Voltage - Pentode or Tetrode (under 100V) vacuum tubes

Pentode

Directly heated subminiature Russian pentode designed for high-frequency voltage amplification. Its compact construction and filamentary cathode suit miniature RF signal equipment where small physical size and low heater demand are important.

Base

Not recorded

Socket

Not recorded

Heater

1.2 V

Sections

1

Pentode

Directly heated subminiature Russian pentode for high- and intermediate-frequency voltage amplification. It is a compact RF/IF signal tube intended for miniature equipment rather than power-output service.

Base

Not recorded

Socket

Not recorded

Heater

1.2 V

Sections

1

Pentode

Very-low-consumption Soviet multi-control pentode for RF amplification, oscillation, and frequency conversion. Two control grids support mixer and oscillator functions while an exceptionally economical filament suits battery-powered equipment.

Base

Not recorded

Socket

Not recorded

Heater

1.2 V

Sections

1

Pentode

Directly heated Russian pentode designed for high-frequency voltage amplification in radio-electronic equipment.

Base

Not recorded

Socket

Not recorded

Heater

1.2 V

Sections

1

Heptode

Low-consumption battery heptode for oscillator-converter service in portable superheterodyne radios. Its economical filament and high plate resistance provide useful frequency conversion from modest receiver supply voltages.

Base

7AK

Socket

B8G

Heater

1.4 V

Sections

1

Heptode

Battery heptode converter with exceptionally high plate resistance for oscillator and mixer service in portable superheterodyne receivers. Very low filament consumption emphasizes battery economy over maximum conversion gain.

Base

8AX

Socket

B8G

Heater

1.4 V

Sections

1

Heptode

Battery pentagrid converter for oscillator and mixer service in portable superheterodyne receivers. Its economical filament and modest supply requirements provide useful frequency-changing performance with low battery consumption.

Base

7AK

Socket

B8G

Heater

1.4 V

Sections

1

Tetrode

Directly heated oxide-cathode electrometer tetrode intended for precision measuring applications requiring extremely small currents and sensitive DC signal amplification.

Base

Not recorded

Socket

Not recorded

Heater

1.25 V

Sections

1

Heptode

Widely used battery pentagrid converter for portable superheterodyne receivers. It combines local oscillator and mixer functions while its economical filament and modest supply requirements suit compact battery radios.

Base

7AT

Socket

B7G

Heater

1.4 V

Sections

1

Diode-Pentode

Directly heated diode-pentode combining radio detection with audio-frequency voltage amplification in battery receivers. The diode recovers the signal while the sharp-cutoff pentode supplies subsequent audio gain.

Base

6AU

Socket

B7G

Heater

1.4 V

Sections

2

Pentode

Directly heated battery pentode designed specifically for intermediate-frequency amplifier stages in portable receivers.

Base

6BD

Socket

IO

Heater

1.4 V

Sections

1

Diode-Pentode

GT-envelope battery diode-pentode combining detection with voltage amplification. The diode recovers the signal while the pentode supplies subsequent gain with modest operating-voltage and filament requirements.

Base

6BE

Socket

IO

Heater

1.4 V

Sections

2

Pentode

Directly heated variable-mu pentode designed for RF and IF amplifier service in battery receivers. Its low-power filament and gain-control characteristic make it a widely applicable portable-receiver signal tube.

Base

8AR

Socket

B7G

Heater

1.4 V

Sections

1

Diode-Pentode

Ultra-low-power directly heated diode-pentode for detector and voltage-amplifier service in battery receivers. The diode supplies signal rectification while the pentode provides subsequent gain from very modest filament and plate supplies.

Base

8DA

Socket

Not recorded

Heater

1.25 V

Sections

2

Pentode

Ruggedized directly heated sharp-cutoff pentode for RF and AF voltage amplification in portable military or professional equipment.

Base

6AR

Socket

B7G

Heater

1.25 V

Sections

1

Diode-Pentode

Directly heated diode and sharp-cutoff pentode combination for detector and amplifier service in battery radios. The diode performs signal detection while the pentode provides subsequent gain with low filament consumption.

