SJ 20685-1998 General specification for airborne communication anti-interference radio receiving channel module
Some standard content:
Military Standard of the Electronic Industry of the People's Republic of China FL5963
SJ 20685—1998
General specification for receive channel module of airborne anti-jam set Issued on March 18, 1998 Implementation on May 1, 1998 Approved by the Ministry of Electronics Industry of the People's Republic of China 1 Scope
Subject Content
Scope of Application
2 Reference Documents
Qualification Appraisal
Module Division and Performance Characteristics
Reliability
Maintainability
Environmental Adaptability
Electromagnetic Compatibility·
Interface and Interchangeability
Appearance Quality
Dimensions and Weight
Mark and Code
4 Quality 1 Scope
1.1 Subject content
SJ20685--1998
This specification specifies the general requirements, quality assurance provisions and delivery preparation for the receive channel module of airborne anti-jam set for airborne communication.
1.2 Scope of Application
This specification applies to the receiving channel of modular airborne anti-interference communication radio stations. It also applies to the receiving channel of modular airborne conventional radio stations. It is the basis for the design, manufacture and inspection of receiving channel modules, and is also the basis for the preparation of technical requirements and product specifications for receiving channel modules. 2 References
GJB150.3 Environmental test methods for military equipment High temperature test GJB150.4 Environmental test methods for military equipment Low temperature test GJB151A—97 Requirements for electromagnetic emission and sensitivity of military equipment and subsystems GJB152A--97 Measurement of electromagnetic emission and sensitivity of military equipment and subsystems GJB179A—96 Counting sampling inspection procedures and tables GJB367.1—87 General technical conditions for military communication equipment Design and manufacturing requirements GJB367.2—87 General technical conditions for military communication equipment Environmental test methods GJB367.3—87 General technical conditions for military communication equipment Reliability identification test and acceptance test methods GJB367.4—87 Military Acceptance rules for general technical conditions for communication equipment GJB367.5--87 General technical conditions for military communication equipment Packaging, transportation and storage requirements GJB441—88 Basic dimensions of chassis, mounting racks and accessories of airborne electronic equipment GJB457—88 General specifications for airborne electronic equipment Issued by the Ministry of Electronics Industry of the People's Republic of China on March 18, 1998 and implemented on May 1, 1998
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GJB89990 Reliability identification and acceptance test GJB1128—91 General specifications for airborne ultra-short wave radio stations 3 Requirements
3.1 Qualification identification
Products submitted in accordance with this specification should be products that have passed the identification or have been approved for finalization. 3.2 Module division and performance characteristics
3.2.1 Function
This module, in cooperation with the microcomputer module and the frequency synthesis module, selects, amplifies, frequency converts, filters, etc. the anti-interference DS and DS+FH RF signals, and provides the required anti-interference IF signals for the despreading unit: selects, amplifies, frequency converts, filters, and demodulates the conventional AM and FM RF signals into audio signals: In addition, it also has interfaces such as secret calls, data, automatic receiving channels, automatic forwarding, life-saving audio, self-listening, and anti-interference audio. 3.2.2 Composition
The module consists of a front-end module and a back-end module. The front-end module includes an electrically adjustable high-frequency amplifier, a balanced mixer, a filter, an IF amplifier, state control, automatic gain equalization and other circuits. The back-end module includes a conventional IF amplifier, a demodulator, an audio filter, an audio amplifier, and state control, automatic gain extraction, squelch, and audio interface circuits.
3.2.3 Classification
Modules are divided into Class 1 and Class II according to sensitivity. 3.2.4 Performance characteristics
3.2.4.1 Working frequency band and working type (see 4.6.1.1) Working frequency band: 108MHz~400MHz
Working type: AM, FM, DS, DS+FH and automatic direction-direction (ADF), secret talk, automatic forwarding, data transmission, etc.
3.2.4.2 Frequency hopping rate adaptability (see 4.6.1.2) The maximum frequency hopping rate is 2000 hops per second. AGC response time (AtaGc) and ATC response time (△taIC) should be less than 10s.
