6ET7

Double-diode pentode combining detector and control-voltage rectification with signal amplification. Paired diodes permit complementary detection or control functions while the pentode supplies the active gain stage.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 3
Base: -
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 750 mA

Description

Duo-diode pentode combining two diode sections with a pentode amplifier section.

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: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 750 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.

First separate diode section of Sylvania 6ET7 double-diode pentode with 6.3 V 0.750 A heater (8ET7 alternate heater 8.0 V 0.600 A). Diode-to-other electrodes capacitance approx 1.5 pF and diode cathode/shield reference approx 7.5 pF; coupling to pentode grid-1 max 0.005 pF, to pentode plate max 0.02 pF. Manufacturer typical average diode current 1.5 mA at 10 V DC applied is a test condition, not an absolute diode current maximum. Distinct physical diode retained.

Section 2

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Second separate physical diode of Sylvania 6ET7 double-diode pentode, with common parent heater 6.3 V 750 mA. Manufacturer typical diode current ~1.5 mA at 10 V DC applied per diode, not an unconditional maximum. Direct capacitance approx 1.5 pF for diode plate-to-other electrodes; diode-to-pentode input and output coupling limits published. Two diode rows represent actual separate physical diodes and must not be compressed.

Section 3

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 60000 Ω
Transconductance: 0.0115 S
Max plate voltage: 330 V
Max plate dissipation: 5 W
Max screen dissipation: 1.1 W

Sylvania 6ET7 sharp-cutoff pentode section in double-diode pentode for receiver/video amplification and detector applications; 6ET7 heater 6.3 V 0.750 A; 8ET7 is separate 8 V 0.600 A variant. Pentode design-maximum plate 330 V, plate dissipation 5 W, screen grid-2 dissipation 1.1 W; screen-grid SUPPLY limit 330 V but actual electrode screen voltage conditional on manufacturer rating chart and not promoted to unconditional max_screen_voltage. Class A1 typical Va 200 V, Vg2 150 V, cathode resistor 100 Ω: plate current 25 mA, screen current 5.5 mA, gm 11500 µmhos (0.0115 S), approximate plate resistance 60 kΩ. Unshielded grid-to-plate capacitance max 0.1 pF, input 10 pF, output 4.2 pF. Two physically distinct diode sections with capacitances and test currents remain separate.

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 3

Pentode

Characteristic

Heater Voltage .. ..........ccciiiiiiiinnnnnn 6.3 8.0 Volts
8 V
Heater Voltage .. ..........ccciiiiiiiinnnnnn 6.3 8.0 Volts
Heater Current. ... ....... ... ... ... iiiinn.. 750 600 Ma
600 mA
Heater Current. ... ....... ... ... ... iiiinn.. 750 600 Ma
Output: p to (h+Pk,q3,1.8.,02+ Dk,DSh).......... 4.2 uuf
4.2 pF
Output: p to (h+Pk,q3,1.8.,02+ Dk,DSh).......... 4.2 uuf
Plate Voltage. . .........coiiiiii i 200 Volts
200 V
Plate Voltage. . .........coiiiiii i 200 Volts
Grid No.2 Voltage. . .........coiiiiiiinninnnnnn 150 Volts
150 V
Grid No.2 Voltage. . .........coiiiiiiinninnnnnn 150 Volts
Plate Current. ......... ... .. ittt i, 25 Ma
25 mA
Plate Current. ......... ... .. ittt i, 25 Ma
Grid No. 2 Current 5.5 Ma
5.5 mA
Grid No. 2 Current 5.5 Ma
Plate Resistance (approx.).................... ... 60,000 Ohms
60 Ohms
Plate Resistance (approx.).................... ... 60,000 Ohms
Average Diode Current W|th 10 Volts D C Applied
10 V
Average Diode Current W|th 10 Volts D C Applied

Other

Maximum Heater Current Range. ................. 560-640 Ma
-640 mA
Maximum Heater Current Range. ................. 560-640 Ma
Grid No. 2 Supply Voltage. . ...............coo... 330 Volts Max.
330 V
Grid No. 2 Supply Voltage. . ...............coo... 330 Volts Max.
Grid No.2 Voltage. .. .......coivvirininninannnen See Rating Chart
2 V
Grid No.2 Voltage. .. .......coivvirininninannnen See Rating Chart
Positive Grid No. 1 Voltage. ...................... 0 Volts Max.
0 V
Positive Grid No. 1 Voltage. ...................... 0 Volts Max.
Plate Dissipation........ .. ... ... .0 iiieiiiiinan.n 5.0 Watts Max.
5 W
Plate Dissipation........ .. ... ... .0 iiieiiiiinan.n 5.0 Watts Max.
Grid No. 2 Dissipation. . .............cciiiviirnnn 1.1 Watts Max.
1.1 W
Grid No. 2 Dissipation. . .............cciiiviirnnn 1.1 Watts Max.