Data set 01
1950 Sylvania
Published operating points and test conditions from this source.
SECTION 1
Triode
Application
Service
VHF cascode / cathode follower
Voltage - Dual Triode (dissimilar) ·Triode-Triode
7308
Premium long-life, high-reliability version of the VHF cascode twin-triode family, designed for low-noise high-frequency amplification and demanding professional service.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 2
- Base
- -
- Socket code
- B9A
- Base pins
- 9
- Nominal heater
- 6.3 V / 335 mA
Description
Premium low-noise twin triode with two closely matched sections for precision amplifier 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
- 6.3 V
- Nominal heater current
- 335 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
- 250 V
- Max plate dissipation
- 1.65 W
- Max cathode current
- 110 mA
Published ratings, characteristics, operating conditions and special-service data reviewed.
Section 2
Triode
X-ray radiationInterelectrode capacitances
- Transconductance
- 0.0115 S
- Max plate voltage
- 250 V
- Max plate dissipation
- 1.65 W
- Max cathode current
- 22 mA
Second physical triode restored with section-specific Sylvania transconductance.
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 Amperex Condensed
Published operating points and test conditions from this source.
SECTION 1
Triode
Characteristic
Heater voltage
6.3 V
Published rating
Heater current
335 mA
Published rating
Published characteristic value
1.75
PremiumQuality
Published absolute value
2
PremiumQuality
Other
Maximum plate voltage
250 V
PremiumQuality
Maximum plate current
22 mA
PremiumQuality
Data set 03
1965 Sylvania Electronic Tubes Vol3
Published operating points and test conditions from this source.
SECTION 1
Triode
Characteristics
Heater voltage
6.3 V
Heater current
335 mA
Transconductance section 1
12500 uS
Transconductance section 2
11500 uS
Other
Heater-cathode voltage maximum heater negative
120 V
Heater-cathode voltage maximum heater positive
60 V
Peak cathode current maximum
110 mA
Application
Application
Low-noise precision twin-triode amplifier