Specialized - Cathode Ray ·CathodeRay
P4 monochrome television picture tube using magnetic deflection and high-voltage direct-view operation; manufacturer documentation for 19FP4 provides focusing, deflection, and beam-control characteristics for television picture service.
The 19FP4 is a direct-view cathode ray tube designed for television receiver applications, featuring magnetic focus, magnetic deflection, and a grey filter faceplate.
The 19FP4 is a round glass cathode ray tube (CRT) developed for television display systems. It utilizes magnetic focus and magnetic deflection, with a nominal deflection angle of approximately 66 degrees. To prevent ion burn on the phosphor screen, the tube requires an external double field ion trap. The 19FP4 features a grey filter faceplate to improve picture contrast under ambient lighting conditions, and it is designed to display a standard television raster.
The 19FP4 is constructed with a round glass envelope. Its physical dimensions are characterized by an overall length of 22 ± 1/2 inches and a maximum bulb diameter of 18 7/8 ± 1/8 inches. The neck of the tube has a diameter of 1 7/16 ± 1/16 inches, and a 5-inch space along the neck must be kept clear for the installation of the external ion trap magnet. The minimum useful screen diameter is 17 3/8 inches, which accommodates a standard television raster size of approximately 11 3/8" x 15 3/4" to 11 3/4" x 15 3/4".
The faceplate is a grey filter faceplate designed with approximately 66% light transmission at the center to enhance contrast. The screen is coated with No. 4 phosphor, which produces a white fluorescent and phosphorescent color with medium persistence, suitable for displaying moving television images without excessive trailing or flicker.
The 19FP4 uses a small shell duodecal 5-pin base (designated B5-57) with a 12D basing arrangement. The high-voltage anode connection is made via a recessed small cavity cap (J1-21) located on the bulb cone. This anode contact is aligned with the pin position #3 within a tolerance of ±10 degrees.
The pin connections, viewed from the bottom of the base, are assigned as follows:
| Pin | Connection |
|---|---|
| Pin 1 | Heater |
| Pin 2 | Grid No. 1 (Control Grid) |
| Pin 10 | Grid No. 2 (Screen Grid) |
| Pin 11 | Cathode |
| Pin 12 | Heater |
| Cap | Anode (Recessed small cavity cap J1-21) |
The heater is designed for a nominal operating voltage of 6.3 Volts and draws a nominal current of 0.6 Ampere. The cathode is a unipotential, indirectly heated type.
The operating limits of the 19FP4 are defined under the Design Center rating system. These limits must be observed to ensure reliable operation and prevent damage to the tube's electrodes and phosphor screen.
| Parameter | Value |
|---|---|
| Maximum DC Anode Voltage | 19,000 V |
| Maximum DC Grid No. 2 Voltage | 410 V |
| Maximum Grid No. 1 DC Negative-Bias Value | 125 V |
| Maximum Grid No. 1 DC Positive-Bias Value | 0 V |
| Maximum Grid No. 1 Positive-Peak Value | 2 V |
| Maximum Grid No. 1 Circuit Resistance | 1.5 MΩ |
Under typical operating conditions, the tube is operated with a DC anode voltage of 13,000 Volts and a DC Grid No. 2 voltage of 250 Volts. The control grid (Grid No. 1) voltage required for visual extinction of the undeflected focused spot ranges from -27 to -63 Volts.
Focusing is achieved magnetically using a standard focus coil (such as standard focus coil #109 or equivalent). With the focus coil's air gap center positioned 3.0 inches from the reference line, the typical focusing current is approximately 130 mA. This current is specified under the condition where the combined Grid No. 1 bias and video signal are adjusted to produce a highlight brightness of 20 foot-lamberts on the standard raster size.
An external double field ion trap is required, utilizing a standard coil (such as standard coil #108) operated with a typical DC current of approximately 110 mA to properly align the electron beam and prevent ion damage.
The 19FP4 is a 66-degree, magnetically focused and deflected cathode ray tube designed for television display service. It features a round glass envelope with a 18 7/8-inch diameter, a grey filter faceplate with 66% light transmission, and a No. 4 white phosphor screen. Operating with a 6.3 V, 0.6 A heater, the tube is rated for a maximum anode voltage of 19,000 Volts, with typical operation at 13,000 Volts. It utilizes a small shell duodecal 5-pin base and a recessed small cavity cap for the high-voltage anode connection. Proper operation requires an external double field ion trap and a magnetic focusing coil.
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-specific electrode, focusing and deflection data retained as parameters.
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
13000 V
Maximum Grid2 Voltage
410 V
Typical Grid2 Voltage
260 V
DeflectionAngleApproximate
66 degree
FocusingMethod
Magnetic
DeflectingMethod
Magnetic
PhosphorNumber
4
FluorescentColor
White
Persistence
Medium
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 POS171VE WITH RESPECT TO CATHODE
1
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC GRID #2 VOLTAGE
2 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC GRID #1 VOLTAGE A — value 1
1 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC GRID #1 VOLTAGE A — value 2
3 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC FOCUSING COIL CURRENTS (APPROX.)
13 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC ION TRAP CURRENT STANDARD — value 1
108 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
DC ION TRAP CURRENT STANDARD — value 2
11 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
BFOR — value 1
4109 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
BFOR — value 2
41 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
20 V
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
11 j/4" X 15 j/4" PICTURE SIZE. DISTANCE FROM — value 1
4
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
11 j/4" X 15 j/4" PICTURE SIZE. DISTANCE FROM — value 2
15
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
11 j/4" X 15 j/4" PICTURE SIZE. DISTANCE FROM — value 3
4
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.
MAXIMUM DC ANODE VOLTAGE
19 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
41 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
1 mA
Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.