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Specialized - Cathode Ray ·CathodeRay

7AYP25

Seven-inch P25 cathode-ray instrument tube for oscillographic or measurement display, with manufacturer-specified focusing, deflection, accelerating-voltage, and phosphor characteristics.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
DIHEPTAL12
Base pins
-
Nominal heater
6.3 V / 600 mA

Description

Sylvania seven-inch CRT with electrostatic focus, electrostatic deflection, and P25 orange, medium persistence. Published electrical ratings, capacitances, and operating conditions were extracted from the supplied datasheet.

Socket description

Medium-shell Diheptal 12-contact CRT base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
DIHEPTAL12
Base pins
-
Nominal heater voltage
6.3 V
Nominal heater current
600 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
16000 V

Published Sylvania CRT voltage ratings, capacitances, focusing/deflection, and typical operating conditions extracted.

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

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

  • Heater Voltage

    6.3 V

  • Heater Current

    600 mA

  • FocusingMethod

    Electrostatic

  • DeflectionMethod

    Electrostatic

  • Phosphor

    P25 orange, medium persistence

  • MinimumUsefulScreen

    4.75 x 5.75 in

  • DeflectionFactorUniformityMaximum

    3 %

  • LineWidthMaximum

    0.3 mm

Other

  • Grid1CircuitResistanceMaximum

    1.5 Mohm

  • PostAcceleratorVoltageMaximum

    16000 V

  • AnodeVoltageMaximum

    8000 V

  • PostAcceleratorToAnodeVoltageRatioMaximum

    2

  • FocusElectrodeVoltageMaximum

    2500 V

  • Grid1NegativeBiasMagnitudeMaximum

    200 V

  • HeaterCathodeVoltageMaximum

    180 V

  • PeakVoltageAnodeToDeflectionPlate

    1500 V

  • PostAcceleratorVoltage

    10000 V

  • Anode Voltage

    5000 V

  • FocusElectrodeVoltage

    1375 to 1875 V

  • Grid1VoltageForCutoff

    -50 to -90 V

  • DeflectionFactorD1D2

    125 to 150 V/in

  • DeflectionFactorD3D4

    100 to 125 V/in

  • DeflectionCircuitResistanceMaximum

    3 Mohm