8GU7

Medium-mu twin triode intended for television matrixing, phase-inverter, multivibrator, and general amplifier applications, providing two versatile sections for signal-processing and timing circuits.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: -
Base pins: 9
Nominal heater: 8.4 V / 450 mA

Description

Medium-mu twin triode for television matrixing, phase-inverter, multivibrator, and general amplifier applications.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: 9
Nominal heater voltage: 8.4 V
Nominal heater current: 450 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

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 5500 Ω
Transconductance: 0.0031 S
Amplification factor: 17
Max plate voltage: 330 V
Max plate dissipation: 3 W

Published ratings and characteristics extracted from the approved RCA source. Pulse-only ratings remain parameter rows unless explicitly continuous.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 5500 Ω
Transconductance: 0.0031 S
Amplification factor: 17
Max plate voltage: 330 V
Max plate dissipation: 3 W

Physical triode section added to align rows with SectionCount.

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

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Heater Warm-up Time (Average)
11 s
Other;PublishedValue1
Heater Warm-up Time (Average)
11 s
Other;PublishedValue2
Peak value
200 V
Other;PublishedValue1
Peak value
200 V
Other;PublishedValue2
Average value
100 V
Other;PublishedValue1
Average value
100 V
Other;PublishedValue2
Plate Voltage
330 V
MaximumRating
Grid Voltage, Positive-bias value
0 V
MaximumRating
Plate Dissipation
3 W
MaximumRating
Maximum Plate Voltage
330 V
Section1
Maximum Plate Dissipation
3 W
Section1

Capacitance

Grid to Plate
3 pF
Capacitance;PublishedValue1
Grid to Plate
3 pF
Capacitance;PublishedValue2
Grid to Cathode and Heater
3.4 pF
Capacitance;PublishedValue1
Grid to Cathode and Heater
3.6 pF
Capacitance;PublishedValue2
Plate to Cathode and Heater
0.44 pF
Capacitance;PublishedValue1
Plate to Cathode and Heater
0.34 pF
Capacitance;PublishedValue2
Plate of Unit No.l to Plate of Unit No
2 pF
Capacitance;PublishedValue1
Plate of Unit No.l to Plate of Unit No
1 pF
Capacitance;PublishedValue2

Characteristic

Plate Voltage
250 V
Characteristic
Grid Voltage
-10.5 V
Characteristic
Plate Resistance (Approx.)
5500 ohm
Characteristic
Transconductance
3100 uS
Characteristic
Plate Resistance
5500 ohm
Section1
Transconductance
3100 uS
Section1
Amplification Factor
17
Section1