1、MIL-T-85375(AS) 14 December 1982 MILITARY SPECIFICATION TRANSMITTER, DIGITAL TELEMETRY This specification is approved for use by Naval Air Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the Department of the Defense. 1. SCOPE. 1.1 Scope, This spe
2、cification defines the performance and test requirements for a binary digital pulse-code modulation (PCM) airborne telemetry transmitter, referred to herein as the transmitter. 1.2 Classification. Transmitter shall be one of the following types: a. Type I - 3.500 inches x 2.500 inches Requirement 4,
3、 Fungus-Inert Materials; Requirement 15, Ferrous Alloys, Corrosion Resistance; and Requirement 16, Dissimilar Metals. 3.4 Design and construction. The transmitter shall conform to one of the configurations shown in Figures 1 or 2 (see 6.2.11, and shall meet all the requirements of this specification
4、 and the referenced documents to the extent specified herein. 3.4.1 Standards of manufacture. . 3.4.1.1 Product cleanliness. No oils or solid lubricants of any kind shall be used on any part of the transmitter after final cleaning of components, except as specified herein. 3.4.1.2 Soldering. Procedu
5、res and requirements for preparation and soldering of electrical connections shall be in accordance with WS-6536. 3.4.1.3 Working environment. The contractor shall provide adequate facilities for the fabrication, assembly, and testing of items to be delivered in accordance with this specification. T
6、he working environ- ment shall meet the minimum levels and requirements specified in MIL-STD-1695. 3.5 Performance. The transmitter, while mounted on a heat sink which simulates the subassembly mounting plate (see Figure 3), shall meet the performance requirements specified herein with or without mo
7、dulation by PCM signals in accordance with IRIG Document 106. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.5.1 Input voltage and current. The transmitter shall operate over the voltage range of 22 to 34 Vdc. Unless otherwise specified in the c
8、ontract or purchase order (see 6.2.1), maximum current consumption shall be 0.8 ampere (A) at all temperatures. 3.5.2 Signal input impedance. Signal input impedance shall be a single TTL load, or no less than 3,000 ohms referenced to +5 volts shunted by 25 picofarad maximum capacitance. 3.5.3 Overvo
9、ltage and power reversal. The transmitter shall not be damaged by a voltage of +40 Vdc or a polarity reversal at the power input terminals for 3 minutes. 3.5.4 Warmup. The transmitter shall self-start and generate a radio frequency (RF) carrier output within the specified frequency limits within one
10、 second of application of primary power, and shall generate the minimum RF power output, in watts (W) , specified herein within 10 seconds of application of primary power, at any temperature from -40 to +85 degrees Celsius (OC). 3.5.5 On-off lead. An external lead shall be provided that will cause t
11、he transmitter to operate only when the lead is connected to a voltage less than one volt with respect to power ground. Maximum cur- rent, sorce or sink, shall be 5 milliamperes (mA). 3.5.6 Operating frequency. Operating frequency shall be within the telemetry bands (216 to 2,400 MHz). Specified ope
12、rating frequency is the average frequency resulting from transmission of a steady-state digital “one“ and “zero.“ The operating frequency shall be as specified in the contract or purchase order (see 6.2.1), and shall be an integral number of megahertz or half-way between. 3.5.7 Frequency deviation.
