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Voltage - Triode (with diode, heptode or hexode) ·Diode-Diode-Diode-Triode

5T8

Triple-diode high-mu triode combining several detector or discriminator functions with voltage amplification. Three diode sections permit multiple signal and control-voltage rectification duties while the triode provides substantial gain for the recovered signal.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
4
Base
-
Socket code
B9A
Base pins
9
Nominal heater
4.7 V / 600 mA

Description

Miniature type used as combined audio amplifier, AM detector, and FM detector in AM/FM radio receivers. Diode unit No.l is used for AM detection, and diode units No.2 and No.3 are used for FM detection. Out- lines section, 6B; requires miniature 9-contact socket. For typical operation as resistance-coupled amplifier, refer to Resistance-Coupled Amplifier section. Types 5T8 and 19T8 are identical with type 6T8A except for heater ratings. 5T8 6T8A I9T8

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
4.7 V
Nominal heater current
600 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

4 physical sections, each with unique specifications.

Section 1

Diode

X-ray radiationInterelectrode capacitances
Max cathode current
5.5 mA

Referenced ratings not printed in this source; not inferred.

Section 2

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Referenced ratings not printed in this source; not inferred.

Section 3

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Referenced ratings not printed in this source; not inferred.

Section 4

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
54000 Ω
Transconductance
0.0023 S
Amplification factor
70
Max plate voltage
250 V
Max plate dissipation
1.1 W

Referenced ratings not printed in this source; not inferred.

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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 4

Triode

Other

  • Heater Warmup Time

    11 s

Data set 02

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Maximum continuous diode current per plate

    - to 5.5 mA

    EachDiode

Characteristic

  • Average diode current at 5 V DC

    20 uA

    EachDiode

Capacitance

  • Input capacitance diode 1

    3.8 pF

  • Input capacitance diode 2

    3.8 pF

  • Input capacitance diode 3

    3.4 pF

SECTION 4

Triode

Other

  • Plate voltage

    200 V

    TriodeSection

  • Grid voltage

    -2 V

    TriodeSection

  • Plate current

    0.8 mA

    TriodeSection

  • Plate supply voltage

    90 V

    ResistanceCoupledAmplifier

  • Plate load resistor

    220 kOhm

    ResistanceCoupledAmplifier

  • Grid resistor

    10 MOhm

    ResistanceCoupledAmplifier

Characteristic

  • Amplification factor

    70

    TriodeSection

  • Plate resistance

    54 kOhm

    TriodeSection

  • Transconductance

    2300 uS

    TriodeSection

Capacitance

  • Grid-to-plate capacitance

    1.7 pF

    TriodeSection

Data set 03

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Diode

Characteristic

  • Heater Warmup Time

    11 s

Data set 04

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Diode

Characteristic

  • refer to Resistance-Coupled Amplifier section. Types

    19

    Published value from supplied target entry

  • Heater Voltage (ac/dc)

    18.9 volts

    Published value from supplied target entry

  • Heater Current

    0.15 ampere

    Published value from supplied target entry

  • Heater Warm-up Time (Average)

    11 seconds

    Published value from supplied target entry

  • Plate Voltage

    330 volts

    Published value from supplied target entry

  • Grid Voltage, Positive-bias value

    0 volts

    Published value from supplied target entry

  • Plate Dissipation

    1.1 watts

    Published value from supplied target entry

  • Plate Voltage

    250 volts

    Published value from supplied target entry

  • Grid Voltage

    -3 volts

    Published value from supplied target entry

  • Amplification Factor

    70

    Published value from supplied target entry

  • Plate Resistance (Approx.)

    68000 ohms

    Published value from supplied target entry

  • Transconductance

    1200

    Published value from supplied target entry

  • Plate Current

    1 mA

    Published value from supplied target entry

Capacitance

  • Grid to Plate

    1.7 PF

    Published value from supplied target entry

  • Grid to Cathode, Internal Shield (pin

    7

    Published value from supplied target entry

  • Plate to Cathode, Internal Shield (pin

    7

    Published value from supplied target entry

  • Diode-No

    1

    Published value from supplied target entry

  • Diode-No

    2

    Published value from supplied target entry

  • Diode-No

    3

    Published value from supplied target entry

  • Triode Grid to any Diode Plate

    0.034 PF

    Published value from supplied target entry