Specialized - Cathode Ray ·CathodeRay
P4 high-voltage cathode-ray picture-display tube with magnetic focusing and deflection; this 19AP4B variant differs principally in faceplate treatment, with manufacturer documentation warning about X-ray shielding above 16 kV.
The 19AP4B is a direct-view picture tube designed for television applications. It features a round metal construction, a unipotential cathode, and utilizes magnetic focus and deflection. The tube requires an external single-field ion trap magnet and provides a nominal raster size of 11 3/4" x 15 3/4".
The 19AP4B is built with a round metal envelope. The metal shell lip of the bulb serves as the electrical contact for Grid No. 3 and the anode.
The physical dimensions of the tube are:
The faceplate is a frosted filter type designed to reduce glare and improve contrast, offering approximately 66% light transmission at the center. The screen uses Phosphor No. 4, which produces a white fluorescent and white phosphorescent output with medium persistence, suitable for television picture reproduction. The deflection angle of the tube is approximately 66 degrees.
The tube uses a small shell duodecal 5-pin base (B5-57) with a 12D basing arrangement. The pin connections, viewed from the bottom, are as follows:
| Pin | Connection |
|---|---|
| Pin 1 | Heater |
| Pin 2 | Grid No. 1 |
| Pin 10 | Grid No. 2 |
| Pin 11 | Cathode |
| Pin 12 | Heater |
| Metal Shell Lip | Grid No. 3, Anode |
The approximate interelectrode capacitances of the tube are:
The 19AP4B operates with a standard heater supply and has strict limits on electrode voltages to ensure safe and reliable operation.
Under typical operating conditions, the 19AP4B is configured with the following parameters to achieve a focused, high-brightness display:
The 19AP4B is a 19-inch class round metal-cone cathode ray tube designed for direct-view television receivers. It features a 66-degree deflection angle, magnetic focus, and magnetic deflection, requiring an external single-field ion trap. Operating at a typical anode voltage of 12,000 V (with a design maximum of 19,000 V), it utilizes a frosted filter faceplate with Phosphor No. 4 to deliver a high-contrast white display. The tube is based on a small shell duodecal 5-pin configuration and requires a 6.3 V, 0.6 A heater supply.
Small-shell Duodecal 5-contact CRT base
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
CRT specialized anode, grid, optical, and deflection data retained in TUBE_SECTION_PARAMETER.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Maximum Anode Voltage
19000 V
Typical Anode Voltage
12000 V
Maximum Grid2 Voltage
410 V
Typical Grid2 Voltage
300 V
DeflectionAngleApproximate
66 degree
FocusingMethod
Magnetic
DeflectingMethod
Magnetic
PhosphorNumber
4
FluorescentColor
White
Persistence
Medium
FaceplateVariant
Frosted filter faceplate
Data set 02
Published operating points and test conditions from this source.
DEFLECTION ANGLE (APPROX.)
66 degrees
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
FACEPLATE LIGHT TRANSMISSION
66 percent
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
HEATER
6.3 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
A IF THIS TUBE IS OPERATED AT VOLTAGES IX E%LESS OF 16,000 VOLTS %—RAY RADIATION SHIELD LNG MAY — value 1
16 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
A IF THIS TUBE IS OPERATED AT VOLTAGES IX E%LESS OF 16,000 VOLTS %—RAY RADIATION SHIELD LNG MAY — value 2
0 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC ANODE
12 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC GRID #2 VOLTAGE — value 1
2 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC GRID #2 VOLTAGE — value 2
300 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC FOCUSING COIL CURRENTC (APPROX.) — value 1
140 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC FOCUSING COIL CURRENTC (APPROX.) — value 2
20 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
G FOR STANDARD FOCUS COIL 4106, OR EQUIVALENT S WITH THE COMBINED GRID N1 BIAS VOLTAGE AMD
4106 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
VIDEO SIGNAL VOLTAGE ADJUSTED TO PRODUCE A XiGnL IGnT BRIGHTNESS OF 18 F00T LANBERTS ON A
18 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
11 j/4" % 15 j/R" PICTURE SIZE. DISTANCE FROM REFERENCE LINE TO CENTER OF 41R GAP ON FOCUS — value 1
4
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
11 j/4" % 15 j/R" PICTURE SIZE. DISTANCE FROM REFERENCE LINE TO CENTER OF 41R GAP ON FOCUS — value 2
15
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
11 j/4" % 15 j/R" PICTURE SIZE. DISTANCE FROM REFERENCE LINE TO CENTER OF 41R GAP ON FOCUS — value 3
41
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
MAXIMUM DC ANODE
19000 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
MAXIMUM DC GRID #2 VOLTAGE — value 1
2 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
MAXIMUM DC GRID #2 VOLTAGE — value 2
410 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
MAXIMUM GRID #1 VOLTAGE
1 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
MAXIMUM GRID #1 CIRCUIT RESISTANCE — value 1
1 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
MAXIMUM GRID #1 CIRCUIT RESISTANCE — value 2
1.5 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
Data set 03
Published operating points and test conditions from this source.
Maximum Anode Voltage
16000 V
Maximum Grid2 Voltage
410 V
Maximum Grid1 Negative Bias
125 V
Typical Anode Voltage
14000 V
Typical Grid2 Voltage
300 V
Typical Grid1 Voltage
-72 to -28 V
Maximum Specular Reflection
1.5 %
Cathode To All Other Electrodes Capacitance
5 pF
Grid1 To All Other Electrodes Capacitance
6 pF
Deflection Angle
66 degree