1N2A

High-voltage television flyback/EHT rectifier designed to convert horizontal-output transformer pulses into the DC accelerating supply required by the CRT.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 3C
Socket code: OCTAL7
Base pins: 7
Nominal heater: 1.25 V / 200 mA

Description

Directly heated high-voltage half-wave rectifier diode for television flyback and other high-voltage supplies.

Socket description

7-contact octal-family base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 3C
Socket code: OCTAL7
Base pins: 7
Nominal heater voltage: 1.25 V
Nominal heater current: 200 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

3C - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1Pin 1	—	IC Transcribed directly from EIA chart; independent cross-check not yet performed.	Unverified EIA Base Connections chart, page 127 (uploaded BaseCodeDataCharts_OCR), base 3C
PIN2Pin 2	—	F — Filament Transcribed directly from EIA chart; independent cross-check not yet performed.	Unverified EIA Base Connections chart, page 127 (uploaded BaseCodeDataCharts_OCR), base 3C
PIN3Pin 3	—	IC Transcribed directly from EIA chart; independent cross-check not yet performed.	Unverified EIA Base Connections chart, page 127 (uploaded BaseCodeDataCharts_OCR), base 3C
PIN5Pin 5	—	IC Transcribed directly from EIA chart; independent cross-check not yet performed.	Unverified EIA Base Connections chart, page 127 (uploaded BaseCodeDataCharts_OCR), base 3C
PIN7Pin 7	—	F — Filament Transcribed directly from EIA chart; independent cross-check not yet performed.	Unverified EIA Base Connections chart, page 127 (uploaded BaseCodeDataCharts_OCR), base 3C
PIN8Pin 8	—	IC Transcribed directly from EIA chart; independent cross-check not yet performed.	Unverified EIA Base Connections chart, page 127 (uploaded BaseCodeDataCharts_OCR), base 3C
CAP1Top cap	A	P — Plate (Anode) Transcribed directly from EIA chart; independent cross-check not yet performed.	Unverified EIA Base Connections chart, page 127 (uploaded BaseCodeDataCharts_OCR), base 3C

Section ratings

1 physical section, each with unique specifications.

Section 1

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 28000 V
Rectifier nominal output current: 0.5 mA
Rectifier peak forward current: 50 mA
Rectifier forward voltage drop: 100 V

Published values promoted where applicable; sparse source sheets remain sparse rather than inferred.

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

Rectifier

Other

Total DC and Peak Inverse Plate Voltage
28000 V
Flyback
DC Inverse Plate Voltage
24000 V
Flyback
Peak Plate Current
50 mA
Average Plate Current
0.5 mA

Characteristic

Tube Drop
100 V
Ib approx. 7 mA

Data set 02

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Capacitance

Plate-to-filament capacitance
1.4 pF
Section1

Other

Total DC and peak inverse voltage maximum
28000 V
FlybackRectifier
DC inverse voltage maximum
24000 V
FlybackRectifier
Peak plate current maximum
50 mA
FlybackRectifier
Average plate current maximum
0.5 mA
FlybackRectifier
X-ray shielding note
May be required above specified voltage conditions
FlybackRectifier

Characteristic

Tube drop at 7 mA
100 V
FlybackRectifier