Data set 01
1950 Sylvania
Published operating points and test conditions from this source.
SECTION 1
Triode
Application
Service
Cascode VHF amplifier
Voltage - Dual Triode (similar high frequency) ·Triode-Triode
4CX7
High-transconductance dual triode designed for VHF amplifier and television-tuner service, providing two triode sections optimized for high-frequency signal amplification.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 2
- Base
- -
- Socket code
- B9A
- Base pins
- 9
- Nominal heater
- 4.2 V / 600 mA
Description
High-transconductance dual triode for VHF amplifier and television tuner service.
Socket description
Small-button Noval 9-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B9A
- Base pins
- 9
- Nominal heater voltage
- 4.2 V
- Nominal heater current
- 600 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
Triode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 5600 Ω
- Transconductance
- 0.0064 S
- Amplification factor
- 45
- Max plate voltage
- 250 V
- Max plate dissipation
- 2 W
- Max cathode current
- 20 mA
- Rectifier warm-up time
- 11 s
Published ratings and characteristics promoted where applicable.
Section 2
Triode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 5600 Ω
- Transconductance
- 0.0064 S
- Amplification factor
- 45
- Max plate voltage
- 250 V
- Max plate dissipation
- 2 W
- Max cathode current
- 20 mA
Second physical triode section; electrically identical twin section.
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
1961 Tung Sol
Published operating points and test conditions from this source.
SECTION 1
Triode
Characteristic
Heater Warmup Time
11 s
Data set 03
1966 Tung Sol Electronic Tubes 1 of 4
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
Plate voltage
150 V
EachSection
Plate current
12 mA
EachSection
Characteristic
Transconductance
8000 µS
EachSection
Plate resistance
5600 Ω
EachSection
Amplification factor
45
EachSection