Base

6BW

Socket

B7G

Heater

1.4 V

Sections

2

Diode-Pentode

Ruggedized diode-pentode for detector and voltage-amplifier service in portable or specialized battery equipment. The diode supplies signal detection while the comparatively strong pentode provides subsequent gain with low filament demand.

Base

Not recorded

Socket

B7G

Heater

1.25 V

Sections

2

Pentode-Triode

Directly heated subminiature triode-pentode for low-power battery-operated amplifier circuits.

Base

7BC

Socket

B7G

Heater

1.25 V

Sections

2

Pentode

Directly heated subminiature pentode designed for high-frequency voltage amplification in compact electronic equipment.

Base

Not recorded

Socket

SUBMINIATURE7

Heater

1.2 V

Sections

1

Pentode

Very-low-power directly heated sharp-cutoff RF pentode for Class-A amplification in compact battery electronics.

Base

2E31

Socket

Not recorded

Heater

1.25 V

Sections

1

Pentode

Directly heated sharp-cutoff RF pentode in the low-power 2E31 family for compact battery-operated high-frequency equipment.

Base

2E31

Socket

Not recorded

Heater

1.25 V

Sections

1

Diode-Pentode

Ultra-low-power battery diode-pentode combining signal detection with voltage amplification. The diode supplies detector action while the pentode provides subsequent gain from exceptionally economical filament and plate supplies.

Base

2E41

Socket

Not recorded

Heater

1.25 V

Sections

2

Diode-Pentode

Very-low-power battery diode-pentode for detector and amplifier service. The diode recovers the signal while the pentode supplies subsequent voltage gain from extremely modest battery-operated supplies.

Base

2E41

Socket

Not recorded

Heater

1.25 V

Sections

2

Pentode

Extremely low-power directly heated subminiature pentode for audio and direct-coupled voltage amplification in hearing aids and portable instruments.

Base

512AX

Socket

Not recorded

Heater

0.625 V

Sections

1

Pentode

Directly heated subminiature RF pentode for battery-powered miniature equipment, providing useful gain from low plate and filament supplies.

Base

1AD4

Socket

B5D

Heater

1.25 V

Sections

1

Pentode

Remote- or semi-remote-cutoff pentode designed for RF, IF, variable-mu, or controlled-gain amplifier service.

Base

K8-1

Socket

B8D

Heater

26.5 V

Sections

1

Pentode

Sharp-cutoff pentode designed for RF, VHF/UHF, wide-band, or voltage-amplifier service.

Base

1AD4

Socket

B8D

Heater

1.25 V

Sections

1

Tetrode-Tetrode

Directly heated subminiature double-tetrode electrometer tube designed for extremely low-current measurement circuits.

Base

Not recorded

Socket

SUBMINIATURE8

Heater

1.25 V

Sections

2

Pentode

Subminiature electrometer pentode with exceptionally low filament-current requirements. Designed for ultra-low-current measurement circuits, it serves sensitive electrometer instrumentation where input loading and heater power must be kept extremely small.

Base

Not recorded

Socket

Not recorded

Heater

1.25 V

Sections

1

Pentode

Sharp-cutoff pentode designed for RF, VHF/UHF, wide-band, or voltage-amplifier service.

Base

8DL

Socket

B8D

Heater

26.5 V

Sections

1

Pentode

Remote- or semi-remote-cutoff pentode designed for RF, IF, variable-mu, or controlled-gain amplifier service.

Base

8DL

Socket

B8D

Heater

26.5 V

Sections

1

Pentode

Sharp-cutoff pentode designed for RF, VHF/UHF, wide-band, or voltage-amplifier service.

Base

8DC

Socket

B8D

Heater

26.5 V

Sections

1

Pentode

Filament-type sharp-cutoff miniature pentode designed for radiosonde blocking-oscillator applications.

