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Voltage - Dual Triode (similar high frequency) ·Triode-Triode

M8081

Special-quality VHF double triode for equipment exposed to severe vibration and shock, with statistically controlled characteristics and operation extending to approximately 250 MHz.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
-
Base pins
-
Nominal heater
6.3 V / 450 mA

Description

Special-quality VHF double triode for equipment subject to vibration and shock with statistically controlled characteristics.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
-
Nominal heater voltage
6.3 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
6800 Ω
Transconductance
0.0056 S
Amplification factor
38
Max plate voltage
330 V
Max plate dissipation
1.6 W

Representative of two identical special-quality VHF triode sections.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
6800 Ω
Transconductance
0.0056 S
Amplification factor
38
Max plate voltage
330 V
Max plate dissipation
1.6 W

Second physical triode section; identical twin section represented explicitly.

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

1963 Mullard

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Heater Voltage

    6.3 V

  • Heater Current

    450 mA

  • Plate Voltage

    100 V

    EachSection

  • Plate Current

    9 mA

    EachSection

  • Cathode Voltage

    0.9 V

    EachSection

  • Transconductance

    5600 uS

    EachSection

  • Amplification Factor

    38 ratio

    EachSection

  • Plate Resistance

    6800 ohm

    EachSection

  • Plate-Grid Capacitance

    1.6 pF

    EachSection

  • Input Capacitance

    2.1 pF

    EachSection

Other

  • Maximum Operating Frequency

    250 MHz

Data set 02

1967 Mullard Receiving Tubes for Maintenance

Published operating points and test conditions from this source.

SECTION 1

Triode

Capacitance

  • * Ca - g 1

    6 pF

    Published in approved M8081.pdf target datasheet; Section1

  • * Ci n

    2.1 pF

    Published in approved M8081.pdf target datasheet; Section1

  • Cou t '

    0.45 pF

    Published in approved M8081.pdf target datasheet; Section1

  • Cout "

    0.35 pF

    Published in approved M8081.pdf target datasheet; Section1

  • Cll - I<

    4 pF

    Published in approved M8081.pdf target datasheet; Section1

  • ( in 1.4

    2.8 pF

    Published in approved M8081.pdf target datasheet; Section1

  • 250

    0.55 pF

    Published in approved M8081.pdf target datasheet; Section1

  • ( a - I{ 1.2

    1.8 pF

    Published in approved M8081.pdf target datasheet; Section1

Characteristic

  • la

    9 mA

    Published in approved M8081.pdf target datasheet; Section1

  • gm

    5.6 mA

    Published in approved M8081.pdf target datasheet; Section1

Other

  • II< max

    25 mA

    Published in approved M8081.pdf target datasheet; Section1

  • i. max. 2 x

    4.5 mA

    Published in approved M8081.pdf target datasheet; Section1

  • Maximum acce lerati o n (con ti nu o us op erat io n)

    2.5 g

    Published in approved M8081.pdf target datasheet; Section1

  • Max imum shock (short d u rat ion )

    500 g

    Published in approved M8081.pdf target datasheet; Section1

  • Heater current 0.65 420

    480 mA

    Published in approved M8081.pdf target datasheet; Section1

  • Anode cu rrent 0.65 6.5

    11.5 mA

    Published in approved M8081.pdf target datasheet; Section1

  • Rk = 1, 5kQ , Rg • = Rg • = on. 2.5

    15 mV

    Published in approved M8081.pdf target datasheet; Section1

  • oth e r voltages appli ed ,

    2 g

    Published in approved M8081.pdf target datasheet; Section1

  • No app lied volt ages,

    500 g

    Published in approved M8081.pdf target datasheet; Section1