WhitakerAudio JC Whitaker 20 W Stereo Integrated Audio Amplifier, Руководство пользователя

Страница: 182 / 196

182
WhitakerAudio
R
g 2
= minimum value for the voltage-dropping resistor in ohms
E
c 2
= selected screen grid voltage in volts
E
cc 2
= screen grid supply voltage in volts
P
c 3
= screen grid input in watts corresponding to E
c 2
10.1.2 6973 Beam Power Tube
The 6973 is a 9-pin compact beam power tube used in high-fidelity audio equipment. Operating
characteristics are charted in Figure 10.3. The device pinout is given in Figure 10.4.
This curve also applies to types
in which grids #2 and #4 are connected
together within the tube
Grid #2 input expressed as a percentage of maximum grid #2 input rating
100
80
50
40
20
0 20 40 60 80 100 120
Grid #2 voltage expressed as a percentage of maximum
grid #2 supply voltage rating
Area of
permissible operation
Figure 10.2 Grid #2 (screen grid) input rating curve.
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
)
Figure 10.3 Characteristic curves of the 6973: ( a ) with the voltage on grid no. 2 variable, ( b ) with
the voltage on grid #1 variable.