3.2.4.3 Interference tolerance adaptability (see 4.6.1.3) When the interference signal power falling within the intermediate frequency bandwidth of the receiving channel is 9dB higher than the useful signal power, the receiving channel is not saturated.
3.2.4.4 Sensitivity (see 4.6.1.4)
a. The sensitivity shall comply with the provisions of Table 1.
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Type of work
Conventional work
Anti-interference work
Working mode
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Table sensitivity
Sensitivityuv
b. Under the specified environmental conditions, the sensitivity decrease shall not exceed 6dB:3
Output signal-to-noise ratio
The number of channels that do not meet the sensitivity requirements shall be less than 0.1% (the minimum channel spacing is 25kHz). e
3.2.4.5 Anti-interference intermediate frequency output level (see 4.6.1.5) The anti-interference intermediate frequency output level shall comply with the product specifications. 3.2.4.6 Impedance (see 4.6.1.6)
a. Transmitter impedance: 50Ω
b. Audio output impedance
Plain speech: 150Ω±10%
Secret speech: 20k2±10%
Automatic forwarding: 2kQ±10%
Automatic direction: 10ks2±10%
3.2.4.7 Audio output level (see 4.6.1.7) When a RF signal with a modulation frequency of 1kHz is applied to the input of the module, the audio output level on the load specified in 3.2.4.6 shall comply with the requirements of Table 2.
Table 2 Audio output level
Type of work
Anti-interference work
Automatic direction
Automatic forwarding
3. 2. 4. 8
RF signal
500 μv
Sensitivity
Amplitude modulation 85% or FM deviation ±8kHz
Amplitude modulation 90% or FM deviation ±5.6kHz
Amplitude modulation 85% or FM deviation ±8kHz
Amplitude modulation 30% or FM deviation ±5.6kHz
Audio output distortion (see 4.6.1.8)
Audio output level
Peak value 12 V±1 V
6.5 V±0.5 V
The audio output distortion should be less than 10% under normal test and less than 15% under specified environmental conditions: 3.2.4.9 Frequency output response (see 4.6.1.9) -3
SJ20685--1998
The audio output response should comply with the provisions of Table 3
Table 3 Audio output response
Working type
3. 2. 4. 10
RF signal
Selectivity (see 4.6.1.10)
The selectivity should comply with the provisions of Table 4.
Type of operation
Anti-interference operation
3. 2. 4. 11
±5.6 kHz
Table 4 Selectivity
Minus 6 dB bandwidth
≥6 MH2
≥38 kHz
≥68 kHz
Automatic gain control (see 4.6.1.11）
Audio specification
300 Hz~3.5 kHz
50 Hz~10.24kHz
Attenuation 50dB bandwidth
≤14MHz
Audio output
(relative to 1kHz)
Attenuation 60dB bandwidth
≤80MHz
≤17kHz
Anti-interference communication: When the unmodulated RF signal increases from 6μV to 0.25V, the increase in the anti-interference intermediate frequency output level should not be greater than 6 dB.
Conventional communication: AM operation, when the input RF signal increases from 3μV to 0.25V, the audio output change relative to the 500uV RF signal should be within +3dB. When the input signal increases to 0.5V, the receiving channel is not blocked and can provide understandable signals. During the rated operation, when the input RF signal increases from 1uV to 0.5V, the frequency output change relative to the 500μV RF signal should be within ±3 dB. 3.2.4.12 Squelch (see 4.6.1.12)
3. 2. 4. 12. 1 Squelch sensitivity (see 4.6.1.12.1) When the RF signal with the sensitivity value specified in 3.2.4.4 is added to the input end of the receiving channel, the squelch should automatically open and output the audio signal.
