Voltage Pentode - Sharp Cutoff (single) vacuum tubes

Pentode

Russian pentode documented in bilingual manufacturer literature with guaranteed electrical characteristics. The available source establishes pentode operation but does not expose enough explicit application wording to justify a stronger functional category than its existing sharp-cutoff grouping.

Base

Not recorded

Socket

IO

Heater

10 V

Sections

1

Pentode

Russian universal short-characteristic pentode designed for voltage and power amplification and high-frequency oscillation to about 200 MHz. Manufacturer documentation specifies a 2,500-hour service-life guarantee and broad amplifier/oscillator capability.

Base

Not recorded

Socket

Not recorded

Heater

10 V

Sections

1

Pentode

Russian short-characteristic pentode intended for communications and general signal service. Manufacturer documentation specifies a 1,000-hour service-life guarantee and conventional voltage-amplifier operating characteristics.

Base

Not recorded

Socket

LOCTAL8

Heater

10 V

Sections

1

Pentode

Miniature frame-grid sharp-cutoff pentode with series/parallel heater arrangement, designed as a color-television video-output amplifier. Its high-transconductance construction is optimized for wideband video drive.

Base

9BF

Socket

Not recorded

Heater

11 V

Sections

1

Pentode

Pentode documented with nominal and typical operating conditions and associated with the 7AB7 family. Available source material supports conventional sharp-cutoff signal amplification without a stronger specialized functional identity.

Base

Not recorded

Socket

Not recorded

Heater

6.3 V

Sections

1

Pentode

Special low-microphonics version of the Sylvania 6C6 sharp-cutoff pentode, designed for receiver and amplifier stages requiring reduced mechanical noise. It uses a six-pin base and retains the electrical characteristics of the standard 6C6.

Base

Not recorded

Socket

Not recorded

Heater

6.3 V

Sections

1

Pentode

Sylvania triple-grid amplifier tube with published pentode, tetrode-connected, and triode-connected operating data. Its flexible electrode connections permit several amplifier configurations while retaining a conventional signal-amplifier role.

Base

8-V

Socket

Not recorded

Heater

7 V

Sections

1

Pentode

Sylvania triple-grid amplifier pentode with published operating characteristics and interelectrode capacitances. Manufacturer data establish conventional signal-amplifier service without sufficiently explicit evidence for a stronger functional category.

Base

8-V

Socket

Not recorded

Heater

7 V

Sections

1

Pentode

Sharp-cutoff voltage pentode designed for RF amplification with a series heater. Its abrupt cutoff characteristic suits fixed-gain high-frequency signal stages rather than automatic-gain-controlled remote-cutoff service.

Base

7BK

Socket

B7G

Heater

12.6 V

Sections

1

Pentode

Sharp-cutoff pentode with a separately connected suppressor grid for RF, IF, and general amplifier service. The independent suppressor connection permits additional circuit flexibility beyond ordinary fixed-suppressor pentodes.

Base

Not recorded

Socket

Not recorded

Heater

12.6 V

Sections

1

Pentode

Sharp-cutoff pentode designed as a television video amplifier. Part of the 12BY7A/12BV7/12DQ7 replacement family, it is fundamentally a high-transconductance wideband signal tube rather than an audio power-output pentode.

Base

9BF

Socket

B9A

Heater

12.6 V

Sections

1

Pentode

High-transconductance video-amplifier pentode with series/parallel heater operation. Its wideband fixed-gain characteristics are optimized for television video service rather than conventional low-frequency power output.

Base

Not recorded

Socket

B9A

Heater

12.6 V

Sections

1

Pentode

Sharp-cutoff pentode designed for television video amplification. It belongs to the 12BY7A/12BV7/12DQ7 replacement family and provides high-transconductance wideband signal gain rather than ordinary audio power output.

Base

9BF

Socket

B9A

Heater

12.6 V

Sections

1

Pentode

RCA 12CX6 sharp-cutoff 7-pin miniature pentode for low-voltage automobile radios operating directly from 12 V storage batteries.

Base

Not recorded

Socket

Not recorded

Heater

12.6 V

Sections

1

Pentode

Sylvania pentode documented with manufacturer electrical and operating data. The available source does not provide sufficiently clear application or cutoff terminology in the extracted material to justify a narrower functional classification beyond pentode.

