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f.

Burn-in thermal cycling is to cause failure of marginal parts in
a controlled manner prior to service use. The last 48 hours of
operation, which need to be continuous, must be failure free.
The contractor may halt testing for weekends, holidays and the
like during the period prior to 48 hour failure free test.
providing verification tests are run before and after the
break. Failed modules may be repaired at any point in the
burn-in cycle and upon satisfactory re-runs of the verification
test the burn-in cycle may proceed (except during 48 hour
failure free period, which must be restarted). i.e. individua!
components inserted into the system as a result of repair action
need not accumulate the full 144 hours. In lieu of module
repair the contractor may substitute a tested and burned-in
spare module per (f) below for a module that has failed the
burn-in process.

Burn-in of spare modules (cards and power supplies) shall be
accomplished by an off-line non-system test where modules are
powered but not exercised, except for power supplies which shall
be loaded at 90% of rated load current.

4.6.3 Performance Test. The equipment shall be subjected to a performance test to verify proper operation of the Display System. This test includes operating all operating and maintenance controls and performing all Built in Tests. Simulated. or actual inputs shall be provided to insure proper operation of all external interfaces. This test shall be run under room ambient standard conditions. The test shall include a check of all operating controls, circuit functions, test provisions, and adjustments. 4.6.3.1 Verification Test. A sub-set of the performance test shall be prepared, documented and approved per 4.4. This performance verification test shall utilize the test modes only as the means for verifying DGU operation during 4.6.2 preperformance burn-in and 4.6.4 environmental tests.

4.6.4 Environmental Test. The tests specified below shall be for a fully modified DGU to the DITEG configuration.

4.6.4.1 Temperature Test Sequence. The operating and non-operating test sequence shall be as specified herein.

4.5.4.2 Low Temperature. The low temperature test shall be in accordance with MIL-STD-810 Method 502 as amended herein:

a.

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Step 2 Storage temperature shall be -54°C 5°C for a period of

24 hours

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4.6.4.3 High Temperature. The high temperature test shall be in accordance with MIL-STD-810 Method 501, Procedure 1 as amended herein: a. Step 4 - · Highest operating temperature: +50 degrees C

b.

C.

The combined duration of Steps 4 and 5 shall not be less than 12
hours, at least 6 of which shall be in the stabilized condition prior
to conducting tests.

Step 7 The equipment shall operate for a period of at least 2 hours in the stabilized condition before the Step 7 tests are performed. 4.5.4.4 Humidity. Humidity tests shall be in accordance with MIL-STD-810. Method 507, Procedure IV as amended herein:

2. Equipment shall be non-operating during exposure.

b.

C.

d.

Step 5 - Equipment performance measurements for Class 4 equipment
shall be made at 50°C (122°F).

Step 7 Blistering of organic coatings shall not be cause for rejection. Any parts or materials failing as the result of humidity test shall be replaced by approved parts.

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Step 9 A performance test shall be conducted between the 12th and 24th hour of Step 7. Equipment shall be exposed to Standard test conditions during the Performance Test.

4.6.4.5 Salt Fog. Not applicable.

4.6.4.6 Shock. The equipment shall be designed to meet the requirements of MIL-STD-810, Method 516.1, Procedure I. The equipment shall be subjected 18 half sine wave shocks of 15 g's for a duration of 11 milliseconds. Shock isolators are not allowed.

4.6.4.7 Vibration. The equipment shall be subjected to the Type I vibration test of MIL-STD-167 except that the upper frequency limit may be reduced from 50 Hz to 25 Hz. The equipment shall be energized and fully operating duringa the test. The use of simulated loads such as weights or other rigid dummy masses is not acceptable.

4.6.4.8 Inclination. The equipment shall be subjected to test limits specified herein. The equipment shall be energized and fully operational during the test.

