1、MIL-R-81435A 58 W 7797706 0370664 5 W . MIL-R-81435A(AS) i5 March i969 SUPERSEDING MIL-R-81435(WP) i APRIL 1966 MILITARY SPECIFICATION Receiver-Transmitter , Radio RT-859( Mountings MT-3809( ) /APX-72 and MT-3948 ( ) /APX-72 ) /APX-72 and associated This specification has been approved by the Naval
2、Air Systems Command, Department of the Navy. 1. SCOPE 1.1 Scope - The equipment covered by this specification shall . provide automatic radar identification of an airborne or surface vehicle to all suitably-equipped challenging aircraft, ships and ground forces within the operational range of the sy
3、stem. 1.2 Classification - The equipment covered by this specification will consist of the items listed in table I. Table I. Equipment Classification Type Designation Applicable Paragraph Receiver-Transmitter, Radio RT-859( )/APX-72 3.5.1 Mounting -3809( )/APX-72 3.5.3.1 Mounting MT-3948( ) /APX-72
4、3.5.3.2 1.3 bsaociated Equipment - The equipment will operate . with the associated equipment listed in 6.8. 2. APPLICABLE DOCUMENTS . 2.1 . General - The following do Aircraft, Installation of Electronic Equipment, Aircraft, General Specification for Testing, Environmental, Aircraft Electronic Equi
5、pment 1 Interference Control Requirements, Aircraft Equipment Electronic and Electrical Equipment and Acsocia- ted Repair Parts, Preparation for Delivery of . MIL-T-18303 1 May i963 Test Procedures; Preproduction and Acceptance for Aircraft: Electronic Equipment, Format for MIL-N-OC 1 October i958 A
6、nd Amendment 3 6 August i963 MIL-S-23603 1 March i963 MIL-C-38257 31 March i964 Nomenclature and Nameplates for Aeronautical Electronic and Associated Equipment System Readiness/Maintainabilty; Avionic Systems Design, General Specification for Control, Transponder Set, C-6280( )( p )/APX MIL-E-55301
7、 i April i965 And Amendment 1 i March i966 Electromagnetfc Compatibility - :-., 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-8LLI35A 58 m MIL-1-81219 i June i965 And Supplement-1 i June i965 Naval Air Systems Command WR-98 i5 December i965
8、 STANDARDS . . MIL-R-81435A( AS) Indicator, Elapsed Time, . Electrochemical Microelectronic Devices Used in Avionics Equipment, Procedures for Selection and Approval of Mglitary MIL-STD-704 6 October 1959 Electric Power, Aircraft, Characteristics and Utilization of MIL-STD-78IA i0 December i965 MIL-
9、STD- 30 June i965 MS-90386-4 1 September i965 MIL-STD-7 94 10 March i965 Reliability Test s , Exponential Distribution Reliability Program (for Systems and equipments), Requirements for Indicator , Elapsed Time , Electrochemical (Mercury ) 28 Volt DC Parts and Equipment, Procedures for Packaging and
10、 Packing of 2.1.1 Availability of Documents - When requesting specifications, Copies standards, drawings, and publications, refer to both title and number. of this specification and appzicable specifications required by contractors in connection with specific procurement functions may be obtained up
11、on application to the Commanding officer, Naval Supply Depot, Code 105, 5801 Tabor Avenue, Philadelphia, Pennsylva?iia 19120. 3. REQUIRWNTS 3.1 Preproduction - This specification makes provision for preproduction testing. 3.2 Parts and Materials - In the selection of parts and / materials, fulfillme
12、nt of major design objectives shall be the prime consideration. In so doing the following shall govern: 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-81435A( AS ) a. b. C. d. e. Microelectronic technology shall be considered and microelectr
13、onic . items shall conform to requirements specified herein. Other parts and materials,requirements shall conform to MIL-E-5400. Nonreparable subassemblies , as outlined in MIL-E-5400, shall be uaed when practicable. amount of circuitry to be included therein shall be approved by the procuring activ
14、ity. (See 6.5). The general size of the subassembly and the Nonreparable subassemblies must be reliable. When previously produced models of this equipment did not use non- reparable subassemblies, the design shall not be changed to employ nonreparable assemblies without the approval of the procuring
15、 activity. All plug-in boards described in 3.5.1.4.3.1 through 3.5.1.4.3.7 shall have means of self locking and extraction from the main assembly. This means of locking and extracting shall be approved by the pro- curing activity. ,3.2.1 Nonstandard Parts and Materials Approval - Approval for the us
16、e of nonstandard parts and materials (including electron tubes, transistors and diodes) other than microelectronic devices, shall be obtained as specified in MIL-E-5400. approved in accordance with WR-98, Microelectronic devices shall be 3.2.2 Mcroelectronic Modular Assemblies - When used, micro- el
