1、 MIL-DTL-49285/28A 1 March 2010SUPERSEDING MIL-C-49285/28 19 October 1989 DETAIL SPECIFICATION SHEET CABLE, SPECIAL PURPOSE, ELECTRICAL, TWO PAIRS OF 25 (78 X 33) AWG, ONE PAIR INDIVIDUALLY SHIELDED This specification is approved for use by all Departments and Agencies of the Department of Defense.
2、The requirements for acquiring the product described herein shall consist of this specification sheet and MIL-DTL-49285. FIGURE 1. Cable illustration. AMSC N/A FSC 6145 INCH-POUND Inactive for new design after 16 June 1997. Provided by IHSNot for ResaleNo reproduction or networking permitted without
3、 license from IHS-,-,-MIL-DTL-49285/28A 2 Engineering information: (see table I and figure 1). Note: Not for aerospace use. TABLE I. Description, electrical. Electrical characteristics Requirements Nominal capacitance between conductors Nominal capacitance between the conductor and the shield with o
4、ne conductor tied to the shield Continuous working voltage Continuous working voltage between adjacent shields Shield dc resistance 25 pF/ft (picofarads/foot) 40 pF/ft 400 V rms maximum between conductors 28 ohms/1,000 feet maximum 48.0 ohms/1,000 feet maximum TABLE II. Description, physical. Compon
5、ents Construction details Number of pairs Conductor type and wire size Conductor stranding Conductor insulation Conductor insulation thickness Drain wire type and size Drain wire stranding Jacket material Jacket thickness Finished cable diameter Cable style (UL) Tensile strength (jacket) Elongation
6、(jacket) Overall cabling lay lengths Two pairs one pair individually shielded Stranded 25 AWG 7 X 33 AWG 3 tinned copper 4 tinned coated copper clad steel Polyethylene 0.013 inch nominal thickness Stranded 25 AWG 7 X 33 AWG 3 tinned copper 4 tinned coated copper clad steel Polyvinyl chloride 0.019 i
7、nch 0.174 inch maximum outside diameter Not applicable 2,000 pounds per square inch minimum 150 percent minimum 8.0 twists per foot 10 percent Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-49285/28A 3 REQUIREMENTS: Design and construction:
8、(see table II): Shield location and orientation. This cable consists of a shielded pair and an unshielded pair all enclosed by an overall shield. The polyester aluminum shield associated with the individually shielded pair is to be located on the outer circumference of the pair with the aluminum foi
9、l side outward. Insulation on the interior of the shield is to be complete with no aluminum available for contact. The overall shield encompasses the individually shielded pair and the unshielded pair. The overall shield insulation on the exterior of the shield is to be complete with no aluminum foi
10、l side inward. Shield color code. The shield colors shall be blue. Drain wire location. The drain wire is to be spirally located between the noise reducing tape and the aluminum foil shield, and is to be in continuous contact with the aluminum surface of the foil shield and the noise reducing tape t
11、hroughout the cable. Cable temperature rating. The cable temperature rating shall be -20C to +80C. Conductor color code. 1stpair (individually shielded) 2ndpair (under overall shield) 1stconductor: Red 1stconductor: Green 2ndconductor: Black 2ndconductor: White Cabling. Pairs cabled on a common axis
12、 to reduce diameter. Shield effectiveness evaluation test connections. The cable will be tested as if it were one pair. The test shall be performed with the jacket in place. Install in the test fixture. Test one pair with the other pair floating. Alternate the connections in order to test the second
13、 pair. Care must be taken in order to preserve both shields during testing. Shield integrity test.* The following list of responses refer to the pair located under the overall shield. This pair does not have an individual pair shield covering it. Frequency Response * 100 kHz 115 dB below reference 5
14、00 kHz 105 dB below reference 1 MHz 100 dB below reference 5 MHz 84 dB below reference 10 MHz 76 dB below reference 15 MHz 71 dB below reference 20 MHz 67 dB below reference 25 MHz 63 dB below reference 30 MHz 60 dB below reference Fixture resonance will occur between 40 and 70 MHz. At 100 MHz: At l
15、east 45 dB below reference. The following list of responses refers to the pair covered by an individual pair shield and located within the overall shield. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-49285/28A 4 Frequency Response * 100 kH
16、z 115 dB below reference 500 kHz 105 dB below reference 1 MHz 101 dB below reference 5 MHz 89 dB below reference 10 MHz 85 dB below reference 15 MHz 81 dB below reference 20 MHz 76 dB below reference 25 MHz 71 dB below reference 30 MHz 66 dB below reference Fixture resonance will occur between 40 an
17、d 70 MHz. At 100 MHz: At least 47 dB below reference. * Any two readings may deviate to a value of 0.9 times the stated limits. * All values are a minimum numerical value. Crosstalk test limits. Crosstalk testing is not required for this configuration. Durometer hardness. The cable shall have a duro
18、meter hardness of 85 5. Part or Identifying Number (PIN): The PIN shall be M49285/28. Changes from previous issue. The margins of this specification are marked with vertical lines to indicate where changes from the previous issue were made. This was done as a convenience only and the Government assu
19、mes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the requirements of this document based on the entire content irrespective of the marginal notations and relationship to the last previous issue. Referenced document. This document
20、references MIL-DTL-49285. CONCLUDING MATERIAL Custodians: Preparing activity: Army CR DLA - CC Navy SH Air Force 85 DLA CC Review activities: Army MI (Project 6145-2009-025) Air Force 71 DLA - IS NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change. You should verify the currency of the information above using the ASSIST Online database at http:/assist.daps.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