4.6.4.8.1 Inclination Test Limits (Surface Ship Installation). The equipment shall be inclined at the rate of 5 to 7 cycles per minute in one plane to angles of 15 degrees on either side of the vertical for a period sufficiently long enough tdo determine its characteristics under such motion or for a minimum of 30 minutes. The test shall be repeated with the equipment reoriented 90 degrees to the plane in which it was originally tested. At the conclusion of these cyclic tests, the cyclic motion shall be stopped and the inclination adjusted to an angle of 15 degrees. The equipment shall then be operated for a sufficient period to insure that continuous operation can be maintained. The equipment shall then be rotated through the vertical to 15 degrees in the opposite direction, and the test for continuous operation shall be repeated.

4.6.4.9 Airborne Noise. The equipment shall be subjected to the Airborne noise tests of MIL-STD-740, for Grade C, Type 3 equipment.

4.6.4.10 Magnetic Test. Equipment shall be checked for compliance with the magnetic requirements using a permeability indicator, low-mu (GO-NO-GO) in accordance with MIL-I-17214. The instrument consists of a small bar magnet mounted on the end of a balanced pivot arm. One end of the bar magnet shall be positioned against a known low-mu permeability standard.

4.6.4.10.1 Magnetic Test Measurement. Permeability measurement of a metallic material with unknown permeability is accomplished by placing the maganet against the metallic material. If the magnet is pulled away from the low-au standard the permeability of the material is greater than that of the low-mu standard; if the magnet is not pulled from the low-mu standard, the permeability of the metallic material is less than that of the low-mu standard.

4.6.4.10.2 Magnetic Environment Test. The equipment shall be located at the center of a coil sufficient ampere-turn capacity to produce a steady-state and variable magnetic field of 20 oersted at its center. The field produced by the coil shall be calibrated prior to placing the equipment in its field. Equipment shall be tested for a period sufficiently long enough to determine its characteristics in constant field of zero to 20 cersteds and in a field varying at the rate of 20 oersted per second. The maximum magnetic field within the range of zero to 20 oersteds which can be tolerated by the functionally operating equipment without degradation of the individual equipment specifications requirements and the requirements of this specification shall be recorded and included in the inspection test report.

4.6.4.11 Electromagnetic Interference Tests (EMI). EMI tests shall he conducted per MIL-STD-462. The applicable tests are CEO3, CE04, CS01, CS02, CS06. RE02, RS01, RS02, and RS03.

4.6.5 Reliability Development Test. It is required that a TAAF (test, analyze, and fix) discipline be applied as a design development tool. The TAAF approach is a process whereby the equipment is tested in a mission representative environment to ferret out the weak areas, and, as a result of Fixing design deficiencies, the reliability of the equipment increases to the required level. The reliability development test will be performed in

accordance with AR-104, under environmental conditions. The TAAF program shall be preceded by the Pre-performance burn-in and performance tests of paragraph 4.6.2 and 4.6.3. The test article shall be representative of expected production equipment, in material, configuration, and workmanship. All faults shall be reported and analyzed, and a closed loop corrective action shall be maintained.

4.6.6 Maintainability Demonstration Test. The maintainability of an equipment sample shall be demonstrated to meet the requirements of paragaraph 3.3.5.4 and subparagraphs for corrective maintenance. The tests will be performed in accordance with test method 8 of MIL-STD-471 (Combined Mean/Percentile) for corrective maintenance. A test plan shall be prepared in accordance with paragaraph 4.2 of MIL-STD-471. para. 4.10. A test procedure shall be prepared in accordance with paragaraph 4.3 of MIL-STD-471. Data collection and analysis and corrective action for the maintainability demonstration will be in accordance with the system described in paragazaph 4.4.3 of this specification. Adequate tasks shall be performed as part of this test to demonstrate compliance with the requirement in paragraph 3.3.5.8.2.

4.6.6.1 Test Conditions. One (1) equipment shall be used for this test. The Procuring Activity shall select any one for the equipments that is available. All card drawers shall be in place on the equipment prior to the initiation of this test.

