1、MI L-C- 2 8 7 2 4A (E C) 25 October 1973 SUPERSEDING 12 February 1970 MIL-C-28724 (EC) MILITARY SPECIFICATION CONTROL, REMOTE SWITCHINGy C-7594( )/U AND C-7595 ( ) /U GENERAL SPECIFICATION FOR 1. SCOPE 1.1 Scope. This specification covers the performance, production, and testing requirements for Rem
2、ote Switching Control units C-7594( )/U and C-7595( )/U for use with shipboard secure voice communications systems. 1.2 Classification. The control units shall be of the following types, as specified: Type I for nine telephone sets and five channels. Type II - For use with small craft. for three tel
3、ephone sets and three channels. - For use with surface ships. Provides programming capability Provides programming capability 2. APPLICABLE DOCUMENTS 2.1 The following documents of the issue in effect on date of invitation for bids or request for proposal, form a part of the specification to the ex-
4、 A tent specified herein. SPECIFICATIONS MILITARY MIL-s-901 - MIL-E-16400 - MIL-E-17555 - MIL-1-45208 - STANDARDS FEDERAL FED-STD-595 - MILITARY MIL-STD-105 - MIL-STD-108 - MIL-STD-109 - MIL-STD-461 - Shock Tests, H. I. (High-Impact) , Shipboard Machin- Electronic Equipment, Naval Ship and Shore; Ge
5、neral Electronic and Electrical Equipment, Accessories, Inspection System Requirements ery, Equipment and Systems, Requirements for Specification for and Repair Parts; Packaging and Packing of Color Sampling Procedures and Tables for Inspection by Attribut es Definitions of and Basic Requirements fo
6、r Enclo- sures for Electric and Electronic Equipment Quality Assurance Terms and Definitions Electromagnetic Interference Characteristics Re- quirements for Equipment I FSC 5840 I - A Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-28724A (EC)
7、._ .- MIL-STD-462 - Electromagnetic Interference Characteristics, Measurement of MIL-STD-471 - Maintainability Verification , Demonstration and Evaluation MIL-STD-781 - Reliability Tests : MIL-STD-785 - Reliability Program For Systems and Equipment De- Exponential Distribution velopmen t and Product
8、 ion (Copies of specifications, standards, drawings, and publications required by suppliers in connection with specific procurement functions should be ob- tained from the procuring activity or as directed by the contracting officer.) 3. REQUIREMENTS 3.1 General requirements. The equipment shall con
9、form to the require- ments of MIL-E-16400 to the extent specified herein. 3.1.1 Equipment composition. 3.1.1.1 Type I unit. The Type I unit shall consist of a control panel, audio amplifiers, and a power supply. 3.1.1.1.1 Control panel. The control panel shall contain the necessary controls, indicat
10、ors and switches required to conform to the requirements spec- ified herein. pushbutton switches. The panel shall contain a matrix type array of 63 illuminated - 3.1.1.1.2 Audio amplifier. Five plug-in, solid state audio amplifier cards shall be provided, one for each channel. Each card shall provid
11、e for am- plification in the transmit and the receive mode. mit and receive amplifiers shall be controlled by the interface characteristics in 3.14.6.1, 3.14.6.2, 3.14.7.1 and 3.14.7.2 respectively. Characteristics of the trans- 3.1.1.1.3 Power supply. A 24 VDC regulated power supply shall be provid
12、ed or providing power to external equipment connected to the Type I unit, see 3.14.8. 3.1.1.2 Type II unit. The Type II unit shall be similar to the Type I unit except that the control panel shall contain only 12 illuminated pushbutton switches and only 3 amplifier cards are required. . 3.1.2 Equipm
13、ent description. 3.1.2.1 Type I unit. The Type I unit shall provide for interconnection The of up to nine remote teiephone sets to up to five secure radio channels. Type I unit shall be capable of being cascaded with other Type I units by trans- fer switches, thus providing for expanded switching ca
14、pability. A monitor capa- bility shall be provided whereby any remote unit can monitor any other remote unit. The unit shall have a lock-out feature and a lock-up feature. 3.1.2.2 Type II unit. The Type II unit shall be similar to the Type I unit except that it shall provide for interconnection o th
15、ree remote telephone sets to up to three secure radio channels and the cascading feature is not required. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-28724A (EC) 3.2 First article sample. Prior to beginning production, a sample shall be tes
16、ted as specified in 4.3 (see 6.2.1). 3.3 Finish. The equipment shall conform to the coating and treatment re- -quirements of MIL-E-16400. Finish shall be red enamel, color number 11136 in accordance with FED-STD-595. 3.4 Safety. The equipment shall conform to the safety requirements of MIL-E-16400.
