1、AMSC N/A FSC 5985 MIL-DTL-22354C 14 July 2008 SUPERSEDING MIL-DTL-22354B 18 August 2003 DETAIL SPECIFICATION ANTENNA AT-948/U This specification is approved for use by all Depart- ments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers one type of UHF Antenna,
2、the AT-948/U, a vertically-polarized omni-directional antenna having overhead coverage to fill in the cone of silence and operating over a frequency range of 400 through 550 megahertz (MHz) for shipboard and shore station applications. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in thi
3、s section are specified in sections 3 and 4 of this specification. 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
4、are cautioned that they must meet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this
5、 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 SPECIFICATIONS MIL-PRF-27 - Transformers and Inductors (Audio, Power, and High-Power Pulse), General Specification for.
6、 MIL-S-901 - Shock Tests, H.I. (High-Impact) Shipboard Machinery, Equipment, and Systems, Requirements for. MIL-T-18303 - Test Procedures; Pre-production, Acceptance, and Life, for Aircraft Electronic Equipment, Format for. MIL-DTL-18307 - Nomenclature and Identification for Aeronautical Systems Inc
7、luding Joint Electronics Type Designated Systems and Associated Support Systems. INCH-POUND Comments, suggestions, or questions on this document should be addressed to: Defense Supply Center, Columbus, ATTN: DSCC-VAT, Post Office Box 3990, Columbus, OH 43218-3990, or e-mailed to TubesAmpsdla.mil. Si
8、nce contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at http:/assist.daps.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-22354C 2 DEPARTMENT OF DEFENSE
9、STANDARDS MIL-STD-167-1 - Mechanical Vibrations of Shipboard Equipment (Type I - Environmental and Type II - Internally Excited). MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests. MIL-STD-889 - Dissimilar Metals. DOD-STD-1399-301 - Interface Standard for Shipboard Systems,
10、 Section 301, Ship Motion and Attitude (Metric). (Copies of the above documents are available online at http:/assist.daps.dla.mil/quicksearch/ or http:/assist.daps.dla.mil/, or from the Standardization Document Automation Order Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.) 2.3
11、 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents are those cited in the solicitation or contract (see 6.2). AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) ANSI S2.15 - Specificatio
12、n for the Design, Construction, and Operation of Class HI (High- Impact) Shock-Testing Machine for Lightweight Equipment. (Copies are available online at http:/infoansi.org or from the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.) 2.4 Order of
13、precedence. Unless otherwise noted herein or in the contract, in the event of conflict between text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption
14、has been obtained. 3. REQUIREMENTS 3.1 Design and construction. 3.1.1 General. The equipment shall meet the requirements of best manufacturing practice except as specified herein. The design objectives of a high-strength-to-weight ratio, reliability, simplicity, ease of installation and maintenance
15、consistent with the need of the military service, shall be considered during all phases of equipment design and construction. 3.1.2 Service conditions. 3.1.2.1 Temperature. The equipment shall meet the temperature requirements for exposed - unsheltered (ship or shore) operating temperature range -54
16、C to +65C and non-operating temperature range -62C to +71C. 3.1.2.2 Wind load. The equipment shall be capable of withstanding a 120-knot wind. 3.1.2.3 Salt atmosphere. The equipment shall be capable of operating without failure for a period normal to similar electronic equipment aboard ship, without
17、 being adversely affected by humid salt atmosphere. 3.1.2.4 Inclination, vibration, and shock. The antenna, its mounting, and representative structure for its mounting (what is important to simulate the installation) shall meet the applicable inclination, vibration, and shock requirements of 4.4.1,
18、4.4.2, and 4.4.3. For inclination requirements of 4.4.1, shipboard equipment shall operate in all attitudes encompassed by DOD-STD-1399-301. A shock spectrum and transient duration shall be defined which represents extreme design conditions to be encountered and the shock test levels for use in 4.4.
