1、MIL-M-28743A( EC) SUPERSEDING a MW 19t4 MIL-W-f8743( EC) 11 April 1970 MILITARY SPECIFICATION MIXER, TpANSPONDER SUPPRESSION TD-937( )/SPX This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 This specification covers a Transponder Suppres
2、sion Mixer which provides the necessary suppres- sion gates to a single transponder from up to six suppression sources. 2. APPLICABLE DOCUMENTS 2.1 The following documents of the issue in effect on date of invitation for bids or request for proposal, form a part of the specification to the extent sp
3、ecified herein. SPECIFICATIONS MILITARY MIL-S-901 MIL-Q-9858 MIL-E-16400 MIL-E-17555 MIL-C-39012/21 STANDARDS MILITARY MIL-STD-105 MIL-STD-108 MIL-STD- 167 MIL-STD-275 MIL-STD-454 MIL-STD-461 MIL-STD-470 MIL-STD-471 MIL-STD-781 MIL-STD-785 PUBLICATIONS MILITARY MIL-HDBK-2 17 MIL-HDBK-472 Shock Tests
4、, H.I. (HIGH-IMPACT), Shipboard Machinery, Equip- Quality Program Requirements Electronic Equipment, Naval Ship and Shore, General Specifica- Electronic and Electrical Equipment, Accessories, and Repair Connector, Coaxial, Radio Frequency, (Series Bnc-receptacle- ment and Systems, Requirements for (
5、Navy) tion (Navy) Parts, Packaging and Packing of jam Nut Mounted-class li) Sampling procedures and Tables for Inspection by Attributes Definition of and Basic Requirement for Enclosure for Electric Mechanical Vibrations of Shipboard Equipment Printed Wiring for Electronic Equipment Standard General
6、 Requirements for Electronic Equipment Electromagnetic Interference Characteristics Requirements Maintainability Program Requirements (for Systems and Maintainability Demonstration Reliability Tests Exponential Distribution Reliability Program for Systems and Equipment Development and Electronic Equ
7、ipment. for Equipment Equipments ) and Production Reliability Stress and Failure Rate Data for Electronic Maintainability Prediction Equipment (Copies of specifications, standards, drawings, and publications required by suppliers in connection with specific procurement functions should be obtained f
8、rom the procuring activity or as directed by the contract- iq officer.) FSC-5825 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-M-28743A( EC) 3- REQUIREMENTS 3.1 General. The equipment shall be in accordance with all the provisions of MIL-E-1640
9、0 except as hereinafter specified. The design objectives as specified in MIL-E-16400 for simplicity, ease of maintenance and installation shall be considered during all phases of equipment design. 3.2 First article sample. Prior to beginning production, a sample shall be tested as specified in 4.3 (
10、see 6.2.1). 3.3 Reliability. 3.3.1 Quantitative reliability requirement. The equipment shall be designed for a 20,000 hour mean- time-between-failure (MTBF). For reliability demonstration tests the specified MTBF shall be 6,000 hours. 3.4 Design requirements. 3.4.1 Composition. To the maximum extent
11、 practicable, the equipnent shall consist of solid-state circuitry mounted on printed circuit cards, mounted in an enclosure which is drip-proof in accordance with MIL-STD-108. 3.4.1.1 Printed circuit cards. All printed circuit cards used shall be designed and manufactured in accordance with MIL-STD
12、-275. 3.4.2 Environmental conditions. The equipment shall be capable of operation under any reasonable com- bination of the following conditions as specified in MIL-E-16400. (a) Temperature-class 2 O.) Humidity, up to 95 percent relative. (c) Shock, vibration. inclination and noise 3.4.3 Electrical
13、design. 3.4.3.1 Primary power line voltage and frequency. The equipment shall be capable of operating from a power source whose characteristics are within the following ranges: (a) Voltage: 115 VAC I10 percent single phase (b) Frequency: 50.60, and 400 Hz I10 percent 3.4.3.1.1 Overload-protection. F
14、uses, if used, shall be provided with blown-fuse indicators, The use of circuit breakers, selected in accordance with MIL-E-16400, is preferred. 3.4.3.2 External connectors. All signal connectors shall be type C, and all power and control connec- tors shall be chosen from the AN or MS series. All co
15、nnectors shall be on the rear panel. 3.4.3.2.1 DC isolaton. The video signal inputs shall be capacitively coupled to insure proper system operation with signals which have a dc reference other than ground. This requirement shall not be waived unless the contractor demonstrates to the command or agen
16、cy concerned and obtains approval of a design technique which is immune to such input signals. This requirwnent applies to channels A and B only. 3.4.3.2.2 Output reference level. The video signal outputs shall be referenced to ground -0.1 volt to +0.2 volt except as hereinafter specified. 3.4.3.3 E
17、lectromagnetic, interference emission, susceptibility, and equipment and systems self- compatibility. The equipment shall operate within the electromagnetic interference emission, susceptibility, and equipment and systems self-compatibility limits in accordance with class Gp of MIL-STD-461. 3.4.3.4
18、Electrical design. The following data will be submitted to the command or agency concerned for approval. (a) Schematic diagrams of each electrical circuit card and subassembly. ) Test specification for each subassembly. 3.4.3.5 Synchros. Synchros are not required. 2 Provided by IHSNot for ResaleNo r