3.2.4.12.2 Squelch hysteresis (see 4.6.1.12.2) Squelch hysteresis should comply with the provisions of 3.2.3.10.2 of GJB 1128. 3.2.4.12.3 Noise adjustment (see 4.6.1.12.3) Noise adjustment shall comply with the provisions of 3.2.3.10.3 of GJB 1128. 3.2.4.12.4 Noise isolation (see 4.6.1.12.4) 4
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Noise isolation shall comply with the provisions of 3.2.3.10.4 of GJB1128. 3.2.4.13 Internal noise level (see 4.6,1.13) The internal noise level shall comply with the provisions of 3.3.8 of GJB1128. 3.2.4.14 Parasitic response (see 4.6.1.14) The suppression of parasitic response within the working frequency band (but must deviate from the nominal operating frequency + 500kHz) should be above 55dB, and the suppression of parasitic response outside the working frequency band should be above 60dB: the suppression of intermediate frequency and image frequency should be higher than 70dB. 3.2.4.15 Down-recording (see 4.6.1.15) The receiver down-recording should comply with the provisions of 3.3.13 of GJB1128. 3.2.4.16 Cross modulation (see 4.6.1.16) AM useful signal equal to sensitivity: When subjected to interference signal with modulation frequency of 400Hz and amplitude modulation of 30%, the audio output signal-to-earning ratio of the useful signal shall not be less than 6dB. The interference frequency and level are shown in Table 5. Table 5 Cross modulation
Interference signal
o±0.5MHz
3.2.4. 17 Vibration modulation (see 4.6.1.17) Interference signal level
55dB higher than the sensitivity value
Under the vibration conditions of 3.5.1.4, the module audio output change shall not exceed 2dB. 3.2.4. t8 Input standing wave ratio (see 4.6.1.18) For any operating frequency, the medium voltage standing wave ratio generated by the receiver input terminal connected to the 50Q transmission line should not be greater than 2.5: 1.
3.2.4.19 Input protection (see 4.6.1.19) The module input terminal is not damaged by adding a 2V RF signal. 3.2.4.20 Power consumption (see 4.6.1.20)
The module power consumption is specified by the product specification.
3.2.4.21 Self-test output (see 4.6.1.21) There are no less than three self-test points, and the specific requirements are specified by the product specification. 3.3 Reliability
The reliability design should comply with the provisions of 1.3 in GJB 367.1. The minimum acceptable value of the mean time between failures (MTBF) is specified by the product specification, generally not less than 1600h. 3.4 Maintainability
Maintainability shall comply with the provisions of 6.9 of GJB457. The time for replacing a module shall be less than 5 minutes. 3.5 Environmental adaptability
If there are no other provisions, modules that can be tested at a temperature-altitude level can be exempted from low temperature, high temperature, and low pressure tests: Equipment that can be tested at a temperature-altitude level can be exempted from low temperature, high temperature, humidity, and low pressure tests. 3.5.1 Working state requirements
3.5.1.1 High temperature
SJ20685—1998
T. The working temperature is 70°C. After the test: The sensitivity shall comply with the provisions of 3.2.4.4. The audio input level and the anti-interference intermediate frequency output level shall not change by more than 2dB. 3.5.1.2 Low temperature
The operating temperature is -55℃. After the test, the sensitivity shall comply with the provisions of 3.2.4.4. The audio output level and the anti-interference intermediate frequency output level shall not change by more than 3dB. 3.5.1.3 Temperature and altitude
The module shall be able to withstand the test specified in "414 Temperature and altitude test" in GJB367.2. The severity level and requirements of the test shall be specified by the product specification.
3.5.1.4 Vibration
The module shall be able to withstand the test specified in "409 Vibration test" in GIB367.2. For the receiving channel module working in multiple types of moving environments, the most severe type of test shall be used. The severity level and requirements of the test shall be specified by the product specification.
3.5.1.5 Aircraft bombardment vibration
The module shall be able to withstand the test specified in "419 Aircraft bombardment vibration test" in GJB367.2. The severity and requirements of the test shall be specified by the product specification.
3.5.1.6 Acceleration
The module shall be able to withstand the test specified in "415 Acceleration test" in GJB367.2. The severity and requirements of the test shall be specified by the product specification.
3.5.1.7 Explosive atmosphere
The module shall be able to withstand the test specified in method 1 of "417 Explosive atmosphere test" in GJB367.2. The severity and requirements of the test shall be specified by the product specification. 3.5.1.8 Fungus
The module shall be able to withstand the test specified in "412 Fungus test" in GJB367.2. The severity and requirements of the test shall be specified by the product specification.