17、ectronic modular assemblies shall meet the requirements of WR-98. 3.2.3 Modules - The electronic portions of the equipment shall be divided into maintenance modules in accordance with MIL-S-23603. modules shall normally be considered reparable. Maintenance 3.3 Design and Construction - The equipment
18、 shall conform with all the applicable requirements of MIL-E-5400 for design, construction and - workmanship, except ai otherwise specified herein. “3.3.1 , Total Weight - The cota1 weight of the equipment, excluding cables; shall be a minimum consistent with good design and shall not exceed 16.5 po
19、unds including the mount specified in 3.5.3.1 nor exceed 17.15 pounds including the mount specified in 3.5.3.2. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-83Ll35A 58 9799706 0370668 2 a MIL-R-81435A(AS ) 3.3.2 Reliability - The contriact
20、or shall conduct a reliability . program using MIL-STD-785 as a guide. 3.3 2.1 Operational Stability - The equipment shall operate with satisfactory performance (3.4), continuously or intermittently for a perid of at least 500 hours without the necessity for readjustment of any controls which are in
21、accessible to the operator during normal use. Operating Life - The equipment shall have a total operating 3.3.2.2 life, as defined in MIL-STD-781, of 5000 hours with reasonable servicing. and replacement of parts. Parts requiring scheduled replacement shall be specified by the contractor. Jc3.3.2.3
22、Reliability in Mean Time Between Failures (MTBF) - The equipment shall have a specified mean time between failures of 300 hours when tested and accepted as outlined under the requirements of 4.4.3. 3.3.2.4 Time Totalizing Meter - The RT-849( )/APX-72 shall contain a time totalizing meter in accordan
23、ce with MIL-1-81219 and Ms-90386-4, except that the hour identification scale shall be rotated 90 so as to be read from the horizontal position. 3.3.3 Cabling and Connections - 3.3.3-1 Cables and Connectors - The equipment shall provide for the use of cables and connectors in accordance with MIL-E-5
24、400. 3.3.3.2 Interconnection Cabling - The equipment shall be capable of satisfactory operation using external wiring in accordance with the applicable requirements of MIL-W-5088. The external wiring shall be unshielded except when demonstrated as necessary to meet interference control requirements
25、and provided the assembly of the cable to its plugs may be accomplished. External cables and that portion of the connectors attached to the cables shall not be supplied as part of the equipment. 3.3.4 Interchangeability - The equipment shall meet the interchangeability requirements of MIL-E-5400. 3.
26、3.5 Interference Control - The generation of radio interference by the equipment and the vulnerability of the rquipment to radio interference shall be controlled within the limits of 1-1.-6181 and MIL-E-55301. a conflict of requirements exists, the more stringent requirements shall take precedence.
27、Where 5 /- - - -? I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- P- 3.3.6 Provisions for Maintainsbility - Provisions .for maintenance shall be as specified in MIL-E-5400. shall be provided to the greatest extent practicable for ease of field tes
28、ting and maintenace. Specific test points and test facilites “3.3.7 Nomenclature and Nameplates - Nomenclature assignment and nameplate approval for equipment identification shall be in accordance with MIL-N-18307. Mountings (3.5.3) shall have nameplates in accordance with the foregoing except that
29、attachment of the plates may be made by means of an approved adhesive in lieu of screws. 3.3.8 Standard Conditions - The conditions listed in Table II shall be used to establish normal performance characteristics under standard conditions and for making laboratory bench tests. Table II - Standard Co
30、nditions for Laboratory Tests Temperatur e Room ambient (25OC - + 5C) Altitude Vibration Humi dit y Input power voltage Interrogation Rate Normal ground None Room ambient up to 90 percent relative humidity i15 + 1.0 VAC and 27.5+ - 0.5 VDC 500 interrogations/ second when not otherwise specified or r
31、equired. 3.3.9 Service Conditions - The equipment shall operate satisfactorily under any of the environmental service conditions or reasonable combination of these conditions as specified in MIL-E-5400 for Class 2 equipment, except as modified herein. F 3.3.9.1 Vibration - The equipment shall operat
32、e satisfact 2, 3/A and C and Test shallhesuppressed when the first four pulses of a Mode 4 interrogation are received. generated, the generation of additional Mode 4 triggers shall likewise be suppressed. for 75 to 125 USEC after the fourth pulse, unless this suppression is terminated by a disparity
33、 pulse. If a disparity pulse (3.4.2.15.1.2) is received during this suppression period, suppression due to the Mode .4 interrogation shall be ended within 2 USEC after receipt of the disparity pulse. recognized as a legitimate interrogation side lobe suppression (ISLS) control signal and be processe
