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Voltage Pentode - Remote Cutoff (single) ·Pentode

6F25

Frame-grid variable-mu pentode for high-gain television IF amplification and large-signal AGC-controlled service.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
B9A
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 300 mA

Description

Frame-grid screened variable-mu HF pentode for television IF amplification and large-signal service.

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
B9A
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

B9A - 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

Pentode

X-ray radiationInterelectrode capacitances
Transconductance
0.0125 S
Amplification factor
35
Max plate voltage
250 V
Max screen voltage
250 V
Max plate dissipation
2.5 W
Max screen dissipation
0.5 W

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

1960 Mazda

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Grid1 Earth Capacitance

    8.5 pF

  • Anode Earth Capacitance

    2.7 pF

  • Anode Grid1 Capacitance

    0.006 pF

Other

  • Maximum Heater Cathode Voltage

    150 V

  • Maximum Grid Cathode Resistance

    1 Mohm