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

18FY6A

Double-diode high-mu triode combining radio detection, control-voltage rectification, and audio voltage amplification in compact receiving equipment. The paired diodes handle signal and AVC functions while the triode supplies subsequent gain.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
3
Base
-
Socket code
B7G
Base pins
7
Nominal heater
18 V / 100 mA

Description

The 18FY6A combines a high-mu triode with two detector diodes for compact receiver service and is electrically equivalent to the 18FY6 except for heater characteristics.

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
18 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.

Published ratings and characteristics promoted semantically from the approved source.

Section 2

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Second detector diode section; maximum continuous plate current 1 mA.

Section 3

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
77000 Ω
Transconductance
0.0013 S
Amplification factor
100
Max plate voltage
150 V
Max plate dissipation
0.5 W

Published ratings and characteristics promoted semantically from the approved source.

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

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Maximum Diode Plate Current

    1 mA

    Each diode

SECTION 3

Triode

Characteristic

  • Plate Resistance

    77000 ohm

  • Amplification Factor

    100

Other

  • Maximum Plate Voltage

    150 V

  • Plate Voltage

    100 V

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Diode

Characteristic

  • Average Diode Current

    2 mA

    EachDiode;10VApplied

SECTION 3

Triode

Other

  • Plate Voltage

    100 V

    ClassA

  • Heater Warmup Time

    20 s

Characteristic

  • Plate Current

    0.6 mA

    ClassA

Data set 03

1966 Tung Sol Electronic Tubes 3 of 4

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Maximum diode plate current

    1 mA

    WholeTube

  • Average diode current with 10 V applied

    2 mA

    Section2

SECTION 2

Diode

Other

  • Maximum diode plate current

    1 mA

    WholeTube

  • Average diode current with 10 V applied

    2 mA

    Section3

SECTION 3

Triode

Characteristic

  • Triode grid-to-plate capacitance

    1.8 pF

    WholeTube

  • Triode input capacitance

    2.4 pF

    WholeTube

  • Grid-to-diode plate capacitance maximum

    0.2 pF

    WholeTube

Other

  • Maximum triode plate voltage

    150 V

    WholeTube

  • Maximum triode plate dissipation

    0.5 W

    WholeTube

  • Triode grid voltage

    -1 V

    TypicalOperation

  • Triode plate current

    0.8 mA

    TypicalOperation

  • Triode transconductance

    1300 µS

    TypicalOperation

  • Triode plate resistance

    77000 ohm

    TypicalOperation

  • Triode amplification factor

    100

    TypicalOperation