. 4.1.3 The LST shall be applied longitudinally to the dielectric and shall be free of creases or twists over the entire length. 5.0 CORE (DIELECTRIC + LST) 5.1 Average Core Diameter 5.1.1 The average core diameter shall be determined by measuring the diameter over the LST in the finished product as described in ANSI/SCTE 31. 4
Average Core Diameter (See Table 5.0). SBCA series 6 recommended practices.doc Table 4.0 Core Diameter (inches) 0.188 ± 0.005 (mm) 4.78 ± 0.13 5.2 Core Ovality 5.2.1 Core ovality shall be determined by subtracting the measured minimum from the measured maximum diameter over the LST in the finished product. 5.2.2 Maximum Core Ovality 0.013 (0.33 mm). 6.0 BRAID WIRE 6.1 Material 6.1.1 The braiding wire shall be a round aluminum wire consisting of 34 AWG size (0.0063 ± 0.0003 inches), (0.160 ± 0.01 mm), or 36 AWG size (0.0050 ± 0.0003 inches), (0.127 ± 0.01 mm), using an alloy of 5056, 5154, 5154A, or 5954. 6.2 Mechanical 7.0 JACKET 6.2.1 Minimum tensile strength for individual strands of aluminum alloy braid wire shall be 43,000 psi. 6.2.2 Minimum elongation for individual strands of aluminum alloy braid wire shall be 3 percent. 6.2.3 Braid coverage over the first outer conductor shall be a minimum of 59 percent for single braided products. The braid coverage shall be determined by ANSI/SCTE 51. 7.1 Material 7.1.1 Polyvinylchloride (PVC) compound may be used for aerial and indoor applications. 7.1.2 Polyethylene (PE) compound may be used underground or aerially. 7.1.3 Cables intended for indoor or outdoor use shall meet the latest requirements of the National Electrical Code (NEC), Articles 810 and 820 in accordance with local building codes and ordinances where 5
cable is installed. As a recommended minimum, the following guidelines should be used for indoor installations: Residential Installations: NEC CATVX or CMX Listed Commercial Installations: NEC CATV or CM Listed Remember ALWAYS check the local building codes and with local building inspectors or fire marshals to ensure that the proper cable listing is used for the intended application. 7.1.4 The jacket material shall be UV stable, as defined in UL 1581, paragraph 1200, Reference Standard for Electric Wire, Cables and Flexible Cords, 720 Hour Sunlight Resistance Test 7.1.5 Cables for indoor, aerial or underground applications may contain corrosion protection materials applied between the cable jacket and cable outer conductor. Corrosion protection shall be tested as described in ANSI/SCTE 69. 7.1.6 Cables intended for aerial or indoor applications, which contain a corrosion protection material, shall meet the non-flowing requirement as described in ANSI/SCTE 11. 7.2 Mechanical 7.2.1 The diameter over the jacket (DOJ) shall be measured as described in ANSI/SCTE 33 (See Table 7.0 for standard cable DOJ). Table 7.0 Standard Cable Diameter Over Jacket (DOJ) Series 6 (inches) 0.273 ± 0.008 (mm) 6.93 ± 0.203 7.3 Integral Static Ground Wire (ISGW) Web 7.3.1 The size and type of the ISGW shall comply with the requirements of the National Electrical Code (NEC), Article 810, Section 21, Paragraph H, and local building code requirements. As reference; a typical ISGW is 17 AWG, Copper Clad Steel. 7.3.2 The ISGW must separate from the cable in the web area without leaving any visible signs of splits, holes or grooves as specified in ANSI/SCTE 61. 6
8.0 FINISHED PRODUCT TESTS SBCA series 6 recommended practices.doc 8.1 Mechanical 8.1.1 The cable must be able to withstand a Cold Bend Test at -40 F/C with PVC jacket and -67 F (-55 C) with PE jacket. No visible damage to the jacket is allowed, as described in ANSI/SCTE 09. 8.1.2 The cable must be able to withstand an impact test without damaging the jacket. The test is to be conducted at 5 F (-15 C) for cables with PVC jackets and at -22 F (-30 C) for cables with PE jackets, as described in ANSI/SCTE 10. 8.1.3 Jacket longitudinal shrinkage shall be no more than 5 percent of the length under test as specified in SCTE IPS-TP003 (applicable to cables with PE jackets only). 8.1.4 Thermal Oxidative Stability To ensure the desired life expectancy of the dielectric insulation, determine its Oxidative Induction Time (OIT) before and after aging by measuring OIT according to ASTM D 4565, Section 17. The test utilizes insulation removed from the completed cable. Requirements for OIT Initial: 20 minutes minimum, after aging: 70 percent of initial value. 8.1.5 Center conductor bond to dielectric shall be as specified in Table 8.0 and measured per ANSI/SCTE 59. 8.2 Electrical Table 8.0 Center Conductor Bond To Dielectric Series 6 Minimum (lbs) 5 Minimum (kg) 2.3 8.2.1 Velocity of Propagation (Vp) shall be 82 percent minimum when measured per ANSI/SCTE 49. 8.2.2 Impedance; 75 ± 3 ohms when measured per SCTE IPS-TP006. 8.2.3 Minimum Structural Return Loss; 20 db in the frequency range 5 1000 MHz when measured per ANSI/SCTE 03, and 15 db in the frequency band of 1001 2250 MHz when measured per ANSI/SCTE 03, except Fixed Bridge method using the listed start and stop frequency. 7
