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Tube Tinker — Electron Tube Database
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Power - Pentode (NOT beam) ·Pentode

4307A

Standard Valves power pentode with documented Class-A, Class-B, and Class-C operating modes extending to approximately 70 MHz. Suitable for both amplifier and radio-frequency power applications.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
MEDIUM5
Base pins
5
Nominal heater
5.5 V / -

Description

Pentodes.

Socket description

Medium 5-contact transmitting-tube base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
MEDIUM5
Base pins
5
Nominal heater voltage
5.5 V
Nominal heater current
-
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

Pentode

X-ray radiationInterelectrode capacitances
Max plate voltage
500 V
Max screen voltage
300 V
Max plate dissipation
15 W
Max screen dissipation
6 W

Ratings and characteristics extracted from 4307A.pdf.

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

1937 Standard Valves

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Grid-anode capacitance

    0.55 pF

  • Input capacitance

    15 pF

  • Output capacitance

    12 pF

Other

  • Maximum direct anode current

    60 mA

    ClassA/ClassC

  • Maximum direct screen-grid current

    25 mA

  • Maximum direct control-grid current

    7 mA

    ClassC/ClassB

  • Maximum frequency for 500 V rating

    40 MHz

  • High-frequency anode-voltage rating

    300 V

    70MHz

Data set 02

1946 Standard Telephone and Cables

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Filament voltage

    5.5 volts

  • Nominal filament curren

    0 amps

Other

  • Maximum direct anode voltage 500 500

    500 volts

  • Maximum direct screen-grid voltage 300 250

    250 volts

  • Maximum direct anode current 60 60

    45 mA

  • Maximum direct screen-grid current 25 25

    25 mA

  • Maximum direct control-grid current - 7

    7 mA

  • Maximum anode dissipation 15 15

    15 watts

  • Maximum screen-grid dissipation 6 6

    6 watts

  • voltage on positive swing of input — +30

    30 volts

  • Direct anode voltage

    500 volts

  • Direct screen-grid voltage (approx.)

    200 volts

  • Screen-grid circuit resistance

    14000 ohms

  • Total control-grid bias (approx.)

    -35 volts

  • Control-grid circuit resistance

    10000 ohms

  • Fixed control-grid bias

    -20 volts

  • Suppressor-grid bias

    -50 volts

  • Effective load resistance

    4000 ohms

  • Carrier power outpu

    6 watts

  • Power output on A-F peaks

    24 watts

  • Direct anode voltage 500

    500 volts

  • Direct screen-grid voltage (approx) 250

    250 volts

  • Screen-grid circuit resistance 20,000

    20000 ohms

  • Total control-grid bias (approx) —35

    -35 volts

  • Control-grid circuit resistance 10,000

    10000 ohms

  • Fixed control-grid bias ~20

    -20 volts

  • Suppressor-grid bias 0

    0 volts

  • Direct anode-current 45

    60 mA

  • Direct screen-grid current 12

    13 mA

  • Direct control-grid current -3

    1.4 mA

  • Effective load resistance 6,500

    5000 ohms

  • Carrier power output 15

    20 watts

  • Maximum direct anode voltage 500

    300 volts

  • For class C telegraphy (intermittent) 60

    45 mA

  • For all other classes of service 45

    45 mA

  • g 40

    4 v