17、3.5 Workmanship. Workmanship shall be in accordance with MIL-E-16400 3.6 Environmental conditions. 3.6.1 Temperature. Temperature conditions shall be in accordance with Class 4 of MIL-E-16400, except the non-operating temperature shall be -55C to +75“c. 3.6.2 Humidity. The equipment shall conform to
18、 the humidity requirements of MIL-E-16400. 3.7 Electrical design. The equipment shall conform to the electrical de- sign requirements of MIL-E-16400. 3.7.1 Primary power supply line voltage. The equipment shall be designed to operate within the requirements of this specification when the primary pow
19、er supply line voltage is 120 volts RMS A10 percent and line frequency is 60 Hz +5 percent. +- 3.7.2 Blown fuse indicators. Blown fuse indicators are not required. 3.8 Test points. Test points shall be in accordance with MIL-E-16400. 3.9 Mechanical design. The equipment shall conform to the mechanic
20、al de- sign requirements of MIL-E-16400 and as follows: 3.9.1 Construction. All basic units shall use plug-in printed circuit cards and shall be designed for high reliability and simplicity of operation and maintenance. Mechanical design shall be such that all electrical adjust- ments on basic units
21、 for test and alignment may either be accomplished without need for removal of unit from equipment shelves or by using a module extender or sliding shelf, which permits the unit to operate while test and alignment is accomplished. of enclosure shall be open protected, in accordance with MIL-E-16400
22、and Table I of MIL-STD-108. The unit shall be housed in a ferrous metal case and the degree 3.9.2 Shock. Shock requirements shall be in accordance with Grade A, Class I, Type A of MIL-S-901. 3.9.2.1 Shock test procedures. The shock test procedures shall be as specified in MIL-E-16400. 3 I Provided b
23、y IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-28724A (EC) . ?. 3.9.3 Vibration. Vibration requirements shall be in accordance with XIL-E-16400. 3.9.4 m. .- 3.9.4.1 Type I unit. The Type I unit shall be capable of both standard 19 inch (482.6 m) rack mo
24、unting and bulk head mounting and shall not exceed 12 inches (304.8 mm) in depth and 14 inches (355.6 mm) in height. Mounting brackets -for rack mounting shall be furnished with each equipment. 3.9.4.2 Type II unit. The Type II unit dimensions shall not exceed The unit shall be capable of both bulkh
25、ead and base 12 inches (304.8 mm) in height, 9 inches (228.6 m) in width and 12 inches (304.8 um) in depth. mounting. 3.9.5 Weight. The equipment shall conform to the following weight re- quirements: Type I unit - 70 pounds (31.752 kg) maximum - Type II unit - 38 pounds (17.24 kg) maximum i 3.9.6 Ca
26、ble entrances. Cable entrances shall be provided on top, bottom and twosides of the case, conforming to the C-7594A/U (for Type I unit), and C-7595A/U (for Type II unit). 3.9.7 Mounting dimensions. Mounting dimensions shall conform to the following : Type I unit - Mounting dimensions for the Type I
27、unit shall be iden- Type II unit - Mounting dimensions for the Type II unit shall be iden- tical to the C-7594A/U equipment. tical to the C-7595A/U equipment. 3.10 Parts and materials. Parts and materials shall be selected in ac- cordance with MLL-E-16400 with the exception of magnetic permeability
28、properties -which are not applicable to this equipment. 3.11 Supplementary requirements. Requirements for parts identification and markings shall be in accordance with MIL-E-16400. 3.12 Thermal design. The equipment shall conform to the thermal design requirements of MIL-E-16400. 3.13 Panel layout a
29、nd arrangement of operating controls. Front panel lay- out and arrangement of operating controls shall conform to the following: Type I unit -Type TI unit - Type II unit shall be identical to the C-7595A/U - Type I unit shall be identical to the C-7594A/U equipment. ,equipment-. 3.14 Functianal requ
30、irements. The equipment shall conform to the follow- 5ng functional requirements. 4 f Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i i MIL-C- 28724A(EC) 3.14.1 Switching requirements. The circuits to be switched in the Type I and Type II units sha
31、ll be identical to the switched circuits in the C-7494A/U and the C-7595A/U equipments , respectively. The circuits which are switched straight through from input to output shall conform to the following characteristics: Resistance (switch closed) - 100 ohms maximum Resistance (switch open) - 100 K
32、ohms minimum Current - 3 amperes maximum, noninductive 3.14.2 Switching function characteristics. 3.14.2.1 Type I unit. The pushbuttons with which the switching function is performed shall be arranged in a rectangular matrix consisting of 7 rows and 9 columns. Rows 2 through 6, counting from the top
33、 down, shall be associ- ated with secure radio sets 1 through 5, respectively. Row 1 shall be associ- ated with the monitor function and row 7 shall be associated with the transfer and release functions. Columns 1 through 9 shall be associated with remote telephone sets 1 through 9, respectively. Th
