NJ7P SQL Tube Database Query

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77
Sharp-Cutoff Pentode

EIA Base & Outline

Substitute Data

Preferred Substitutes ......................... 6C6
Substitutes ................................... 57
Source ........................................ RCA RC-13 - 1937

Application

Glass type used as biased detector or high-gain amplifier in radio receivers. Requires six-contact socket.

Mechanical Data

Bulb .......................................... ST-12
Base Type ..................................... Small 6-Pin
EIA Outline ................................... 12-6
EIA Base ...................................... 6F
Top Cap ....................................... Small Metal
Mounting Position ............................. Any

Electrical Data

Heater Voltage ................................ 6.3 V
Heater Current ................................ 0.3 A

Direct Interelectrode Capacitances (approx)

Pentode
Input ......................................... 4.7 pf
Output ........................................ 11.0 pf
Grid to Plate ................................. 0.007 pf

Maximum Ratings (Design Center Values)

Pentode
Plate Voltage ................................. 250 V
Grid No. 2 Voltage ............................ 100 V
Plate Current ................................. mA
Grid Current .................................. mA
Cathode Current ............................... mA
Grid No. 1 Circuit Resistance
Fixed Bias ................................. Ω
Self Bias .................................. Ω
Bulb Temperature (At Hottest Point) ........... °C

Characteristics and Typical Operation

Class A Amplifier
Plate Voltage ................................. 250 V
Grid No. 2 Voltage ............................ 100 V
Grid No. 1 Voltage ............................ -3 V
Amplification Factor .......................... 1500
Plate Resistance (approx) ..................... 1.5M Ω
Transconductance .............................. 1250 µ
Plate Current ................................. 2.3 mA
Grid No. 2 Current ............................ 0.5 mA
Grid No. 1 Voltage for Ib ..................... 0 µa @ -7.5 V

Class A Amplifier
Plate Voltage ................................. 100 V
Grid No. 2 Voltage ............................ 60 V
Grid No. 1 Voltage ............................ -1.5 V
Amplification Factor .......................... 715
Plate Resistance (approx) ..................... 650K Ω
Transconductance .............................. 1100 µ
Plate Current ................................. 1.7 mA
Grid No. 2 Current ............................ 0.4 mA
Grid No. 1 Voltage for Ib ..................... 0 µa @ -5.5 V

If you are uncertain about the EIA designator for a particular tube please use the "Index" button to list all the tubes in the database. You can click on the designator for the closest tube.

(c) 1994-2021 by William A. Beech, NJ7P

Sat, 25 Mar 2023 19:53:35 -0700