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Voltage Pentode or Tetrode (with diode) ·Diode-Pentode

5AS8

General-purpose combination of a high-perveance diode and sharp-cutoff pentode for receiver detector and amplifier applications.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
9DB
Socket code
B9A
Base pins
9
Nominal heater
4.7 V / 600 mA

Description

General-purpose diode-pentode combining a high-perveance diode with a sharp-cutoff pentode.

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
9DB
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

9DB - 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

Diode

X-ray radiationInterelectrode capacitances
Plate resistance
300 Ω
Rectifier peak inverse voltage
330 V
Rectifier nominal output current
5 A
Rectifier peak forward current
50 A
Rectifier max heater-cathode voltage
200 V
Rectifier warm-up time
11 s

High-perveance detector/restorer diode section.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
300000 Ω
Transconductance
0.0062 S
Max plate voltage
300 V
Max screen voltage
300 V
Max plate dissipation
2.5 W
Max screen dissipation
0.5 W
Rectifier max heater-cathode voltage
200 V
Rectifier warm-up time
11 s

Sharp-cutoff pentode for IF/video/AGC amplification.

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

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Diode

Characteristic

  • PLATE TO HEATER &CATHODE &INTERNAL SHIELD

    3 pF

    Diode Unit | PLATE TO HEATER &CATHODE &INTERNAL SHIELD 3.0 pf

SECTION 2

Pentode

Characteristic

  • PENTODE GRID TO DIODE PLATE (MAX.)

    0.005 pF

    Pentode Unit | PENTODE GRID TO DIODE PLATE (MAX.) 0.005 pf

  • PENTODE PLATE TO DIODE CATHODE (MAX.)

    0.15 pF

    Pentode Unit | PENTODE PLATE TO DIODE CATHODE (MAX.) 0.15 pf

  • PENTODE PLATE TO DIODE PLATE (MAX.)

    0.1 pF

    Pentode Unit | PENTODE PLATE TO DIODE PLATE (MAX.) 0.10 pf

  • POSITIVE BIAS VALUE

    0 V

    Pentode Unit | POSITIVE BIAS VALUE 0 VOLTS

  • CATHODE BIAS OPERATION

    1 Mohm

    Pentode Unit | CATHODE BIAS OPERATION 1.0 MEGOHM

  • FIXED BIAS OPERATION

    0.25 Mohm

    Pentode Unit | FIXED BIAS OPERATION 0.25 MEGOHM

Other

  • HEATER WARM-UP TIME APPROX

    11 s

    Average Characteristics | HEATER WARM-UP TIME APPROX. 11 SECONDS

  • LIMITS OF SUPPLIED CURRENT

    40 mA

    Average Characteristics | LIMITS OF SUPPLIED CURRENT 600 ± 40 MA

  • HEATER NEGATIVE WITH RESPECT TO CATHODE

    200 V

    Average Characteristics | HEATER NEGATIVE WITH RESPECT TO CATHODE 200 VOLTS

  • MAXIMUM PLATE VOLTAGE

    300 V

    Pentode Unit | MAXIMUM PLATE VOLTAGE 300 VOLTS

  • MAXIMUM GRID p

    0 V

    Pentode Unit | MAXIMUM GRID p3 VOLTAGE 0 VOLTS

  • MAXIMUM GRID it

    300 V

    Pentode Unit | MAXIMUM GRID it2 SUPPLY VOLTAGE 300 VOLTS

  • MAXIMUM PLATE DISSIPATION

    2.5 W

    Pentode Unit | MAXIMUM PLATE DISSIPATION 2.5 WATTS

  • MAXIMUM GRID k

    0.5 W

    Pentode Unit | MAXIMUM GRID k2 INPUT 0.5 WATT

  • MAXIMUM PEAK INVERSE PLATE VOLTAGE

    330 V

    Pentode Unit | MAXIMUM PEAK INVERSE PLATE VOLTAGE 330 VOLTS

  • MAXIMUM PEAK PLATE CURRENT

    50 mA

    Pentode Unit | MAXIMUM PEAK PLATE CURRENT 50 MA

  • MAXIMUM DC PLATE CURRENT

    5 mA

    Pentode Unit | MAXIMUM DC PLATE CURRENT 5 MA

  • PLATE SUPPLY VOLTAGE

    200 V

    Typical Operating Conditions | PLATE SUPPLY VOLTAGE 200 VOLTS

  • GRID k

    150 V

    Typical Operating Conditions | GRID k2 SUPPLY VOLTAGE 150 VOLTS

  • CATHODE BIAS RESISTOR

    160 ohm

    Typical Operating Conditions | CATHODE BIAS RESISTOR 160 OHMS

  • PLATE CURRENT

    9.5 mA

    Typical Operating Conditions | PLATE CURRENT 9.5 MA

  • GRID b

    3 mA

    Typical Operating Conditions | GRID b2 CURRENT 3 MA

  • TRANSCONDUCTANCE

    6.2 ΜMHOS

    Typical Operating Conditions | TRANSCONDUCTANCE 6.200 µMHOS

  • PLATE RESISTANCE (APPRO X.)

    300 ohm

    Typical Operating Conditions | PLATE RESISTANCE (APPRO X.) 300.000 OHMS

  • GRID qI BI AS (APPROX.) FOR I y

    8 V

    Typical Operating Conditions | GRID qI BI AS (APPROX.) FOR I y =10µA —8 VOLTS

  • GRID

    2 V

    Typical Operating Conditions | GRID 2 VOLTS

Data set 02

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Maximum peak inverse plate voltage

    330 V

    DiodeSection

  • Maximum peak plate current

    50 mA

    DiodeSection

  • Maximum DC plate current

    5 mA

    DiodeSection

SECTION 2

Pentode

Other

  • Plate voltage

    200 V

    ClassA1

  • Grid 2 voltage

    150 V

    ClassA1

  • Cathode resistor

    180 ohm

    ClassA1

  • Plate current

    9.5 mA

    ClassA1

  • Grid 2 current

    3 mA

    ClassA1

Characteristic

  • Plate resistance

    300000 ohm

    ClassA1

  • Transconductance

    6200 uS

    ClassA1

  • Grid 1 cutoff reference voltage

    -8 V

    ClassA1

  • Heater warm-up time

    11 s

    ControlledWarmUp