Alternatives & variations Download PDF datasheet

Voltage Radio Detector Converter ·Heptode

6BA7

Pentagrid oscillator-converter for AM and FM superheterodyne receivers. Its multi-grid structure combines local oscillation and mixing in one tube for compact receiver frequency conversion.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 8CT
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 300 mA

Description

Miniature pentagrid converter used for frequency conversion in AM and FM receivers, with separately excited converter characteristics and oscillator-grid data.

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: 8CT
Socket code: B9A
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

8CT - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1G2	A	G2 — Screen GridGroup 8CT1 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN1G4	A	G4 — Fourth GridGroup 8CT1 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN2G1	A	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN3K	A	K — Cathode EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN4H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN5H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN6G5	A	G5 — Fifth GridGroup 8CT6 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN6IS	A	IS — Internal ScreenGroup 8CT6 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN7G3	A	G3 — Suppressor Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN8IS	A	IS — Internal Screen EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT
PIN9P	A	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8CT

Section ratings

1 physical section, each with unique specifications.

Section 1

Heptode

X-ray radiationInterelectrode capacitances

Transconductance: 0.00055 S
Max plate voltage: 300 V
Max screen voltage: 100 V
Max plate dissipation: 2 W
Max screen dissipation: 1.5 W
Max cathode current: 22 mA

Published promoted fields populated semantically; identical repeated sections compressed where applicable.

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

Heptode

Other

Plate voltage
250 V
Converter
Screen-grid voltage
100 V
Converter
Grid voltage
-1 V
Converter
Plate current
3.8 mA
Converter
Screen-grid current
10 mA
Converter

Characteristic

Conversion transconductance
950 uS
Converter
Oscillator grid current
0.35 mA
Converter
Oscillator grid resistor
20000 ohm
Converter

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Heptode

Characteristic

Conversion Transconductance
550 uS
Converter

Data set 03

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Heptode

Capacitance

Grid 3 to plate capacitance maximum
0.19 pF
Section1
Grid 1 to grid 3 capacitance maximum
0.1 pF
Section1
RF input capacitance
9.5 pF
Section1
Oscillator input capacitance
6.7 pF
Section1
Mixer output capacitance
8.3 pF
Section1

Other

Plate voltage
250 V
Converter
Screen voltage
100 V
Converter
Application
Local oscillator and mixer, especially FM broadcast band
Section1

Characteristic

Conversion transconductance
550 µS
Converter

Data set 04

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

Current
300 mA

Capacitance

(RF Input)
9.5 pF
(Mixer Output)
8.3 pF
(Osc. Input)
6.7 pF
Grid No. to Plate max
3 pF
PublishedColumn1
Grid No. to Plate max
0.19 pF
PublishedColumn2
Grid No. to Grid No.l max
3 pF
PublishedColumn1
Grid No. to Grid No.l max
0.1 pF
PublishedColumn2
Grid No.l to Plate max
0.05 pF
Except Cathode
3.4 pF
Grid No.l to Cathode
3.3 pF
Except Grid No.i
4 pF
PLATE VOLTAGE D max
3 V
PublishedColumn1
PLATE VOLTAGE D max
0 V
PublishedColumn2
GRID-No. d INTERNAL-SHIELD VOLTAGE max
5 V
PublishedColumn1
GRID-No. d INTERNAL-SHIELD VOLTAGE max
0 V
PublishedColumn2
GRIDS-No. d No. VOLTAGE max
4 V
PublishedColumn1
GRIDS-No. d No. VOLTAGE max
100 V
PublishedColumn2
GRIDS-No. d No. SUPPLY VOLTAGE max
4 V
PublishedColumn1
GRIDS-No. d No. SUPPLY VOLTAGE max
300 V
PublishedColumn2
PLATE DISSIPATION max
2 W
GRIDS-No. No. DISSIPATION max
4 W
PublishedColumn1
GRIDS-No. No. DISSIPATION max
1.5 W
PublishedColumn2
TOTAL CATHODE CURRENT max
22 mA
Negative bias value max
100 V
Positive bias value max
0 V
Heater negative with respect to cathode. max
90 V
Heater positive with respect to cathode. max
90 V
Plate Voltage
100 V
PublishedColumn1
Plate Voltage
250 V
PublishedColumn2
Grids-No. & No. (Screen) Voltage
100 V
PublishedColumn1
Grid-No. (Control Grid) Voltage
-1 V
PublishedColumn1
Grid-No.l (Cscillator Grid) Resistor
20000 ohm
PublishedColumn1
Plate Resistance (Approx.)
0.5 Mohm
PublishedColumn1
Plate Resistance (Approx.)
1 Mohm
PublishedColumn2
Conversion Transconductance
900 µS
PublishedColumn1
Conversion Transconductance
950 µS
PublishedColumn2
Plate Current
3.6 mA
PublishedColumn1
Plate Current
3.8 mA
PublishedColumn2
Grids-No. & No. Current
10.2 mA
PublishedColumn1
Grids-No. & No. Current
10 mA
PublishedColumn2
Grid-No.l Current
0.35 mA
PublishedColumn1
Total Cathode Current
14.2 mA
PublishedColumn1
zero Dias; grids—No. and xo.n and plate at
2 V
PublishedColumn1
zero Dias; grids—No. and xo.n and plate at
300 V
PublishedColumn2

Data set 05

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Heptode

Capacitance

Grid No.3-to-all-other-electrodes capacitance
9.5 pF
Plate-to-all-other-electrodes capacitance
8.3 pF
Grid No.1-to-all-other-electrodes capacitance
6.7 pF
Grid No.3-to-plate capacitance
0.19 pF
Grid No.1-to-plate capacitance
0.05 pF

Other

Plate voltage
100 V
ConverterSeparateExcitation
Conversion transconductance
900 uS
ConverterSeparateExcitation;PlateVoltage=100V
Plate current
3.6 mA
ConverterSeparateExcitation;PlateVoltage=100V
Plate voltage
250 V
ConverterSeparateExcitation
Conversion transconductance
950 uS
ConverterSeparateExcitation;PlateVoltage=250V
Plate current
3.8 mA
ConverterSeparateExcitation;PlateVoltage=250V
Screen-grid current
10 mA
ConverterSeparateExcitation;PlateVoltage=250V
Oscillator-grid current
0.35 mA
ConverterSeparateExcitation