34、d as required under 3.4.2.5. suppression gate resulting from a Mode 4 interrogation may (but shall not necessarily) be reset by a disparity pulse coincident with it. Once a Mode 4 trigger has been Suppression due to a Mode 4 interrogation shall continue The first two pulses of a Mode 4 interrogation
35、 shall also be The ISLS 3.4.2.2.2 Suppression During Transmission of Mode 4 Replies - Decoding of Modes 1, 2, 3/A, 4, C and Test shall be suppressed during transmission of Mode 4 replies. triggering level shall occur within 5.0 USEC after the last transmitted pulse. Recovery to within 3 DB of minimu
36、m 3.4.2.2.3 Suppression During Transmission of Replies in Modes 1, 2, 3/A, C and Test - Decoding of Modes 1, 2, 3/A, 4, C, and Test shall be suppressed during transmission of replies in Modes 1, 2, 3/A, C and Test, second transmittedframing pulseof a normal, IDENT or Emergency reply, but. no longer
37、than 100 USEC. Suppression shall continue for at least 75 USEC after the 3.4.2.2.4 Suppression Input - Decoding of all modes shall be suppressed upon reception of a suppression pulse having characteristics as listed in table VI. Table VI. Suppreqsion Input Pulse Characteristics C haract eri s t i c
38、Value , Polarity Pos it ive Amplitude 15 to 70 V . Duration 1.5 to 250 USEC 15 - I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-81435A 58 7777706 0170677 7 MIL-R-8143 5A( AS Input Imp edanc e Rise Time (slope) Decay Time (slope) Noise 2200 +
39、.i0 percent ohms resistance and 50 picofarad (PF) or less capacitance No suppression shall result from any input of less than. 5. OV peak amplitude. lOV/USEC or greater iOV/USEC or greater 3.4.2.2.4.1 Suppression Operation - Upon application to the receiver-transmitter of a suppression pulse having
40、the above characteristics, decoding of Modes 1, 2, 3/A, C, Test and 4 shall be suppressed for an interval starting not more than 1.0 USEC after the suppression pulse has reached an amplitude of 10 V and shall continue for at least the duration of the suppression pulse. the receiver shall regain norm
41、al sensitivity, within 3 DB, no later than i5 USEC after the suppression pulse has fallen to 5.OV. transmitter shall be insensitive t proper radio frequency (RF) interrogations on all modes, with signal levels of -20 DBV, for the uration of the suppression pulse. connector shall be provided for this
42、 input. After the end of the suppression pulse TIS receiver- An input connection which is part of the main chassis 3.4.2.2.5 External Suppression Output - The equipment shall generate a suppression pulse during the time of transmission for each Mode 1, 2, 3/A, C, and 4 output train, which is urired
43、to suppress other equipments. in table VII. . The suppression pulse shall have the characteristics listed Table VII. Suppression Output Pulse Characteristics Character i st ic Value Amplitude Polar it y Synchronization 18 to 30 V Pos it ive The pulse shall reach 18 V minimum by the time an RF output
44、 pulse has reached 10 percent of its detected amplitude Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-BL435A 58 q77qOb 0370680 3 W Table (Cont. ) Duration MIL-R-81435A(AS) The suppression pulse shall remain at 18v or greater until the trailin
45、g-edge of the last trans- mitted pulse has decayed to the 10 percent level. Suppression output shall also be less than 5V, 5.0 USEC after-the last transmitted pulse of the reply train has fallen to 10 percent level. . Rise Time Decay Time. 20V or more per USEC 1OV or more per USEC System Impedance T
46、he load impedance presented to the suppressor output shall not be more than 2200 ohms nor less than 300 ohms shunted by not more than1850p capaci- tance Spurious Output Combined steady-state and tran- sient voltages shall not exceed l.OV, either polarity, with the system loads described above. 3.4.2
47、.3 Echo Rejection - The transponder shall contain echo rejection ckwdesigned to permit normal operation .in the presence of echoes of Signal-s in space and be compatible with the requirements specified in 3.4.2.5. 3.4.2.4 Auxiliary DC Power Utilization - When the equipment is operating on either li5
48、 VAC or 28 VDC primary input power, 28 VDC from the * aircraft supply shall be utilized by the equipment for the operation of internal relays, auxiliary equipment and external lights as specified herein: a. Provision shall be made to enable an external CAUTION light from the external 28 VDC input to
49、.the equipment. The equipment shall be capable of furnishing one ampere of current to the CAUTION light output lead. b. The power for an external Mode 4 REPLY light shall be provided from the external 28 VDC input to the equipment. REPLY light is enabled the equipment shall be capable of furnishing one hundred milliamperes of current to the REPLY light output lead with a maximum internal voltage drop of 2 VDC under any combi
