1、AMSC N/A FSC 5985 INCH-POUND MIL-DTL-24215D 14 December 2010 SUPERSEDING MIL-DTL-24215C 16 January 2007 DETAIL SPECIFICATION ATTENUATORS, VARIABLE (COAXIAL), GENERAL SPECIFICATION FOR This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Sc
2、ope. This specification covers variable continuously and variable in steps attenuators for use as attenuating elements in coaxial lines. These attenuators are used for armed services application in the transmission lines of radar, radio, and associated equipment (see 6.1). 1.2 Classification. Attenu
3、ators consist of the following classes, as specified (see 3.1 and 6.2): Class Type of RF connector Connector specification 5 SMA MIL-PRF-39012 7 BNC MIL-PRF-39012 1.3 Part or Identifying Number (PIN). The PIN consists of the letter “M”, the basic number of the specification sheet, and an assigned da
4、sh number as shown in the following example (see 3.1): M24215/ 9 001 Military designator Slash sheet Dash number designated and specification number on specification sheet number 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 or 4 of this specif
5、ication. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requiremen
6、ts documents cited in sections 3 or 4 of this specification, whether or not they are listed. Comments, suggestions, or questions on this document should be addressed to DLA Land and Maritime, ATTN: - VAT, Post Office Box 3990, Columbus, OH 43218-3990 or emailed to TubesAmpsdscc.dla.mil. Since contac
7、t information can change, you may want to verify the currency of this address information using the ASSIST Online database at https:/assist.daps.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24215D 2 2.2 Government documents. 2.2.1
8、 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract (see 6.2). DEPARTMENT OF DEFENSE SP
9、ECIFICATIONS MIL-DTL-3922 - Flanges, Waveguide, General Purpose, General Specification for. MIL-DTL-14072 - Finishes for Ground Based Electronic Equipment. MIL-DTL-24044 - Flanges, Coaxial Line, Rigid, Air Dielectric, General Specification for. See supplement 1 for list of associated specification s
10、heets. FEDERAL STANDARDS FED-STD-H28 - Screw-Thread Standards for Federal Services. DEPARTMENT OF DEFENSE STANDARDS MIL-STD-129 - Military Marking for Shipment and Storage. MIL-STD-202 - Electronic and Electrical Component Parts. MIL-STD-1285 - Marking of Electrical and Electronic Parts. (The above
11、specifications, standards, and handbooks are available online at https:/assist.daps.dla.mil or from the Document Automation and Production Service, Building 4D (DPM-DODSSP), 700 Robbins Avenue, Philadelphia, PA 19111-5094.) 2.3 Non-Government publications. The following documents form a part of this
12、 document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract (see 6.2). NATIONAL CONFERENCE OF STANDARDS LABORATORIES (NCSL) NCSL-Z540.3 - Requirements for the Calibration of Measuring and Test Equipment (Copies a
13、re available online at http:/www.nclsi.org or from National Conference of Standards Laboratories (NCSL), 2995 Wilderness Place, Suite 107, Boulder, CO 80301-5404.) ASTM INTERNATIONAL (ASTM) ASTM-A582/A582M - Free-Machining Stainless Steel Bars. ASTM-B194 - Copper-Beryllium Alloy Plate, sheet, Strip,
14、 and Rolled Bar. ASTM-B196/B196M - Copper-Beryllium Alloy Rod and Bar. ASTM-B197/B197M - Copper-Beryllium Alloy Wire. ASTM-B700 - Electrodeposited Coatings of Silver for Engineering Use. ASTM-B783 - Materials for Ferrous Powder Metallurgy Structural Parts. ASTM-G21 - Determining Resistance of Synthe
15、tic Polymeric Materials to Fungi. (Copies are available online at http:/www.astm.org or from ASTM International, 100 Barr Harbor Drive, P. O. Box C700, West Conshohocken, PA 19428-2959.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24215D
16、3 SAE INTERNATIONAL (SAE) AEROSPACE MATERIALS SPECIFICATIONS (AMS) SAE-AMS-QQ-S-763 - Corrosion Resistant Steel Bars, Wire, Shapes and Forgings. (Copies are available online at http:/www.sae.org or from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001.) 2.4 Order of precedence. U
17、nless otherwise noted herein or in the contract, in the event of a conflict between the text of this document and the references cited herein (except for related specification sheets), the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regul
18、ations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with the applicable specification sheet. In the event of any conflict between the requirements of this specification and the
