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Specialized - Cathode Ray ·CathodeRay

16CMP4A

Large-screen cathode-ray display tube with a projected screen area around 125 square inches, typical 16 kV anode operation, and adjustable electrostatic focusing.

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

Description

16CMP4A Picture Tube

The 16CMP4A is a PAN-O-PLY type cathode-ray tube designed for television display applications. It features a 114-degree magnetic deflection system, a short neck, and an electron gun design that does not require an external ion-trap magnet. The tube incorporates integral implosion protection hardware and an aluminized P4-sulfide phosphor screen.

Electrical Specifications and Heater Ratings

The 16CMP4A utilizes an indirectly heated cathode. The heater is designed to operate within a specified voltage range, with performance characteristics optimized around a nominal operating point.

ParameterValue
Nominal Heater Voltage6.3 V
Heater Voltage Range5.7 V to 6.9 V
Heater Current (at 6.3 V)450 ± 20 mA
Average Heater Warm-Up Time11 s

Direct Interelectrode Capacitances

  • Cathode to all other electrodes: 5 pF
  • Grid No. 1 to all other electrodes: 6 pF
  • External conductive coating to anode: 1000 pF minimum, 1500 pF maximum

Heater-Cathode Voltage Limits

To prevent insulation breakdown, the voltage difference between the heater and the cathode must be maintained within strict limits:

  • Heater negative with respect to cathode:
    • During equipment warm-up period (less than or equal to 15 seconds): 450 V maximum
    • After equipment warm-up period: 300 V maximum
  • Heater positive with respect to cathode:
    • Combined AC and DC voltage: 200 V maximum
    • DC component: 100 V maximum

Mechanical Design and Physical Dimensions

The 16CMP4A is constructed with a rectangular glass envelope, a filterglass faceplate, and an external conductive coating. The external coating is a regular-band type, with a designated contact area for grounding located near the reference line.

Physical Dimensions and Weight

  • Overall Length: 10.569 ± 0.242 inches
  • Neck Length: 4.375 ± 0.125 inches
  • Neck Diameter: 1.125 +0.043 / -0.025 inches
  • Weight (Approximate): 9.5 lbs (including implosion protection hardware)
  • Deflection Angles: 114° diagonal magnetic deflection, 102° horizontal deflection

Screen and Faceplate Characteristics

  • Phosphor: Aluminized P4-Sulfide type
  • Faceplate Material: Filterglass
  • Light Transmission at Center: Approximately 54%
  • Projected Area of Screen: 125 sq. in.
  • Minimum Screen Dimensions:
    • Diagonal: 14.875 inches
    • Height: 10.250 inches
    • Width: 12.938 inches
  • Minimum Rim-Band Opening Dimensions:
    • Diagonal: 15.167 inches
    • Height: 10.494 inches
    • Width: 13.141 inches

The tube is equipped with a Recessed Small Cavity anode cap (JEDEC No. J1-21) and a Small-Button Neoeightar 7-Pin base (Arrangement 1, JEDEC No. B7-208). The reference line of the neck is determined using a JEDEC No. G-126 gauge.

Terminal Connections and Pinout

The 16CMP4A uses the 8HR base arrangement. The terminal connections, viewed from the bottom of the tube, are configured as follows:

Pin NumberConnection
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 (Grounding)

Note: Grid No. 1 is internally connected to both Pin 2 and Pin 6.

Maximum Ratings and Operating Conditions

The ratings of the 16CMP4A are established under the Design-Maximum system. All voltages are positive with respect to the cathode unless otherwise specified.

Design-Maximum Ratings

  • Anode Voltage: 10,000 V minimum to 18,000 V maximum
  • Grid-No. 4 Voltage:
    • Positive value: 1100 V maximum
    • Negative value: 550 V maximum
  • Grid-No. 2 Voltage: 200 V minimum to 550 V maximum
  • 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

Typical Operating Conditions (Cathode-Drive Service)

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

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

Maximum Circuit Values

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

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
6.9 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

  • Grid No.1 to al l other electrodes

    6 pF

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

  • External conductive coatino to anode. 1000 min — 1500 max pF — published value 1

    1000 mA

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

  • External conductive coatino to anode. 1000 min — 1500 max pF — published value 2

    1500 mA

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

  • i.~, — published value 1

    6.3 mA

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

  • i.~, — published value 2

    450 mA

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

  • i.~, — published value 3

    20 mA

    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.

  • P'n 4 -Grid No.A

    4

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

  • Anode Voltage — published value 1

    10000 V

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

  • Anode Voltage — published value 2

    18000 V

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

  • Grid-No.2 Voltage — published value 1

    200 V

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

  • Grid-No.2 Voltage — published value 2

    550 V

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

  • Heater Voltage — published value 1

    5.7 V

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

  • Heater Voltage — published value 2

    6.9 V

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

  • Combined AC & DC voltage

    200 V

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

  • Voltages are positive with respect to grid No. 1

    1 V

    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.4 Voltage — published value 1

    -100 V

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

  • Grid-No.4 Voltage — published value 2

    300 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.

  • Cathode Voltage — published value 1

    28 V

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

  • Cathode Voltage — published value 2

    60 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.