Voltage - Triode (under 100V) vacuum tubes

Triode

Early directly heated triode for general receiving service. Available source material confirms basic triode construction but does not establish a narrower application confidently.

Base

4D

Socket

UX4

Heater

5 V

Sections

1

Diode-Diode-Triode

Double-diode triode for low-voltage automobile-radio detector and audio voltage-amplifier service. Two diodes provide signal detection and rectification while the triode operates effectively from the vehicle's low-voltage supply.

Base

7BT

Socket

B7G

Heater

12.6 V

Sections

3

Diode-Diode-Triode

Improved low-voltage double-diode triode for automobile-radio detector and voltage-amplifier service. Two diode sections provide detection and control-voltage rectification while the triode is optimized for automotive supply voltages.

Base

7BT

Socket

B7G

Heater

12.6 V

Sections

3

Triode-Triode

Low-voltage dissimilar dual triode containing medium- and low-mu sections, designed to operate from unusually low plate supplies and provide useful gain and current drive.

Base

9A

Socket

B9A

Heater

12.6 V

Sections

2

Diode-Diode-Triode

Double-diode high-mu triode for low-voltage detector and voltage-amplifier service. The diode sections handle detection or control-voltage rectification while the triode provides substantial subsequent signal gain.

Base

7BT

Socket

B7G

Heater

12.6 V

Sections

3

Diode-Diode-Triode

Double-diode triode for second-detector and audio-amplifier service in automobile radios. The diodes recover and rectify receiver signals while the triode operates directly from the vehicle's low-voltage supply.

Base

Not recorded

Socket

B9A

Heater

12.6 V

Sections

3

Diode-Triode-Triode

Low-voltage combination tube containing two dissimilar triodes and a diode for automobile receiver circuitry. The triodes provide complementary amplification or driver functions while the diode supplies detection or rectification.

Base

Not recorded

Socket

B9A

Heater

12.6 V

Sections

3

Diode-Diode-Triode

Double-diode high-mu triode for low-voltage automobile-radio detector and voltage-amplifier service. Two diode sections provide detection and rectification while the triode operates effectively from automotive supply voltage.

Base

Not recorded

Socket

B7G

Heater

12.6 V

Sections

3

Diode-Diode-Triode

Double-diode low-mu triode for detector, AVC, and first audio-amplifier service in automobile receivers. The diodes provide detection and control rectification while the triode offers useful low-voltage current drive.

Base

7BT

Socket

B7G

Heater

12.6 V

Sections

3

Diode-Diode-Triode

Double-diode medium-mu triode for detector and audio voltage-amplifier service in low-voltage automobile receivers. Two diodes handle detection and control rectification while the triode provides moderate gain and strong current drive.

Base

7BT

Socket

B7G

Heater

12.6 V

Sections

3

Diode-Diode-Triode

Double-diode triode for second-detector and audio-driver service in hybrid automobile radios. The diodes recover and rectify the signal while the low-voltage triode drives subsequent transistorized circuitry.

Base

7BT

Socket

B7G

Heater

12.6 V

Sections

3

Triode-Triode

Low-voltage twin triode designed to operate from unusually small plate supplies, making it particularly suitable for automobile, battery-powered, and other low-voltage electronic equipment.

Base

Not recorded

Socket

IO

Heater

12.6 V

Sections

2

Triode

Russian 1S38A miniature directly heated low-voltage triode for audio amplification and HF oscillation, with 0.9 V 85 mA filament, mu 24.5 and gm 0.77 mA/V.

Base

Not recorded

Socket

Not recorded

Heater

0.9 V

Sections

1

Triode

Western Electric directly heated triode with a one-volt filament for low-power professional or battery-operated electronic service.

Base

Not recorded

Socket

SMALL4BAYONET

Heater

1 V

Sections

1

Triode

General-purpose receiving triode for voltage amplification, detection, oscillator, or Class-A service as documented by the manufacturer.

Base

Not recorded

Socket

UV99

Heater

3.3 V

Sections

1

Diode-Diode-Triode

Western Electric double-diode triode integrating two low-voltage rectifying sections with a medium-mu amplifier. All sections share a common cathode, supporting combined detection and subsequent signal amplification.

Base

Not recorded

Socket

UX6

Heater

10 V

Sections

3

Triode-Triode

Very-low-current directly heated electrometer triode for electrochemical, ionization, X-ray, and low-light measurements requiring extremely small input-current detection.

Base

Not recorded

Socket

Not recorded

Heater

0.7 V

Sections

2

Triode-Triode

Premium industrial twin triode intended for dependable amplifier and control service, with special-quality construction for equipment requiring stable operation and extended reliability.

Base

K8-1

Socket

Not recorded

Heater

26.5 V

Sections

2

Triode-Triode

Directly heated dual-anode electrometer triode designed for balanced measurement of extremely small currents, a specialized instrumentation device rather than a conventional dual amplifier triode.

Base

Not recorded

Socket

Not recorded

Heater

1.25 V

Sections

2

Triode

Medium-mu high-perveance triode designed for amplifier or oscillator service using approximately 26.5 V on both plate and heater.

