1、$-i I*Q3 MIL-A-28880 57 7777706 0053872 MIL-A-28880( EC) 30 March 1984 MILITARY SPECIFICATION ANTENNA COUPLER GROUP , AN/SRA-49( ) This specification is approved for use by the Naval Electronic Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the D
2、epartment of Defense. 1. SCOPE 1.1 s. This specification covers the design, performance, and testing of the high frequency (HF) antenna coupler group, hereinafter referred to as the antenna coupler group, for use aboard surface ships for general communications pur oses. receive operations over the 2
3、 megahertz (MHzy through 30 MHz frequency range with a high degree of frequency-selective isolation. The antenna coupler group 1s designed for 1.1.1 AN/SRA-49A. The antenna coupler group is designed to connect up to a maximum of 20 receivers to two antennas. 1.1.2 AN/SRA-49B. receivers to three ante
4、nnas. The antenna coupler group is designed to connect up to a maximum of 20 2, APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications and standards. IJnless otherwise specified, the following specifications and standards of the issue listed in that issue of the Department of Defense In
5、dex of Specifications and Standards (DoDISS) specified in the solicitation form a part of this specification to the extent specified herein. SPECIFICATIONS MILITARY MIL-S-901 Shock Tests, H.I. (High-Impact); Shipboard Machinery, Equipment And Systems, Requirements For MIL-E-16400 Electronic, Interio
6、r Communication And Navigation Equipment, Naval Ship And Shore: General Specification For MI L - W - 16 8 78 Wire, Electrical, Insulated, General Specification For MIL-E-17555 Electronic And Electrical Equipment, Accessories, And Repair Parts; Packaging And Packing Of MIL-F-19207 Fuseholders, Extrac
7、tor Post Type, Blown Fuse Indicating And Noni ndicat ing , General Spec if icat ion For MIL-E-21981 Electronic Type Designations, Identification Plates And Mark- ings: Requirements For NAVAL SEA SYSTEMS COMMAND (NAVSEA) SHIPS-R-4984 STANDARDS MILITARY MIL-STD-105 MIL-STD-108 MIL-STD-109 MIL-STD-167-
8、1 MIL- STO -45 4 MIL-STD-461 MIL-STD-462 MI L-STD-781 Receiving Multicoupler Groups Sampling Procedures And Tables For Inspection by Attributes Definitions Df And Basic Requirements For Enclosures For Electric And Electronic Equipment Quality Assurance Terms And Definitions Mechanical Vibrations Of
9、Shipboard Equipment (Type I - Environmental And Type II - Internally Excited) Standard General Requirements For Electronic Equipment Electromagnetic Emission And Susceptibility Requirements For The Control Of Electromagnetic Interference Electromagnetic Interference Characteristics, Measurement Of R
10、eliability Design Qualification And Producion Acceptance Tests: Exponential Distribution Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to Commander, Naval Electronic Systems Command (ELEX-8111) ,
11、Washington, DC 20363, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document, or by letter. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- r MIL-A-2BO 57 7977706 0053873 T W MI
12、L-A-28880( EC) MIL-STD-1310 DoD-STD-1399, Section 300 Alternating Current (Metric) Shipboard Bonding, Grounding, And Other Techniques For Electromagnetic Compatibility And Safety Interface Standard For Shipboard Systems Electric Power 2.1.3 Other Government publicatiom. The following other Governmen
13、t publication forms a part of this specification to the extent specified herein. NAVAL SEA SYSTEMS COMMAND (NAVSEA) 0967-LP-283-5010 Handbook, Electromagnetic Shielding Practices, Submarine (Copies of specifications, standards, and publications required by manufacturers in connection with specific a
14、cquisition functions should be obtained from the contracting activity or as directed by the contracting officer.) 2.1.3 Order of precedence. In the event of a conflict between the text of this specification and the references cited herein, the text of this specification shall take precedence. 3. REQ
15、UIREMENTS 3.1 General. The antenna coupler group shall be in accordance with MIL-E-16400, to the extent specif ied herein. 3.1.1 First article. When specified, a sample shall be subjected to first article inspection (see 4.3 and 6.3). 3.1.7 Operational requirements. Each antenna coupler group shall
16、give reliable performance within the limits specified herein, under conditions of intermittent or continuous operation during exposure to the adverse conditions normally encountered in Naval ship communication service. Mechanical and electrical ruggedness is of paramount importance for assurance of
17、reliableper- formance without failure. 3.2 Characteristics. Antenna coupler group characteristics shall be as specified in 3.2.1 through 3.2.3.7. 3.3.1 Performance characteristics. Performance characteristics shall be as specified in 3.2.1.1 throy 3.2.1.1 Input parameters. The antenna coupler group
18、antenna input distribution lines shall be capable of handling 1000 watts (W) root-mean-square (rms) (continuous) of radio frequency (RF) power over the 2 MHz to 30 MHz frequency range. kilovolts (kV) or greater. dummy load capable of continuously dissipating 500 W rms. as specified herein over the i
19、nclusive frequency range of 2 MHz to 30 MHz. group shall include couplers capable of being tuned over the ranges specified in TABLE I. The peak RF voltage capability shall be 2.1 Each antenna input distribution line shall be terminated in a 50 ohm 3.2.1.2 Operating frequency range. The antenna coupl
20、er group shall be capable of operating Each antenna coupler TABLE I. Antenna coupler frequency ranges. Antenna Frequency Range coupler low limit nominal CU-l799/SRA 1.990 2-6 CU-lSOO/SRA 3.990 4-12 CU-l801/SRA 9 -900 10-17 CU-l802/SRA 16 -600 17-30 (MHz) high limit 6 .O20 12 .o20 17.400 30 -500 3.2.