3.5.1.9 Sand and Dust
The module shall be able to withstand the test specified in Method 1 of "407 Sand and Dust Test" in GJB367.2. The severity and requirements of the test shall be specified by the product specification.
3. 5. 1.10 Noise
The module shall be able to withstand the test specified in Method 2 of "416 Noise Test" in GJB367.2. The severity and requirements of the test shall be specified by the product specification.
3.5.1. 11 Temperature-Humidity-Altitude
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The module shall be able to withstand the test specified in "418 Temperature-Humidity-Altitude Test" in GJB367.2. The severity and requirements of the test shall be specified by the product specification. 3.5.2 Non-operating state requirements
3.5.2.1 Storage temperature
The module shall be able to withstand the high temperature storage condition of 70°C and the low temperature storage condition of -50°C. 3.5.2.2 Humidity
The module shall be able to withstand the test specified in "411 Humidity test" in GJB367.2. The severity level and requirements of the test shall be specified by the product specification.
3.5.2.3 Temperature shock
The module shall be able to withstand the test specified in "405 Temperature shock test" in GJB367.2. The severity level and requirements of the test shall be specified by the product specification.
3. 5.2. 4 Shock
The module shall be able to withstand the test specified in "408 Shock test" in GJB367.2. The severity level and requirements of the test shall be specified by the product specification.
3.5.2.6 Salt spray
The module should be able to withstand the test specified in the "413 salt spray test" in GJB367.2. The severity and requirements of the test are specified by the product specification.
3.6 Electromagnetic compatibility
The electromagnetic compatibility of the module should meet the requirements of GJB151A. The specific requirements are specified in the product specification. 3.7 Interface and interchangeability
3.7.1 Interface
a. The high-frequency signal interface uses SSMB connector b. The low-frequency signal interface uses CS32--2.54-44TJWBJ connector, interface characteristics see Table 6. - 7
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Table 6 Low-frequency signal interface
Digital ground
Digital ground
Self-test enable
Band conversion control
Normal, anti-interference conversion
Baseband, dual-data conversion control
Digital transmission enable
Secret speech enable
AM, FM conversion control
Receiving, transmitting control
3.7.2 Interchangeability
Squelch enable
Broadband narrowband conversion control
Self-listening voice input
Teaching and inducing input
Forward enable
Digital-analog AGC Forward control
Digital AGC Input
Related combined peak input
Anti-interference audio input
AGC voltage output
ATC voltage input
FH clock input
Self-test output
Life-saving voice input
Forwarded voice
AGC test
Baseband data output
Broadband, directional audio output
Audio output
The overall dimensions should comply with the provisions of 3.4. Good dimensional tolerance design ensures that the modules can be interchanged at will. After replacing the module, it should work normally without adjustment, and it should meet the electrical performance index requirements after slight adjustment. - 8-
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3.8 Appearance quality
SJ20685—1998
The module surface should be free of scratches and dents, and the coating color should be consistent. 3.9 Dimensions and weight
On the principle of ensuring module performance, the volume should be as small as possible and the weight should be as light as possible. The module's dimensions should comply with the provisions of GJB441. The specific dimensions and weight should be specified by the product specification. 3.10 Marking and code
The marking characters should be clear and durable. If there are no other provisions, the module code is composed as follows: MAR
Classification number
Airborne receiver channel module
Example: The anti-interference sensitivity is less than or equal to 3μV. The airborne receiver channel module with serial number 15 is represented by: MAR-1-15.
4 Quality assurance regulations
4.1 Inspection responsibility
Unless otherwise specified in the contract or order, the contractor shall be responsible for completing all inspections specified in this specification. If necessary, the ordering party or the superior appraisal agency has the right to inspect any inspection item described in this specification. 4.1.1 Qualifications
All products must meet all requirements of Chapter 3 and Chapter 5 of this specification. The inspections specified in this specification shall become an integral part of the contractor's entire inspection system or quality program. If the contract includes inspection requirements not specified in this specification, the contractor shall also ensure that the products submitted for acceptance meet the contract requirements. Quality political sampling does not allow the submission of products that are known to be defective, nor can the ordering party be required to accept defective products. 4.2 Inspection categories
The inspection categories specified in this specification are as follows:
a. Identification inspection:
b. Quality consistency inspection.
