QP21

Quiescent push-pull double pentode for 2-volt battery receiver output stages, designed for low standing current and economical high-tension battery consumption.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: B7
Base pins: 7
Nominal heater: 2 V / 400 mA

Description

Two pentode systems in one envelope for quiescent push-pull output service in 2-volt battery receivers, designed for low standing anode current and increased power output with economical average H.T. current.

Socket description

Medium 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B7
Base pins: 7
Nominal heater voltage: 2 V
Nominal heater current: 400 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

Pentode

X-ray radiationInterelectrode capacitances

Transconductance: 0.0023 S
Max plate voltage: 150 V
Max screen voltage: 150 V

Published ratings and characteristics promoted from the approved datasheet.

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Transconductance: 0.0023 S
Max plate voltage: 150 V
Max screen voltage: 150 V

Second physical pentode section; added to align rows with SectionCount.

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

1937 Osram Valves

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Heater Voltage
2 V
Published datasheet value
Heater Current
400 mA
Published datasheet value
Anode Voltage Maximum
150 V
Published datasheet value
Screen Voltage Maximum
150 V
Published datasheet value
Output Load Resistance
25000 ohm
AnodeToAnode; AnodeVoltage=150V
Average Full Load Anode Current
12.5 mA
AnodeVoltage=150V

Characteristic

Mutual Conductance
2300 µS
Published datasheet value

Data set 02

193X Osram

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

Output load resistance anode-to-anode
25000 ohm
Published datasheet value
Average quiescent anode current
3.5 mA
Published datasheet value