Data set 01
1951 Mullard Valve and Service Manual
Published operating points and test conditions from this source.
SECTION 1
Pentode
Application
Primary application
Audio-frequency voltage amplification
Construction
Low-microphony construction
Yes
Voltage Pentode ·Pentode
EF40
Low-noise pentode developed specifically for audio preamplification of microphone, pickup, and other weak low-level signals.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- RIMLOCK
- Socket code
- B8A
- Base pins
- 8
- Nominal heater
- 6.3 V / 200 mA
Description
Low-noise voltage-amplifier pentode for audio-frequency preamplifier service.
Socket description
Rimlock 8-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- RIMLOCK
- Socket code
- B8A
- Base pins
- 8
- Nominal heater voltage
- 6.3 V
- Nominal heater current
- 200 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
RIMLOCK - 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
- 2300000 Ω
- Transconductance
- 0.002 S
- Max plate voltage
- 300 V
- Max screen voltage
- 200 V
- Max plate dissipation
- 1 W
- Max screen dissipation
- 0.4 W
- Max cathode current
- 15 mA
Published ratings/characteristics promoted from the approved source.
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 02
1953 La Radiotechnique
Published operating points and test conditions from this source.
SECTION 1
Pentode
Other
HeaterVoltageNominal
6.3 V
Nominal
HeaterCurrentNominal
200 mA
Nominal
Maximum Plate Voltage
300 V
Maximum Screen Voltage
200 V
Maximum Plate Dissipation
1 W
Characteristic
Transconductance
2000 µS
Typical
Amplification Factor
4600
Typical
Plate Resistance
2300000 ohm
Typical
Data set 03
1963 Philips Electron Tubes Handbook V1a
Published operating points and test conditions from this source.
SECTION 1
Pentode
Characteristic
Heater voltage
6.3 V
Published heater rating
Heater current
200 mA
Published heater rating
Transconductance
1850 µS
AFAmplifier
Other
Plate voltage
250 V
AFAmplifier
Screen voltage
140 V
AFAmplifier
Grid bias
-2 V
AFAmplifier
Plate current
3 mA
AFAmplifier
Screen current
0.55 mA
AFAmplifier
Data set 04
1967 Mullard Receiving Tubes for Maintenance
Published operating points and test conditions from this source.
SECTION 1
Pentode
Other
Cross-reference type
EF86
Electrical ratings and characteristics
Maximum heater-cathode voltage
50 V
Application
Intended service
High-gain RC-coupled AF voltage amplifier
Data set 05
1968 Mazda Belvu
Published operating points and test conditions from this source.
SECTION 1
Pentode
Other
HeaterVoltageNominal
6.3 V
Nominal
HeaterCurrentNominal
200 mA
Nominal
Maximum Plate Voltage
300 V
Maximum Screen Voltage
200 V
Maximum Plate Dissipation
1 W
Maximum Screen Dissipation
0.4 W
Maximum Cathode Current
15 mA
Characteristic
Transconductance
2000 µS
Typical
Amplification Factor
4600
Typical
Plate Resistance
2300000 ohm
Typical
Data set 06
1999 Philips E-Z
Published operating points and test conditions from this source.
SECTION 1
Pentode
Characteristics
Heater voltage
6.3 V
Heater current
200 mA
Typical plate voltage
250 V
Typical screen voltage
140 V
Typical grid voltage
-2 V
Typical plate current
3 mA
Typical screen current
0.55 mA
Transconductance
1850 uS
Screen-grid amplification factor
38
Plate resistance
2.5 Mohm
Capacitance
Grid input capacitance
4.5 pF
Plate capacitance
5.2 pF
Plate-grid capacitance maximum
0.04 pF
Grid-heater capacitance maximum
0.002 pF