21、1.3 Passband characteristics. Passband characteristics shall be as through 3.2.1.3.3. ipecified in 3.2.1.3.1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-28880 57 W 777770b 0053874 1 W MI L-A-28880( EC) 3.2.1.3.1 Insertion loss. Insertion lo
22、ss is the power ratio at the receiver before and after insertion of the antenna coupler group in the transmission line. within +2 decibels (dB) of that shown in FIGURE 1. Insertion loss shall be a o U i3 z a E FREQUENCY- MHt FIGURE 1. Insertion loss. 3.2.1.3.2 Bandwidth. The bandwidth of each copler
23、 unit shall be equal to or greater than 3.3.1.3.3 Ripple. Ripple is variation of signal output within the passband, referenced to The ripple within the 3 dB passband shall be 3 dB or less for each 12 kilohertz (kHved at the 3 dB points. the center frequency signal. coupler unit. 3.3.1.4 Isolation. I
24、solation is the sum of frequency-selective attenuation and center 3.3.1.4.1 In-band isolation. The isolation of frequencies separated 5 percent or more from frequency insertion loss. passband center shall be equal to or greater than that specified in TABLE II. L Provided by IHSNot for ResaleNo repro
25、duction or networking permitted without license from IHS-,-,- _- MIL-A-28880 57 7777706 0053875 3 I MIL-A-28880( EC) TABLE II. In-band isolation. Coupler type Frequency (MHz) Insertion loss (dB) Isolation (dB) 2 .o0 14.5 80 .O CU-l799/SRA 3 -50 12.3 74.5 6 .O0 10 .o 69 .O 4 .o0 11.7 73 .O CU-l8OO/SR
26、A 7 .o0 9.7 68 .O 12 .o0 8 -3 63 .O 10 .o0 8 -8 64.5 CU-l801/SRA 13 -00 8.1 62 .O 17 -00 7.4 59 .O 17 .O0 7.4 59 .O CU-l802/SRA 23 .O0 6.7 56.5 30 .O0 6 .O 54 .O 3.2.1.4.2 Out-of-band isolation. The isolation at all frequencies in the 2 MHz to 30 MHz frequency range, separated 10 percent or more fro
27、m center of tuned passband, shall be equal to or greater than that shown on FIGURE 2. FIGURE 2. Required stop band attenuation vs. frequency. 3.2.1.5 Output load impedance. Each coupler unit shall provide an unbalanced 50 ohm load. Provided by IHSNot for ResaleNo reproduction or networking permitted
28、 without license from IHS-,-,-MIL-A-28880 57 7777706 0053876 5 a O a MIL-A-28880( EC) 3.2.1.6 RF overload protection. Each coupler unit shall include overload protection and indication to: a. b. Provide visual local and remote indications of overload condition. The Limit coupler unit output voltage
29、to 1.0 volts root-mean-square (V rms) when terminated in 50 ohms overload protection and indication circuit shall be actuated automatically by received RF signals within +3 percent of the tuned frequency. 800 milliseconds and not more than 1 second after removal of overload condition. Overload recov
30、ery shall be automatic in not less than 3.3.1.7 Noise generation. Each coupler unit will be equipped with a random noise generator to faciliate tuning. unit unless the coupler unit has been decoupled from the antenna. It shall not be possible to connect the noise generator to the coupler 3.2.1.7.1 N
31、oise level. The noise level from a coupler unit with noise generator operating shall be 20 dB or more above the ambient noise level of the coupler unit. 3.2.1.7.2 Noise interference. The operation of a coupler unit noise generator shall not genercte noise interference levels greater than 3 dB more t
32、han ambient noise level in any other coupler unit of the antenna coupler group. 3.2.2 Physical characteristics. Physical characteristics of the antenna coupler group shall be as specified in 3.2.3.1 through 3.2.3.7. 3.3.2.1 Weight. The weight of the antenna coupler group shall be as specified in 3.2
33、.3.1.1 and 3.2.3.1.3. 3.2.3.1.1 Weight (excluding dummy load). The antenna coupler group (excluding dummy loads) shall have a nominal maximum weight of 500 pounds (lbs), exclusive of packing, crating, and main- tenance and installation kits. exclusive of packing and crating. 3.2.2.2.2. 3.2.2.1.3 Dum
34、my load. Each dummy load shall have 3.2.3.2 Dimensions. The si2.e of the antenna coup 3.2.3.2.1 Antenna coupler group (excluding dummy ina dummv loads) shall have maximum dimensions of 72 in a maximum nominal weight of 20 lbs, er group shall be specified in 3.2.3.3.1 and oads). The antenna coupler g
35、roup (exclud- min.) high, 15 in. deep, and 29 in. wide, providingfor interchangeability of CU-1799, CU-1800, CU-1801, and CU-1802. 3.222.3 Dummy loads. Dummy loads shall have maximum dimensions of 8.5 in. high, 17 in. deep, and 5.3125 in. wide. 3.2.3 Environmental service conditions. EnvironmentaT s
36、ervice conditions of the antenna coupler group shall be as specified in 3.2.3.1 through 3.2.3.7. 3.3.3.1 Operating temperature range. The antenna coupler group shall have the operating temperature range specified in MIL-E-16400 for equipment used in a sheltered controlled environment (Range 4). 3.2.