19、 specification sheet, the latter shall govern. 3.2 First article inspection. When specified (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.5. 3.3 Material. The material shall be as specified. When a definite material is not specified, a material shall be used
20、 which will enable the attenuators to meet the performance requirements of this specification. Acceptance or approval of any constituent material shall not be construed as a guaranty of the acceptance of the finished product. 3.3.1 Fungus. All material shall be inert or fungus resistant in accordanc
21、e with ASTM-G21. 3.4 Design and construction. Attenuators shall be of the design, construction, and physical dimensions specified (see 3.1). Attenuators shall be of the lightest practicable weight consistent with the strength required for sturdiness, safety, and reliability. Mechanical stops shall b
22、e provided at the minimum and maximum attenuation positions to prevent damage to the attenuator cards. Bearing surfaces and gears shall be made of a durable metal that shall resist wear. A cam or detent shall be used on step attenuators that provide a positive step at each position. End play in shaf
23、ts and bearings shall be kept to a minimum and gear mesh to comply with the backlash requirement. Control knobs, or dials, or stub-shafts with screwdriver slot, shall be so designed that attenuator adjustment may be readily made. The adjustment shall not change in setting as a result of shock and vi
24、bration tests. 3.4.1 Operating frequency range. The frequency range shall be as specified (see 3.1). 3.4.2 Nominal impedance. The nominal impedance for coaxial-line attenuators shall be as specified (see 3.1). 3.4.3 Threaded parts. All threaded parts shall be in accordance with FED-STD-H28. 3.4.4 Pl
25、astic parts. All plastic parts shall be free from visible cracks or flaws. 3.4.4.1 Plastic caps. The RF connector ends of the attenuators shall be sealed with push-on plastic caps to prevent damage and the entrance of moisture and foreign material during storage. 3.4.5 Metal parts. All metal parts s
26、hall be free from chips, burrs, and scratches in accordance with good commercial practice. Metal parts shall be inherently corrosion resistant or treated to resist corrosion. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24215D 4 3.4.6 Conn
27、ectors. The connectors shall be as specified (see 3.1). The material and gauging for receptacle connectors shall conform to the requirements of the applicable specification. 3.4.6.1 Connector metal parts. Unless otherwise specified, the connectors and the male center contact pins shall be made of co
28、rrosion resisting steel, type 302 or 304 in accordance with SAE-AMS-QQ-S-763, or type 303 in accordance with ASTM-B783 and ASTM-A582/A582M. The female center contact pins shall be made of beryllium copper conforming to ASTM-B196/B196M, ASTM-B197/B197M and ASTM-B194, silver plated in accordance with
29、ASTM-B700. 3.4.7 Flange. Flanges shall be designed and manufactured to provide the mating characteristics of the flange specified (see 3.1) in accordance with MIL-DTL-3922 or MIL-DTL-24044. 3.4.8 Weight. The weight for attenuators shall be as specified (see 3.1). 3.4.9 Finish. The attenuators shall
30、be given a protective coating in accordance with MIL-DTL-14072. Unless otherwise specified (see 3.1), all exterior surfaces except flange mating surfaces, connectors, dials, knobs, and working parts shall be painted with enamel in accordance with MIL-DTL-14072, as specified (see 3.1). 3.4.9.1 Pure t
31、in. The use of pure tin, as an underplate or final finish, is prohibited both internally and externally. Tin content of variable attenuator components and solder shall not exceed 97 percent, by mass. Tin shall be alloyed with a minimum of 3 percent lead, by mass (see 6.6). 3.5 Performance. 3.5.1 Ins
32、ertion loss. When tested as specified in 4.7.2, the value of attenuation at the minimum attenuation position, across the operating frequency range, shall be no greater than specified (see 3.1). 3.5.2 Voltage standing wave ratio (VSWR). When tested as specified in 4.7.2, the VSWR of the attenuator, a
33、t any attenuation position, at the frequencies specified, shall be no greater than specified (see 3.1). 3.5.3 Dial calibration (when applicable, see 3.1). When tested as specified in 4.7.2, the calibration of the dial assembly, if included with the attenuator, shall be checked and shall be within th
34、e specified limits (see 3.1). 3.5.4 Frequency sensitivity. When tested as specified in 4.7.2, the total variation in attenuation value across the operating frequency range shall be no greater than specified (see 3.1). 3.5.5 Attenuation range. When tested as specified in 4.7.2, the attenuation range