19、eproduction or networking permitted without license from IHS-,-,-MIL-M-28743A 5B W 7777906 0354547 2 MIL-M-28743A( EC) 3.4.4 Maintenance. 3.4.4.1 Test points and test features are required, and shall comply with the following: 3.4.4.1.1 External test points. External and internal test points shall b
20、e provided on the front panel to allow malfunction isolation to the defective equipment. Location of, and parameters to be measured will be subject to the approval of the command or agency concerned. Mechanical design of the front panel test points shall be as specified herein. It shall be possible
21、to monitor the six input signals and the suppression output at the front panel test points. 3.4.4.1.2 Internal test points. Internal test points shall be provided on each circuit board or module. Observation of these test points will identify a defective board or module immediately. All test points
22、for printed circuit cards shall be brought to the top of the card. The test points shall be of the probe type, suit- able for insertion of a standard, flexible tip probe. 3.4.4.2 Maintainability. 3.4.4.2.1 Quantitative maintainability requirements. The equipment shall have an equipment repair time (
23、ER“) of fifteen (15) minutes when corrective maintenance by module or circuit card is performed. 3.4.4.3 Service and access. The equipment design shall permit easy and ready access to internal parts, test points, and adjustments. Removal and replacement of subassemblies shall not require the removal
24、 or displacement of other subassemblies. 3.4.4.3.1 Accessibility. Equipment procured under this specification shall be designed to permit ready access to internal test points and replaceable modules via the front of the equipment. Requirement 36 of MIL-STD-454 shall apply. 3.4.4.3.1.1 Loosening of c
25、aptive fasteners on the front panel shall provide for withdrawal of the equip- ment, from the case, for maintenance. 3.4.4.3.1.2 Slideslguides with safety stops to prevent accidental complete removal shall be employed. Safety interlocks and by-pass switches, selected in accordance with MIL-E-16400 a
26、nd MIL-STD-454, are required. 3.4.4.3.1.3 The internal power and signal cables shall be of sufficient length to allow full extension of the unit from the case. Provisions must be supplied to support all cables coming from the rear panel to the removable component chassis, such that these cables sust
27、ain no damage. 3.4.4.3.2 Accessibility of external test points. Test points shall be provided on the front panel of the equipment. Signals available shall be all of the equipment input/output signals. Type BNC UG-625 connectors in accordance with MIL-C-39012/21 shall be mounted on the front panel of
28、 the equipment for measurement of these signals. 3.4.4.4 Reversibility. The equipment shall incorporate features such that it is mechanically or elec- trically impossible to install incorrectly its modules, circuit card assemblies, and subassemblies. 3.4.5 Mechanical design. the following sub-paragr
29、aphs: The mechanical design of the equipment shall conform to the requirements of 3.4.5.1 W. The equipment shaU be designed in accordance with the requirements of Grade A, Class I, Type A, on the lightweight machine, in accordance with MIL-S-901. 3.4.5.2 Vibration. Vibration resistance shall be in a
30、ccordance with the requirements of type I as defined by MIL-STD-167. 3.4.5.3 Enclosure. The degree of enclosure shall be dripproof, in accordance with the requirements of MIL-STD-1 O. 3.4.6 Controls, indicators, and panel layout. 3.4.6.1 Tactile identification of controls is not required. 3 Provided
31、 by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-M-28743A 58 W 7999906 OL5L1550 9 MIL-M-Z8743A( EC) 3.4.6.2 Classification. All controls shall be classified as continually required except those used pri- mariiy in initial installation and adjustment or f
32、or maintenance adjustmenf and alignment. 3.4.7 SLirplementar.y requirements. 3.4.7.1 Instruction plates. Instruction plates are not required. 3.4.7.2 Time meters. Time meters are not required. 3.5 Performance and detail requirements. 3.5.1 Design and construction details. 3.5.1.1 Electrical connecto
33、rs. The equipment shall be provided with one connector for AC power input, The equipment shall be provided with one Type C coaxial connector for each of the six trigger inputs and the suppression gate output. 3.5.1.1.1 Power connector. The power connector shall be a three pin Ms or AN (male) connect
34、or to accept 115VAC. 1 0, with the following pin assignments: pinA 115 VAC pin E Ground pin C 115 VAC 3.5.1.2 Front panel controls. The equipment front panel controls shal1,consist of a Power ON-OFF toggle switch. 3.5.1.3 Front panel indicators. The equipment shall be provided with a Power - On indi
35、cator lamp. 3.5.1.4 w. The dimensions of the equipment shall not exceed. the following: (a) Height - 6 inches ) Width - 5 inches (c) Depth - 13 inches The envelope described by these dimensions includes all projections from the surfaces of the equipment such as connectors, handles, and screw heads.
