<< 211 Vacuum Tube


Classification- Dome-type bulb of glass, filametary of carbennation Th-w a copper ceramic base with four-prong bayonet golden pins, carbon plate triode.

Application -Audio power amplifier Class A or Class B or Class C.

Dimensions -Dimensions, outline diagrams of the tube and bases, and the arrangement of electrode connections to the base terminals are shown in Figures 1 and 2.
Fig 1
 
Fig 2
 

Nominal operating conditions and parameters
Filament voltage ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­ 10V
Nominal filament current ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­ 3.2A
Plate voltage ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­ 1250V
Grid voltage ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­ -70V
Plate current ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­100mA
Amplification factor ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­12
Load resistance ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­ 7 kohms
Output power ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­ 10W
Grid to plate transconductance ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­ 3.8mA / V

Suggest Operating conditions and parameters
Class A power amplifier of single tube (A-F)

Plate voltage
750
1000
1250
V
Grid voltage
-46
-61
-80
V
Load resistance
8.8
7.6
9.2
kohms
Plate current
34
53
60
mA
Signal voltage(pk)
41
56
75
V
Plate resistance
4.4
3.8
3.6
kohms
Output power
5.6
12
19.7
W

Class B power amplifier of push-pull (A-F)
Plate voltage
1000
1250
V
Grid voltage
-72
-95
V
Load resistance
6.9
9
kohms
Plate current(0 single)
20
20
mA
Plate current(max single)
320
320
mA
Signal Voltage(pk)
380
410
V
Output power
200
260
W

Class B power amplifier of single tube(modulate coefficient shall be 1) (R-F)
Plate voltage
1000
1250
V
Grid voltage
-72
-95
V
Plate current
130
106
mA
Signal Voltage(pk)
125
125
V
Output power
40
42
W
Grid current(approx)
5
1
mA
Grid power(input)(approx)
10
7.5
W

Class C power amplifier of single trbe(max modulate coefficient shall be 1)
Plate voltage
750
1000
V
Grid voltage
-200
-260
V
Plate current
150
150
mA
Signal Voltage(pk)
350
410
V
Output power
65
100
W
Grid current (approx)
35
35
mA
Grid power (input)(approx)
12
14
W

Characteristics-Average characteristics
Figure 3. Shown typical curves of plate currents of grid voltage for several values of plate voltages. It is alternating-current filament supply.

Fig 3
Limiting Operation Conditions for Safe Nor simultaneous ratings
Class
ClassA(A-F)
A push-pull Class B(A-F)
Class B(R-F)
Class C
Maximum plate voltage
1250
1250
1250
1000
V
Maximum plate dissipation
75
100
100
67
W
maximum plate current (max sig. Per tube)
175
150
175
mA
maximum Grid current
50
mA
maximum plate dissipation(in)
175
W
max Grid voltage
-400
V