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Specialized - Cathode Ray ·CathodeRay

16BGP4

Sixteen-inch P4 direct-view picture tube using low-voltage electrostatic focusing and magnetic deflection. RCA data show approximately 16 kV anode operation and a large projected screen area for television-picture presentation.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
-
Base pins
7
Nominal heater
6.3 V / 20 A

Description

16BGP4 — Rectangular Picture Tube with Integral Implosion Protection

Overview

The 16BGP4 is a rectangular glass-envelope picture tube designed for television display applications. It features PAN-O-PLY integral implosion protection, which utilizes a formed rim and welded tension bands around the periphery of the tube panel. This design eliminates the need for a separate safety glass or an integral protective window in the receiver cabinet.

The tube incorporates an aluminized screen with a P4-sulfide phosphor, low-voltage electrostatic focusing, and a 114-degree magnetic deflection system. Its electron gun is designed to operate without the need for an external ion-trap magnet.

Mechanical and Optical Characteristics

The 16BGP4 is built with a rectangular glass bulb and a filterglass faceplate. The faceplate provides an approximate light transmission of 54% at its center, enhancing picture contrast under ambient light conditions.

Physical Dimensions and Weight

  • Overall Length: 10.569" ± 0.242"
  • Neck Length: 4.375" ± 0.125"
  • Projected Screen Area: 125 sq. in.
  • Weight: Approximately 9.5 lbs (including the integral implosion protection hardware)

External Coatings and Connections

The tube features a regular band type external conductive coating. The contact area for grounding this coating is located near the reference line. High-voltage connection to the anode is made via a recessed small cavity cap (JEDEC No. J1-21). The base is a Small-Button Neoeightar 7-pin configuration (Arrangement 1, JEDEC No. B7-208).

Basing and Electrical Connections

The 16BGP4 utilizes the 8HR bottom-view basing arrangement. The pin and cap connections are defined as follows:

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

Grid No. 1 is internally connected to both Pin 2 and Pin 6. The anode cap provides connection to Grid No. 3, Grid No. 5, the screen, and the collector. The external conductive coating (C) forms a capacitance with the internal anode coating.

Heater and Interelectrode Capacitances

The 16BGP4 is equipped with an indirectly heated cathode. The heater is designed for a nominal 6.3 V supply.

  • Heater Current: 450 ± 20 mA (at 6.3 V)
  • Average Heater Warm-Up Time: 11 seconds

Direct Interelectrode Capacitances

  • Grid No. 1 to all other electrodes: 6 pF
  • Cathode to all other electrodes: 5 pF
  • External conductive coating to anode: 1300 pF maximum, 800 pF minimum (including implosion protection hardware)

Design-Maximum Ratings

The ratings below are established under the Design-Maximum system. Unless otherwise specified, all voltage values are positive with respect to the cathode.

Electrode Voltages

  • Anode Voltage: 20,000 V maximum, 12,000 V minimum
  • Grid-No. 4 Voltage (Focusing Electrode):
    • Positive value: 1100 V maximum
    • Negative value: 550 V maximum
  • Grid-No. 2 Voltage: 550 V maximum, 200 V minimum
  • Grid-No. 1 Voltage:
    • Negative peak value: 220 V maximum
    • Negative bias value: 155 V maximum
    • Positive bias value: 0 V maximum
    • Positive peak value: 2 V maximum
  • Heater Voltage: 6.9 V maximum, 5.7 V minimum

Peak Heater-Cathode Voltage

  • Heater negative with respect to cathode:
    • During equipment warm-up period (not exceeding 15 seconds): 450 V maximum
    • After equipment warm-up period: 300 V maximum
  • Heater positive with respect to cathode:
    • Peak value: 200 V maximum
    • DC component: 100 V maximum

Maximum Circuit Values

  • Grid-No. 1-Circuit Resistance: 1.5 MΩ maximum

Typical Operating Conditions (Cathode-Drive Service)

In typical cathode-drive service, the electrode voltages are specified with respect to Grid No. 1:

  • Anode Voltage: 16,000 V
  • Grid-No. 4 Voltage: 100 V
  • Grid-No. 2 Voltage: 300 V
  • Cathode Voltage for visual extinction of focused raster: 28 to 60 V
  • Field Strength of required adjustable centering magnet: 0 to 8 gauss

Focus Voltage Variation

While the typical Grid-No. 4 focus voltage is listed as 100 V, the actual voltage required for optimum focus on any individual tube may vary between -100 V and +300 V. This range is applicable when the combined cathode voltage and video-signal voltage are adjusted to produce an anode current of 100 microamperes on a 9-inch by 12-inch pattern (using an RCA-2F21 monoscope or equivalent).

Technical Summary

The 16BGP4 is a 114-degree magnetic deflection, low-voltage electrostatic focus picture tube featuring PAN-O-PLY integral implosion protection. It operates with a 6.3 V, 450 mA heater and utilizes a Small-Button Neoeightar 7-pin base with an 8HR basing designation. The tube provides a 125 sq. in. projected screen area on an aluminized P4-sulfide phosphor screen. Designed for cathode-drive service, it operates typically at an anode voltage of 16,000 V and a Grid-No. 2 voltage of 300 V, with a focus voltage range of -100 to +300 V for optimum raster sharpness.

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
20 A
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 screen voltage
550 V

CRT-specific ratings, operating conditions, capacitances, focus/deflection, cutoff, optical, and screen data are retained in section parameters.

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

Characteristics

  • LOW-VOLTAGE ELECTROSTATIC FOCUS — published value 1

    1 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • LOW-VOLTAGE ELECTROSTATIC FOCUS — published value 2

    14 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid No.l to all other electrodes

    6 pF

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Current at 6.3 volts — published value 1

    6.3 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Current at 6.3 volts — published value 2

    450 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Current at 6.3 volts — published value 3

    20 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Warm-Up Time (Average)

    11

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Light transmission at center (Approx )

    54

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Projected Area of Screen

    125

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Anode Voltage

    16000 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No.2 Voltage

    300 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • of focused raster — published value 1

    28 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • of focused raster — published value 2

    60 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

Other

  • External conductive coating to anode°

    1300 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No.2 Voltage

    550 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No.l-Circuit Resistance

    1.5 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.