L22DD

Double-diode triode for battery receiver detector and amplifier service. The paired diode systems handle signal rectification while the triode provides useful voltage gain and current drive for the recovered audio signal.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 3
Base: -
Socket code: -
Base pins: -
Nominal heater: 2 V / 100 mA

Description

Indirectly heated double-diode triode for receiver amplifier/detector service.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: -
Nominal heater voltage: 2 V
Nominal heater current: 100 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

No fixed ratings are recorded for this section.

Diode section 1.

Section 2

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Diode section 2.

Section 3

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 10000 Ω
Transconductance: 0.00185 S
Amplification factor: 18.5
Max plate voltage: 150 V

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

1960 Mazda

Published operating points and test conditions from this source.

SECTION 3

Triode

Capacitance

Anode-grid capacitance
3.25 pF