Data set 01
1947 Westinghouse
Published operating points and test conditions from this source.
SECTION 1
Pentode
Application
Application
WideBand_IF_RF_Amplifier text
Characteristic
TriodeConnectedAmplificationFactor
41 ratio
TriodeConnection
Voltage Pentode - Sharp Cutoff (single) ·Pentode
8425
Sharp-cutoff pentode designed for RF, IF, wide-band, or high-frequency voltage-amplifier service.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- -
- Socket code
- B7G
- Base pins
- 7
- Nominal heater
- 6.3 V / 300 mA
Description
Sharp-cutoff pentode for wide-band IF/RF amplification with high transconductance-to-current ratio.
Socket description
Miniature 7-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B7G
- Base pins
- 7
- Nominal heater voltage
- 6.3 V
- Nominal heater current
- 300 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
1 physical section, each with unique specifications.
Section 1
Pentode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 1100000 Ω
- Transconductance
- 0.0062 S
- Max plate voltage
- 330 V
- Max screen voltage
- 330 V
- Max plate dissipation
- 3.5 W
- Max screen dissipation
- 0.75 W
Published ratings and characteristics promoted from the approved Westinghouse 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
1965 Sylvania Electronic Tubes Vol3
Published operating points and test conditions from this source.
SECTION 1
Pentode
Characteristic
Heater Voltage
6.3 V
Heater Current
300 mA
GridToPlateCapacitanceMaximum
0.003 pF
Input Capacitance
5.9 pF
Output Capacitance
5.1 pF
Plate Voltage
250 V
Screen Voltage
150 V
Cathode Bias Resistance
68 ohm
Transconductance
6200 uS
Plate Resistance
1100000 ohm
Plate Current
10.5 mA
Screen Current
4.1 mA
GridCutoffBias
-5.8 V
TriodeConnectedPlateVoltage
250 V
TriodeConnection
TriodeConnectedCathodeResistance
330 ohm
TriodeConnection
TriodeConnectedAmplificationFactor
41
TriodeConnection
TriodeConnectedTransconductance
6000 uS
TriodeConnection
TriodeConnectedPlateCurrent
11.2 mA
TriodeConnection