25BK5

Beam-power tube documented for power-amplifier service with approximately 3.5 watts Class-A output; the family is also rated for television deflection applications.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 9BQ
Socket code: B9A
Base pins: 9
Nominal heater: 25 V / 300 mA

Description

Beam-power tube for television horizontal-deflection or power-amplifier service. Heater characteristics come from the supplied variant sheet; exact parent electrical characteristics are reused only when the explicitly referenced parent datasheet is already present in the project corpus.

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: 9BQ
Socket code: B9A
Base pins: 9
Nominal heater voltage: 25 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

9BQ - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Beam Power

X-ray radiationInterelectrode capacitances

Plate resistance: 100000 Ω
Transconductance: 0.0085 S
Max plate voltage: 250 V
Max screen voltage: 250 V
Max plate dissipation: 9 W
Max screen dissipation: 2.5 W

Supplied 25BK5 sheet identifies this as a heater-voltage variant of 6BK5. Promoted beam-power electrical fields were populated from the exact parent-type technical data; heater values remain specific to the supplied 25BK5 sheet.

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

Beam Power

Capacitance

Input capacitance
3 pF
Output capacitance
5 pF
Grid-to-plate capacitance
0.6 pF

Other

Plate voltage
250 V
ClassA
Screen-grid voltage
250 V
ClassA
Grid voltage
-5 V
ClassA
Plate current
35 mA
ClassA
Screen-grid current
3.5 mA
ClassA
Load resistance
6500 ohm
ClassA
Power output
3.5 W
ClassA

Data set 02

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

Plate Voltage
250 V
ClassA
Screen Voltage
250 V
ClassA
Grid1 Voltage
-5 V
ClassA
Peak AF Grid1 Voltage
5 V
ClassA
Zero Signal Plate Current
35 mA
ClassA
Maximum Signal Plate Current
37 mA
ClassA
Zero Signal Screen Current
3.5 mA
ClassA
Maximum Signal Screen Current
10 mA
ClassA
Load Resistance
6500 ohm
ClassA
Total Harmonic Distortion
7 %
ClassA
Maximum Signal Power Output
3.5 W
ClassA

Capacitance

Grid1 To Plate Capacitance
0.6 pF
Input Capacitance
13 pF
Output Capacitance
5 pF

Data set 03

1971 RCA HB3 Binder 5 of 7

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Characteristics

Heater voltage
25 V
Nominal heater rating from supplied sheet
Heater current
300 mA
Nominal heater rating from supplied sheet
Plate resistance
100000 ohm
ExactParentElectricalData 6BK5
Transconductance
8500 uS
ExactParentElectricalData 6BK5

Other

Maximum plate voltage
250 V
ExactParentElectricalData 6BK5
Maximum screen-grid voltage
250 V
ExactParentElectricalData 6BK5
Maximum plate dissipation
9 W
ExactParentElectricalData 6BK5
Maximum screen-grid dissipation
2.5 W
ExactParentElectricalData 6BK5