Base

8DK

Socket

B8D

Heater

26.5 V

Sections

1

Triode-Triode

Directly heated subminiature twin triode for push-pull Class-A RF amplification, mixing, and oscillator service at VHF, combining compact construction with high-frequency capability.

Base

Not recorded

Socket

SUBMINIATURE8

Heater

1.25 V

Sections

2

Triode

General-purpose triode for receiving, amplification, driver, or electronic service as documented by the manufacturer.

Base

Not recorded

Socket

OCTAL6

Heater

6.3 V

Sections

1

Triode-Triode

Low-voltage frame-grid twin triode designed for RF amplifier and mixer service, capable of useful operation from unusually low plate supplies in compact receiver front ends.

Base

9DE

Socket

B9A

Heater

6.3 V

Sections

2

Triode-Triode

Russian double triode designed for low-frequency voltage amplification, providing two triode sections for compact small-signal amplifier circuits.

Base

Not recorded

Socket

Not recorded

Heater

6.3 V

Sections

2

Triode

Russian high-frequency triode for RF amplification and related signal service.

Base

Not recorded

Socket

B9A

Heater

Not recorded

Sections

1

Triode

Russian high-frequency triode designed for high-frequency voltage amplification in receiving and general electronic equipment.

Base

Not recorded

Socket

B9A

Heater

6.3 V

Sections

1

Triode

Premium subminiature medium-mu triode designed for low-voltage operation in compact electronic equipment.

Base

Not recorded

Socket

B8D

Heater

26.5 V

Sections

1

Triode

General-purpose receiving triode for detection, amplification, oscillator, or low-power electronic service as documented by the manufacturer.

Base

Not recorded

Socket

UV99

Heater

3.3 V

Sections

1

Triode

Subminiature triode for microphone and low-frequency preamplifier service.

Base

Not recorded

Socket

Not recorded

Heater

4 V

Sections

1

Triode

Early directly heated receiving triode for detector and amplifier service.

Base

Not recorded

Socket

Not recorded

Heater

1.7 V

Sections

1

Triode-Triode

Directly heated subminiature twin triode designed for RF amplifier service, emphasizing compact high-frequency operation rather than ordinary audio-frequency amplification.

Base

8CK

Socket

SUBMINIATURE8

Heater

1.25 V

Sections

2

Triode-Triode

Directly heated subminiature twin triode specifically intended for mixer service in compact high-frequency receiving or frequency-conversion equipment.

Base

8CE

Socket

SUBMINIATURE8

Heater

1.25 V

Sections

2

Diode-Triode

Diode-triode for VHF/UHF frequency-changing service, combining a mixer/detector diode with a triode oscillator. Manufacturer data supports frequency conversion to roughly 300 MHz and oscillation considerably higher.

Base

Not recorded

Socket

B7G

Heater

6.3 V

Sections

2

Triode-Triode

Low-voltage RF double triode designed for RF amplification and self-oscillating mixer service from 6-, 12-, or 24-volt battery supplies, enabling tuner operation without conventional high plate voltage.

Base

9DE

Socket

B9A

Heater

6.3 V

Sections

2

Triode

Electrometer triode designed for input stages of precision electrometer instruments measuring extremely small electrical currents.

Base

Not recorded

Socket

P8A

Heater

1.3 V

Sections

1

Diode-Triode

Dry-cell battery diode-triode combining a detector diode with a triode amplifier for portable receiving equipment.

Base

Not recorded

Socket

Not recorded

Heater

1.4 V

Sections

2

Triode

Subminiature electrometer triode for extremely low-grid-current DC measurement and very-high-input-resistance instrumentation.

Base

Not recorded

Socket

Not recorded

Heater

1.25 V

Sections

1

Triode

Subminiature electrometer triode for linear and logarithmic measurement service with controlled grid-current/anode-current relationship.

Base

Not recorded

Socket

Not recorded

Heater

1.25 V

Sections

1

Triode

Receiving triode for amplification, detection, oscillator, or general electronic service as documented by the manufacturer.

Base

Not recorded

Socket

Not recorded

Heater

Not recorded

Sections

1

Triode

Receiving triode for amplification, detection, oscillator, or general electronic service as documented by the manufacturer.

Base

Not recorded

Socket

Not recorded

Heater

Not recorded

Sections

1

Triode

Receiving triode for amplification, detection, oscillator, or general electronic service as documented by the manufacturer.

Base

Not recorded

Socket

Not recorded

Heater

Not recorded

Sections

1

Triode

German transmitting triode with published limiting ratings and operating data for RF service.

Base

Not recorded

Socket

Not recorded

Heater

2.6 V

Sections

1

Triode

Medium-mu ceramic-metal planar triode designed for low-voltage high-frequency operation.

Base

Not recorded

Socket

Not recorded

Heater

6.3 V

Sections

1

Triode

Directly heated Telefunken electrometer triode for measuring extremely small currents in bridge, pH, radiation, and vacuum-tube voltmeter circuits.

Base

Not recorded

Socket

Not recorded

Heater

1.25 V

Sections

1