Alternatives & variations Download PDF datasheet

19ENP4

Wide-angle aluminized P4 monochrome television picture tube using electrostatic focusing and magnetic deflection, designed for high-voltage direct-view service with a large approximately 19-inch screen.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: -
Socket code: B8H
Base pins: -
Nominal heater: 6.3 V / 450 mA

Description

19ENP4 — 19-Inch Cathode-Ray Tube

The 19ENP4 is a 19-inch, 114-degree deflection cathode-ray tube (CRT) designed primarily for cathode drive television service. It features a straight electron gun that eliminates the need for an ion trap magnet, a unipotential focus lens, electrostatic focusing, and magnetic deflection. The tube is constructed with a banded implosion protection system without cloth.

Mechanical and Optical Characteristics

The 19ENP4 is built using a JEDEC J1-149-F1 glass envelope. It features an aluminized P4 phosphor screen with a light transmittance of approximately 49% at the center, and does not have an antireflection treatment.

Physical Dimensions

Overall Length: 11 5/8 + 1/4 inches
Neck Length: 4 3/8 ± 1/8 inches
Greatest Diagonal: 18 7/8 inches maximum
Greatest Width: 16 11/16 inches maximum
Greatest Height: 13 39/64 inches maximum

Minimum Useful Screen (Projected)

Diagonal: 17 9/16 inches
Horizontal: 15 1/8 inches
Vertical: 12 inches
Area: 172 square inches

Mounting and Protection

The tube uses a JEDEC B7-208 base with a maximum wafer diameter of 1 3/4 inches. To prevent lateral strain on the pins, a non-rigid socket mounting is required. The bulb contact is a JEDEC J1-21 ultor terminal, which aligns with Pin 4 ± 30° and is located on the same side of the envelope as Pin 4.

The tube features a banded implosion protection system. The electrical resistance between the external conductive coating and the implosion hardware is specified at a minimum of 50 MΩ.

Electrical Connections and Pinout

The 19ENP4 utilizes the JEDEC 8HR basing configuration. The pin assignments, viewed from the bottom of the base, are as follows:

Pin	Connection
Pin 1	Heater
Pin 2	Grid No. 1
Pin 3	Grid No. 2
Pin 4	Grid No. 4 (Focusing Electrode)
Pin 6	Grid No. 1
Pin 7	Cathode
Pin 8	Heater
Bulb Contact	Anode, Grid No. 3, Grid No. 5 (Ultor)

Heater Ratings and Interelectrode Capacitances

The heater is designed for operation under the following nominal conditions:

Heater Voltage (AC or DC): 6.3 V nominal (5.8 V minimum, 6.9 V maximum)
Heater Current: 450 ± 20 mA at 6.3 V
Heater Warm-up Time: 11 seconds

Interelectrode Capacitances

Cathode to all other electrodes: approximately 5 pF
Grid No. 1 to all other electrodes: approximately 6 pF
External conductive coating to anode: 1,000 pF minimum to 1,500 pF maximum (measured with the implosion protection hardware connected to the external coating)

Absolute Maximum Ratings

The following ratings are established under the Design Maximum System. All voltages are positive and measured with respect to Grid No. 1 unless otherwise specified.

Anode Voltage: 12,000 V minimum, 21,000 V maximum
Grid No. 4 (Focusing Electrode) Voltage: -500 V to +1,000 V maximum
Grid No. 2 Voltage: 25 V minimum, 60 V maximum
Cathode Voltage:
- Maximum negative DC value: 0 V
- Maximum negative peak value: 2 V
- Maximum positive DC value: 100 V
- Maximum positive peak value: 150 V
Heater-Cathode Voltage:
- Heater negative with respect to cathode during warm-up (≤ 15 seconds): 450 V maximum
- Heater negative with respect to cathode after equipment warm-up: 200 V maximum
- Heater positive with respect to cathode: 200 V maximum
Grid No. 1 Circuit Resistance: 1.5 MΩ maximum

Typical Operating Conditions

Under typical cathode drive service conditions, voltages are positive and measured with respect to Grid No. 1:

Anode Voltage: 16,000 V DC
Grid No. 4 (Focusing Electrode) Voltage: 250 V DC
Grid No. 2 Voltage: 50 V DC
Cathode Voltage (for visual extinction of focused raster): 32 V to 50 V DC

During testing, individual tubes focus between 0 V and +400 V on Grid No. 4 under test conditions of 100 µA anode current on a 15 1/8" x 12" pattern.

Socket description

Neoeightar 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B8H
Base pins: -
Nominal heater voltage: 6.3 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

1 physical section, each with unique specifications.

Section 1

Cathode Ray

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Television CRT electron-gun/display section.

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 01

1964 RMA EIA

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristics

Heater Voltage
6.3 V
Heater Current
450 mA
Heater Warm-up Time
11 s
Focusing Method
Electrostatic text
Deflection Method
Magnetic text
Horizontal Deflection Angle
102 deg
Vertical Deflection Angle
85 deg
Diagonal Deflection Angle
114 deg
Cathode-to-All Capacitance
5 pF
Approximate
Grid1-to-All Capacitance
6 pF
Approximate
External Coating-to-Anode Capacitance Minimum
1000 pF
External Coating-to-Anode Capacitance Maximum
1500 pF
Phosphor
P4 Aluminized text
Fluorescence
White text
Light Transmittance
49 percent
ScreenCenter

Other

Grid2 Voltage
50 V
CathodeDriveDesign