1、I INCH-POUNDI MIL-DTL-6248 1 A(AT) 30 September 1998 SUPERSEDING 20 August 1985 MIL-1-6248 1 (AT) Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: U.S. Army Tank-automotive and Armaments Command,
2、 ATTN: AMSTA-TR-E/BLUE, Warren, MI 48397-5000, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document, or by letter. DETAIL SPECIFICATION INTERCOMMUNICATION CONTROL UNIT This specification is approved for use by the U.S. Army Tank-automotive a
3、nd Armaments Command, Department of the Army, and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification establishes the requirements and acceptance of an intercommunication control unit for use on military vehicles requiring selecti
4、ve communication between crew members. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or
5、 as examples. While every effort has been made to ensure the completeness of this list., document users are cautioned that they must meet all specified requirement documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specification
6、s, standards. and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards
7、(DoDISS) and supplement thereto, cited in the solicitation (see 6.2). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- - NIL-DTL-bZ481A 9999906 2075727 707 MIL-DTL-6248 1 A(AT) SPECIFICATIONS DEPARTMENT OF DEFENSE MIL-PW-22750 - Coating, Epoxy, High
8、Solids. MIL-PRF-62488 - Amplifier, Audio Frequency. STANDARDS FEDERAL FED-STD-595 - Colors Used in Government Procurement. DEPARTMENT OF DEFENSE MIL-STD-462 MIL-STD-8 1 O - Measurement of Electromagnetic Interference - Environmental Test Methods and Engineering Characteristics, Test Methods for. Gui
9、delines. (Unless otherwise indicated, copies of the above specifications, standards, and handbooks are available from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 191 11-5094.) 2.2.2 Other Government documents, drawinns, and mblications. The following ot
10、her Government documents, drawings, and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues are those cited in the solicitation. DRAWINGS 123 10226 - Control Unit Assembly. (Copies of this drawing are available from the U.S. Army Tank-auto
11、motive and Armaments Command, ATTN: AMSTA-TR-EBLUE, Warren, MI 48397-5000.) 2.3 Order of Drecedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws
12、 and regulations unless a specific exemption has been obtained. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- NIL-DTL-6248LA Ob 2075728 643 MIL-DTL-6248 1 A(AT) 3. REQUIREMENTS 3.1 First article. When specified (see 6.2), a sample shall be subje
13、cted to first article inspection in accordance with 4.1.1. 3.2 Materials. Unless otherwise specified, the materials selection shall be the prerogative of the contractor as long as all articles submitted to the Government fully meet the operating, interface, support and ownership, and operating envir
14、onment requirements specified. 3.2.1 Recycled, recovered, or environmentally meferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible provided that the material meets or exceeds all specified requirements, and promotes economical
15、ly advantageous life cycle costs. 3.2.2 Corrosion resistance. All ferrous metal parts shall be of corrosion resistant type or treated for corrosion resistance. 3.3 Design and construction. The design, construction, and assembly of the control unit shall conform to Drawing 12310226. The control unit
16、shall be painted Forest Green (color No. 34079) in accordance with FED-STD-595 or equivalent with an epoxy-polyamide chemical agent resistant coating per MIL-PRF-22750, type I, or equivalent. 3.4 Interface requirements. The assembly shall conform to the envelope dimensions, electrical interfaces, an
17、d mounting dimensions and locations as specified on Drawing 123 10226. 3.4.1 Size and weight. The control unit shall not exceed 3.25 pounds (lb) (1.48 kilograms (kg) in weight. The size shall not exceed the following dimensions: 4.5 inches (in.) long by 4.88 in. wide by 3.38 in. deep (1 1.43 centime
18、ters (cm) by 12.39 cm by 8.58 cm). 3.4.2 Monitor switches. The control unit shall contain four independent monitor switches which will permit the crew member to monitor any combination of four radios. 3.4.3 Transmitter selector switch. The control unit shall contain a five position switch to permit
19、selection of RADIO 1, RADIO 2, RADIO 3, RADIO 4, and Intercom only. As permitted by the radio transmission selector switch as specified in MIL-PRF-62488, this switch routes microphone audio and keying signals to the selected radio. Selection of a radio shall also permit monitoring of the receiver au
