6690

Professional small-signal pentode for conventional voltage-amplifier service, without a more specialized detector, output, or power function.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 7BD
Socket code: B7G
Base pins: 7
Nominal heater: 6.3 V / 150 mA

Description

The 6690 is a other described in the approved English datasheet.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 7BD
Socket code: B7G
Base pins: 7
Nominal heater voltage: 6.3 V
Nominal heater current: 150 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7BD - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1G1	A	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN2G3	A	G3 — Suppressor GridGroup 7BD2 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN2IS	A	IS — Internal ScreenGroup 7BD2 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN2K	A	K — CathodeGroup 7BD2 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN3H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN4H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN5P	A	P — Plate (Anode) EIA chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN6G2	A	G2 — Screen Grid EIA chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN7G3	A	G3 — Suppressor GridGroup 7BD7 EIA chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN7IS	A	IS — Internal ScreenGroup 7BD7 EIA chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD
PIN7K	A	K — CathodeGroup 7BD7 EIA chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7BD

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 300000 Ω
Transconductance: 0.002 S
Max plate voltage: 180 V
Max screen voltage: 140 V

Published values promoted where clearly attributable to this section.

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

Pentode

Other

Maximum plate voltage
180 V
Published handbook rating
Maximum screen voltage
140 V
Published handbook rating
Plate voltage
90 V
ClassA
Screen voltage
90 V
ClassA
Plate current
3.9 mA
ClassA
Screen current
1.4 mA
ClassA

Characteristic

Plate resistance
300000 ohm
Published handbook characteristic
Transconductance
2000 µS
Published handbook characteristic
Heater/filament voltage
6.3 V
Published heater/filament rating
Heater/filament current
150 mA
Published heater/filament rating

Capacitance

Input capacitance
3.4 pF
Published capacitance column
Output capacitance
2.9 pF
Published capacitance column
Grid-to-plate capacitance
0.01 pF
Published capacitance column