This standard specifies the test method for the maximum anode dissipation power and anode overload dissipation power of the transmitting tube. This standard is applicable to the test of anode current and grid current of space charge controlled oscillation, modulation, adjustment and power amplifier tubes with anode dissipation power above 25W. GB/T 3789.2-1991 Test method for electrical performance of transmitting tubes Test method for anode current and grid current GB/T3789.2-1991 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 anode current and grid current1 Subject content and scope of application
This standard specifies the test methods for trap current and grid current of transmitting tubes. GB/T 3789. 2-91
Replaces GB3789.2-83
This standard is applicable to the test of anode current and grid current of space charge controlled oscillation, modulation, adjustment and power amplifier tubes with anode dissipation power of more than 25W.
2 Reference standards
GB/T 3789.1 Test methods for electrical properties of transmitting tubes General 3 Terminology
3. 1 Anode current
Anode current refers to the current flowing through the anode under specified working conditions. The anode current under certain specific conditions is defined as follows: 3.1.1 The first grid zero voltage anode current refers to the current flowing through the anode when the first grid potential to the cathode is zero under the working conditions specified in the detailed specifications of the electron tube.
3.1.2 The anode current in the initial part of the anode-first cathode characteristic curve refers to the current flowing through the anode when the first grid voltage is a certain value at the initial part of the anode-first grid characteristic curve of the electron tube. 3.1.3 The anode current when the cathode is underheated refers to the current flowing through the anode under the cathode underheating conditions specified in the detailed specifications of the electron tube. 3.2 Grid current grid current
The grid current refers to the total current in the grid lead of the electron tube under the specified working conditions. The grid current is when electrons flow from the grid terminal to the external electrode.
4 Electrical schematics
Figure 1 Power supply schematic for testing anode current and grid current by direct current method Approved by the State Administration of Technical Supervision on August 15, 1992 and implemented on April 1, 1992Www.bzxZ.net
GB/T 3789. 2 -91
Figure 2 Electrical schematic for testing anode current and grid current by pulse methodFigure 3 Electrical schematic for testing anode current and grid current of pulse modulator tubeFigure 4 Electrical schematic for testing anode current of the first grid zero voltage by direct current methodIn Figure 2 and Figure 5:
Peng I, Road 2, Ra
GB/T 3789. 2—91
Figure 5 Electrical schematic for testing anode current of the second grid zero voltage by pulse method - Pulse signal generator:
Switch:
Non-inductive resistor. Its error is not more than 1%. The resistance value should meet the following requirements: R, 0.03RimanR0.03Rg2kmin
The voltage drop on B should be less than 5% of the gate pulse voltage value. When measuring the first gate pulse current, Rs is connected, and the other states should be short-circuited by switch S:
In the formula, Bina
The minimum internal resistance of the electron tube when it is turned on;
The equivalent minimum resistance between the second gate and the cathode when the electron tube is turned on; When the resistance values ​​of R, B, and R are small, the influence of the wire and contact resistance should be considered. Due to the influence of heat dissipation, the change in resistance should not exceed ±0.5% of the normal value. Capacitor. Capacity should meet the following requirements:
F-1n2p
Resistor. Resistance should meet the following requirements:
R5TR5T
-Pulse drop coefficient;
In the formula: P
T-Pulse width;
T-Pulse period.
Zz,l——resistance (t,) or inductance (L,1), the DC voltage drop across it should not exceed 0.5% of the first gate DC voltage: inductor. The DC voltage drop across it should not exceed 0.5% of the second gate DC voltage; Cs.C\……capacitor. Its selection condition is that when the gate pulse current flows through, the voltage drop across the capacitor should not exceed 1% of the pulse amplitude.
P,~-P,-
Figure 3
Pulse voltage meter (or oscilloscope).
Photosensitive resistor. The total resistance value should be specified in the product standard, and its error should not exceed 0.5%, capacitor. Capacity should meet:
Requirements for other components are the same as those in Figure 2
5 Test equipment and test rules
GB/T 3789.2--91
C.≥'R+R+n
Test equipment and test rules should meet the requirements of GB/T3789.1. 6 Test methods
6. 1 Test method of Figure 1
Add the filament voltage and the voltage of each pole according to the specification, and read the anode current value and the grid current value respectively. 6.2 Test method of Figure 2 and Figure 3
6.2.1 Add the filament voltage and the DC voltage of each pole according to the specification. 6.2.2 Add a specified positive pulse voltage to the first grid. 6.2.3 Read the anode current value from Table P., and the pole current value from Table P, P:. The average value of the anode current can also be used to convert the pulse current value. The conversion formula is as follows: p = 7
Wherein; I -- pulse current;
Average current:
Pulse width;
-pulse repetition frequency.
6.3 Test method for zero-voltage anode current of the first anode 6.3.T Test method of Figure 2
6.3.1.1 Add the filament voltage, the first grid negative voltage and other anode voltages according to the specification. 6.3.1.2 Adjust the first grid pulse voltage so that the algebraic sum of the first grid voltage is equal to zero, and read the anode current value. 6.3.2 Test method of Figure 4
6.3.2.1 Add the filament voltage and anode voltage according to the specification, and the second grid voltage in 6.3.2.2 to the specified value, and read the anode current value with the ammeter. 6.3.3 Test method of Figure 5
6.3.3.1 Add filament voltage and anode voltage according to the specification. 6.3.3.2 Adjust the negative voltage of the second grid to stop the anode current. 6.3.3.3 Adjust the second grid pulse voltage to the specified value and read the anode current value from Table P. Additional explanation,
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. (1)
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