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

7724

Double-diode triode combining radio detector and AVC rectification with subsequent voltage amplification. The paired diodes handle signal and control-voltage functions while the triode provides receiver audio or voltage gain.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 3
Base: -
Socket code: B9A
Base pins: -
Nominal heater: 14 V / 150 mA

Description

Twin-diode high-mu triode for mobile-communications detector and audio voltage-amplifier service; co-designated 7724/14GT8.

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: -
Nominal heater voltage: 14 V
Nominal heater current: 150 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

3 physical sections, each with unique specifications.

Section 1

Diode

X-ray radiationInterelectrode capacitances

Max cathode current: 5 mA

Diode section 1.

Section 2

Diode

X-ray radiationInterelectrode capacitances

Max cathode current: 5 mA

Diode section 2.

Section 3

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 72000 Ω
Transconductance: 0.001 S
Amplification factor: 72
Max plate voltage: 330 V
Max plate dissipation: 1.1 W
Max cathode current: 5 mA

High-mu triode section.

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

1971 RCA HB3 Binder 3 of 7

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

Peak diode current
5 mA
EachDiode

Capacitance

Diode plate-to-cathode capacitance
2.4 pF
EachDiode

SECTION 2

Diode

Other

Peak diode current
5 mA
EachDiode

Capacitance

Diode plate-to-cathode capacitance
2.4 pF
EachDiode

SECTION 3

Triode

Other

Heater voltage
14 V
Heater current
150 mA
Plate voltage
250 V
Triode
Grid voltage
-3 V
Triode
Plate current
0.7 mA
Triode
Maximum plate voltage
330 V
Triode
Maximum plate dissipation
1.1 W
Triode

Characteristic

Amplification factor
72
Triode
Plate resistance
72000 ohm
Triode
Transconductance
1000 uS
Triode

Capacitance

Triode grid-to-plate capacitance
1.8 pF
Triode