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Voltage Pentode or Tetrode (under 100V) ·Tetrode-Tetrode

5885

Directly heated subminiature double-tetrode electrometer tube designed for extremely low-current measurement circuits.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
SUBMINIATURE8
Base pins
8
Nominal heater
1.25 V / 20 mA

Description

Directly heated double-tetrode electrometer tube for very-low-current measurement circuits.

Socket description

Subminiature 8-lead base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
SUBMINIATURE8
Base pins
8
Nominal heater voltage
1.25 V
Nominal heater current
20 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

Tetrode

X-ray radiationInterelectrode capacitances
Transconductance
0.00016 S
Amplification factor
2.4
Max plate voltage
22.5 V
Max cathode current
0.3 mA

Published maximum ratings and characteristics promoted from the approved source; repeated identical sections compressed where applicable.

Section 2

Tetrode

X-ray radiationInterelectrode capacitances
Transconductance
0.00016 S
Amplification factor
2.4
Max plate voltage
22.5 V
Max cathode current
0.3 mA

Second physical tetrode section restored under one-row-per-physical-section policy; identical to section 1.

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

1938 Raytheon

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

  • HeaterVoltageNominal

    1.25 V

    Nominal

  • HeaterCurrentNominal

    20 mA

    Nominal

  • Maximum Plate Voltage

    22.5 V

  • Maximum Cathode Current

    0.3 mA

Characteristic

  • Transconductance

    160 µS

    Typical

  • Amplification Factor

    2.4

    Typical