Data set 01
1959 Rogers
Published operating points and test conditions from this source.
SECTION 1
Triode
Application
Application
Low-noise RF cascode amplifier
Characteristics
Equivalent noise resistance
300 ohm
Voltage - Dual Triode (similar high frequency) ·Triode-Triode
7DJ8
High-transconductance low-noise double triode designed for cascode RF amplification in television tuners, with low equivalent noise resistance supporting sensitive VHF front-end service.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 2
- Base
- -
- Socket code
- B9A
- Base pins
- 9
- Nominal heater
- 7 V / 300 mA
Description
High-transconductance low-noise double triode for television tuner cascode amplifiers.
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
- 7 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
2 physical sections, each with unique specifications.
Section 1
Triode
X-ray radiationInterelectrode capacitances
- Transconductance
- 0.0125 S
- Amplification factor
- 33
- Max plate voltage
- 130 V
- Max plate dissipation
- 1.8 W
- Max cathode current
- 25 mA
Grounded-cathode input triode, pins 6 (plate), 7 (grid), 8 (cathode). Typical operation: plate 90 V, grid -1.3 V, plate current 15 mA. In specified grid-current-bias cascode circuit without AGC, plate voltage should not exceed 75 V. Rogers 7DJ8 and Sylvania Technical Manual.
Section 2
Triode
X-ray radiationInterelectrode capacitances
- Transconductance
- 0.0125 S
- Amplification factor
- 33
- Max plate voltage
- 130 V
- Max plate dissipation
- 1.8 W
- Max cathode current
- 25 mA
Grounded-grid output triode, pins 1 (plate), 2 (grid), 3 (cathode). Typical operation: plate 90 V, grid -1.3 V, plate current 15 mA. Grounded-grid cathode-to-heater voltage DC component maximum 130 V (with additional specified peak voltage limits). Rogers 7DJ8 and Sylvania Technical Manual.
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.