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27UP4

Twenty-seven-inch rectangular direct-view television picture tube with spherical gray-filter faceplate, low-voltage electrostatic focusing, magnetic deflection, and external ion trap. Published high-voltage capability reaches about 20 kV.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: 12L
Socket code: DUODECAL6
Base pins: 12
Nominal heater: 6.3 V / 600 mA

Description

The 27UP4 is a rectangular direct-view television picture tube with a spherical grey-filter faceplate, low-voltage electrostatic focus, magnetic deflection and an external ion trap.

Socket description

Small-shell Duodecal 6-contact CRT base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 12L
Socket code: DUODECAL6
Base pins: 12
Nominal heater voltage: 6.3 V
Nominal heater current: 600 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

12L - 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: 20000 V
Max screen voltage: 500 V
Rectifier max heater-cathode voltage: 180 V

CRT anode and grid-2 maximum ratings are promoted from the printed ratings block; other CRT-specific focus/drive/deflection values are preserved in 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

1956 National Video

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

Typical Anode Voltage
16000 V
Phosphor
P4

Characteristic

Heater Voltage Nominal
6.3 V
Heater Current Nominal
600 mA

Capacitance

Cathode to All Other Electrodes Capacitance
5 pF
Approximate
Grid 1 to All Other Electrodes Capacitance
6 pF
Approximate

Data set 02

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
Low-voltage electrostatic
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
20000 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