19、3. 3.1.3 Construction. Equipment shall be constructed to conform to the service conditions as specified herein. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-22354C 3 3.1.3.1 Dissimilar metals. Unless suitably protected against electrolytic
20、 corrosion, dissimilar metals (see MIL-STD-889) shall not be used in intimate contact with each other. Dissimilar metals are defined as metal specimens that are in contact or otherwise electrically connected to each other in a conductive solution and that generate an electrical current. 3.1.3.2 Pres
21、surization. The antenna shall be normally operated non-pressurized. Design shall be such that when mounted vertically on a supporting structure, water, or other liquids cannot collect to an extent that could ultimately result in failure or deterioration of performance of the antenna. 3.1.3.3 Mainten
22、ance and repair. The antenna shall be so constructed that maintenance and repairs can be made with a minimum of disturbance to other components. Antennas shall be readily demountable and interchangeable to provide ease of servicing, maintenance, and replacement. 3.1.3.4 Mounting brackets. The antenn
23、a shall have, at its base, a mounting flange with bolt holes to anchor the antenna firmly in position when it is installed aboard ship. 3.1.3.5 Standardization. Every effort shall be made to standardize the units and parts entering into the construction, in conformance with MIL-PRF-27, however, it i
24、s not intended to compromise the design or performance of the antenna produced as a result of this specification. 3.1.3.6 Tropicalization. Tropicalization will not be required. 3.1.3.7 Pure tin. The use of pure tin, as an underplate or final finish, is prohibited both internally and externally. Tin
25、content of antenna components and of solder shall not exceed 97 percent, by mass. Tin shall be alloyed with a minimum 3 percent lead, by mass (see 6.5). 3.2 Performance requirements. 3.2.1 Performance. The antenna shall be so manufactured that when mounted, in an unobstructed area, and sufficiently
26、elevated above ground (or equivalent), the pattern of the antenna shall be such as to provide essential spatial coverage throughout a hemispherical volume. 3.2.2 Frequency. Antenna and feed system shall operate over the frequency range of 400 to 550 megahertz (MHz). 3.2.3 Polarization. The antenna s
27、hall transmit rf energy, vertically polarized in the horizontal field. 3.2.4 Gain. The gain of the antenna in the horizontal field shall be approximately five (5) decibels (db) above an isotropic (spherical radiation) source, or approximately three (3) db above a half-wave dipole source. 3.2.4.1 Ver
28、tical gain. The gain of the antenna in the vertical (overhead) direction shall be approximately nine (9) db below an isotropic or approximately eleven (11) db below a half-wave dipole source. This is approximately fourteen (14) db below the maximum horizontal gain. 3.2.5 Power rating (RF). The anten
29、na shall be capable of handling 2,000 watts of rf power over the frequency range of 400 to 550 megahertz (MHz). 3.2.6 Voltage Standing Wave Ratio (VSWR). The impedance at the input to the antenna shall match the 50-ohm impedance of the input coaxial cable so that the VSWR does not exceed 1.8:1.0 ove
30、r the entire 400 to 550 megahertz range. 3.2.7 Circularity. The antenna shall have a horizontal pattern that is omni-directional to within 1.0 dB over the 400 to 550 megahertz frequency band. 3.2.8 Tilt. The antenna shall be designed to tilt the vertical lobe upwards to place the lower half-power po
31、int on or below the horizon. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-22354C 4 3.3 Detail requirements. 3.3.1 Functional description. Antenna AT-948/U shall be a two-element dipole colinear array housed within a polyester fiberglass va
32、por-tight cylindrical supporting structure. The dipole array shall produce omni-directional vertically- polarized energy and overhead coverage sufficient to fill in the cone of silence. The mounting flange shall be an integral part of the fiberglass watertight enclosure. 3.3.2 Overhead coverage. To
33、produce minimum interference with the rest of the pattern and optimum overhead coverage over the entire frequency region, the upper element of the dipole array shall be designed to provide orthogonal current distributions so as to fill in the cone of silence overhead. 3.3.3 Dimensions and weight. Th
34、e AT-948/U shall have a maximum height of 50 inches (1270 mm) and a nominal diameter of 5.81 inches (147.6 mm). The weight of the complete antenna shall not exceed 25 pounds. 3.3.4 Mounting provisions. The mounting flange base of the AT-948/U Antenna shall be an integral part of the fiberglass weath
35、erproof housing and shall be a flange 10 inches (254 mm) in diameter and approximately .75-inch (19.1 mm) thick with an 8.50-inch (215.9 mm) bolt circle on which there are eight .75-inch (19.1 mm) diameter holes for mounting. The mounting flange shall mate with a standard class 125-type flange. 3.3.