4.3 Inspection conditions
4.3.1 Atmospheric conditions
If there are no other specifications, the electrical performance test shall be carried out under the specified normal test conditions: a. Temperature: 15°C~35°C:
b. Relative humidity: 20%~80%;
c. Cylinder pressure: normal indoor atmospheric pressure:
d. Vibration: None: bzxz.net
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e: The measurement of electrical performance indicators should be carried out in the shielded room, and the electromagnetic suppression of the shielded room should be less than 80dB4.3.2 Test instruments
The test instruments should be qualified by measurement, and their errors should comply with the provisions of 2.1.3 in GJB367.2: a.
b. The test instruments should comply with the provisions of Table 7
Table 7 Test instruments
Instrument name
Dual-trace oscilloscope
Network analyzer
Signal source
Impulse generator
Audio analyzer
Control box
Comprehensive food tester
Spectrum analyzer
4.4 Identification and inspection
Performance requirements||tt ||Working frequency band: 100MHz, with data readout function Voltage: 24V, 15V, -15V, 5V: with digital display Working frequency band: 300kHz~1.3GHz
Working frequency band: 300kHz~2.7GHz; Input level: 0~2V, with internal AM, FM feedback Frequency can be adjusted to 200kHz, pulse width can be adjusted to 0.2us, pulse amplitude can be adjusted to peak value 10V Working frequency band: 20Hz100kHz Output level: 0~5V With state control, power supply control, audio interface, ATC, AGC interface and its display Working section: 300kHz~2GHz: Output level: 0~1V Working frequency band: 300kHz~2GHz
The purpose of identification inspection is to conduct a comprehensive assessment of the quality of the inspection sample and to identify whether it meets all technical requirements.
4.4.1 Inspection samples
Inspection samples must be inspected and qualified by the quality inspection department of the contractor and have complete records approved by the ordering party’s representative. The number of samples shall be at least 4.
4.4.2 Inspection plan
The inspection is divided into performance inspection, environmental test and reliability inspection. The inspection items and methods are shown in Table 8. The reliability identification test shall be carried out in accordance with the provisions of 4.6.2 of this specification. 4.4.3 Qualification criteria
When all items meet the requirements of Chapter 3 and Chapter 5, the identification inspection is judged to be qualified. If any inspection item does not meet the specified requirements, the inspection shall be stopped. The contractor shall analyze the unqualified items, find out the causes of the defects and take corrective measures before continuing the inspection. If all items meet the specified requirements, the identification inspection is judged to be passed. If there is still an item that does not meet the requirements, it is judged to be unqualified: 10-
TTTKAoNr KAca-2 Inspection categories
The inspection categories specified in this specification are as follows:
a. Identification inspection:
b. Quality consistency inspection.
4.3 Inspection conditions
4.3.1 Atmospheric conditions
If there are no other specifications, the electrical performance test should be carried out under the specified normal test conditions: a. Temperature: 15°C~35°C:
b. Relative humidity: 20%~80%;
c. Cylinder pressure: normal indoor atmospheric pressure:
d. Vibration: None:
SJ20685—1998
e: The measurement of electrical performance indicators should be carried out in the shielded room, and the electromagnetic suppression of the shielded room should be less than 80dB4.3.2 Test instruments
The test instruments should be qualified by measurement, and their errors should comply with the provisions of 2.1.3 in GJB367.2: a.
b. The test instruments should comply with the provisions of Table 7
Table 7 Test instruments
Instrument name
Dual-trace oscilloscope
Network analyzer
Signal source
Impulse generator
Audio analyzer
Control box
Comprehensive food tester
Spectrum analyzer
4.4 Identification and inspection
Performance requirements||tt ||Working frequency band: 100MHz, with data readout function Voltage: 24V, 15V, -15V, 5V: with digital display Working frequency band: 300kHz~1.3GHz
Working frequency band: 300kHz~2.7GHz; Input level: 0~2V, with internal AM, FM feedback Frequency can be adjusted to 200kHz, pulse width can be adjusted to 0.2us, pulse amplitude can be adjusted to peak value 10V Working frequency band: 20Hz100kHz Output level: 0~5V With state control, power supply control, audio interface, ATC, AGC interface and its display Working section: 300kHz~2GHz: Output level: 0~1V Working frequency band: 300kHz~2GHz
The purpose of identification inspection is to conduct a comprehensive assessment of the quality of the inspection sample and to identify whether it meets all technical requirements.
