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Power - Beam (NOT sweep) ·BeamPower-Rectifier

70L7GT

Combined half-wave rectifier and beam-power amplifier designed for AC/DC receiver power supply and audio-output service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 8AA
Socket code: IO
Base pins: 8
Nominal heater: 70 V / 150 mA

Description

Combined half-wave rectifier and beam-power amplifier for AC/DC receiver service. Data was extracted from the supplied Tung-Sol source, including published ratings, characteristics, and operating information.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 8AA
Socket code: IO
Base pins: 8
Nominal heater voltage: 70 V
Nominal heater current: 150 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

8AA - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

2 physical sections, each with unique specifications.

Section 1

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 350 V
Rectifier nominal output current: 70 mA
Rectifier peak forward current: 350 mA
Rectifier forward voltage drop: 20 V
Rectifier max heater-cathode voltage: 175 V

Amplifier unit absolute maxima and Class-A characteristics promoted.

Section 2

Beam Power

X-ray radiationInterelectrode capacitances

Plate resistance: 15000 Ω
Max plate voltage: 117 V
Max screen voltage: 117 V
Max plate dissipation: 10 W
Max screen dissipation: 1 W
Max cathode current: 65 mA
Rectifier peak inverse voltage: 390 V
Rectifier nominal output current: 77 mA
Rectifier peak forward current: 462 mA
Rectifier forward voltage drop: 20 V
Rectifier max heater-cathode voltage: 175 V

Rectifier-unit absolute ratings promoted; OCR-corrupted table checked semantically against headings.

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

1937 Ken Rad

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

Plate Voltage
110 V
Plate Voltage 110 Volts Max.
Screen Voltage
110 V
Screen Voltage 110 Volts Max.
Grid Voltage
-7.5 V
Grid Voltage -7.5 Volts Min.
Plate Current
40 mA
Plate Current EZero Signalg 40 Milliamperes
Plate Current
43 mA
Plate Current (Max. Signal 43 Milliamperes
Screen Current
3 mA
Screen Current (Zero Sﬁgnalg 3.0 Milliamperes
Screen Current
6 mA
Screen Current (Max. Signal 6.0 Milliamperes
Mutual Conductance
7500 µS
Mutual Conductance 7,500 Micromhos
Load Resistance
2000 ohm
Load Resistance 2,000 Ohms
Plate voltage
110 V
BeamPowerSection
Screen voltage
110 V
BeamPowerSection
Control grid voltage
-7.5 V
BeamPowerSection

Characteristics

Power output
1.8 W
BeamPowerSection

SECTION 2

Beam Power

Other

Plate Voltage
125 V
AC Plate Voltage (RMS) 125 Volts Max.
Plate Current
350 mA
Peak Plate Current 350 Milliamperes Max.
Average Tube Voltage Drop
140 V
Average Tube Voltage Drop 20 Volts at 140 Milliamperes
AC plate voltage RMS
125 V
HalfWaveRectifier
Peak plate current
350 mA
HalfWaveRectifier

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

Maximum plate voltage
117 V
Published handbook rating
Maximum screen voltage
110 V
Published handbook rating
Plate voltage
110 V
ClassA
Screen voltage
110 V
ClassA
Control-grid bias
7.5 V
ClassA
Plate current
40 mA
ClassA
Screen current
3 mA
ClassA
Load resistance
2000 ohm
ClassA
Power output
1.8 W
ClassA

Characteristic

Plate resistance
15000 ohm
Published handbook characteristic
Transconductance
7500 µS
Published handbook characteristic
Heater voltage
70 V
Published heater rating
Heater current
150 mA
Published heater rating

Data set 03

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

Heater voltage
70 V
Nominal
Heater current
150 mA
Nominal
Plate voltage
110 V
ClassA
Screen voltage
110 V
ClassA
Grid voltage
-7.5 V
ClassA
Load resistance
2000 ohm
ClassA
Maximum-signal power output
1.8 W
ClassA
Total harmonic distortion
10 %
ClassA

Characteristic

Zero-signal plate current
40 mA
ClassA
Zero-signal screen current
3 mA
ClassA
Maximum-signal plate current
43 mA
ClassA
Maximum-signal screen current
6 mA
ClassA
Plate resistance
15000 ohm
ClassA
Transconductance
7500 uS
ClassA

SECTION 2

Beam Power

Other

Heater voltage
70 V
Nominal
Heater current
150 mA
Nominal
Maximum AC plate voltage RMS
117 V
CapacitorInputFilter
Minimum total effective plate supply impedance
15 ohm
CapacitorInputFilter

Data set 04

1966 Tung Sol Electronic Tubes 3 of 4

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

Maximum peak inverse voltage
350 V
PromotedValue
MAX. PEAK INVERSE PLATE VOLTAGE
35 VOLTS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MAX. PEAK PLATE CURRENT
2 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MAX. DC OUTPUT CURRENT — published value 1
7
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MAX. DC OUTPUT CURRENT — published value 2
4
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MAX. PLATE
117 VOLTS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MAX. PLATE DISSIPATION
5 WATTS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MAX.— SIGNAL PLATE CURRENT
43 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.

Characteristics

DC output current
70 mA
PromotedValue
HEATER VOLTAGE ~AC OR DC~
70 VOLTS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
HEATER CURRENT
0.17 AMP
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MA%. DC HEATER-CATHODE POTENTIAL
175 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MA%. AC PLATE
117 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
GRID VOLTAGE
7
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
PEAK AF GRID VOLTAGE
5 VOLTS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Z ER O—SIGNAL PLATE CURRENT
4 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
LOAD RESISTANCE
2000 OHMS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
TRANSCONDUC TA NCE — published value 1
7
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
TRANSCONDUC TA NCE — published value 2
0
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Ef = 70 Volts
70 Volts
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Plate Volts = 117 RMS
117 Volts
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Ef = 70 Volts — published value 1
70 Volts
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Ef = 70 Volts — published value 2
11 Volts
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.

SECTION 2

Beam Power

Characteristics

Plate resistance
15000 ohm
PromotedValue
THE 70L7GT IS A COMBINED RECTIFIER AND POWER OUTPUT BEAM TETRODE DE — published value 1
70
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
THE 70L7GT IS A COMBINED RECTIFIER AND POWER OUTPUT BEAM TETRODE DE — published value 2
7
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MA%. SCREEN DISSIPATION
1 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
SCREEN VOLTAGE
11 VOLTS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
ZERO—SIGNAL SCREEN CURRENT ~APPROX.~
3 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
MA%.— SIGNAL POWER OUTPUT
1 MA
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Screen Volts = 110
110 Volts
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Screen Volts — published value 1
110 Volts
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.
Screen Volts — published value 2
-7.5 Volts
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.

Other

Maximum plate voltage
117 V
PromotedValue
Maximum screen voltage
117 V
PromotedValue
Maximum plate dissipation
10 W
PromotedValue
Maximum screen dissipation
1 W
PromotedValue
Maximum cathode current
65 mA
PromotedValue
MAX. SCREEN VOLTAGE
117 VOLTS
OCR table transcription; verify against supplied datasheet layout where multiple columns represent operating conditions.

Data set 05

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

Plate Voltage
110 V
ClassA
Screen Voltage
110 V
ClassA
Power Output
1.8 W
ClassA
Load Resistance
2000 ohm
ClassA

SECTION 2

Beam Power

Other

AC Plate Voltage RMS
123 V