Base

Not recorded

Socket

B7G

Heater

12.6 V

Sections

1

Pentode

Sharp-cutoff miniature pentode designed as an IF amplifier in color and black-and-white television receivers. Its fixed-gain high-frequency characteristics suit television intermediate-frequency signal stages.

Base

Not recorded

Socket

B7G

Heater

12.6 V

Sections

1

Pentode

Sharp-cutoff television video-amplifier pentode in the 12BY7A/12BV7/12DQ7 replacement family. Its high-frequency wideband characteristics make it a fixed-gain video signal tube rather than a conventional power pentode.

Base

9BF

Socket

B9A

Heater

12.6 V

Sections

1

Pentode

Seven-pin miniature sharp-cutoff pentode with manufacturer-published ratings, characteristics, and application information. Its abrupt transfer characteristic identifies it as a fixed-gain signal amplifier rather than a remote-cutoff AGC tube.

Base

Not recorded

Socket

B7G

Heater

12.6 V

Sections

1

Pentode

Seven-pin miniature sharp-cutoff pentode designed for low-voltage amplifier service from automotive battery supplies. It combines fixed-gain signal amplification with operating conditions suited to vehicle electrical systems.

Base

THE

Socket

B7G

Heater

12.6 V

Sections

1

Pentode

150 mA series-heater RF and IF pentode designed for high-frequency amplifier service. Manufacturer documentation provides nominal, operating, and maximum data for receiver signal stages using series heater strings.

Base

Not recorded

Socket

Not recorded

Heater

12.6 V

Sections

1

Pentode

Frame-grid sharp-cutoff pentode designed for video-amplifier service in color and black-and-white television receivers. Its high transconductance and wideband response suit demanding television video stages.

Base

9BF

Socket

B9A

Heater

12.6 V

Sections

1

Pentode

Frame-grid sharp-cutoff pentode designed for television video-amplifier service. Its specialized grid construction provides high transconductance and bandwidth for color and monochrome television signal amplification.

Base

9BF

Socket

B9A

Heater

12.6 V

Sections

1

Pentode

Frame-grid sharp-cutoff pentode used as a video-output amplifier in color television receivers. Its high-transconductance wideband construction provides the signal drive required by television video-output stages.

Base

9BF

Socket

B9A

Heater

12.6 V

Sections

1

Pentode

Russian universal pentode designed to withstand demanding ambient conditions. Bilingual manufacturer literature provides guaranteed electrical characteristics, but the available application wording is not specific enough to assign a narrower functional family conservatively.

Base

Not recorded

Socket

B8G

Heater

12.6 V

Sections

1

Pentode

Brimar RF pentode with documented pentode and triode-connected Class A operation. Its 12.6 V heater and high anode impedance suit fixed-gain high-frequency signal-amplifier service.

Base

7R

Socket

IO

Heater

12.6 V

Sections

1

Pentode

Sharp-cutoff RF pentode designed for Class A RF and IF amplifier service. Its abrupt cutoff characteristic suits fixed-gain receiver signal stages rather than automatic-gain-controlled variable-mu operation.

Base

8BK

Socket

Not recorded

Heater

12.6 V

Sections

1

Pentode

RF pentode with documented pentode and triode-connected Class A operation. Its signal-amplifier characteristics suit RF and general voltage-amplifier stages requiring a sharp-cutoff transfer characteristic.

Base

8N

Socket

IO

Heater

12.6 V

Sections

1

Pentode

Single-ended RF pentode designed for amplifier or anode-bend detector service in AC/DC equipment. Its ability to serve as a detector supplements its primary fixed-gain signal-amplifier function.

Base

8N

Socket

IO

Heater

12.6 V

Sections

1

Pentode

Russian universal short-characteristic pentode designed for voltage and power amplification and high-frequency oscillation to about 200 MHz. Manufacturer documentation specifies a 2,000-hour service-life guarantee.

Base

Not recorded

Socket

B8G

Heater

12.6 V

Sections

1

Pentode

Series-heater counterpart of the 7C7 sharp-cutoff general-purpose pentode amplifier. It provides fixed-gain signal amplification in equipment using series-connected heater strings.

