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27NP4

Twenty-seven-inch direct-view television CRT with gray-filter faceplate, magnetic focusing and deflection, external conductive coating, and an external single-field ion trap. Its anode is rated around 18 kV.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: -
Socket code: DUODECAL5
Base pins: 12
Nominal heater: 6.3 V / 600 mA

Description

The 27NP4 is a 27-inch direct-view television CRT with a grey filter faceplate, magnetic focusing and deflection, an external conductive coating and an external single-field ion trap.

Socket description

Small-shell Duodecal 5-contact CRT base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: DUODECAL5
Base pins: 12
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: 18000 V
Max screen voltage: 500 V
Rectifier max heater-cathode voltage: 410 V

Direct-view television CRT; high-voltage electrode rating mapped to MaxPlateVoltage as the section high-voltage limit.

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

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

Heater Current (approx ) . . . . . . . 06 Ampere
6 A
Heater Current (approx ) . . . . . . . 06 Ampere
Grid No. 2 Voltage . . . . . . . . . . . . . . .500 Vol dc
2 V
Grid No. 2 Voltage . . . . . . . . . . . . . . .500 Vol dc
Anode Voltage2 . . . . . . . . . . . . . . .16000 Volts dc
16000 V
Anode Voltage2 . . . . . . . . . . . . . . .16000 Volts dc
Grid No. 2 Voltage . . .. . . . . .300 Vol dc 12-N
2 V
Grid No. 2 Voltage . . .. . . . . .300 Vol dc 12-N
Grid No. 1 Voltage® Reqmred for Cutoff . . . . -28 to 72 Volts dc
72 V
Grid No. 1 Voltage® Reqmred for Cutoff . . . . -28 to 72 Volts dc
Focusing Coil Currentt . . oo o095 =209 Ma dc
209 Ma
Focusing Coil Currentt . . oo o095 =209 Ma dc
Anode Voltage or 16,000 volts, whichever is less.
16 V
Anode Voltage or 16,000 volts, whichever is less.

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Capacitance

Heater Cathode Capacitance
5 pF
Approximate

Other

HighVoltageElectrodeMaximum
18000 V
CRT

Data set 03

1966 Tung Sol Electronic Tubes 4 of 4

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristic

Cathode to all other electrodes capacitance
5 pF
WholeTube
Grid 1 to all other electrodes capacitance
6 pF
WholeTube
External conductive coating to anode capacitance maximum
750 pF
WholeTube
External conductive coating to anode capacitance minimum
500 pF
WholeTube
Focusing method
Magnetic
WholeTube
Deflecting method
Magnetic
WholeTube
Horizontal deflection angle
85 degree
WholeTube
Diagonal deflection angle
90 degree
WholeTube
Phosphor color
White
Screen
Persistence
Medium
Screen

Other

Maximum DC anode/accelerator voltage
18000 V
WholeTube
Maximum DC grid 2 voltage
500 V
WholeTube
Maximum negative grid 1 bias magnitude
125 V
WholeTube
Maximum positive peak grid 1 voltage
2 V
WholeTube
Maximum heater-cathode voltage during warm-up
410 V
Warmup15Seconds
DC anode/accelerator voltage
16000 V
TypicalOperation
DC grid 2 voltage
300 V
TypicalOperation