This standard specifies the mechanical and electrical connection requirements for interconnection between independent devices used in cable distribution systems. Independent devices refer to single devices (such as modulators, etc.) and device combinations (such as radio frequency distribution networks, etc.) that can independently perform more complex functions. The internal connection of the device group is not subject to this standard. GB/T 9025-1988 Electromechanical connection values ​​for cable distribution systems for 30MHz~1GHz sound and television signals GB/T9025-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Electrical and mechanical matching values ​​of cable distribution systems primarily intended for sound and television signals operating between 30 MHz and 1 GHz
Cabled distribution systems primarily intended for sound and television signals operating between 30 MHz and 1 GHz--Electrical and mechanical matching valuesGB 9025—88
This standard specifies the mechanical and electrical matching requirements to be followed when independent devices used in cable distribution systems are connected to each other. Independent devices refer to single devices (such as modulators, etc.) and device combinations (such as radio frequency distribution networks, etc.) that can independently perform more complex functions. The internal matching of device combinations is not subject to the constraints of this standard. Note: The radio frequency distribution network mentioned above refers to a network composed of multiple radio components, such as a radio distribution network composed of various radio frequency amplifiers, splitters, distributors, system output ports, etc.
1 Electromechanical matching value for interconnection of audio signals 1.1 Input impedance of equipment
The input impedance of the equipment should be 600α unbalanced, but measures should be taken to make it 50kα unbalanced. For example, the method of switching with a built-in switch can be adopted, or the equipment itself is 50k2, but it is equipped with two parallel sockets for external 600 load. Other methods can also be used to meet the requirements.
1.2 Output impedance of equipment
The output impedance of the equipment should be low impedance. It can also terminate a 600Q unbalanced resistive load. The output level reduction of the 600Q resistive load should not be greater than 0.3dB compared with the non-termination. 1.3 Input level of equipment
The input level rating of the equipment should be 0.775V effective value, and it should be able to work normally when it is 6dB lower than the rated value. However, it is allowed to adjust the relevant potentiometers or switches of the equipment. 1.4 Output level of the equipment
When the output level of the equipment is terminated with a 600Ω resistive load, its rated value should be 0.775V effective value. However, when it is 2dB higher than the rated value, it should still meet the nonlinear distortion tolerance specified by the equipment. 1.5 Requirements for mechanical matching
The input and output of the equipment should use connectors. The connectors should meet the requirements of Figures 1 and 2 (equivalent to the requirements of YCJ5P and YCK5F in GB5819.3). The characteristic arrangement of the contact numbers should meet Tables 1 and 2. Approved by the Ministry of Electronics Industry of the People's Republic of China on March 2, 1988 248
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1988-10-01 implementation
GB9025-88
Contact arrangement position number is from the plug-in surface Figure 1
Contact arrangement position number
is from the plug-in surface
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For grounding or shielding
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GB 9025-88
Table 1 Arrangement and use of contacts
Contact number, from the mating side of the pin connector Pin connector
Jack connector
Headphone
Receiver
Phonetic player and
Tuner
Recording/playback
Amplifier
Recording/playback
Recorder
Stereo
Unbalanced
Mono
Stereo
Mono
Stereo
Mono
Stereo
Mono
Stereo
Mono
Mono| |tt||Stereo
Mono
Stereo
5/180°
5/180°
5/180°
5/180°
5/180°
5/180°
Electromechanical matching values ​​for mutual connection of video signals 2.1 Input and output impedance of equipment
Phonetic player, telephone, headset, headphones Audio signal connection plug-in device phono input, telephone input, tuner input, tuner output, connection of combined recorder and player in equipment, input and output of headset in equipment , the output table 2 of the earphone in the equipment contact symbol
left signal
left signal
left output
input (recording)
left input (recording)
and return linebZxz.net
shielding and
return line
shielding and
return line
shielding and
return line
shielding and
return line
left return line
earphone signal
left earphone signal
earphone signal
left earphone signal
left signal
left input
output ( (Amplifier)
Left output (Amplifier)
Right signal
Right signal
Return line
Return line
Connected to 1
Right output
Connected to 1
Right input (recording)
Right return line
Connected to 3
Right headphone signal
Connected to 3
Right headphone signal
Connected to 3
Right signal
Connected to 3
Right input
Connected to 3
Right output (Amplifier)
The input and output impedance of the equipment should be 75α unbalanced. In the frequency range of 6MHz, the reflection loss at the input and output ends should not be less than 30dB.
2.2 Input and output levels of equipment
The input and output levels of the equipment should be 1V peak-to-peak. The useless DC component should not be greater than 2.75V when there is a terminating resistor and should not be greater than 5.5V when open circuit.
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2.3 Requirements for mechanical matching
GB 9025-88
The input and output of the equipment should use connectors. The connector should meet the requirements of 75QBNC type. 3 Mechanical and electrical matching values ​​for interconnection of RF signals 3.1 Input and output impedance of equipment
The input and output impedance of the equipment should be 75 unbalanced. Within the operating frequency range, the reflection loss of the input and output terminals should not be less than 9.5dB, that is, the voltage standing wave ratio should not be greater than 2. 3.2 Input and output levels of equipment
The input and output levels of equipment are not specified in this standard. 3.3 Requirements for mechanical matching
3.3.1 The input and output of independent equipment should use connectors. The connector should comply with the requirements of Figure 4 (equivalent to the screw-on type of IEC169-2) or Type F.
Optional insulation
Other dimensions are the same as Figure 3
Usually with main
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GB 9025-88
The socket of the output port should comply with Figure 3 (equivalent to the non-screw-on type of IEC169-2), and the pin type should be used for TV signals; the jack type should be used for FM signals.
Additional remarks:
This standard was drafted by Beijing Television Equipment Factory. The main drafter of this standard is Huang Wuming.
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