8.2.4 The maximum DC Loop Resistance for a 59 percent braid and one LST shall be as specified in Table 8.1 when measured per SCTE IPS- TP008. Table 8.1 Maximum DC Loop Resistance @ 68 F (20 C) Series 6 Ω / kft Ω / km Loop 20.00 65.6 8.2.5 The maximum attenuation shall be as specified in Table 8.2 when measured per SCTE IPS-TP009. 8.2.6 The cable ampacity shall be determined per ANSI/SCTE 32. 8.2.7 The overall cable jacket integrity shall be subject to a spark test with a minimum 2.5 kv rms to ensure the absence of faults in the jacket during manufacturing. 8.2.8 The dielectric between inner conductor and outer conductor of the cable shall withstand without breakdown, for one minute, an alternating voltage of 1000V at a frequency of 60 Hz at room temperature as described in SCTE IPS-TP012. 8
Table 8.2 Maximum Attenuation @ 68 F (20 C) Series 6 Attenuation Frequency (MHz) db/100 feet db/100 meters 5 0.57 1.87 55 1.60 5.25 211 2.87 9.43 250 3.12 10.24 270 3.24 10.63 300 3.43 11.25 330 3.61 11.84 350 3.72 12.20 400 4.00 13.12 450 4.28 14.04 500 4.51 14.80 550 4.76 15.62 600 4.98 16.34 750 5.62 18.44 870 6.09 19.99 950 6.50 21.33 1000 6.54 21.46 1450 8.00 26.25 1750 8.74 28.67 2050 9.46 31.04 2250 10.00 32.81 9
GLOSSARY Attenuation: The decrease in magnitude of a wave as it travels through any transmitting medium, such as cable or circuitry. It is the difference between transmitted and received power. Coaxial Cable: A type of cable used for broadband data cable and satellite systems. Composed of a center conductor, insulating dielectric, conductive shield and optional protective covering. This type of cable has excellent broadband frequency characteristics, noise immunity and physical durability. In a DBS system the transmission cable from the antenna dish to a dwelling. Conductivity: The ability of a material to allow electrons to flow, measured by the current per unit of voltage applied. It is the reciprocal of resistivity. Core Ovality: The difference between the minimum and maximum dimensions over the first Laminated Shield Tape. DC Resistance: The opposition a material offers to current flow, measured in ohms. DC Loop Resistance: A resistance measurement of the center conductor and outer conductor when hooked in series (measured in ohms/1000 feet). Dielectric: A nonconductive insulator material between the center conductor and outer conductor of coaxial cable. Dielectric Withstand: The ability of the cable insulation to withstand a minimum Voltage. Impedance: The total opposition a circuit, cable or component offers to alternating current flow. It includes both resistance and reactance and is generally expressed in ohms and designated by the symbol Z. Ohm: The electrical unit of resistance. The value of resistance through a potential difference of one volt will maintain a current of one ampere. Radio Frequency (RF): The frequency region of the electromagnetic spectrum that is between audio frequencies and infrared. Spark Test: A test procedure to check the outer jacket continuity and insulation integrity of a coaxial cable. Static Ground: Copper covered steel conductor (or other material) typically used alongside the DBS cables and integrated with the same outer jacket in a figure-eight design for grounding purposes. Structural Return Loss (SRL): Magnitude of the internal cable reflections, measured in decibels (db), relative to the actual cable impedance, no the system impedance. Velocity of Propagation (VP): The transmission speed of electrical energy in a length of a cable compared to the speed of light in a vacuum. Usually expressed as a percentage. 10
ABREVIATIONS: ANSI ASTM NEC NFPA IEEE UL db AWG American National Standards Institute American Society for Testing and Materials National Electrical Code National Fire Protection Association Institute of Electrical and Electronic Engineers Underwriters Laboratories Decibel American Wire Gauge 11
REFERENCES The following standards form a part of the Flexible RF Coaxial Drop Cable for Direct Broadcast Satellite Installations Specification and associated test methods to the extent indicated herein. ANSI/UL1581 ASTM D 4565 ASTM B1 ASTM B193 IEEE Jones Dictionary NFPA-70-2002 SCTE SP-001 Reference Standard for Electrical Wires, Cables and Flexible Cords Physical and Environmental Performance Properties of Insulations and Jackets for Telecommunications Wire and Cable Standard Specification for Hard-Drawn Copper Wire Resistivity of Electrical Conductive Materials Standard Dictionary of Electrical and Electronic Terms Cable Television Terminology 3 rd Edition National Electrical Code Society of Cable Telecommunications Engineers Specification for Flexible RF Coaxial Drop Cable 12