1、MIL-D- 28 79 5 (EC ) 18 June 1973 MILITARY SPECIFICATION DIGITIZER, VOICE: FULL AM) HALF DUPLEX SPEECH COMPRESSION AND DIGITAL ENCODING 1. SCOPE 1.1 This specification describes the performance, interface, and test re- quirements for a voice digitizer (VODIG). full and half duplex speech compression
2、 and digital encoding capability at 2400 bits per sec. both HF and wireline terminals. The VODIG equipment shall provide a VODIG will be employed as part of a secure voice system in 2. APPLICABLE DOCUMENTS 2.1 The following documents of the issue in effect on the data of invi- tation for bids or req
3、uest for proposal, 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 Sys terns, Require- ments for MIL-Q-9858 - Quality Program Requirements MIL-E-16400 - Electronic Equipment, N
4、aval Ship and Shore: MIL-E-17555 - Electronic and Electrical Equipment, Accessories, MIL-M-38793 - Manuals, Technical; Calibration Procedures , MIL-W38793/1 - Manuals, Technical; Calibration Procedures, General Specification and Repair Parts; Packaging and Packing of Prepara tion of Submission STAND
5、ARDS MILITARY MIL-STD-12 - MIL-STD-105 - MIL-STD-108 - MIL-STD-109 - MIL-STD-188 - MIL-STD-189 - MIL-STD-198 - Abbreviations for Use on Drawings and in Sampling Procedures and Tables for Inspection Definition of and Basic Requirement for Enclosure Quality Assurance Terms and Definitions Military Com
6、munication System Technical Standards Racks, Electrical Equipment, 19 inch and Capacitors, Selection and Use of Technical Type Publications by Attributes for Electrical and Electronic Equipment Associated Panels FSC 5895 A Provided by IHSNot for ResaleNo reproduction or networking permitted without
7、license from IHS-,-,-MIL-STD-199 - MIL-STD-242 - MIL-STD-415 - MIL-STD-454 - MIL-STD-461 - MIL-STD-462 - MIL-STD-470 - MIL-STD-471 - MIL-STD-701 - MIL-STD-781 - MIL-STD-785 - MIL-STD-794 - MIL-STD-810 - MIL-STD-1345 - MIL-STD-1364 - MIL-STD-1472 - IA.NDBOOKS MILITARY MIL-HDBK-217 - MIL-HDBK-472 - PU
8、BLICATIONS Resistors, Selection and Use of Electronic Equipment Parts, Selected Standards Test Provisions for Electronic System and Associated Equipment, Design Criteria for Equipment Requirements for Equipment Measur emen t of Systems and Equipments) Standard General Requirements for Electronic Ele
9、ctromagnetic Interference Characteristics Electromagnetic Interference Characteristics Maintainability Program Requirements (for Maintainability Demonstration List of Standard Semiconductor Devices Reliability Test, Exponential Distribution Reliability Program for System and Equipment Part and Equip
10、ment, Procedures for Packaging Environmental Test Methods Data Measurement in Support of Maintenance, Development and Production and Packing of Calibration and Repair of Electronic Equipment Standard General Purpose Electronic Test Equipment Human Engineering Design Criteria for Military Systems, Eq
11、uipment and Facilities Reliability Stress and Failure Rate Data for Electronic Equipment Maintainability Prediction NAVPERS 18068 - Manual of Qualification for Advancement in NACESM 5100 - Electromagnetic, Compromising Emanations Rating Lab or at ory Test Standard (Copies of specifications, standard
12、s, drawings, and publications re- quired by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer . ) 2.2 Other publications. The following documents form a part of this specification to the extent specifi
13、ed herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal shall apply. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-D-28795 58 E 9799306 OL54923 L = UNITED STATES OF AMERICA STANDARDS I
14、NSTITUTE ANSI Y32.16-1968 - Electrical and Electronics Reference Designations. (Application for copies should be addressed to the United States of America Standards Institute, 10 East 40th Street, New York, New York 10016.) 3. REQUIREMENTS 3.1 General requirements. The equipment shall meet the requi
15、rements of MIL-33-16400, to the extent specified herein. 3.1.1 First article sample. Prior to beginning production, a sample shall be tested as specified in 4.3 (see 6.3). 3.1.2 General description. The VODIG equipment covered by this specifi- cation shall be a rugged, lightweight, versatile, micro-
16、miniaturized design. The VODIG will be used to provide digitized voice at 2400 bits per sec (bps). 3.1.3 System compatibility. The equipment shall be compatible with KG30 series electronic key generators and digital data modems MD-923/U and AN/ACQ-5. 3.1.4 Contractor responsibility. All hardware, ca
17、ble, connectors, parts, material and electronics required to makethe VODIG a complete and operable unit as specified herein shall be provided by the contractor. it shall be the responsibility of the contractor to provide all cables, con- nectors, test instrumentation and test facilities and other de