Before beginning the test, the equipment shall be checked to determine that it is operating normally. Test equipment, tools. spare parts. diagnostic computer programs, and documentation shall be available for the test.

4.6.5.2 Simulated Failures. The failure shall be randomly introduced, one at a time, throughout the equipment. The points of failures shall be approved by the procuring activity prior to the initiation of the test. The contractor and the procuring activity shall jointly propose the 200 most probable malfunctions as determined by reliability prediction. Further conference will determine the 50 most probable malfunctions including the critical reliability components. Two technicians approved by the procuring activity will be utilized in the maintainability demonstration.

4.6.6.2.1 Inducing Failures. Single failures shall be induced into the equipment by substituting modules that are known to be defective or where defective modules are not available, simulated failures will be induced by applying grounds at test jacks or on extended modules. Any failure induced for demonstration purposes will consist of a continuous malfunction.

4.6.6.3 Repair Time Measurements. The time required for the technician to perform each repair action, including the use of technical manuals and support equipment, shall be measured starting at the time the technician is made aware that a malfunction exists and ending at the time the equipment is restored to normal operation. Any delay, such as waiting for parts, obtaining test equipment, or administrative delays shall be excluded.

4.7 Presubmission Inspection.

No module shall be submitted for government approval (4.3.1) or acceptance (4.3.2) unless such item has been previously and satisfactorily inspected either by the contractor or by others acceptable to the contractor and found to comply, to the best of his knowledge and belief, with specification(s) and the contract. When deviations from requirements are authorized by the procuring activity, the contractor shall keep a record of all equipment incorporating the deviations and notify the government inspector when submitting such equipment for approval or acceptance. When feasible, at the discretion of the government inspector or procuring activity, presubmission inspection may be participated in or witnessed by a government representative so that duplicative inspection or testing may thereby be reduced during subsequent testing of equipment submitted for government approval or acceptance.

4.S Rejection and Retest. Equipment which has been rejected during approval testing (4.3.1) or acceptance testing (4.3.2) may be reworked or have modules replaced with burned in spares to correct defects and then resubmitted. Before resubmitting, full particulars concernaing previous rejection and the action taken to correct the defects found in the original shall be furnished to government inspector.

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5.1 General. All major units of the equipment shall be preserved, packaged, packed and marked for the level of shipment specified in the contract or order in accordance with Specification MIL-E-17555.

6.0 NOTES

6.1 Intended Use. The equipment covered by this specification shall provide formatting and generation of tactical displays in carrier Tactical Support Centers. This specification defines a digital television display generator as a self-contained entity, functionally and physically. The initial procurred hardware will be a modification of deployed 0-1707/SSQ-78 Tactical Display Generators and thus shall include the basic DGU structure, power supply drawers and power control unit as contractor supplied equipment. Preproduction (RE) and production models shall be produced by modifying GFE models of 0-1707/SSQ-78 Tactical Display Generators unless otherwise specified in purchase order.

6.2 Performance Objectives. Minimum size and weight, simplicity of operation, ease of maintenance, and an improvement in the performance and reliability of the specific functions beyond the requirements of this specification are objectives which shal! be considered in the production of this equipment. Where it appears a substantial reduction in size and weight or improvement in simplicity of design, performance, ease of maintenance or reliability will result from the use of materials, parts, and processes other than those specified in this specification, it is desired they be investigated. When investigation shows advantages can be realized, a request for approval shall be submitted to the procuring activity for consideration. Each request shall be accompanied by complete supporting information.

6.3 Parentheses. The parentheses (*), when used in the type designation.. will be deleted or replaced by either a number of letter furnished by the procuring activity upon application by the contractor for assignment of nomenclature in accordance with 3.3.6. The complete type number shall be used on nameplates, shipping records and instruction books. as applicable.

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