Data set 01
1961 Tung Sol
Published operating points and test conditions from this source.
SECTION 1
Cathode Ray
Other
HighVoltageAnodeMaximum
20000 V
CRT
Capacitance
CathodeToOtherElectrodesCapacitance
5 pF
Approximate
Specialized - Cathode Ray ·CathodeRay
21FP4A
Twenty-one-inch direct-view monochrome television picture tube with magnetic deflection and high-voltage operation. Manufacturer documentation describes its focusing system, picture-screen construction, and receiver-display characteristics for large-screen television service.
Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
- Sections
- 1
- Base
- -
- Socket code
- B12D
- Base pins
- 12
- Nominal heater
- 6.3 V / 600 mA
Description
21FP4-family rectangular picture tube with electrostatic focus, magnetic deflection, grey-filter faceplate, and external conductive coating.
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
- B12D
- Base pins
- 12
- Nominal heater voltage
- 6.3 V
- Nominal heater current
- 600 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
1 physical section, each with unique specifications.
Section 1
Cathode Ray
X-ray radiationInterelectrode capacitances
- Max plate voltage
- 18000 V
- Max screen voltage
- 500 V
Maximum anode voltage mapped to MaxPlateVoltage; CRT grid/focusing limits retained as parameters rather than mis-promoted as ordinary screen-grid data.
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
1966 Tung Sol Electronic Tubes 4 of 4
Published operating points and test conditions from this source.
SECTION 1
Cathode Ray
Construction
Focusing method
Electrostatic
Deflecting method
Magnetic
Phosphor
P4
White;MediumPersistence
External conductive coating
Present
Characteristic
Deflection angle
70 deg
Approximate
Faceplate light transmission at center
66 %
Approximate
Other
Heater voltage
6.3 V
Heater current
600 mA
Maximum DC anode voltage
18000 V
Maximum DC grid #2 voltage
500 V
Maximum grid #1 negative-bias magnitude
125 V
Maximum grid #1 positive DC voltage
0 V
Maximum grid #1 positive peak voltage
2 V
Typical DC anode voltage
14000 V
TelevisionPictureTube
Typical DC grid #2 voltage
300 V
TelevisionPictureTube
Typical grid #1 voltage minimum
-77 V
VisualExtinctionRange
Typical grid #1 voltage maximum
-33 V
VisualExtinctionRange
Maximum grid #1 circuit resistance
1.5 megohm
Ion trap magnet rated strength
35 gauss
Approximate
Focusing electrode voltage minimum
-570 V
ElectrostaticFocus
Focusing electrode voltage maximum
330 V
ElectrostaticFocus
Maximum focusing electrode voltage minimum
-500 V
ElectrostaticFocus
Maximum focusing electrode voltage maximum
1000 V
ElectrostaticFocus
X-ray shielding warning
Present
HighAnodeVoltage
Capacitance
Cathode-to-all-other-electrodes capacitance
5 pF
Approximate
Grid #1-to-all-other-electrodes capacitance
6 pF
Approximate
Application
Application
Direct-view television picture tube
Data set 03
1968 General Electric Co
Published operating points and test conditions from this source.
SECTION 1
Cathode Ray
Other
Maximum Anode Voltage
18000 V
Maximum Grid No. 2 Voltage
500 V
Anode Voltage
16000 V
Typical
Heater Voltage
6.3 V
Heater Current
600 mA