WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Руководство пользователя, Страница: 174 / 194

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Selected tube parameters are listed in Table 10.2.
Table 10.2 Key Parameters of the 6973
General Characteristics
Heater (ac/dc) 6.3 V, 0.45 A
Heater-cathode voltage
Peak value ±200 V max.
Average value 100 V max.
Direct interelectrode capacitance
Grid to plate 0.4 pF max.
Grid #1 to cathode, heater, grid #2, grid #3 9 pF
Plate to cathode, heater, grid #2, grid #3 6 pF
Push-Pull Class AB
1
Amplifier, Maximum Ratings (Design-Maximum Values)
Plate voltage 440 V
Grid #2 (screen grid) voltage 330 V
Plate dissipation 12 W
Grid #2 (screen grid) input 2 W
Envelope temperate, at hottest point 250ºC
Push-Pull Class AB
1
Amplifier with Grid #2 of Each Tube Connected to Output Transformer Tap
Design Maximum Values
Plate and grid #2 supply voltage 410V
Plate dissipation 12 W
Grid #2 input 1.75 W
Envelope temperature, at hottest point 250ºC
Typical Operation with Fixed Bias (values are for two tubes)
Plate supply voltage 375 V
Grid #2 (screen grid) supply voltage Note 1
Figure 10.4 Characteristic curves of the 6973: ( a ) with the voltage on grid no. 2 variable, ( b ) with
the voltage on grid #1 variable.
Plate volts Plate volts
Type 6973
grid #1 = 0 V
with E
variable
c2
Type 6973 grid #2 = 250 V with E variable
c1
Plate milliamperes
0 100 200 300 400
0 100 200 300 400
Plate (I ) or grid #2 (I ) milliamperes
b c2
175
150
125
100
75
50
25
175
150
125
100
75
50
25
(
a
) (
b
)