34、e depressing of any one switch in rows 2 through 6 in a vertical column shall connect the radio associated with that respective row with the telephone associated with the selected column. Depressing a pushbutton in row 7 shall release any previously depressed push- button in that respective column e
35、xcept in row 1 and shall transfer the remote telephone set connected to that column to the cascaded switching unit. 3.14.2.2 Type II unit. The pushbuttons with which the switching function is performed shall be arranged in a rectangular matrix consisting of 4 rows and 3 columns. Rows 1, 2 and 3, cou
36、nting from the top down, shall be associated with secure radio sets, 1, 2 and 3, respectively. Row 4 shall be associated with the release function. Columns 1, 2 and 3, counting from left to right, shall be associated with remote telephone sets 1, 2 and 3, respectively. The depressing of any one swit
37、ch in rows 1, 2 and 3 in a vertical column shall con- nect the radio associated with that respective row with the telephone associ- ated with the selected column. Depressing a pushbutton in row 4 shall release any depressed pushbutton in that respective column. 3.14.3 Monitor function. The Type I un
38、it shall permit any remote tele- Both Push-To-Talk (PTT) phone set to monitor any other remote telephone set. lines and both audio transmit lines shall be disconnected when the monitor switch is actuated. The monitor function shall not degrade equipment perform- ance in the transmit and receive cond
39、ition. 3.14.4 Lock-out feature. The Type I and Type II units shall be so de- signed that only one pushbutton in a vertical column (with the exception of the monitor pushbuttons on the Type I unit) can be depressed at any time. 3.14.5 Lock-up feature. The Type I and Type II units shall be provided wi
40、th a lock-up feature which shall lock the matrix in a programmed condition, thereby preventing unauthorized access of any channel by a telephone set. The lock shall be key controlled. Red and green indicator lamps shall be provided on the front panel of the matrix to indicate the locked and unlocked
41、 conditions. The red lamp shall be labeled “Lockedt. “Unlocked“. The green lamp shall be labeled 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-28724A (EC) 3.14.6 Input interface characteristics. The input interface shall -be ca- pable of op
42、erating with a remote secure telephone set. ified in 3.14.6.1 through 3.14.6.5. This 3.14.6.1 Transmit audio. The transmit audio interface the following characteris tics : interface is spec- shall conform to Level from telephone - -20 dBm average, O dBm peak Erequency characteristic of telephone - 7
43、0 Hz to 4 8 dB, peak to peak kHz, flat within Impedance - 600 ohms 210 percent at 1 kHz, balanced Open circuited when the telephone is in the monitor mode . 3.14.6.2 Receive audio. -The receive audio interface shall conform to the following characteris tics : Level - Average O dBm Frequency response
44、 - 200 Hz to 4 kHz, flat within 12 dB peak to peak Impedance - 600 ohms I10 percent at 1 kHz balanced Distortion - 5 percent maximum Noise - The signal to noise ratio shall be greater than 40 dB refer- enced to a O dBm input signal level. and any other extraneous signal noise. All audio inputs and o
45、utputs including the one under test shall be terminated into 600 ohms I10 percent. Noise shall be considered hum 3.14.6.3 Disconnect indicator. The disconnect indicator is used with cer- tain, but not all, types of secure telephone sets. A disconnect signal shall be provided at the telephone interfa
46、ce when no connection to the telephone is made on the matrix switches. The interface shall conform to the following characteris tics : Disconnect - +24 volts 210 percent with series resistance of 150 ohms Connect - Ground with a series resistance of 150 ohms t20 percent +20 percent 3.14.6.4 +24 volt
47、s DC. +24 volts DC is supplied to each telephone, and is unswitched, and derived from the power supply described in 3.14.8. rent to each telephone will be 150 mA maximum. The cur- 3.14.6.5 Sima1 ground. Each telephone interface shall have a terminal for signal ground. 3.14.7 Output interface charact
48、eristics. The output interface shall be -capable of operating with a secure radio system. This interface is specified in 3.14.7.1 through 3.14.7.3. -L_ . L. . . : 3.14.7.1 Transmit audio. The transmit audio interface shall conform to the following characteristics: Level - -20 dBb average, O dBm peak
49、 Frequency response (referenced to a selected input 3.14.6.1) - 70 Hz -to 4 Hz flat withh i3 dB peak to peak 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Impedance - 600 ohms ?lo percent at 1 kHz balanced Distortion - 3 percent maximum Noise - The signal to noise ratio shall be greater than 40 dB refer- enced to O dBm signal level. other extraneous signal. All inputs and outputs including the one under t