20、dio from the selected radio regardless of the monitor switch position. 3.4.4 Intercom cable assembly. The control unit shall interconnect with other audio system components by means of CX-4723NRC cable. The 18 socket connector shown in figure 1 shall interface with the male connector on cable CX-472
21、3NRC. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- NIL-DTL-62481A 9999906 2075729 5BT m MIL-DTL-6248 1 A(AT) 3.4.5 Audio interface. The control Unit shall interface with a variety of audio accessories. Primary interface details are shown in fig
22、ure 2. When handsets are used with the control units, they are connected to the control unit through J802 to allow radio transmission or to 5803 to allow intercom transmission. When headsets are used with the control unit, they are connected to the control unit through 5802 and 5803 to allow both ra
23、dio and intercom transmission. Monitoring of the intercom and radio shall not be affected by connection to either 5802 or 5803. The control unit shall interface with the distribution unit through either J801 or J804 to enable radio and intercom functions. 3.5 Operating requirements. Each control uni
24、t shall provide the following functional, operational, and performance capabilities. 3.5.1 Microphone amplifier. 3.5.1.1 Input imDedance. The input impedance from pin D to pin A of 5802 and 5803 shall be 150 223 ohms (52) at 1000 Hertz (Hz). 3.5.1.2 Microphone to radio aain. The voltage gain fiom pi
25、n D of J802 and J803 to pins K, N, U and V of J801 and 5804 shall be 1 10 210 volts (V) per V at 1000 Hz. 3.5.1.3 Radio oumut impedance. The output impedance at pins K, N, U and V of 5801 and 5804 shall be 1330 2133 S2 at 1000 Hz. 3.5.1.4 Microphone to radio frequency response. The microphone to rad
26、io frequency response shall be flat 22 decibels (dB) fiom 500 Hz to 3000 Hz. 3.5.1.5 MicroDhone to radio distortion. With a 7 millivolt (mV) root mean square (rms) 1000 Hz signai applied to the microphone input of 5802 or J803, and output taken at pins K, Ny U and V of 5801 and 5804, the total harmo
27、nic distortion shall be less than 2 percent (%). 3.5.1.6 Microphone to radio crosstalk. The voltage at any unselected output shall be at least 50 dB below the output of the selected radio output. 3.5.2 Radio to headset. 3.5.2.1 Radio to headset gain. The voltage gain from pins J, M, T and S of J801
28、and 5804 to pin B or E at 5802 shall be 140 230 V per V with a 500 S2 load at pin B or E and a frequency of 1000 Hz. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-6248 1 A(AT) A- C D E F H- J K- M- N R S T u- V B TO DISTRIBUT101 UNIT OTHE
29、R CREW CONTROL UNIT OR - TO HEAD c- SET GND GND - A - +v +v - C -KEY1 KEY1 - D - KEY 2 KEY2 - E - KEY 3 KEY3 - F KEY4 KEY4 - H - RCVR 1 RCVR1 - J MIKE 1 MIKE1 - K RCVR 2 RCVR2 - M -MIKE2 MIKE2 - N - INTERCOM INTERCOM - R - RCVR4 RCVR4- S - RCW RCVR3 - T MIKE 3 MIKE 3 - U - MIKE4 MIKE 4 - V B L P .L
30、P I I J802 ! I 5803 GND HEAD SET AMPLIFIER OUTPUT INTERCOM PUSH TO TALK MIKE IN 1 A B C D E TO DISTRIBUTION UNIT OTHER CREW CONTROL UNIT -+ OR TO SET - HEAD FIGURE 1. Control unit electrical interface. 3.5.2.2 Headset output power. The headset output shall be capable of delivering 200 milliwatts (mW
31、) minimum into 500 R at 1000 Hz. The output shall not be damaged by operating into a short circuit. 3.5.2.3 Radio to headset fiequencv response. The radio to headset frequency response shall be as shown below with output terminated into 500 Q. Frequency 500 Hz 1000 Hz 3000 Hz Output Level - +2 dB O
32、dB (Reference) - +7 dB 3.5.2.4 Radio to headset distortion. The radio to headset total harmonic distortion shall be less than 5% with output delivering 200 mW ms into 500 i2 at 1000 Hz. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TO cvc HELMET
33、OR OTHER AUDIO ACCESSORIES CX-4723NRC CREW 5041 801 CABLE TO cvc HELMET OR OTHER AUDIO ACCESSORIES TO RADIO ply SET #I TO cvc HELMET OR OTHER AUDIO ACCESSORES TO cvc HELMET OR OTHER AUDIO ACCESSORIES I cx-4723NRc UNIT CABLE CREW MIL-DTL-6248 1 A(AT) #3 EXTERNAL POWER SOURCE WHEN NOT OTHER STATION I
34、3 AUDIO WIRE LINE . AUXILIARY RADIO RECEIVER FIGURE 2. Control unit interface connections. 3.5.2.5 Radio to headset crosstalk. The voltage output at the headset from any unselected input shall be at least 50 dl3 below the output from a selected input. 3.5.3 Microphone to headset. 3.5.3.1 Microphone
