This standard specifies the test method for the electrical strength of transmitting tubes. This standard is applicable to the test of the electrical strength of space charge controlled oscillation, modulation, adjustment and power amplifier tubes with anode dissipation power above 25W. GB/T 3789.17-1991 Test method for electrical properties of transmitting tubes Test method for electrical strength GB/T3789.17-1991 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 electrical intensity
Measurements of the electrical properties of transrnitting tubesMeasuring methods of electrical intensitySubject content and scope of application
This standard specifies the test methods for electrical intensity of transmitting tubes. GB/T3789.17-91
Replaces GB 3789. 17
This standard applies to the test of electrical intensity of space charge controlled oscillation, modulation, adjustment and power amplifier tubes with anode dissipation power of 25W or more.
Cited standards
GB/T3789.1 Test methods for electrical properties of transmitting tubesGeneral principles
3 Terms
Electrical intensityelectricalintensity
Electrical intensity refers to the ability of an electron tube to withstand anode voltage for a certain period of time under specified working conditions. 4 Schematic diagram of the circuit
DC test schematic diagram
Figure 1:
- Charging resistor. The resistance value should be in the range of 100 kg to 500 k, and its withstand voltage should be able to withstand the requirements of the highest test voltage of the tube under test R
Energy storage capacitor:
- Current limiting resistor. Its withstand voltage should be able to withstand the requirements of the highest test voltage of the tube under test and the selection principle: When the tube is ignited, the energy storage capacitor C discharges to the electron tube under test at the moment, the energy consumption of the electron tube under test should not exceed 1J, and the resistance R should not be less than 1 k, and the capacity of C should not be less than 0. 1 μF; National Technical Supervision Bureau approved on August 15, 1991 and implemented on April 1, 1992
GB/T 3789.1791
Measurement resistor. Its resistance value should ensure the sensitivity required by the electronic counter PC at the moment of ignition. An electronic counter is used to record the number of ignitions of the tested tube. The counter should be able to reliably record the next ignition when the ignition interval is greater than 3 (R:·C). The error of the circuit counter should be within the range of 1000 pulses + 10 pulses allowed. Capacity should meet the following requirements: C
-pulse drop coefficient;
where: l_
the minimum internal resistance of the electron tube when it is turned on;
-the equivalent minimum resistance between the first grid and the cathode when the electron tube is turned on; GB/T 3789. 17-91
RB., R2-a resistor. The value should meet the following requirements:
RA5TRN5
where: T--pulse width+
T----pulse period;bzxz.net
Z,-resistance (Rt) or inductor (L,). The DC voltage drop on it should not exceed 0.5% of the DC voltage of the first grid; Cl-a capacitor. The selection condition: when the gate pulse current passes, the voltage drop on the capacitor should not exceed 1% of the pulse amplitude. PV-pulse voltmeter (or oscilloscope). 5 Test equipment and test rules
Test equipment and test rules shall comply with the provisions of GB/T3789.1. 6. Test method
B. 1 Test method of Figure 1
6.1.1 Add the filament voltage and the negative grid voltage according to the specification. For the indirectly heated cathode electron tube, the filament voltage should be added in one step, while for the directly heated cathode electron tube, the filament voltage should be added steadily or in steps. 6.1.2 After the specified time, add the positive voltage to the anode and the second grid of the electron tube. The addition of the anode voltage of the electron tube under test is specified as follows:
When the anode voltage of the electron tube under test does not exceed the test voltage of 20 kV, its anode voltage should be added in one step; for the anode voltage higher than the test voltage of 20kV, the anode voltage should be increased by 50% (but still not less than 20kV) in one step and then the voltage should be increased to the required specified value in several steps or steadily.
The test voltage range of the tube under test: for the tube in continuous working state, it should be 1.8~~~2 times of the anode DC voltage limit value; for the tube in pulse working state, it should be 1.2~1.5 times of the anode pulse voltage limit value. 6.1.3 Within the time specified in the specification, record the number of sparks recorded by the electronic counter. : The method of applying the voltage to each pole of the tube under test and the selection of the test voltage should be specified in the product standard. 6.2 Test method of Figure 2 (applicable to pulse modulation tube) 6.2.1 Add the filament voltage and the DC voltage of each pole according to the specification. For the tube with anode voltage within 40kV, the anode voltage is added once. For the tube with a trap voltage higher than 40kV, the anode voltage is added in several steps or evenly. The first step is added by 50% (but still not less than 10kV). 6.2.2 Add a specified positive pulse voltage to the grid. 6-2.3 Observe the number of sparks of the tube under test within the time specified in the product standard. 6.3 Test method of Figure 3 and Figure 4
can be carried out by any of the following methods (the oscillation frequency used shall be specified in the detailed specification). 6.3.1 Method of increasing anode voltage
Add the filament voltage and the voltage of each pole according to the specification, and adjust the working state of the tube under test to the same state as when testing the output power. Then, increase the anode voltage to the specified value within the specified time, and keep the voltage unchanged within the time specified in the detailed specification, and observe the number of sparks of the tube under test. 6.3.2 Method of cutting off the load
Add the filament voltage and the voltage of each pole according to the specification, and adjust the working state of the tube under test to the same state as when testing the output power, and then cut off the load connected in parallel to the anode oscillation circuit (when the load is connected in series to the oscillation circuit, short-circuit the load), so that the tube under test is in a no-load state, and observe the number of sparks of the tube under test within the time specified in the detailed specification. Note: If the detailed specification stipulates that the test of the first grid reverse current is the inspection standard, after this test, the first grid reverse current should be tested according to GB/T3789.1.
Additional Notes:
GB/T 3789. 17—91
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 Research Institute of the Ministry of Machinery and Electronics Industry and Factory 779.
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