Data set 01
1950 Sylvania
Published operating points and test conditions from this source.
SECTION 1
Triode
Application
Service
Vertical deflection oscillator
SECTION 2
Beam Power
Application
Service
Vertical deflection amplifier
Power - TV Vertical Output ·BeamPower-Triode
21LU8
Combined triode and beam-power tube for television vertical-deflection oscillator and output-amplifier service, with the power section rated for high positive plate pulses.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 2
- Base
- -
- Socket code
- B12C
- Base pins
- 12
- Nominal heater
- 21 V / 450 mA
Description
21LU8 is a combined triode and beam-power tube for television deflection service. The supplied RCA manual excerpt was reviewed for heater data, physical sections, maximum ratings, electrical characteristics, capacitances, and stated operating conditions.
Socket description
Duodecar 12-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B12C
- Base pins
- 12
- Nominal heater voltage
- 21 V
- Nominal heater current
- 450 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
2 physical sections, each with unique specifications.
Section 1
Triode
X-ray radiationInterelectrode capacitances
- Transconductance
- 0.0036 S
- Amplification factor
- 58
- Max plate voltage
- 400 V
Reference/equivalence-only source: ratings/characteristics for this section are not reproduced; missing promoted values intentionally not inferred from the referenced 6-series datasheet.
Section 2
Beam Power
X-ray radiationInterelectrode capacitances
- Plate resistance
- 12000 Ω
- Transconductance
- 0.0093 S
- Amplification factor
- 6.5
- Max plate voltage
- 400 V
- Max screen voltage
- 300 V
- Max plate dissipation
- 14 W
Reference/equivalence-only source: ratings/characteristics for this section are not reproduced; missing promoted values intentionally not inferred from the referenced 6-series datasheet.
Source-dependent data
Operating conditions by source
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 02
1968 General Electric Co
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
Heater Voltage
21 V
SharedHeater
Heater Current
450 mA
SharedHeater
Heater Warm-up Time
11 s
SharedHeater
SECTION 2
Beam Power
Other
Heater Voltage
21 V
SharedHeater
Heater Current
450 mA
SharedHeater
Heater Warm-up Time
11 s
SharedHeater
Data set 03
1975 RCA RC30
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
Heater Voltage 6.3 16
21 V
Heater Voltage 6.3 16 21 volts
Heater Current 1.5 0.6
450 mA
Heater Current 1.5 0.6 0.45 amperes
Heater Warm-up Time (Average) 11
11 s
Heater Warm-up Time (Average) 11 11 seconds
Plate Voltage 400
400 V
Plate Voltage 400 400 volts
Peak Positive-Pulse Plate Voltage*
2500 V
Peak Positive-Pulse Plate Voltage* 2500 volts
Average Cathode Current 30
75 mA
Average Cathode Current 30 75 mA
# Pulse duration must not exceed 15% of a horizontal scanning cycle (
10 us
# Pulse duration must not exceed 15% of a horizontal scanning cycle (10 microseconds).
Maximum plate/supply voltage
2500 V
Published section value
Maximum screen-grid voltage
300 V
Published section value
Characteristic
Plate Voltage 250 45 135
120 V
Plate Voltage 250 45 135 120 volts
Grid-No.l (Control-Grid) Voltage —4 0 —10 —
10 V
Grid-No.l (Control-Grid) Voltage —4 0 —10 —10 volts
Plate Current 2.3 200"
56 mA
Plate Current 2.3 200" 56 mA
For plate current of 100 fiA —
30 V
For plate current of 100 fiA —30 volts
For plate current of
1 mA
For plate current of 1 mA . —26 volts
Amplification factor
58
Published section value
SECTION 2
Beam Power
Characteristic
Plate Resistance (Approx.) 16000
12000 ohm
Plate Resistance (Approx.) 16000 12000 ohms
Amplification factor
58
Published section value
Other
Grid-No.2 Voltage
300 V
Grid-No.2 Voltage 300 volts
Grid-No.2 Input
2.75 W
Grid-No.2 Input 2.75 watts
Maximum plate/supply voltage
2500 V
Published section value
Maximum screen-grid voltage
300 V
Published section value