This standard specifies the test method for the power gain of transmitting tubes. This standard applies to transmitting tubes used in television transmitting equipment. GB/T 3789.26-1991 Test method for electrical properties of transmitting tubes Test method for power gain GB/T3789.26-1991 Standard download decompression password: www.bzxz.net

Guohao Standard of the People's Republic of China
Test method of electrical performance of transmitting tubes
Test method of power gain
Measureinenes of the ekectrical propartlas ot tranemdtding tubesMethods of measuring the power gainSubject content and applicable scope
This standard specifies the test method of power gain of transmitting tubes. This standard applies to transmitting tubes used in television transmitting equipment. 2 Reference standardsbZxz.net
GB/T 3789.1 Test method of electrical performance of transmitting tubesGeneral GB6277 Measurement method of television transmitter
3 Terms
Power gainpowergain
GB/T 3789.2691
Power gain refers to the ratio of the synchronous output power of the transmitting tube to the synchronous top excitation power when the transmitting tube is under the specified working state and the matching is optimal. It is usually expressed in decibels. And calculate according to the following formula (1): Where: -
-power gain dB;
-synchronous excitation power, W,
synchronous top output power, W.
G= 10 1s Pal
The transmitting tube is used for power amplification. If the working conditions (current, voltage, frequency, etc.) are fixed, when the excitation power is small, its output power is proportional to the excitation power. The power gain is a constant value. This value is the small signal gain. As the excitation power increases, the amplifier enters the nonlinear working range, and its power gain decreases by several decibels. Therefore, when testing the power gain, it is often necessary to specify the output power level at a certain rated value. That is, the useful power gain required to be measured is to be measured. It is usually given by formula (2):
4 Test steps
useful power gain, dB;
useful synchronous top excitation power, W,
useful synchronous top output power, W.
Gar = 1 8 P
According to the power level, GB/T3789.25 is used to measure the excitation power and the image output power of the transmitting tube. Approved by the State Administration of Technical Supervision on August 15, 1991 (2)
Implemented on April 1, 1992
Data processing
GB/T 3789.26—91
Substitute the values ​​of image output power and excitation power into (2) to calculate the power gain of the transmitting tube under test. Additional remarks:
This standard was proposed by the Ministry of Machinery and Electronics Industry of the People's Republic of China. This standard was drafted by the Electronic Standardization Institute of the Ministry of Machinery and Electronics Industry and Factory 779.
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