Base

8V

Socket

LOCTAL8

Heater

12.6 V

Sections

1

Pentode

Sharp-cutoff seven-pin miniature pentode designed for television intermediate-frequency amplifier service. Its fixed-gain high-frequency characteristics suit IF stages in television receivers.

Base

Not recorded

Socket

B7G

Heater

15 V

Sections

1

Pentode

Low-noise, low-microphonic heater-cathode pentode designed for preamplifier service. RCA documentation emphasizes sensitive low-level amplification where both electrical noise and vibration-induced microphonics must be minimized.

Base

Not recorded

Socket

UX6

Heater

6.3 V

Sections

1

Pentode

Coated-filament sharp-cutoff pentode designed for Class A amplifier service. RCA later recommended type 1620 for new equipment, but the 1609 remains a fixed-gain signal amplifier with filamentary cathode construction.

Base

Not recorded

Socket

UX5

Heater

1.1 V

Sections

1

Pentode

Metal sharp-cutoff pentode electrically similar to the 6J7 but selected for low-microphonic applications. Manufacturer data include normal pentode and triode-connected operation for sensitive Class A signal amplification.

Base

7R

Socket

IO

Heater

6.3 V

Sections

1

Pentode

Sharp-cutoff dual-control-grid pentode designed for gated AGC and television noise-inverter service. The second control grid enables specialized gating and noise-control functions beyond ordinary fixed-gain pentode amplification.

Base

Not recorded

Socket

B7G

Heater

16 V

Sections

1

Pentode

Sharp-cutoff high-transconductance pentode co-designated 6AC7/1852. Manufacturer data specify substantial transconductance for Class A RF or IF amplification, making it a high-gain fixed-control signal tube.

Base

Not recorded

Socket

IO

Heater

6.3 V

Sections

1

Pentode

Sharp-cutoff miniature pentode for RF and IF amplification in AC/DC receivers using 100 mA series-heater strings.

Base

Not recorded

Socket

B7G

Heater

18 V

Sections

1

Pentode

Controlled-warm-up sharp-cutoff pentode for RF and IF amplification in transformerless series-heater receiver circuits.

Base

Not recorded

Socket

B7G

Heater

18 V

Sections

1

Pentode

Sharp-cutoff high-transconductance pentode for RF and IF voltage amplification, using an 18.9 V heater for series-string equipment.

Base

Not recorded

Socket

B9A

Heater

18.9 V

Sections

1

Pentode

Long-life sharp-cutoff pentode developed for voltage amplification in professional wire-communications equipment.

Base

E7-1

Socket

Not recorded

Heater

19 V

Sections

1

Pentode

Directly heated high-slope pentode for low-voltage RF and general voltage amplification in portable battery equipment.

Base

6AR

Socket

B7G

Heater

1.25 V

Sections

1

Pentode

Ultra-low-drain directly heated sharp-cutoff pentode for battery-operated RF and small-signal voltage amplification.

Base

6AR

Socket

B7G

Heater

1.4 V

Sections

1

Pentode

Directly heated sharp-cutoff RF pentode for fixed-gain Class-A amplification in battery receivers.

Base

4M

Socket

UX4

Heater

2 V

Sections

1

Pentode

Directly heated sharp-cutoff pentode for Class-A RF voltage amplification in economical battery-operated receivers.

Base

5Y

Socket

UX5

Heater

2 V

Sections

1

Pentode

Directly heated fixed-mu pentode for RF or audio-frequency voltage amplification in battery equipment.

Base

6AR

Socket

B7G

Heater

1.4 V

Sections

1

Pentode

Directly heated sharp-cutoff RF pentode for small-signal amplification in low-drain battery receivers.

Base

7AO

Socket

B8G

Heater

1.4 V

Sections

1

Pentode

Directly heated sharp-cutoff RF pentode for low-voltage battery receivers, providing high voltage gain with economical filament consumption.

Base

7AO

Socket

B8G

Heater

1.4 V

Sections

1

Pentode

Low-drain loctal battery RF pentode intended for radio-frequency amplifier service, related to the 1N5 receiving family.

Base

Not recorded

Socket

B8G

Heater

1.4 V

Sections

1