36、5 RF connectors. The rf input to the antenna shall be by means of a connector capable of mating with connector UG-154A/U (controlling P/N MS91604-154A). 3.3.6 Nomenclature and nameplates. Nomenclature assignment and nameplate approval for equipment identification shall be in accordance with specific
37、ation MIL-DTL-18307. 3.4 Workmanship. Antenna and subcomponents shall be manufactured and processed in a careful and workmanlike manner, with good design and sound engineering and production practice, and to the requirements of this specification. Antenna shall be free from tool marks, deep scratche
38、s, corrosion, and defects that affect life, serviceability, and appearance. 4. VERIFICATION 4.1 Classification of tests. Equipments shall be subjected to the following tests to determine compliance with all the applicable requirements. a. Pre-production tests. b. Acceptance tests. 4.2 Pre-production
39、 tests. Pre-production tests shall be made on one or more equipments representative of the production equipments to be supplied under the contract. Pre-production tests shall consist of the following: a. Contractors demonstration tests. b. Service approval tests. 4.2.1 Contractors demonstration test
40、s. Contractors demonstration tests shall be accomplished under the responsibility of the contractor and shall be conducted in accordance with the approved test procedure of 4.6. Data obtained by the contractor in conducting these tests shall be submitted to the acquiring activity for review and appr
41、oval prior to shipping the equipment to the specified destination for service approval tests. The Government Inspector and the acquiring activity shall be advised when tests are to be conducted so that a representative may be designated to witness or supervise the tests when so desired. Contractors
42、not having adequate facilities to conduct all required tests shall obtain the service of a commercial testing laboratory satisfactory to the acquiring activity. 4.2.2 Service approval tests. At the completion of the contractors demonstration tests and when requested by the acquiring activity, the eq
43、uipment shall be delivered to a specified government laboratory for additional testing. This additional testing may consist of duplicating tests previously conducted and such other tests deemed necessary to determine compliance with all applicable design and performance requirements. Provided by IHS
44、Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-22354C 5 4.2.3 Scope of tests. Pre-production tests shall include all tests deemed necessary to determine that the equipment meets all the requirements of this specification and the contract. Pre-production te
45、sts shall include as a minimum the tests of 4.4. 4.2.4 Pre-production approval. Approval of the pre-production model shall be by the acquiring activity upon satisfactory completion of all tests. No production equipments shall be delivered prior to the approval of the pre-production model. Prefabrica
46、tion of production equipment prior to the approval of the pre-production model is at the contractors own risk. The approved pre-production model will be returned to the contractor for his use in the fabrication and testing of equipment to be submitted for acceptance. The pre-production model shall n
47、ot be considered as one of the equipments under the contract; however, it may be reworked by the contractor and submitted for acceptance as production equipment. 4.3 Acceptance tests. The contractor shall furnish all samples and shall be responsible for accomplishing the acceptance tests. All inspec
48、tion and testing shall be under the supervision of the Government Inspector. Contractors not having testing facilities satisfactory to the acquiring activity shall engage the service of a commercial testing laboratory acceptable to the acquiring activity. The contractor shall furnish test reports sh
49、owing quantitative results for all acceptance tests. Such reports shall be signed by an authorized representative of the contractor or laboratory, as applicable. Acceptance or approval of material during the course of manufacture shall not be construed as a guarantee of the acceptance of the finished product. Acceptance tests shall consist of the tests of 4.5 as a minimum. 4.4 Pre-production tests. The pre-production model antenna shall be subje