18、vices required to set up and perform all tests at the contractors plant or other place of test, to show compliance with the requirements specified herein. In addition, 3.1.5 Implementation. Implementation of the VODIG may either be analog, However, the use of a central processing unit (CPU) digital
19、or a combination. to perform the voice digitized function is prohibited. 3.2 Performance requirements. 3.2.1 Modes of operation, The equipment shall be capable of operating either full or half duplex. shall be provided for test purposes with the sidetone muted. In addition, a back-to-back internal l
20、oop test 3.2.2 Intelligibility. The intelligibility of the VODIG shall be at least 75 percent as measured by the Dia ostic Rhyme Test at 2400 bps back- to-back, and at least 70 percent at 10 !? bit error rate. 3.2.3 Vogad. An automatic (voice operated) gain control device (Vogad) The shall be provid
21、ed to compensate for variations in average speech levels. operating range of the Vogad shall be -31.5 dBm to -8.5 dBm. 3.2.4 Pitch-extractor. The pitch extractor shall automatically and con- tinuously track the fundamental frequency of the speakers voice over a range of at least 70 to 300-Hertz (Hz)
22、. 3 o Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-D-28795 (EC) 3.2.5 Adjustments. There shall be no adjustments in the VODIG other than input and output level and the test, measurement, and diagnostic equipment (TMDE) 3.2.6 Handset. Operator
23、audio interface to the VODIG shall be by means of a contractor furnished handset. earphone, and a momentary push-to-talk switch and shall be a Western Electric G1 or equivalent. cable, approximately one foot long when retracted and at least four feet long at fullest extension. When not in use, the h
24、andset shall rest in a hanger on the front panel. The level shall be nominally from minus 3 decibels -This handset shall include a microphone, Connection of the handset to the VODIG shall be by a coiled 3.2.7 Sidetone. (db) to minus 6 db relative to the received signal. 3.2.8 Loudspeaker. A loudspea
25、ker shall be provided on the front panel in order to listen to the synthesized voice messages. provided on the front panel to control speaker volume from off through maximum volume. watt/cm2 measured at-a distance of 2 meters in a sound absorbing booth or cham- ber when the volume control is at the
26、maximum setting. A volume control shall be The maximum intelligible volume shall be at least 76 db above 10-16 3.2.9 Data, control, and timing interface. The VODIG shall provide the standard low level (Polar) interfaces for all data, control, and timing in accordance with MIL-STD-188. 3.2.10 Clock a
27、nd data phase relationship Clock and data phase relation- . ship shall be in ,accordance with MIL-S“D-188. for clock shall be strap selectable. In addition,. the opposite phase 3.2.11 Back-to-back timing requirements. An internal frequency source shall provide the clock required for digital back-to-
28、back operation of a single equipment. 3.2.12 Transmitter timinq. The analyzer (transmitter) shall operate from 3.2.13 Receiver timing. The synthesizer (receiver) shall operate from an an externally provided 2400 baud MIL-STD-188 low level timing signal. externally provided MIL-STD-188 low level sign
29、al at 2400 baud. 3.2.14 Synchronization. The VODIG shall sync in less than 8 frames con- taining frame bits only with no errors present. than 300 mec, 95 percent of the time when the bit error rate is 10 percent or less. The VODIG shall sync in less 3.2.15 Pre-synchronization tone. Upon receipt of d
30、ata consisting of only binary ones, the Vodig shall apply a steady audio tone to the audio out- puts. This tone shall cease when voice information is detected in the data. 3.2.16 Out of synchronization detection. An out of synchronization de- tector shall be provided to indicate when the VODIG is ou
31、t of synchronization. A front panel indicator and signal to an output terminal shall be provided to indicate when the detector is activated, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-D-28775 58 9977706 0354733 T 3.2.17 Push-to-talk (PTT). T
32、he VODIG shall provide a PTT control signal which is active when the local or remote PTT is activated and complies with MIL-STD-188. 3.2.18 Transmit frames only. The VODIG shall inhibit all data bits in the PCM stream and only transmit synchronization bits when the transmit frames- only control line
33、 is activated. 3.2.19 Synthesizer inhibit. The VODIG shall inhibit the synthesizer out- put when the synthesizer inhibit control line is activated. 3.2.20 Remote audio output. A remote audio output shall be provided. The output level shall be O dbm nominal and active at all times. impedance shall be
