This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of pilot signal generators (hereinafter referred to as equipment) in cable distribution systems for 5MHZ~1750MHz television and sound signals. This standard applies to pilot signal generators in cable distribution systems for 5MHZ~1750MHz television and sound signals. GB/T 11318.2-1996 Cable distribution systems for television and sound signals Equipment and components Part 2: General specification for pilot signal generators GB/T11318.2-1996 Standard download decompression password: www.bzxz.net

1 Scope
National Standard of the People's Republic of China
Equipment and components used in cabled distribution systems primarily intended for television and sound signals
Part 2: Generic specifications for pilot signal generators GB/T 11318.2-1996
Replaces GB/T14948.3-1994
This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of pilot signal generators (hereinafter referred to as equipment) in cabled distribution systems for television and sound signals of 5MHz to 1750MHz. This standard applies to pilot signal generators in cabled distribution systems for television and sound signals of 5MHz to 1750MHz. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard by reference in this standard. When this standard was published, the versions shown were valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest version of the following standards. GB/T11318.1-1996 Cable distribution system equipment and components for television and sound signals Part 1: General specifications 3 Product classification
Equipment is divided into single signal and dual signal according to the pilot signal. Note: The pilot signal frequency of the equipment should be specified in the product standard. 4 Requirements
4.1 General requirements
The general requirements of the equipment shall comply with the provisions of 4.1.1 in GB/T11318.1-1996. 4.2 Performance parameters
Performance parameter requirements are shown in Table 1.
Frequency accuracy
Total frequency deviation
Output level
Approved by the State Administration of Technical Supervision on September 9, 1996 338
Performance parameters
Nominal value: 110; 120
Allowable deviation: ±2dB
Measurement method
Implemented on May 1, 1997
4.3 Environmental adaptability
Output level temperature stability
Output level adjustment range
Parasitic output suppression
GB/T 11318.2-1996
Table 1 (end)
Performance parameters
0～-15
Measurement method
The environmental adaptability requirements of the equipment shall comply with the provisions of 4.3 of GB/T11318.1--1996. The intermediate and final test items are frequency accuracy, output level and parasitic output suppression, and the test results shall comply with the provisions of Table 1. After high temperature, constant humidity, sweep frequency vibration and collision tests, the test items are frequency accuracy and output level. After low temperature and free fall tests, performance tests are carried out according to the items specified in Table 1, and the test results shall comply with the relevant provisions of Table 1.
4.4 Reliability
The lower limit value of the mean time between failures (MTBF) of the equipment6, the value shall not be less than 30000h. The failure criterion is that the total frequency deviation exceeds 100kHz or the output level changes by more than 2dB. 4.5 Safety
The safety requirements of the equipment shall comply with the relevant provisions of 4.5 of GB/T11318.1-1996. 4.6 Electromagnetic compatibility
The electromagnetic compatibility requirements of the equipment shall comply with the relevant provisions of 4.6 of GB/T11318.1-1996. 5 Test methods
5.1 General requirements
The test methods for general requirements of the equipment shall be carried out in accordance with the provisions of 4.1.2 of GB/T11318.1-1996. 5.2 Performance parameters
5.2.1 Frequency accuracy and total frequency deviation
5.2.1.1 The connection of the test equipment
is shown in Figure 1.
Equipment under test
Narrowband filter
Frequency meter
Figure 1 Connection of frequency accuracy and total frequency deviation measurement equipment 5.2.1.2 Measurement
The frequency of the equipment should be measured using a digital frequency meter with an accuracy of not less than 1kHz. When measuring with a dual signal generator, it is necessary to use a corresponding narrowband filter (the suppression of the other frequency should be not less than 40dB), or turn off the other signal accordingly to avoid measurement errors. The difference between the frequency measured at room temperature and the nominal frequency is its frequency accuracy. When measuring the total frequency deviation, place the product in a constant temperature box, adjust the temperature in the box to 5℃, power on the product, keep it for 2 hours, and measure its frequency. After that, heat it up to 40℃ and keep it for 2 hours, and then measure its frequency. During the measurement process, the equipment should not be powered off. The difference between the measured frequency and the nominal frequency is its total frequency deviation. 5.2.2 Pilot signal output level, output level temperature stability and output level adjustment range 5.2.2.1 Connection of test equipment
As shown in Figure 2.
Equipment under test
Narrowband filter
Millivoltmeter
Figure 2 Pilot signal output level, output level temperature stability and output level adjustment range Connection of measuring equipment 339
5.2.2.2 Measurement
GB/T 11318.2-1996
The output level of the pilot signal should be measured using an ultra-high frequency millivoltmeter with an accuracy of not less than 5% (or only reached after adding the correction value). When measuring with a dual signal generator, it is necessary to use a corresponding narrowband filter (the suppression of the other frequency should be not less than 40dB), or turn off one of the signals accordingly to avoid measurement errors. When using a filter, the millivoltmeter reading plus the insertion loss of the filter is the signal output level. When measuring the level stability, place the product in a constant temperature box, add power, measure the level value at room temperature, and use this as a reference. Without cutting off the power of the product, adjust the temperature in the box to 5°C, keep it for 2 hours, and then measure its output level. Then raise the temperature to 40°C and keep it for 2 hours, and then measure its output level. The difference between the measured output level and the reference is the stability of the output level. When measuring the output level adjustment range, at room temperature, when the output attenuator of the device is adjusted to the minimum attenuation, measure its output level; when the output attenuator of the device is adjusted to the maximum attenuation, measure its output level. The difference between the two measured output levels is the adjustment range of the output level.
5.2.3 Parasitic output suppressionWww.bzxZ.net
5.2.3.1 Connection of test equipment
As shown in Figure 3.
Equipment under test
Spectrum analyzer
Figure 3 Connection of parasitic output suppression test equipment 5.2.3.2 Measurement
The parasitic output suppression of the equipment can be measured by a spectrum analyzer. The difference between the pilot signal and any product other than the pilot signal is the parasitic output suppression.
5.3 Environmental adaptability
The environmental adaptability test method of the equipment shall be carried out in accordance with the provisions of 4.3 of GB/T11318.1-1996. The test temperature group is Group 1. 5.4 Reliability
The reliability test method of the equipment shall be carried out in accordance with the provisions of 4.4 of GB/T11318.1-1996, and the test plan is Plan I. 5.5 Safety
The safety test method of the equipment shall be carried out in accordance with the provisions of 4.5 of GB/T11318.1-1996. 5.6 Electromagnetic compatibility
The electromagnetic compatibility test method of the equipment shall be carried out in accordance with the relevant provisions of 4.6 of GB/T11318.1-1996. 6 Inspection rules
The inspection rules of the equipment shall comply with the provisions of Chapter 5 of GB/T11318.1-1996. The electrical performance items for acceptance inspection are frequency accuracy, output level and parasitic output suppression. 7 Marking, packaging, transportation and storage
The marking, packaging, transportation and storage of the equipment shall comply with the relevant provisions of Chapter 6 of GB/T11318.1-1996.
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