GU-78B |
Tetrode |
The GU-78B tetrode is used for power amplification in distributed
amplifiers and single-sideband signal amplifiers at frequencies up to 250 MHz, in RF
industrial engineering equipment.
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GENERAL | |
Cathode: indirectly heated, oxide-coated. | |
Envelope: metal ceramic, with ring leads of cathode, grid 2 and anode and pin leads of grid 1. | |
Cooling: forced air | |
Height, mm, at most: | 120 |
Diameter, mm, at most: | 111 |
Mass, Kg, at most: | 1.8 |
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OPERATING ENVIRONMENTAL CONDITIONS | |
Vibration loads: | |
frequencies, Hz | 1-60 |
acceleration, m/s² | 20 |
Multiple impacts with acceleration, m/s² | 150 |
Ambient temperature, °C | -60 to +70 |
Relative humidity at up to +25 °C without moisture condensation, % | 98 |
BASIC DATA Electrical Parameters |
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Heater voltage (AC or DC), V | 27 |
Heater current, A | 3.4-4 |
Anode voltage, kV | 1.7 |
Grid 2 voltage, V | 300 |
Negative grid 1 bias voltage, V | 51-25 |
Negative cutoff voltage (at anode voltage 3 kV, anode current 20 mA), absolute value, V |
-150 |
Anode current, A | 1.5 |
Anode current at zero grid 1 voltage (at anode voltage 250 V), mA, at most | 4.2 |
Grid 2 current at zero grid 1 voltage (at anode voltage 250 V), mA, at most | 0.9 |
Mutual conductance, mA/V | 40-80 |
Output power under amplification of class AB1, kW: | |
at heater voltage 27 V, at least | 2.5 |
at heater voltage 25.7 V, at least | 2.2 |
Common-cathode interelectrode capacitance, pF: | |
input | 100-150 |
output | 15-30 |
transfer, at most | 0.25 |
Limit Operating Values | |
Heater voltage (AC or DC), V | 25.5-28.3 |
Anode voltage, V: | |
DC | 3,200 |
instantaneous value | 6,200 |
Grid 2 voltage (DC), V | 350 |
Negative grid 1 voltage (DC, absolute value), V | 150 |
Cathode-heater voltage (either polarity, absolute value), V | 150 |
Cathode current (DC component), mA | 2,200 |
Grid 1 current (DC component), mA | 25 |
Dissipation, W: | |
anode | 2,500 |
grid 2 | 30 |
grid 1 | 1 |
Operating frequency, MHz | 250 |
Cathode heating time, s | 240 |
Envelope temperature at hottest point, °C | 200 |
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