4.4.1 Inspection samples
Inspection samples must be inspected and qualified by the quality inspection department of the contractor and have complete records approved by the ordering party’s representative. The number of samples shall be at least 4.
4.4.2 Inspection plan
The inspection is divided into performance inspection, environmental test and reliability inspection. The inspection items and methods are shown in Table 8. The reliability identification test shall be carried out in accordance with the provisions of 4.6.2 of this specification. 4.4.3 Qualification criteria
When all items meet the requirements of Chapter 3 and Chapter 5, the identification inspection is judged to be qualified. If any inspection item does not meet the specified requirements, the inspection shall be stopped. The contractor shall analyze the unqualified items, find out the causes of the defects and take corrective measures before continuing the inspection. If all items meet the specified requirements, the identification inspection is judged to be passed. If there is still an item that does not meet the requirements, it is judged to be unqualified: 10-
TTTKAoNr KAca-2 Inspection categories
The inspection categories specified in this specification are as follows:
a. Identification inspection:
b. Quality consistency inspection.
4.3 Inspection conditions
4.3.1 Atmospheric conditions
If there are no other specifications, the electrical performance test should be carried out under the specified normal test conditions: a. Temperature: 15°C~35°C:
b. Relative humidity: 20%~80%;
c. Cylinder pressure: normal indoor atmospheric pressure:
d. Vibration: None:
SJ20685—1998
e: The measurement of electrical performance indicators should be carried out in the shielded room, and the electromagnetic suppression of the shielded room should be less than 80dB4.3.2 Test instruments
The test instruments should be qualified by measurement, and their errors should comply with the provisions of 2.1.3 in GJB367.2: a.
b. The test instruments should comply with the provisions of Table 7
Table 7 Test instruments
Instrument name
Dual-trace oscilloscope
Network analyzer
Signal source
Impulse generator
Audio analyzer
Control box
Comprehensive food tester
Spectrum analyzer
4.4 Identification and inspection
Performance requirements||tt ||Working frequency band: 100MHz, with data readout function Voltage: 24V, 15V, -15V, 5V: with digital display Working frequency band: 300kHz~1.3GHz
Working frequency band: 300kHz~2.7GHz; Input level: 0~2V, with internal AM, FM feedback Frequency can be adjusted to 200kHz, pulse width can be adjusted to 0.2us, pulse amplitude can be adjusted to peak value 10V Working frequency band: 20Hz100kHz Output level: 0~5V With state control, power supply control, audio interface, ATC, AGC interface and its display Working section: 300kHz~2GHz: Output level: 0~1V Working frequency band: 300kHz~2GHz
The purpose of identification inspection is to conduct a comprehensive assessment of the quality of the inspection sample and to identify whether it meets all technical requirements.
4.4.1 Inspection samples
Inspection samples must be inspected and qualified by the quality inspection department of the contractor and have complete records approved by the ordering party’s representative. The number of samples shall be at least 4.
4.4.2 Inspection plan
The inspection is divided into performance inspection, environmental test and reliability inspection. The inspection items and methods are shown in Table 8. The reliability identification test shall be carried out in accordance with the provisions of 4.6.2 of this specification. 4.4.3 Qualification criteria
When all items meet the requirements of Chapter 3 and Chapter 5, the identification inspection is judged to be qualified. If any inspection item does not meet the specified requirements, the inspection shall be stopped. The contractor shall analyze the unqualified items, find out the causes of the defects and take corrective measures before continuing the inspection. If all items meet the specified requirements, the identification inspection is judged to be passed. If there is still an item that does not meet the requirements, it is judged to be unqualified: 10-
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