36、3.5.1.5 Weight. The weight of the equipment shall not exceed 12 pounds. 3.5.1.6 Mounting. The equipment shall be designed for mounting to a flat surface without resilient mounts. 3.5.1.7 Component chassis. The chassis assembly shall be composed of a front panel and a component chassis. Ali circuit b
37、oards and subassemblies shali be accessible when the chassis is withdrawn from the equipment case. Accessibility shall be as specified in MIL-E-16400 and further described herein. Access to the equipment interior shall be accomplished by releasing no more than six (6) securing devices located on the
38、 front panel surface only. 3.5.1.8 Equipment case. The case shall form the top, bottom, and two lateral sides of the rectangular box comprising the equipment enclosure. The case shall have provisions for direct mounting to an equipment sheif by the bottom surface only. 3.5.1.9 Rear panel. The rear p
39、anel of the equipment shall be a removable part of the enclosure and not a part of the equipment chassis. All signal input and output connectors shall be installed on the removable rear panel. Test signal outputs shaii be on the front panel (see 3.4.4.3.2). 4 Provided by IHSNot for ResaleNo reproduc
40、tion or networking permitted without license from IHS-,-,-MIL-M-Z8743A( EC) 3.5.1.10 Enclosure. The equipment shall be mounted by devices secured to the base of the enclosure. The equipment shall be designed to permit ready access to internal test points and replaceable modules via the front of the
41、equipment. MIL-STD-454, requirement 36 shall apply as modified below. 3.5.2 Performance. 3.5.2.1 Input signals. The equipment shall operate with input signals having the following characteristics: (a) Polarity: Positive (b) Amplitude: 5 to 55 volts (c) Duration: 0.30 microseconds minimum, 500 micros
42、econds maximum (d) Rise time: Up to 25 percent of pulse duration, or 0.04 microsecond per volt times pulse amplitude, whichever is smaller. (e) Fall time: 1 to 5 times pulse rise time (f) Source impedance 75 ohms resitive, I5 ohms. 3.5.2.1.1 Any number of the six trigger/gate inputs shall be able to
43、 feed any of the three operational channels within the equipment. Selection of the six inputs may be made by link on a printed circuit board as an initial setup procedure. It shall be possible to change the input selection by changing the links. 3.5.2.1.2 The input signals may have up to three volts
44、 of noise which shall not affect equipment operation. 3.5.2.2 Input power. The equipment shall require no more than 25 volt-amperes primary power. The equipments power factor shall be no less than 0.85. 3.5.2.3 Output. The equipment shall produce a single output signal in accordance with the charact
45、eris- tics specified as follows: 3.5.2.3.1 Internal channels. The equipment shall contain three channels of operation, the outputs of which shall be mixed so as to produce a single output from the equipment, The channels are identified as A, B, and C. All measurements of equipment performance shall
46、be made at the single equipment output. 3.5.2.3.2 Channels A and B within the equipment shall accept signals from Category A suppression sources, and shall perform in essentially an identical manner. When supplied with an input signal in accord- ance with 3.5.2.1, the output signal shall be a gate i
47、nternally adjustable in length over the range of 5 to 50 microseconds for Channel A and 50 to 500 microseconds for Channel B. The gate shall be of a renewable type so that any subsequent trigger will reinitiate the timing cycle with no loss of output. The gate length, once setup, will maintaL-M-2874
48、3A( E.,) 4.4.2 Production control inspection. Production control inspection, including sampling, shall conform to table I below and to the procedures for special inspection levels of MIL-STD-105. The inspecfion level shall be S-3 for normal. tightened, and reduced inspection. Production control insp
49、ection shall be performed on equipments that have passed production inspection. Production control tests shall be performed in ac- cordance with MIL-E-16400. The equipment shall satisfactorily meet the requirements of production control inspection prior to release for shipment. Temperature Humidity Shock, vibration, inclination Salt spray test and noise Weights and dimensions Supply line voltage and frequency Temperature Power Controls and control circuits Enclosure 3.4.2 3.4.2 3.4.5.1, 3.4.5.2, 3.4.2(c) 3
