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27AFP4

Twenty-seven-inch direct-view monochrome television picture tube with magnetic deflection and high-voltage operation. Manufacturer documentation provides focusing, optical, and electrical characteristics for large-screen receiver display service.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: 8HR
Socket code: NEOEIGHTAR7
Base pins: -
Nominal heater: 6.3 V / 300 mA

Description

Twenty-seven-inch bonded-shield 110-degree television CRT electrically similar to 27ADP4 but with 300 mA heater.

Socket description

Small-button Neoeightar 7-contact CRT base family

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 8HR
Socket code: NEOEIGHTAR7
Base pins: -
Nominal heater voltage: 6.3 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

8HR - 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: 16 V

Electrical section extracted from supplied datasheet.

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 Voltage 6.3 Volts
6.3 V
Heater Voltage 6.3 Volts
Minimum Anode Voltage . 12,000 Volts dc ELECTRONIC TUBES
12 V
Minimum Anode Voltage . 12,000 Volts dc ELECTRONIC TUBES
Grid No. 4 Voltage (Focusing Electrode) —55.0 t.o +1100 Volts dc
1100 V
Grid No. 4 Voltage (Focusing Electrode) —55.0 t.o +1100 Volts dc
Minimum Grid No. 2 Voltage 200 Volts dc
200 V
Minimum Grid No. 2 Voltage 200 Volts dc
Grid No. 1 Voltage PICTURE TUBE
1 V
Grid No. 1 Voltage PICTURE TUBE
Minimum Anode Voltage . . . . . . . . . . .. .00 12,000 Volts dc
12 V
Minimum Anode Voltage . . . . . . . . . . .. .00 12,000 Volts dc
Grid No. 4 Voltage (Focusing Electrode) . . . . . . . . . . . . . . .. ... -400 to +1250 Volts dc
1250 V
Grid No. 4 Voltage (Focusing Electrode) . . . . . . . . . . . . . . .. ... -400 to +1250 Volts dc
Minimum Grid No. 2 Voltage . . . . . . . . . . . . .. ..o 350 Volts dc
350 V
Minimum Grid No. 2 Voltage . . . . . . . . . . . . .. ..o 350 Volts dc
Anode Voltage . . . . . . . . L oL L s e e e e e e 18,000 Volts dc
18 V
Anode Voltage . . . . . . . . L oL L s e e e e e e 18,000 Volts dc
Grid No. 4 Voltagefor Focus . . . . . . . . . . . . ... ... .. ... 0 to 400 Volts dc
400 V
Grid No. 4 Voltagefor Focus . . . . . . . . . . . . ... ... .. ... 0 to 400 Volts dc
Grid No. 2 Voltage . . . . . . . . . .. L. 300 Volts dc
300 V
Grid No. 2 Voltage . . . . . . . . . .. L. 300 Volts dc
Grid No. 1 Voltage Required for Cutoft® . . . . . . . . . . . . . ... ... -37 to —74 Volts
74 V
Grid No. 1 Voltage Required for Cutoft® . . . . . . . . . . . . . ... ... -37 to —74 Volts
Grid No. 4 Voltage for Focus . . . . . . . . . . . . . . . ... ... ... 0 to 400 Volts dc
400 V
Grid No. 4 Voltage for Focus . . . . . . . . . . . . . . . ... ... ... 0 to 400 Volts dc
Grid No. 2 Voltage . . . . . . . . . . . Lo
2 V
Grid No. 2 Voltage . . . . . . . . . . . Lo
Cathode Voltage Required for Cutoff> . . . . . . . . . .. ... ... ... +37 to +62 Volts dc
62 V
Cathode Voltage Required for Cutoff> . . . . . . . . . .. ... ... ... +37 to +62 Volts dc
Visual extinction offocused raster. Extinction of stationary focused spot will require that these va
5 V
Visual extinction offocused raster. Extinction of stationary focused spot will require that these values be increased by about 5 volts.

Other

External Conductive Coating to Anode? 2500 uuf Max.
2500 pF
External Conductive Coating to Anode? 2500 uuf Max.
Maximum Anode Voltage 22,000 Volts dc SYLVANIA
22 V
Maximum Anode Voltage 22,000 Volts dc SYLVANIA
Maximum Grid No. 2 Voltage 550 Volts dc Sylvania Electric Products Inc.
550 V
Maximum Grid No. 2 Voltage 550 Volts dc Sylvania Electric Products Inc.
Maximum Anode Voltage . . . . . . . . . . . . . . .00 22,000 Volts dc
22 V
Maximum Anode Voltage . . . . . . . . . . . . . . .00 22,000 Volts dc
Maximum Grid No. 2 Voltage . . . . . . . . . . . . . .. ..o 700 Volts de
700 V
Maximum Grid No. 2 Voltage . . . . . . . . . . . . . .. ..o 700 Volts de
range if this tube is operated at higher than the manufacturer's Maximum Rated Anode Voltage or 16,0
16 V
range if this tube is operated at higher than the manufacturer's Maximum Rated Anode Voltage or 16,000 volts, whichever is less.

Data set 02

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

Maximum Anode voltage
0 V
Maximum Anode voltage ...... • . . 22'000Volts SYLVANIA
Maximum Grid No. 2 Voltage
550 V
Maximum Grid No. 2 Voltage .... . . . 550Volts Sylvania Electric Products Inc.
MinimumGridNo.2Voltage
200 V
MinimumGridNo.2Voltage . . . . . . 200Volts
Maximum Anode voltage
22000 V
Maximum Anode voltage .................... . . . 22,000Volts
Minimum Grid No. 2 Voltage
350 V
Minimum Grid No. 2 Voltage ................. . . . 350Volts
Heater positive with Respect to cathode
200 V
Heater positive with Respect to cathode ........... 200 Volts
Anode voltage
18000 V
Anode voltage ........................ . . 18,000Volts
Grid No. 4 Voltage for Focus
400 V
Grid No. 4 Voltage for Focus .................., 0 to 400 Volts
Grid No. 2 Voltage
300 V
Grid No. 2 Voltage ......................, . . 300 Volts
Cathode voltage Required for cutoff5
62 V
Cathode voltage Required for cutoff5 .............., +37 to +62 Volts

CircuitValue

Grid No. 1 Circuit Resistance
1.5 Mohm
Grid No. 1 Circuit Resistance ................... 1.5 Megohms Max.