35、shall be as specified and shall be variable as specified (see 3.1). 3.5.6 Temperature coefficient (when required, see 3.1). When tested as specified in 4.7.10, the temperature coefficient shall be as specified (see 3.1). 3.5.7 Backlash. The variable control mechanism used shall have provisions to el
36、iminate backlash to the point that the accuracy of the dial calibration is applicable when approaching an attenuation value from either direction (see 4.7.2). 3.5.8 Power capability. When tested as specified in 4.7.3, at the specified maximum power (see 3.1), the VSWR and dial calibration requiremen
37、ts shall be met (see 3.5.2 and 3.5.3). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-24215D 53.5.9 Life (rotational). When tested as specified in 4.7.4, the attenuators shall meet the requirements of 3.5.1 through 3.5.8 (see 3.1) after 500
38、cycles of operation. 3.5.10 Shock. When tested as specified in 4.7.5, attenuators shall meet the requirements for VSWR and attenuation (see 3.1). 3.5.11 Vibration. When tested as specified in 4.7.6, attenuators shall meet the requirements for VSWR and attenuation (see 3.1). 3.5.12 Salt atmosphere (c
39、orrosion) When tested as specified in 4.7.7, attenuators shall show no evidence of corrosion or pitting (see 3.1). 3.5.13 Thermal shock Attenuators shall withstand the thermal shock specified in 4.7.8. 3.5.14 Seal-coaxial type attenuators (when required). There shall be no evidence of escaping bubbl
40、es when the attenuator is tested as specified in 4.7.11. 3.5.15 Humidity (when required). When tested as specified in 4.7.9, the VSWR and attenuation range shall be within the limits specified (see 3.1). 3.6 Marking. Attenuators shall be marked in accordance with MIL-STD-1285, with the following inf
41、ormation: a. Class, part number, and manufacturers code symbol. b. Attenuation, in decibels (dB) as specified (see 3.1). c. Frequency range, as specified (see 3.1). d. Average power rating, in watts (see 3.1). f. Marking shall be in permanent lettering at least .125 inch (3.18 mm) high and shall be
42、legible. 3.7 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible provided that the material meets or exceeds the operational and maintenance requirements, and promotes economically ad
43、vantageous life cycle costs. All components supplied shall be new and unused. 3.8 Workmanship. Surfaces shall be free from burrs, die marks, chattermarks, scratches, grease, scale, splinters, and other defects that will affect life, serviceability, or appearance. Provided by IHSNot for ResaleNo repr
44、oduction or networking permitted without license from IHS-,-,-MIL-DTL-24215D 6 4. VERIFICATION 4.1 Test equipment and inspection facilities. Test and measuring equipment and inspection facilities of sufficient accuracy, quality and quantity to permit performance of the required inspection shall be e
45、stablished and maintained by the supplier. The establishment and maintenance of a calibration system to control the accuracy of the measuring and test equipment shall be in accordance with NCSL-Z540.3. 4.2 Classification of inspections. The inspections specified herein are classified as follows: a.
46、Materials inspection (see 4.3). b. First article inspection (see 4.5). c. Conformance inspection (see 4.6). 4.3 Materials inspection. Materials inspection shall consist of certification supported by verifying data that the materials listed in table I, used in fabricating the attenuator, are in accor
47、dance with the applicable referenced specifications or requirements prior to such fabrication. TABLE I. Materials inspection. Material Requirement paragraph Applicable specification Fungus Silver Copper-beryllium Steel bars, shapes and forgings 3.3.1 3.4.6.1 3.4.6.1 3.4.6.1 ASTM-G21 ASTM-B700 ASTM-B
48、196/B196M, ASTM-B197/B197M, ASTM-B194 SAE-AMS-QQ-S-763 or ASTM-B783, A582/A582M 4.4 Inspection conditions. Unless otherwise specified herein, all inspections shall be performed in accordance with the test conditions specified in the “GENERAL REQUIREMENTS” of MIL-STD-202. 4.5 First article inspection
49、. First article inspection shall be performed by the supplier after award of contract and prior to production, at a location acceptable to the Government. First article inspection shall be performed on sample units that have been produced with equipment and procedures normally used in production. First article approval is valid only on the contract or purchase order under which
