Data set 01
1951 Mullard Valve and Service Manual
Published operating points and test conditions from this source.
SECTION 1
Pentode
Characteristics
Cutoff characteristic
Variable-mu
Voltage Pentode - Remote Cutoff (single) ·Pentode
EF39
Variable-mu RF pentode with sliding-screen characteristics for controlled RF or IF amplification. Its specialized control behavior supports smooth gain regulation across changing receiver signal levels.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- OCTAL
- Socket code
- IO
- Base pins
- 8
- Nominal heater
- 6.3 V / 200 mA
Description
Variable-mu RF pentode with sliding-screen characteristics for controlled RF or IF amplification.
Socket description
International Octal
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- OCTAL
- Socket code
- IO
- Base pins
- 8
- Nominal heater voltage
- 6.3 V
- Nominal heater current
- 200 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
OCTAL - 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
- 1250000 Ω
- Transconductance
- 0.0022 S
- Max plate voltage
- 300 V
- Max screen voltage
- 125 V
- Max plate dissipation
- 2 W
- Max screen dissipation
- 0.3 W
- Max cathode current
- 10 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 02
1963 Mullard
Published operating points and test conditions from this source.
SECTION 1
Pentode
Characteristics
Heater Voltage
6.3 V
Heater Current
200 mA
Plate Voltage
250 V
Screen Voltage
100 V
Plate Current
6 mA
Screen Current
1.7 mA
Transconductance
2200 uS
Plate Resistance
1250000 ohm
Plate-Grid Capacitance Maximum
0.003 pF
Input Capacitance
5.8 pF
Output Capacitance
7.2 pF
Transconductance
4.5 uS
LowGain; Approximate
Other
Maximum Plate Voltage
300 V
Maximum Screen Voltage
125 V
Maximum Plate Dissipation
2 W
Maximum Screen Dissipation
0.3 W
Grid Voltage
-2.5 V
HighGain
Grid Voltage
-49 V
LowGain
Data set 03
1967 Mullard Receiving Tubes for Maintenance
Published operating points and test conditions from this source.
SECTION 1
Pentode
Other
Plate voltage
250 V
RFOrIFAmplifier
Screen-grid voltage
100 V
RFOrIFAmplifier
Control-grid voltage
-2.5 V
RFOrIFAmplifier
Plate current
6 mA
RFOrIFAmplifier
Screen-grid current
1.7 mA
RFOrIFAmplifier
Transconductance
2.2 mA/V
RFOrIFAmplifier
Plate resistance
1.25 MOhm
RFOrIFAmplifier
Maximum plate voltage
300 V
Maximum plate dissipation
2 W
Maximum screen-grid voltage
125 V
Ia=6mA
Maximum screen-grid dissipation
0.3 W
Maximum cathode current
10 mA
Capacitance
Input capacitance
5.5 pF
Output capacitance
7.2 pF
Data set 04
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
Uncontrolled
Typical screen voltage
100 V
Uncontrolled
Typical plate current
6 mA
Uncontrolled
Transconductance
2200 uS
Uncontrolled
Plate resistance
1.2 Mohm
Uncontrolled
Other
Maximum no-current plate voltage
550 V
Maximum plate voltage
300 V