37、3.3 Nonoperating temperature range. The antenna coupler group shall have the non- operating temperature range specified in MIL-E-16400 for equipment used in a sheltered controlled environment (Range 4). 3.2.3.3 Humidity. The antenna coupler group shall maintain the performance specified herein when
38、exposed to the relative humidity ranges of MIL-E-16400. 3.3.3.4 Shock. The antenna coupler group shall be capable of withstanding Grade A, Class I, Medium weight,- A shock test for shipboard equipment of MIL-S-901. 3.2.3.5 Vibration. The antenna coupler group shall withstand the Type I vibration tes
39、t of MIL-STD-167-1 at an upper vibration frequency limit of 50 hertz (Hz). shall be selected randomly, not in incremental steps. Vibration test frequencies Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-28880 59 9977906 O053877 7 W MIL-A-28880
40、( EC) 3.2.3.6 Inclination. The antenna coupler group shall be capable of withstanding the inclination test of MIL-E-16400. equipment of MIL-E-16400. 3.2.3.7 Salt fog. The antenna coupler group shall withstand the salt fog test for sheltered 3.3 Parts, materials, and processes. Parts, materials, and
41、processes shall be as specified in 3.3.1 through 3.3.3.3. 3.3.1 Selection. Parts, materials, and processes used to manufacture the antenna coupler 3.3.1.1 Nonstandard parts. Requests for approval for the use of nonstandard parts shall be group shall conform the the requirements of MIL-E-16400, excep
42、t as specified herein. submitted in accordance with MIL-E-16400. 3.3.1.1.1 Nonstandard part documentation. All nonstandard parts shall have been documented in accordance with MIL-E-16400, and approved, prior to conducting first article tests (see 4.3). 3.3.1.2 Previous nonstandard part approval. Gov
43、ernment-furnished equipment (GFE) , if provided, may include nonstandard parts. The equipment furnished in accordance with this specification shall employ standard parts or approved nonst.andard parts. under earlier contracts for equipment represented by the GFE shall not be construed as being exten
44、ded to equipment furnished in accordance with this specification. Government furnished drawings shall not be construed as being approved for use in equipment furnished in accordance with this specification. 3.3.1.3 Use of ferrous material and nonlinear parts. No ferrous material or nonlinear part sh
45、all be used in the main RF signal path. resonator for use with overload detect ion/protect ion. Nonstandard part approvals previously granted Nonstandard parts cited in Nonlinear parts shall not be connected to the input 3.3.2 Parts. Parts shall be as specified in 3.3.2.1 through 3.3.2.3. 3.3.2.1 Tu
46、ning capacitors. All tuning capacitors shall have an air dielectric and shall Tuning capacitors shall have midline or straightline Alignment provisions shall be incorporated for each tuning conform to Requirement 2 of MIL-STD-454. frequency tuning characteristics. capacitor. and shall conform to the
47、 requirements of MIL-E-16400. cable clamps. 3.3.2.2.1 RF input and output connectors. The coaxial RF connectors for the receiving antenna inputs and receiver antenna output shall be Type C. The receptacles shall be mounted Gt the top of the equipment cabinet and shall be suitably labeled. connectors
48、 shall be made captive in all directions. RF inserts, if used, shall be constrained from nonperpendicular movement to ensure proper mating. type; crimped pin types shall not be used. be provided in accordance with MIL-E-16400. shall be provided with cable clamps. All external mounted connector recep
49、tacles shall be pro- vided with a suitable protective plastic cap to prevent damage to the connector when the mating connector is not installed. Connectors shall conform to MIL-E-16400. Separate internal and external connectors shall be used for the application specified in a through c: 3.3.2.2 Electrical connectors. Electrical connectors shall be provided in accordance with Mating connectors shall be provided with The center pin of the Type C All connectors shall be of the
