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Specialized - Cathode Ray ·CathodeRay

19GEP4A

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
-
Base pins
7
Nominal heater
6.3 V / 450 mA

Description

19GEP4A Picture Tube

The 19GEP4A is a PAN-O-PLY type cathode-ray picture tube designed for television display applications. It features a 114° magnetic deflection angle and incorporates an electron gun that does not require an ion-trap magnet. The tube is constructed with integral implosion protection hardware and mounting lugs to facilitate installation.

Physical and Mechanical Characteristics

The 19GEP4A is built using the JEDEC Bulb J149F2A envelope. Its faceplate is made of filterglass, which provides approximately 48% light transmission at the center to improve picture contrast under ambient light. The screen utilizes an aluminized P4-Sulfide type phosphor.

Dimensions and Weight

  • Overall Length: 11.625 ± 0.250 inches
  • Neck Length: 4.375 ± 0.125 inches
  • Projected Screen Area: 172 square inches
  • Minimum Screen Dimensions:
    • Diagonal: 17.562 inches
    • Width: 15.188 inches
    • Height: 12.000 inches
  • Weight: Approximately 15 pounds

Electrical Connections and Pinout

The tube utilizes a Small-Button Neoeightar 7-Pin base (Arrangement 1, JEDEC No. B7-208) and a Recessed Small Cavity cap (JEDEC No. J1-21).

Pin Configuration (8HR Bottom View)

Pin / CapConnection
Pin 1Heater
Pin 2Grid No. 1
Pin 3Grid No. 2
Pin 4Grid No. 4
Pin 6Grid No. 1
Pin 7Cathode
Pin 8Heater
CapAnode (Grid No. 3, Grid No. 5, Screen, Collector)
CExternal Conductive Coating

Interelectrode Capacitances

  • Cathode to all other electrodes: 5 pF
  • Grid No. 1 to all other electrodes: 6 pF
  • External conductive coating to anode: 1250 minimum to 1750 maximum pF

Heater and Design-Maximum Ratings

All voltages are specified positive with respect to the cathode unless otherwise noted.

Heater Ratings

  • Nominal Voltage: 6.3 V
  • Design-Maximum Voltage Range: 5.7 V minimum to 6.9 V maximum
  • Current: 450 mA at 6.3 V
  • Average Warm-Up Time: 11 seconds

Design-Maximum Ratings

  • Anode Voltage: 11,000 V minimum to 23,000 V maximum
  • Grid-No. 4 Voltage: Positive 1100 V maximum, Negative 550 V maximum
  • Grid-No. 2 Voltage: 200 V minimum to 550 V maximum
  • Grid-No. 1 Voltage:
    • Negative peak: 220 V maximum
    • Negative bias: 155 V maximum
    • Positive bias: 0 V maximum
    • Positive peak: 2 V maximum
  • Peak Heater-Cathode Voltage:
    • Heater negative to cathode: 450 V maximum during the first 15 seconds of warm-up; 300 V maximum after warm-up
    • Heater positive to cathode: 200 V maximum (combined AC & DC); 100 V maximum (DC component only)
  • Maximum Grid-No. 1 Circuit Resistance: 1.5 MΩ

Typical Operating Conditions (Cathode-Drive Service)

Under typical cathode-drive operating conditions, voltages are specified positive with respect to Grid No. 1:

  • Anode Voltage: 16,000 V
  • Grid-No. 4 Voltage: 0 to 400 V
  • Grid-No. 2 Voltage: 300 V
  • Cathode Voltage (for visual extinction of focused raster): 28 to 62 V
  • Centering Magnet Field Strength: 0 to 8 Gauss

Technical Summary

The 19GEP4A is a 114° magnetic deflection picture tube featuring a PAN-O-PLY construction with mounting lugs and integrated implosion protection. It operates with a 6.3 V, 450 mA heater and utilizes a Small-Button Neoeightar 7-pin base. Designed for cathode-drive service, it operates typically with an anode voltage of 16,000 V and a Grid-No. 2 voltage of 300 V, requiring no ion-trap magnet for its electron gun.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
7
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
Max plate voltage
23000 V

Cathode-ray electron-gun/screen system; anode/ultor maximum promoted to MaxPlateVoltage when explicitly published. Explicit X-ray warning/precaution or X-radiation characteristic is present in the supplied source.

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

1971 RCA HB3 Binder 1 of 7

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • Heater Voltage

    6.3 V

    Nominal heater voltage

  • Heater Current

    450 mA

    Nominal heater current

  • Phosphor

    P4

    Published phosphor designation

  • External conductive coating to anode

    1250 to 1750 pF

    External conductive coating to anode. . 1250 min— 1750 max pF

  • Projected Area of Screen

    172 sq in

    Projected Area of Screen 172 sq in

  • Anode Voltage

    1000 to -23000 V

    Anode Voltage 1 1000 min-23000 max V

  • Grid-No.2 Voltage

    200 to -550 V

    Grid-No.2 Voltage 200 min-550 max V

  • Heater Voltage

    5.7 to -6.9 V

    Heater Voltage 5.7 min-6.9 max V

  • During equipment warm-up period <

    450 V

    During equipment warm-up period < 15 s 450 max V

  • After equipment warm-up period

    300 V

    After equipment warm-up period 300 max V

  • Combined AC & DC voltage

    200 V

    Combined AC & DC voltage 200 max V

  • Anode Voltage

    16000 V

    Anode Voltage 16000 V

  • Grid-No.4 Voltage

    0 to 400 V

    Grid-No.4 Voltage 0 to 400 V

  • Grid-No.2 Voltage

    300 V

    Grid-No.2 Voltage 300 V

  • Cathode Voltage

    28 to 62 V

    Cathode Voltage 28 to 62 V

Construction

  • Deflection Method

    Magnetic

    Published deflection method

Characteristic

  • PAN-O-PLY TYPE WITH MOUNTING LUGS

    14 deg

    PAN-O-PLY TYPE WITH MOUNTING LUGS 1 14° MAGNETIC DEFLECTION

Capacitance

  • Cathode to al l other electrodes

    5 pF

    Cathode to al l other electrodes. 5 pF

  • Grid No.1 to all other electrodes

    6 pF

    Grid No.1 to all other electrodes 6 pF

  • Heater Current at

    450 mA

    Heater Current at 6.3 V 450 mA