This standard specifies the test method for the thermal radiation current of the grid of the transmitting tube. This standard is applicable to the test of the thermal radiation current of the first grid and the second grid of the space charge controlled oscillation, modulation, adjustment and power amplifier tube with anode dissipation power above 25W. GB/T 3789.5-1991 Test method for electrical performance of transmitting tube Test method for thermal radiation current of grid GB/T3789.5-1991 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test methods for electrical properties of transmitting tubes
Test methods for grid thermo-emigion current
Measurements ot the electrical properties of transmitting tubesMeasuring methols of grid thermo-emigion current1 Subject content and scope of application
This standard specifies the test methods for grid thermo-emigion current of transmitting tubes. GB/T 3789.5-91
Replaces GB 3789. 5- 83
This standard is applicable to the test of the first anode and second grid thermo-emigion current of space charge controlled oscillation, modulation, adjustment and power tubes with anode dissipation power of more than 25W. 2
Referenced Standards
GB/T3789.1 General Rules for Test Methods of Electrical Performance of Transmitter Tubes 3 Terms
Grid thermo-emission current
grid thermo-emission current 3.1 The first grid thermo-emission current refers to the emission current caused by the temperature on the surface of the first grid under the specified working conditions. 3.2 The second grid thermo-emission current refers to the emission current caused by the temperature on the surface of the second grid under the specified working conditions. 4 Electrical schematics
Schematic diagram of DC test circuit
Schematic diagram of AC test circuit
Approved by the State Administration of Technical Supervision 1991-08-15 Figure 26
Schematic diagram of anode floating test power supply
Implementation on 1992-04-01
In Figure 1, Figure 2 and Figure 3:
Negative pulse signal generator:
GB/T 3789.591
Figure 2c Schematic diagram of AC test circuit
Figure 3 Schematic diagram of pulse test circuit
Non-inductive resistor. The resistance value is specified in the detailed specification, and the error does not exceed ±1%; pulse voltmeter (or oscilloscope);
Rectifier diode,
Switching diode;
Power meter,
Ca capacitor. The selection conditions are as follows: when the gate pulse current flows through, the voltage drop on the capacitor should not exceed 1% of the pulse amplitude; L-
inductor, its impedance value should be more than 10 times greater than the gate thermal radiation equivalent resistance. 5 Test equipment and test rules
Test equipment and test rules should comply with the provisions of GB/T3789.1. 6 Test method
6.1 Test method for thermal radiation current of the first-electrode 6. 1. 1 Test method of Figure 1www.bzxz.net
Close the switch *S", add the filament voltage and the negative voltage of the first grid according to the specification. Open the switch \S", and read the thermal radiation current value of the first-grid.
6.1.2 Test method of Figure 2
6.1.2.1 Test method of Figure 2a or Figure 26
Add the filament voltage according to the specification, adjust the AC voltage of the first grid, and make the current value through the ammeter A1 reach the specified value. Read the thermal radiation current value of the first grid on the ammeter A:. 6.1.2.2 Test method of Figure 2c
Add the filament voltage according to the specification, adjust the grid AC voltage, so that the power value through the AC power meter B reaches the specified value. Read the grid thermal radiation current value on the ammeter A. 6.1.3 Test method of Figure 3
GB/T3789.5-91
Add filament voltage according to the specification, set switch "S\ to position "1", and apply positive voltage to the grid so that the product of grid voltage and grid current reaches the specified value. After holding for a certain time (the time is specified in the product standard), switch "S" is changed to position "2", and pulse voltage is applied to the specified value. The grid pulse thermal radiation current value is read on the table PI. 6.1.4 After the specification is established, the holding time until the test is specified in the detailed specification. 6.2 The test method for the second grid thermal radiation current is the same as the test method for the first grid thermal radiation current. Additional notes:
This standard is proposed by the Ministry of Machinery and Electronics Industry of the People's Republic of China. This standard is drafted by the Electronic Standardization Institute of the Ministry of Machinery and Electronics Industry and Factory 779.
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