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Voltage Tetrode ·Tetrode

5800

Subminiature low-filament-power tetrode designed as an electrometer amplifier. Very high input resistance and tiny heater demand suit sensitive portable instrumentation.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B9A
Base pins
9
Nominal heater
1.25 V / 10 mA

Description

Subminiature low-filament-power tetrode designed as an electrometer amplifier with very high input resistance.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B9A
Base pins
9
Nominal heater voltage
1.25 V
Nominal heater current
10 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

1 physical section, each with unique specifications.

Section 1

Tetrode

X-ray radiationInterelectrode capacitances
Max plate voltage
25 V

Victoreen 5800 low-filament-power directly heated subminiature electrometer tetrode, nominal filament 1.25 V, 10 mA, published current range 9–13 mA. Absolute maximum POSITIVE voltage on any electrode 25 V; this is not a normal operating point. Source gives 250 µA as a total cathode-current characteristic, without an explicit maximum qualifier. Previous max_cathode_current of 12 µA was actually a nominal PLATE-current characteristic from manufacturer plate-current test (anode 4.5 V, accelerator grid arrangement), so removed rather than treated as cathode limit. Manufacturer requires light-tight and electrostatic shielding to avoid photoelectric grid currents, treated envelope to reduce leakage, and application of filament power about one second before positive electrode potentials; remove positive potential before filament cools. Published electrode capacitances.

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 Victoreen

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

  • Filament Voltage

    1.12 to 1.38 V

  • Filament Current

    9 mA

    Nominal

Other

  • Total Cathode Current

    12 uA

  • PositiveVoltageOnAnyElectrode

    25 V

  • PlateCurrentAt250V

    6 to 18 uA

Capacitance

  • Grid1Capacitance

    2 pF

  • Grid2Capacitance

    2 pF

  • Plate Capacitance

    3 pF