Base

Not recorded

Socket

B7G

Heater

1.4 V

Sections

1

Pentode

Radiation-cooled directly heated miniature voltage-amplifier pentode, co-designated with 6008 in manufacturer literature. It is intended for compact signal-amplifier service using a filamentary cathode rather than conventional indirectly heated construction.

Base

Not recorded

Socket

B9A

Heater

0.625 V

Sections

1

Pentode

Remote- or semi-remote-cutoff pentode designed for RF, IF, variable-mu, or controlled-gain amplifier service.

Base

Not recorded

Socket

B8D

Heater

1.25 V

Sections

1

Pentode

Radiation-cooled directly heated miniature voltage-amplifier pentode, co-designated with 5911 in manufacturer literature. Its filamentary cathode and compact construction suit miniature signal-amplifier applications rather than power-output service.

Base

512-AX

Socket

B9A

Heater

0.625 V

Sections

1

Pentode

Directly heated subminiature pentode for resistance-coupled audio and direct-coupled amplifiers. Manufacturer documentation emphasizes low battery drain, long life, and low microphonics, making it well suited to compact low-level audio equipment.

Base

Not recorded

Socket

SUBMINIATURE8

Heater

0.625 V

Sections

1

Pentode

Directly heated subminiature low-power pentode. Manufacturer operating tables document compact signal-amplifier service with low heater demand, making it suitable for miniature equipment where power consumption and physical size are constrained.

Base

Not recorded

Socket

B5D

Heater

1.25 V

Sections

1

Pentode

Ultra-low-drain directly heated subminiature pentode for voltage amplification in portable and wearable equipment, using only a 0.625 V, 10 mA filament.

Base

Not recorded

Socket

B5D

Heater

0.625 V

Sections

1

Pentode

Extremely low-drain directly heated subminiature RF pentode for battery-powered miniature equipment, providing useful gain from low plate voltages.

Base

Not recorded

Socket

B5D

Heater

1.25 V

Sections

1

Pentode

Fully shielded directly heated subminiature pentode for higher-gain RF amplification in compact battery-powered high-frequency equipment.

Base

Not recorded

Socket

B5D

Heater

1.25 V

Sections

1

Pentode

Extremely low-drain directly heated subminiature pentode for portable low-voltage amplifier service, using a 1.25 V, 20 mA filament.

Base

Not recorded

Socket

SUBMINIATURE7

Heater

1.25 V

Sections

1

Diode-Diode-Pentode

Receiving tube combining radio signal detection or control-voltage rectification with associated voltage amplification. Its detector function is integral to receiver signal processing and supports classification within the radio detector/converter family.

Base

InternationalOctal

Socket

IO

Heater

6.3 V

Sections

3

Pentode

Low-voltage pentode for automobile-radio IF amplification, oscillator, and AF amplifier service from vehicle-compatible plate supplies.

Base

Not recorded

Socket

B7G

Heater

6.3 V

Sections

1

Pentode

Russian pentode for both high- and low-frequency voltage amplification using a low-voltage anode and screen supply. Its broad signal-amplifier role is distinguished by operation from comparatively low supply voltages.

Base

B7G

Socket

Not recorded

Heater

6.3 V

Sections

1

Tetrode

Screen-grid electrometer tetrode with extremely low grid current and very high effective gain, designed for precision instrumentation involving minute input currents.

Base

Not recorded

Socket

B7G

Heater

2.5 V

Sections

1

Pentode

Subminiature frame-grid sharp-cutoff pentode for VHF RF/IF amplification and mixer service at unusually low plate voltage. Severe-environment construction suits airborne, military, and demanding professional electronics.

Base

Not recorded

Socket

B8D

Heater

26.5 V

Sections

1

Tetrode

Early directly heated Philips high-vacuum tetrode for battery receivers, designed for low-voltage detector and amplifier service with exceptionally economical filament operation.

Base

Philips 4-pin

Socket

Not recorded

Heater

1.15 V

Sections

1