1FD9

Battery diode-pentode combining signal detection with subsequent voltage amplification. The diode supplies detector action while the pentode operates from low-voltage receiver supplies with an economical directly heated filament.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: B7G
Base pins: 7
Nominal heater: 1.4 V / 50 mA

Description

Combined diode and R.F. pentode, directly heated for battery operation.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B7G
Base pins: 7
Nominal heater voltage: 1.4 V
Nominal heater current: 50 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

2 physical sections, each with unique specifications.

Section 1

Diode

X-ray radiationInterelectrode capacitances

Max cathode current: 0.2 mA

Mazda 1FD9 directly heated diode and RF pentode for portable battery receiving equipment, filament 1.4 V, 50 mA. This diode section has maximum mean diode current 200 µA (0.2 mA), distinct from the pentode/overall maximum cathode current of 3 mA. The published 90 V anode and 90 V screen maxima belong to the pentode, not this diode. Seven-pin B7G base, physical diode plate at pin 3; interelectrode capacitances published.

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 600000 Ω
Transconductance: 0.000625 S
Max plate voltage: 90 V
Max screen voltage: 90 V
Max cathode current: 3 mA

Mazda 1FD9 directly heated RF pentode section combined with a distinct detector diode, filament 1.4 V 50 mA. Manufacturer maxima pentode plate voltage 90 V, screen voltage 90 V, total cathode current 3 mA; diode current limited separately to 200 µA. Typical at anode 67.5 V, screen 67.5 V, grid bias 0: plate current 1.6 mA, screen current 0.4 mA, transconductance 0.625 mA/V (0.000625 S), approximate anode resistance 0.6 MΩ. Published interelectrode capacitances. Seven-pin B7G base.

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 1

Diode

Characteristic

Pentode mutual conductance
0.625 mA/V
Typical operation