35、to headset gain. The voltage gain from the microphone input to headset output shall be 1610 i430 V per V with the headset output terminated into 500 SZ and input frequency of 1000 Hz. 3 53.2 Microphone to headset frequency remonse. The microphone to headset frequency response shall be flat chipped,
36、scratched or peeling paint: rust: corrosion or incorrect finish. 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- flIL-DTL-6248LA W O6 2075737 656 MIL-DTL-6248 1 A(AT) Title Materials Design and construction interface requirements: Size and weight
37、 Monitor switches Transmitter selector switch Intercom cable assembly Audio interface Operating requirements: Microphone amplifier Radio to headset Microphone to headset Microphone to intercom Volume control Keying Support and ownership requirements: Identification and marking Operating environment
38、requirements : Temperature Altitude Humidity Fungus Salt fog Sand and dust Water spray Explosive atmosphere Vibration Shock Electromagnetic interference TABLEII. 1 Requirement 3.2 thru 3.2.2 3.3 3.4 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 3.5 3.5.1 thru 3.5.1.6 3.5.2 thru 3.5.2.5 3.5.3 thni 3.5.3.3 3.5.4 thru
39、 3.5.4.1 3.5.5 3.5.6 3.6 3.6.1 3.7 3.7.1 3.7.2 3.7.3 3.7.4 3.7.5 3.7.6 3.7.7 3.7.8 3.7.9 3.7.10 3.7.1 1 ification methods. Inspection 4.2.3 4.2.3 4.2.4 4.2.4 4.2.4 4.2.4 4.2.4 4.2.4 4.2.5 4.2.5.1 thru 4.2.5.1.6 4.2.5.2 thni 4.2.5.2.5 4.2.5.3 thni 4.2.5.3.3 4.2.5.4 thru 4.2.5.4.1 4.2.5.5 4.2.5.6 4.2.
40、6 4.2.6.1 4.2.7 4.2.7.1.1 requirement verification. Except as otherwise specified herein, equipment performance shall be measured with a 56 R resistor in parallel with an 825 Cl and 0.27 microfarad series combination connected between pin R and signal ground in order to simulate system operation. Ex
41、cept as otherwise specified herein, gain measurements shall be made with equipment volume controls set to maximum. 4.2.5.1 Microphone amplifier. 4.2.5.1.1 Input imDedance. The input impedance shall be measured fi-om pin D to pin A of 5802 and J803, and the input impedance shall be 150 +, 23 ohms at
42、1000 Hz. 4.1.5.1.2 Microphone to radio ah. With a 7 mV rms, 1000 Hz signal applied to pin D of J802 or 5803 and output taken at pins K, N, U and V of J801 and J804 and the TALK switch in the appropriate position while pin C of J802 is grounded, each output voltage shall measure 0.77 V rms 170 mV. Th
43、is output corresponds to a gain of 1 10 210 V per V per at 1000 Hz. 4.2.5.1.3 Radio output impedance. The output impedance shall be measured at pins Ky Ny U and V of 5801 and 5804 with respect to pin A of 5801 or 5804. The headset output shall be capable of delivering 200 mW minimum into 500 Q at 10
44、00 Hz. 4.2.5.1.4 Microphone to radio frequency response. With a constant amplitude, variable frequency input signal applied to pin D of J802 or 5803, the rms voltage at pins K, N, U and V of J801 and 5804 with the proper output selected shall be as shown below. Frequency 500 Hz 1000 Hz 3000 Hz Outpu
45、t Level - +2 dB O dB (Reference) - +2 dB 4.2.5.1.5 Microphone to radio distortion. With a 7 mV rms, 1000 Hz signal applied to pin D of 5802 or 5803, the distortion measured at pins IS, Ny U and V of 5801 and J804 shall be less than 2% at each output. 4.2.5.1.6 MicroDhone to radio crosstalk. With a 7
46、 mV rms, 1000 Hz signal applied to pin D of 5802 or J803 and output taken at pins Ky N, U and V of 5801 and J804 and the TALK switch in the appropriate position while pin C of 5802 is grounded, the voltage output at the headset from any unselected input shall be at least 50 dB below the output fi-om
47、 a selected input. 13 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-b248LA = 99999Ob 2075739 429 MIL-DTL-6248 1 A(AT) 4.2.5.2 Radio to headset. 4.2.5.2.1 Radio to headset nain. With a 70 mV rms, 1000 Hz signal applied to pins J, M, T and S
48、of 5801 and 5804 and output taken at pin B or E of 5802 with a 500 Rload and the appropriate channel selected, the output voltage shall measure 9.8 V rms k2.1 V. This output corresponds to a gain of 140 230 V per V. 4.2.5.2.2 Headset output power. With sufficient input voltage applied to pin J of J8
49、01 or 5804 and pin B or E of 5802 terminated into a 500 i2 load, the output power shall be at least 200 mW rms at pin B or E of 5802. The amplifier shall not be damaged by operating into a short circuited load at maximum output. 4.2.5.2.3 Radio headset fieauencv res-ponse. With a constant amplitude, variable frequency input signal applied to pins J, M, T and S of J801 or 5804 and output taken at pin B or E of