13、Transmitter frequency deviation with input shall be as specified in the contract or purchase order. Input data rates shall be as specified (see 6.2.1). 3.5.8 Modulator characteristics. e- 3.5.8.1 Sense. Modulation sense shall be such that a “one“ at the input of the transmitter shall cause the highe
14、r output frequency and a “zero“ at the input shall cause the lower output frequency. With no input connected, the higher output frequency shall be transmitted. 3.5.8.2 Spectral characteristics. When modulated with an alter- nating “ones“ and “zeros“ signal at a rate equal to 1.4 times the deviation
15、specified in 3.5.7, the transmitted radio frequency spectrum shall not produce any spectral products greater than 40 decibels (dB) below the level of the unmodulated carrier at frequencies greater than 5 _ (-1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from
16、IHS-,-,-2.2 times the bit rate removed from the center frequency, nor produce any frequency component of amplitude greater than -25 decibels referenced to one milliwatt (dBm) at any frequency other than the carrier when unmodulated. 3.5.8.3 Deviation as a function of input voltage. Output carrier fr
17、equency shall assume the lower of the two steady-state frequencies when input voltage is less than or equal to 0.8 volt, and the higher frequency when input voltage is greater than 2.4 volts and less than 5.5 volts. The two steady-state frequencies shall not be a function of voltages within these ra
18、nges, power supply voltage, nor environmental conditions to an extent greater than 25 percent of the difference between each frequency and the average of the two, which shall be con- sidered the center frequency. 3.5.8.4 TTL source voltage. When specified in the contract or pur- chase order (see 6.2
19、.1), an internal 4.75 to 5.25-volt source capable of 40 mA loading shall be provided for powering of an external optoisolator. When this option is selected, a six-pin power connector shall be pro- vided (see Figure l or 2, as applicable). 3.5.9 Incidental frequency modulation (IPM). IFM (see 6.4.1)
20、shall not exceed 3 kilohertz (kHz) root-mean-square (rms) when tested with a receiver with 500 kHz intermediate frequency (IF) bandwidth and 200 kHz output filters, where rms frequency is one standard deviation from center frequency in gaussian noise. The receiver functions as a frequency- to-voltag
21、e converter. NOTE Receiver local oscillator freqency insta- bility produces measurement system IFM. 3.5.10 Signal-induced incidental amplitude modulation (IAM). IAM shall not cause a peak-to-peak voltage excursion exceeding 3 percent of the carrier average voltage for any modulating frequency at any
22、 devia- tion up to and including maximum. 3.5.11 Output power. Unless otherwise specified in the contract or purchase order (see 6.2.1), the transmitter power output, with a 24 Vdc or greater input,shall be 2 W minimum into a 50-ohm resistive load at any combination of electrical and environmental c
23、onditions. Power output shall be 1.5 W minimum at 22 Vdc under the same conditions. P 6 . . . . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_. . . . - MIL-T-85375 58 W 9999906 0374375 E W 3.5.12. Output load mismatch. When operating into an open
24、or short circuit, the transmitter shall not be damaged nor its operation impaired except for reduced power output. This mismatch applies to all load phase angles. Power so reflected shall be dissipated in an isolating device integral to the transmitter. 3.5.13 Power-supply induced frequency modulati
25、on. Power-supply induced frequency modulation shall be no greater than the limit speci- fied in the contract or purchase order for any frequency above 440 Hz, and with the power input presumed to be a 50-ohm port (see 6.2.1). 3.5.14 Power-supply induced amplitude modulation. Power-supply induced amp
26、litude modulation shall be no greater than the limit speci- fied in the contract or purchase order for any frequency above 440 Hz, and with the power input presumed to be a 50-ohm port (see 6.2.1). 3.5.15 Isolated power ground. When specified in the contract or purchase order (see 6.2.1), the transm
27、itter shall be provided with a power supply ground isolated from the case and radio-frequency ground try a resistance of greater than 1 megohm (case and radio-frequency ground may be common to each other). Isolation breakdown voltage shall be greater than 50 volts (V) in either polarity. 3.5.16 Spik
28、e. The transmitter shall not be damaged by a power-line overvoltage spike of an amplitude of up to 60 V (including normal power supply voltage) and a duration of up to 100 milliseconds (ms). 3.5.17 Electromagnetic interference (EMI). The generation of EM1 by the transmitter and the vulnerability of
29、the transmitter to EM1 shall be within the limits of MIL-STD-461, equipment Class Al, except as specified herein. 3.5.17.1 Antenna terminal conducted emission. All spurious and harmonically-related outputs over the frequency range of 150 kHz to 10 gigahertz (GHz), measured in the transmission line b
30、etween the trans- mitter output and load, shall be at least 60 dB down i=n power from the carrier power level, and with voltage standing-wave ratios up to and including 1.5:l at all phase angles. 3.5.17.2 .Electric field radiated emission. Radiated emissions over the frequency range of 14 kHz to 10
31、GHz shall be within the limits of MIL-STD-461, Test Method FtE02, except that narrow band emission over the range of 500 kHz to 10 GHz may exceed the limits of MIL-STD-461, Fig- ure 2-9, by no more than 35 dB. 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license fro
