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Specialized - Cathode Ray ·CathodeRay

DB42

High-vacuum Mullard and Philips electrostatic oscilloscope tube with an approximately 1.5-inch screen and blue short-persistence phosphor, intended for compact oscillographic measurement equipment.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
B8G
Base pins
-
Nominal heater
6.3 V / 310 mA

Description

The Mullard DB42 is a high-vacuum electrostatic oscilloscope tube with an approximately 1.5-inch screen and blue short persistence phosphor.

Socket description

Loctal 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B8G
Base pins
-
Nominal heater voltage
6.3 V
Nominal heater current
310 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
1000 V

Electrostatic focusing/deflection CRT section; electrical/screen/deflection data retained in parameter rows.

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

1951 Mullard Valve and Service Manual

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • Screen Colour / Persistence

    Blue, short persistence

  • Focusing Method

    Electrostatic

  • Deflecting Method

    Double Electrostatic

Other

  • Anode Voltage

    800 V

  • Focusing Electrode Voltage Minimum

    200 V

  • Focusing Electrode Voltage Maximum

    300 V

Data set 02

1957 Philips Receiving and Amplifying Tubes

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • Maximum Plate Voltage

    400 V

  • Grid 2 Operating Voltage Minimum

    200 V

  • Grid 2 Operating Voltage Maximum

    300 V

  • Maximum Grid 2 Voltage

    400 V

Characteristic

  • Focusing Method

    Electrostatic

  • Deflection Method

    Double electrostatic

  • Screen Variant

    blue, short persistence

Data set 03

1963 Philips Electron Tubes Handbook V2

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • Accelerating-grid voltage

    800 V

  • Focusing-grid voltage

    200 to 300 V

  • Maximum accelerating-grid voltage

    1000 V

  • Maximum focusing-grid voltage

    400 V

Characteristic

  • Deflection sensitivity N1

    0.25 mm/V

  • Deflection sensitivity N2

    0.16 mm/V

Data set 04

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • Heating: indirect by A.C. or D.C. Ve

    6.3 V

    Published datasheet condition

  • Cg1

    10 pF

    Published datasheet condition

  • Cpq

    5.3 pF

    Published datasheet condition

  • Cpq = 5,3 pF Cp1p1?

    0.6 pF

    Published datasheet condition

  • Cpqe

    5.3 pF

    Published datasheet condition

  • Cpqe = 5,3 pF Cpopot

    0.8 pF

    Published datasheet condition

  • Cpz

    4.5 pF

    Published datasheet condition

  • Cpz = 4,5 pF Cpipit-peper

    0.1 PF

    Published datasheet condition

  • Epaisseur de la ligne ( Vg3

    800 V

    Published datasheet condition

  • Epaisseur de la ligne ( Vg3 =800V)

    0.7 mm

    Published datasheet condition

  • Betriebsdaten Vg3

    800 V

    Published datasheet condition

  • Vg2 = 200

    -300 V

    Published datasheet condition

  • _Vg«] = 0

    -50 V

    Published datasheet condition

  • Nt

    0.25 mm

    Published datasheet condition

  • No

    0.16 mm

    Published datasheet condition

  • 1) Measured on a circle of

    30 mm

    Published datasheet condition

  • Mesuré & un cercle de

    30 mm

    Published datasheet condition

  • Gemessen an einem Kreis von

    30 mm

    Published datasheet condition

  • Cg1

    7 pF

    Published datasheet condition

  • Cg1 = 7,0 pF Cpo

    2.8 pF

    Published datasheet condition

  • Cp1

    3.27 pF

    Published datasheet condition

  • Cp1 = 3,27pF Cp1p1!

    0.7 PF

    Published datasheet condition

  • Cpyr

    3.5 pF

    Published datasheet condition

  • Cpyr = 3,5 pF Cp2pa!

    0.9 PF

    Published datasheet condition

  • Cp2

    3 pF

    Published datasheet condition

  • Epaisseur de la ligne ( Vg3

    8007 V

    Published datasheet condition

  • Epaisseur de la ligne ( Vg3 =8007V)

    0.7 mm

    Published datasheet condition

  • Vgt

    50 V

    Published datasheet condition

  • N4

    0.25 mm

    Published datasheet condition

  • N2

    0.16 mm

    Published datasheet condition

  • Va2

    1000 V

    Published datasheet condition

  • ————la2

    800 V

    Published datasheet condition

  • 7 i / : ] i

    71 v

    Published datasheet condition

  • AP

    4 v

    Published datasheet condition

  • Published value

    4 V

    Published datasheet condition

  • Published value

    -60 V

    Published datasheet condition

  • 11

    11.1949 A

    Published datasheet condition

  • Vo3

    800 V

    Published datasheet condition

  • Published value

    40 V

    Published datasheet condition

  • Published value

    5 A

    Published datasheet condition

  • Published value

    6 A

    Published datasheet condition

Other

  • Vg3

    1000 V

    Published datasheet condition

  • Vg3 = max. 1000 V VD1D1'p

    450 V

    Published datasheet condition

  • Vg3 = min.,

    800 V

    Published datasheet condition

  • Vg3 = min., 800 V Vp2p2'p

    750 V

    Published datasheet condition

  • Vg2

    400 V

    Published datasheet condition

  • Vg2 = max. 400 V We

    3 mW

    Published datasheet condition

  • —Vg1

    100 V

    Published datasheet condition

  • —Vg1 = max. 100 V Rg1

    0.5 MΩ

    Published datasheet condition

  • Vg3 = max. 1000 V VD1D1'p = mex

    450 V

    Published datasheet condition

  • Ve3 = min,

    800 V

    Published datasheet condition

  • Ve3 = min, 800 V Vp2p2'p

    750 V

    Published datasheet condition

  • Vg1 = max. ov Rp

    5 MΩ

    Published datasheet condition

  • Vg1

    1007 V

    Published datasheet condition

  • Vg1 =max. 1007V Rg1

    0.5 MΩ

    Published datasheet condition