1、MIL-A-255YbC (2) m 999990b 1988728 537 = INCH-POUND MIL-A-25546C (USAF) AMENDMENT 2 26 AUGUST 1994 SUPERSEDING AMENDMENT 1 6 April 1984 MILITARY SPECIFICATION AMPLIFIER, AUDIO FREQUENCY AM-944/AIC-13 This amendment forms a part of Military Specification MIL-A-25546C (USAF) dated 18 June 1970 and is
2、approved for use by the Department of the Air Force and is available for use by all Departments and Agencies of the Department of Defense. PAGE 1 2.1: Delete: * Delete: * Delete: Delete: Add : Delete : Delete: Add : Both “MIL-E-5272“ and “MIL-C-8384“ and its title. The title of MIL-STD-461 and subst
3、itute: “Requirements for the Control of Electromagnetic Interference Emissions and Susceptibility“. The title of MIL-STD-704 and substitute: “Aircraft Electric Power Characteristics“. The title of MIL-STD-781 and substitute: “Reliability Testing for Engineering Development, Qualification, and Produc
4、tion“. “MIL-STD-810, Environmental Test Methods“ and “MIL-C-28748, Connector, Electrical, (Molded Body) and Accessories“. The title of MIL-STD-810 and substitute: “Environmental Test Methods and Engineering Guidelines“. The title of MIL-STD-28748 and substitute: “Connector, Electrical, Rectangular,
5、Rack and Panel, Solder Type Pin Contacts, Size 16“. The headings “HANDBOOK“ and “MILITARY“ and list “MIL-HDBK-781, Reliability Test Methods, Plans, and Environments for Engineering Development, Qualification, and Production“ PAGE 2 3.2.2 : Delete “MIL-C-8384“ and add “MIL-C-28748“. AMSC N/A 1 of 4 F
6、SC 5831 DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-A-2554bC (2) D 9999906 L98729 473 MIL-A-25546C AMENDMENT 2 PAGE 5 * Add: “3.5.7.1 Talk-Listen Test. A talk-l
7、isten test shall be employed as specified in paragraph 4.5.6.“ * Add: “3.5.9 Environmental Tests: Environmental testing shall be conducted as discussed in paragraph 4.5.7. PAGE 6 * Table IV: Insert between Inspection or Test entries “Electrical Tests“ and “Input-Output Characteristics Test“: Inspect
8、ion or Test Paragraph or Preproduction Individual Sampling Requirement “Impedance Tests 4.5.2.1 3 All“ PAGE 7 * Table IV: Delete the following Environmental Tests: Salt Spray Temperature Shock Sand and Dust Fungus and add under Environmental Tests (to be performed on 2 Preproduction amplifiers only)
9、: Salt Fog Explosive Atmosphere * Table IV: Add under the following headings: Inspection or Test Paragraph o Preproductio Individual Sampling Requirement “Environmental Stress Screeni 4.5.9 all all all“ PAGE 8 * Add: “4.5.2.1 Impedance Tests. The amplifiers shall be tested for input impedances and o
10、utput impedances as detailed in paragraphs 3.5.1 and 3.5.2, respectively. I * 4.5.3 Add at the end of the paragraph: “Linearity shall be tested for all amplifiers as specified in paragraph 3.5.3.1 and Table I. Clipping tests shall be performed on preproduction and sampling amplifiers per paragraph 3
11、 * 5.3.2 * * 4.5.4 Add at the end of the paragraph: “The response is characterized in Table II“ * Add: “4.5.5.1 Power Drain. Power drain tests shall be performed as specified in paragraph 3.5.6.“ f 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MI
12、L-A-2554bC (2) 9999906 1988730 195 MIL-A-25546C AMENDMENT 2 * Add: “4.5.5.2 Phasinq. Phasing tests shall demonstrate the relationship described in paragraph 3.5.7.“ * Add: “4.5.6.1 Operation. The amplifier shall perform as specified in paragraph 3.5.8. * Add: “4.5.6.2 Electromagnetic Interference Te
13、st. The amplifier shall meet the characteristics for Electromagnetic interference control as specified in paragraph 3.2.4. I * Add: “4.5.6.3 Output Variation. The output of the amplifier shall remain within the bounds specified in paragraph 3.5.8.“ 4.5.7: Delete in its entirety and add: “Environment
14、al Tests. The applicable environmental tests shall be performed in accordance with MIL-STD-810. Tests not listed do not waive the requirements in designing the component for airborne use or storage under extreme conditions. The following tests shall be conducted on the components of an intercommunic
15、ation set: a. Temperature-Altitude, Method 504, Procedure I b. Humidity, Method 507, Procedure I c. Salt Fog, Method 509, Procedure I d. Explosive Atmosphere, Method 511, Procedure I e. Vibration, Method 514, Procedure I, Curve Ml Parts 1, 2, and 3 f. Shock, Method 516, Procedures I and II PAGE 9 *
16、4.5.8.1: Delete in its entirety and add: “Reliability Test. The preproduction samples of the equipment shall be tested by the contractor for reliability in accordance with MIL-STD-781 and MIL-HDBK- 781 using test plan V-D and the parameters 00 = 6000 and 01 = 2000. accept-reject criteria shall be in
17、 accordance with test plan V-D of MIL-HDBK- 781. The performance parameters to be monitored during the reliability testing shall be as specified in the individual tests of Table IV o this document. These parameters shall be included in the detailed reliability test procedure prepared by the supplier
18、.“ The * 4.5.8.2 through 4.5.8.6: Delete text. * Add: “4.5.9 Environmental Stress Screening (ESS). Each amplifier shall be non-energized and subjected to 25 temperature cycles from -54OC to +7loC chamber temperature at a temperature rate change of 15OC per minute minimum. Temperature dwell at temper
19、ature extremes shall be that time required for the item to stabilize in tempeyature. Stabilization occurs when the temperature of the part of the amplifier having the longest thermal lag has met or exceeded the maximum or minimum temperature or 5 minutes.“ Provided by IHSNot for ResaleNo reproductio
20、n or networking permitted without license from IHS-,-,-MIL-A-25546C AMENDMENT 2 NOTE: The margins of this amendment are marked with an asterisk or vertical lines to indicate where changes (additions, modifications, corrections, deletions) from the previous amendment were made. This was done as a con
21、venience only and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the requirements of this document-based on the entire content irrespective of the marginal notations and relationship to the last previous amendment. Custodian: Air Force - 99 Preparing Activity: Air Force - 84 Project Number: 589 5-F436 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
