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Voltage - Dual Triode (similar) ·Triode-Triode

14AF7

RCA 14AF7 medium-mu dual triode with two identical indirectly heated sections, 12.6 V 0.15 A heater, 300 V and 2.5 W maximum ratings per section, 8AC lock-in base.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
8AC
Socket code
-
Base pins
8
Nominal heater
12.6 V / 150 mA

Description

14AF7 is listed in the supplied receiving-tube handbook as a medium-mu twin triode. The published heater rating is 12.6 V at 0.15 A.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8AC
Socket code
-
Base pins
8
Nominal heater voltage
12.6 V
Nominal heater current
150 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

8AC - 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

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
7600 Ω
Transconductance
0.0021 S
Amplification factor
16
Max plate voltage
300 V
Max plate dissipation
2.5 W

RCA Tube Department 14AF7 medium-mu twin triode, 15 November 1948, confirmed by GE Essential Characteristics. Each identical physical triode: design-center maximum plate voltage 300 V, plate dissipation 2.5 W, grid positive DC bias max 0 V, peak heater-cathode voltage ±90 V. Heater 12.6 V 0.15 A rating (nominal 14 V 0.16 A for series-string application). Typical Class A operating conditions per section: Va 100 V, grid 0 V: mu 17, rp 6500 Ω, gm 2600 µmhos, Ia 10.8 mA; Va 100 V, cathode resistor 600 Ω: mu 16, rp 8400 Ω, gm 1900 µmhos, Ia 5 mA; Va 250 V, cathode resistor 1100 Ω: mu 16, rp 7600 Ω, gm 2100 µmhos, Ia 9 mA. Direct capacitances each section without external shield: Cgp 2.3 pF, Cgk 2.2 pF, Cpk 1.6 pF; inter-section max grid1-grid2 0.20 pF, plate1-plate2 0.60 pF, grid1-plate2 0.06 pF, grid2-plate1 0.10 pF. T-9 lock-in octal 8-pin base 8AC, pin1 heater, pin2 cathode triode2, pin3 plate triode2, pin4 grid triode2, pin5 grid triode1, pin6 plate triode1, pin7 cathode triode1, pin8 heater, base shell via plug. Source continuation was also filed erroneously under 14AF7_2, which has been deleted.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
7600 Ω
Transconductance
0.0021 S
Amplification factor
16
Max plate voltage
300 V
Max plate dissipation
2.5 W

RCA Tube Department 14AF7 medium-mu twin triode, 15 November 1948, confirmed by GE Essential Characteristics. Each identical physical triode: design-center maximum plate voltage 300 V, plate dissipation 2.5 W, grid positive DC bias max 0 V, peak heater-cathode voltage ±90 V. Heater 12.6 V 0.15 A rating (nominal 14 V 0.16 A for series-string application). Typical Class A operating conditions per section: Va 100 V, grid 0 V: mu 17, rp 6500 Ω, gm 2600 µmhos, Ia 10.8 mA; Va 100 V, cathode resistor 600 Ω: mu 16, rp 8400 Ω, gm 1900 µmhos, Ia 5 mA; Va 250 V, cathode resistor 1100 Ω: mu 16, rp 7600 Ω, gm 2100 µmhos, Ia 9 mA. Direct capacitances each section without external shield: Cgp 2.3 pF, Cgk 2.2 pF, Cpk 1.6 pF; inter-section max grid1-grid2 0.20 pF, plate1-plate2 0.60 pF, grid1-plate2 0.06 pF, grid2-plate1 0.10 pF. T-9 lock-in octal 8-pin base 8AC, pin1 heater, pin2 cathode triode2, pin3 plate triode2, pin4 grid triode2, pin5 grid triode1, pin6 plate triode1, pin7 cathode triode1, pin8 heater, base shell via plug. Source continuation was also filed erroneously under 14AF7_2, which has been deleted.

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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Maximum plate voltage

    300 V

    Published handbook rating

  • Plate voltage

    250 V

    ClassA

  • Control-grid bias

    10 V

    ClassA

  • Plate current

    9 mA

    ClassA

Characteristic

  • Plate resistance

    7600 ohm

    Published handbook characteristic

  • Transconductance

    2100 µS

    Published handbook characteristic

  • Amplification factor

    16

    Published handbook characteristic

  • Heater voltage

    12.6 V

    Published heater rating

  • Heater current

    150 mA

    Published heater rating