Data set 01
1958 Mullard Receiving Tubes
Published operating points and test conditions from this source.
SECTION 1
Diode
Application
Application
Detector diode
SECTION 2
Pentode
Application
Application
AF amplifier
Voltage Pentode or Tetrode (under 100V) ·Diode-Pentode
DAF70
Subminiature directly heated diode-pentode for battery equipment, combining a detector diode with an audio-frequency pentode. Its exceptionally economical 1.25 V, 25 mA filament suits compact low-power portable electronics.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 2
- Base
- -
- Socket code
- WIRE8
- Base pins
- 8
- Nominal heater
- 1.25 V / 25 mA
Description
Subminiature directly heated AF pentode combined with a single diode, suitable for battery operation. It includes resistance-coupled AF amplifier and Class A output operating data.
Socket description
Subminiature all-glass 8-wire lead family
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- WIRE8
- Base pins
- 8
- Nominal heater voltage
- 1.25 V
- Nominal heater current
- 25 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
2 physical sections, each with unique specifications.
Section 1
Diode
X-ray radiationInterelectrode capacitances
No fixed ratings are recorded for this section.
Published Mullard/Philips ratings and characteristics promoted where applicable; additional values retained as parameters.
Section 2
Pentode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 400000 Ω
- Transconductance
- 0.00004 S
- Amplification factor
- 16
- Max plate voltage
- 90 V
- Max screen voltage
- 90 V
- Max cathode current
- 1.3 mA
Published Mullard/Philips ratings and characteristics promoted where applicable; additional 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 2
Pentode
Capacitance
Anode-grid capacitance
0.15 pF
Output capacitance
4.3 pF
Characteristic
Anode voltage
67.5 V
Anode current
1 mA
Screen current
250 uA
Transconductance
40 uS
Plate resistance
400000 ohm
Amplification factor g1-g2
16
Other
Anode voltage
67.5 V
ClassA Va=67.5 V
Control-grid voltage
-1.8 V
ClassA Va=67.5 V
Anode current
400 uA
ClassA Va=67.5 V
Screen current
85 uA
ClassA Va=67.5 V
Load resistance
150 kohm
ClassA Va=67.5 V
Output power
10.5 mW
ClassA Va=67.5 V
Total distortion
10 %
ClassA Va=67.5 V
Anode voltage
90 V
ClassA Va=90 V
Control-grid voltage
-2.6 V
ClassA Va=90 V
Anode current
600 uA
ClassA Va=90 V
Screen current
135 uA
ClassA Va=90 V
Load resistance
150 kohm
ClassA Va=90 V
Output power
20 mW
ClassA Va=90 V
Total distortion
10 %
ClassA Va=90 V
Plate voltage maximum
90 V
Screen voltage maximum
90 V
Cathode current maximum
1.3 mA
Screen current maximum
250 uA