34、 600 ohm 210 percent and shall be balanced to ground. The output 3.2.21 Remote audio input. A remote audio input to the analyzer shall be provided and shall be activated at all times. O dbm peak and the input impedance shall be 600 ohm 110 percent and shall be balanced to ground, “he input level sha
35、ll be 3.2.22 Remote PTT. A remote PTT input shall be provided. The input from the remote source shall be a contact closure when active and an open circuit (10,000 ohm) when inactive. 30 volts, The voltage across the contacts shall not exceed 3.2.23 Control tone input. An input shall be provided to a
36、llow direct application of an externally produced audio tone to all the Vodig audio outputs. The input shall accept signals of O dBm, and shall have an input impedance of 600 ohms, balanced to ground. 3.3 Electrical design. 3.3.1 “he equipment shall be designed to operate with input power of nom- in
37、al 115 +lo percent alternating current (VAC), 50 Hz - 5 percent to 400 Hz + 10 percent single-phase. 3.3.2 The equipment shall be designed to operate within of the Primary power supply line voltage and frequency requirements of MIL-E-16400. 3.3.3 Primary power circuits. The equipment shall be design
38、ed to meet the primary power circuits requirements of MIL-E-16400. 3.3.4 Overload protection. Overload protection shall be in accordance with the requirements of MIL-E-16400. Overload indication shall be provided. 3.4 Reliability. 3.4.1 Quantitative reliability requirement. The specified MTBF (eo as
39、 defined by. MIL-STD-781) of this equipment shall be 4000 hours. 3.4.2 Reliability program plan. The contractor shall prepare a reli- ability.program plan in accordance with and in paragraph sequence with 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
40、-,-,-MIL-D-28775 58 9999906 L5Li932 1 MIL-D- 28 7 95 (EC) MIL-STD-785. Particular attention should be paid to those sections of MIL- STD-785 which require submission of detailed tasks, procedures to implement and control these tasks, and time schedules. The reliability program plan shall be prepared
41、 as a separate and complete entity within the total system or equipment project delineation. The plan, including reliability test plans, must describe an integrated effort within the total project; it shall provide information to show how the contractor will meet specified quantitative reli- ability
42、 requirements during development and manufacture. 3.4.3 Reliability prediction. The contractor shall prepare a reli- ability prediction using the method and K factor for shipboard equipment of MIL-DBK-217 entitled, How to Mah a Reliability Prediction Based on Stress Factors and Part Populations. tem
43、perature plus the estimated internal heat rise of the equipment. The con- tractor shall evaluate the prediction with respect to the reliability expected from a production unit, If there is a discrepancy between the predicted MTBF and the specified MTBF the contractor shall identify the causes of the
44、 dis- crepancies and the proposed corrective action required to ensure that the specified MTBP of the equipment is attained. quired to ensure production of reliable equipment shall be thoroughly docu- mented. (see 6.2). The prediction shall assume a 5OoC ambient The processes and procedures re- 3.4.
45、4 Source of failure rates, The primary source of failure rate data shall be MIL-HDBK-217. For items not included in MIL-HDBK-217, other sources of data may be used with the approval of the command or agency concerned. When such alternate sources of data are proposed, enough information shall be furn
46、ished to enable the command or agency concerned to evaluate the validity and applicability of the results derived therefrom. 3.4.5 Reliability reports. Reports providing a complete accounting of progress on each element defined by the reliability program plan, results -achieved, and status of action
47、s to resolve problems and correct weak links shall be prepared (see 6.2). 3.5 Maintainability. 3.5.1 Maintenance concept. The maintenance concept for this equipment is for the removal and replacement of plug in subassemblies (printed circuit cards) or modules for restoring equipment to specification
48、 operating requirements. The equipment maintenance shall be facilitated by providing self-test features which permit isolation of failures to the printed circuit card or module level. Built-in self-test features shall provide indication of operational readiness when repairs have been completed, Faul
49、t localization and isolation (trouble shooting) procedures for replacement of plug-in subassemblies or modules should not exceed skills or capabilities of a Navy Oceanographic Technician Third Class (OT-3). Skills and capabilities of Navy Oceanographic Technicians are as outlined in NAVPERS Manual 18068. Module and printed circuit card repairs will be accomplished by the intermediate maintenance service provided at the installation site or at the depot depending upon the degree of rew
