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Voltage Pentode - Sharp Cutoff (single) ·Pentode

EF55

Sharp-cutoff video-frequency pentode with very high mutual conductance. Mullard documentation identifies it for wideband video amplification where substantial fixed gain and high-frequency response are required.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: B9G
Socket code: B9G
Base pins: 9
Nominal heater: 6.3 V / 1 A

Description

Sharp-cutoff video-frequency pentode with very high mutual conductance.

Socket description

Loctal 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: B9G
Socket code: B9G
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 1 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

B9G - 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

Plate resistance: 55000 Ω
Transconductance: 0.012 S
Max plate voltage: 300 V
Max screen voltage: 250 V
Max plate dissipation: 10 W
Max screen dissipation: 2 W
Max cathode current: 15 mA

Published source values promoted where applicable; additional published values retained as parameters.

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

1951 Mullard Valve and Service Manual

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Cutoff characteristic
Sharp cutoff

Application

Application
Video amplification

Other

Maximum operating frequency
250 MHz

Data set 02

1963 Mullard

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Heater Voltage
6.3 V
Heater Current
1 A
Plate Voltage
250 V
Screen Voltage
250 V
Plate Current
40 mA
Screen Current
5.5 mA
Transconductance
12000 uS
Plate Resistance
55000 ohm
Plate Voltage
250 V
LowerCurrentPoint
Screen Voltage
150 V
LowerCurrentPoint
Plate Current
10 mA
LowerCurrentPoint
Screen Current
1 mA
LowerCurrentPoint
Transconductance
7000 uS
LowerCurrentPoint
Plate Resistance
100000 ohm
LowerCurrentPoint

Other

Maximum Plate Voltage
300 V
Maximum Screen Voltage
300 V
Maximum Plate Dissipation
10 W
Maximum Screen Dissipation
2 W
Maximum Peak Plate Supply Voltage
500 V
Peak Cathode Current
1.5 A
PulseWidth=50us; Repetition=500Hz

Data set 03

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Heater voltage
6.3 V
Heater current
300 mA
Plate voltage
250 V
HighCurrent
Screen voltage
250 V
HighCurrent
Grid voltage
-4.5 V
HighCurrent
Plate current
40 mA
HighCurrent
Screen current
5.5 mA
HighCurrent
Transconductance
12000 uS
HighCurrent
Screen-grid amplification factor
28
HighCurrent
Plate resistance
55000 ohm
HighCurrent
Plate voltage
250 V
LowerCurrent
Screen voltage
150 V
LowerCurrent
Grid voltage
-4 V
LowerCurrent
Plate current
10 mA
LowerCurrent
Screen current
1 mA
LowerCurrent
Transconductance
7000 uS
LowerCurrent
Screen-grid amplification factor
27
LowerCurrent
Plate resistance
100000 ohm
LowerCurrent

Capacitance

Plate-grid capacitance
0.15 pF
Plate capacitance
12 pF
Grid input capacitance
15 pF

Other

Maximum peak cathode current
1.5 A
500PulsesPerSecond;PulseDuration=50us