32、m IHS-,-,-MIL-T-85375 58 7777706 0374376 4 = 3.6 Environmental requirements. The transmitter shall meet the requirements of 3.5.1, 3.5.6, 3.5.8.1, 3.5.8.2, and 3.5.8.3 before, during, or after exposure to the following environmental conditions or any natural combination thereof. a. Vibration. b. Sho
33、ck. c. Ejection shock. d. Handling shock. e. Temperature shock. f. Temperature - altitude. g. Low temperature. h. High temperature. . i. Sand and dust. j. Humidity. k. Salt fog. 3.7 Burn-in and screening. Each transmitter shall complete a minimum of 6 cycles of burn-in and screening as shown in Figu
34、re 4. 3.8 Mean-time-between-failure (MTBF) demonstration. When specified in the contract or purchase order (see 6.2.1), transmitters supplied in accordance with this specification shall be capable of demonstrating a specified MTBF O of 200 hours at a 90 percent confidence level. O 3.8.1 MTBF determi
35、nation. The transmitter operating time shall be used in MTBF determination. Each sample transmitter shall accumulate a minimum operating time of not less than one-half the average operating time of all sample transmitters submitted to the MTBF demonstration testing. For the purpose of MTBF determina
36、tion, the transmitter operat- ing time shall be that time during the thermal cycle of Figure 4 when the transmitter is operating. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-85375 5 W 77977Ob 0174377 b MIL-T-85375 (AS) 3.9 Identification an
37、d marking. The transmitter shall be identified and marked in accordance with MIL-STD-130 and Figure 1 or 2, as appli- cable. Markings shall include, but shall not be limited to, the following: a. The number and revision of this specification. b. NAVAIR code identification number, 30003. c. Manufactu
38、rers name and symbol or code identification from Federal Cataloging Handbook H4. d. A unique serial number. e. Operating frequency. f. Deviation. 3.10 Workmanship. The transmitter, including all parts and acces- sories, shall be constructed and finished in a manner that will assure compliance with a
39、ll requirements of this specification. Unless otherwise specified herein, fabricating and assembly practices shall be in accord- ance with MIL-STD-454, Requirement 9. $ 4. QUALITY ASSURANCE PROVISIONS. 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, t
40、he contractor is responsible for the per- formance of all inspection requirements specified herein (see 6.2.1). Except as otherwise specified, the contractor may use his own or any other facilities suitable for the performance of the inspection require- ments specified herein, unless disapproved by
41、the cognizant Government technical activity. The Government reserves the right to perform or witness any of the inspections set forth in this specification where such inspections are deemed necessary to ensure that supplies and services conform to prescribed requirements. 4.2 Classification of inspe
42、ctions. The inspection requirements specified herein are classified as follows: a. First article inspections (see 4.4). b. Quality conformance inspections (see 4.5). 4.3 Inspection conditions. 4.3.1 Test equipment. For performance of the tests specified herein, all test equipment utilized by the con
43、tractor shall be calibrated and maintained in accordance with MIL-STD-45662. When specified in the I 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-5375 5 777770b 017L1378 m MIL-T-85375 (AS) contract or purchase order, the contractor shall p
44、repare a calibration plan (see 6.2.2). 4.3.1.1 Test equipment accuracy. All test equipment used in the performance of the specified electrical tests shall have an accuracy greater than one-fifth the tolerance for the variable to be measured. 4.3.2 Test environment. Unless otherwise specified herein,
45、 the in- spection methods of 4.6 shall be performed under the conditions specified in 3.4.1.3. 4.3.3 Test documentation. 4.3.3.1 Test procedures. Test procedures shall conform to the requirements of MIL-T-18303 and shall be prepared prior to commencement of testing (see 6.2.2). 4.3.3.2 Test data. Te
46、st data shall be prepared as specified on the data sheets (see Figure 5) (see 6.2.2). 4.3.3.3 Failure analysis and report. The testing activity shall prepare a failure analysis and report for all transmitter failures (see 6.2.2). 4.3.3.4 Certification. The contractor shall have available for the Gov
47、ernment representative written certification, accompanied by objective quality evidence (as defined in MIL-STD-log), that the components used as a part of the transmitter meet the applicable requirements. 4.4 First article inspec.tion. Unless otherwise specified in the contract or purchase order, th
48、e contractor shall furnish a first article of four transmitters to the testing activity designated in the contract or purchase order for first article inspection and approval (see 6.3). First article approval is valid only on the contract under which it is granted, unless specifically extended by th
49、e procuring activity to other contracts. The first article shall be manufactured using the same methods, materials, processes, and procedures proposed for production. Any production prior to approval of the first article shall be at the risk of the contractor. After pproval of the first article sample, changes in material, process procedures or design shall require prior written approval from the procuring activity and requalification may be required. 4.4.1
