NJ7P SQL Tube Database Query

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28D7
Twin Beam Power Tube

EIA Base & Outline

Mechanical Data

EIA Outline ................................... 9-31
EIA Base ...................................... 8BS

Electrical Data

Heater Voltage ................................ 28.0 V
Heater Current ................................ 0.4 A

Characteristics and Typical Operation

Class A Amplifier
Plate Voltage ................................. 28 V
Grid No. 2 Voltage ............................ 28 V
Grid No. 1 Voltage Derived from
Cathode Bias Resistor ...................... 390 Ω
Plate Current ................................. 9.0 mA
Grid No. 2 Current ............................ 0.7 mA
Load Resistance ............................... 4K Ω
Power Output (approx) ......................... 0.08 W

Push Pull Class A Amplifier
Plate Voltage ................................. 28 V
Grid No. 2 Voltage ............................ 28 V
Grid No. 1 Voltage Derived from
Cathode Bias Resistor ...................... 180 Ω
Plate Current ................................. 18.5 mA
Grid No. 2 Current ............................ 1.2 mA
Load Resistance ............................... 6K Ω
Power Output (approx) ......................... 0.175 W

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 Jun 2022 16:58:01 -0700