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Preferred Substitutes ......................... EL503
Source ........................................ GE - 1973
Beam power pentode intended as a AF power amplifier.
Bulb .......................................... T-9
Base Type ..................................... Magnoval
Maximum Overall Height ........................ 3.38 In.
Maximum Seated Height ......................... 3.00 In.
Maximum Diameter .............................. 1.18 In.
EIA Base ...................................... 9QB
Heater Voltage ................................ 6.3 V
Heater Current ................................ 1.2 A
Pentode
Input ......................................... 22.5 pf
Output ........................................ 13.5 pf
Grid to Plate ................................. 1.7 pf
Pentode
Plate Voltage ................................. 300 V
Grid No. 3 Voltage ............................ 300 V
Plate Dissipation ............................. 25 W
Grid No. 2 Dissipation ........................ 4.0 W
Class A Amplifier
Plate Voltage ................................. 250 V
Grid No. 2 Voltage ............................ 250 V
Grid No. 1 Voltage ............................ -12.5 V
Plate Resistance (approx) ..................... 7.3K Ω
Transconductance .............................. 24000 µ
Plate Current ................................. 100 mA
Grid No. 2 Current ............................ 8.0 mA
Push Pull Class AB1 Amplifier
Plate Voltage ................................. 265 V
Grid No. 2 Voltage ............................ 265 V
Grid No. 1 Voltage Derived from
Cathode Bias Resistor ...................... 56 Ω
Plate Current ................................. 200 mA
Grid No. 2 Current ............................ 16.0 mA
Power Output (approx) ......................... 40 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
Sun, 05 Feb 2023 19:28:36 -0700