EL53

Power Pentode — P8A

+ Compare

Philips

↗ Radiomuseum

Known Equivalents & Substitutes

EL3/425

Similar Tubes (Not Drop-In Compatible)

4694

Related type listed as similar by Radiomuseum

EL3

Original design with lower voltage rating and higher heater current (1.2 A vs 0.9 A)

EL3/375

Intermediate voltage-rated variant (375 V) of the same family

EL3N

Same base and similar characteristics but lower voltage rating (250 V vs 425 V) — the EL53 is a voltage-selected EL3N

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)425V

Screen Voltage (max)Screen Voltage (max)425V

Anode Dissipation (max)Anode Dissipation (max)9W

Screen Dissipation (max)Screen Dissipation (max, at max output)2.5W

Cathode Current (max)Cathode Current (max)

Notes

The EL53 is identical to the EL3/425 designation — a factory-selected EL3N rated for 425 V anode and screen operation.
Anode connection is via top cap. The P8A side-contact base carries heater, cathode, grids, and metallization.
Maximum voltage ratings significantly higher than the standard EL3/EL3N (250 V), enabling use in higher-power push-pull configurations.
Heater current 0.9 A (same as EL3N, using the improved profile-cathode design).
Electrical characteristics at the standard 250 V operating point are identical to the EL3N.

Pin Layout — P8A

1Control Grid

2Cathode

3Heater

Socket-Compatible Tubes ⚠ Not electrically compatible

EL2 EL3 EL3N EL5

55mA

Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)100V

Max Grid ResistorMax Grid Resistor1MΩ

Typical Operating

Anode Voltage (typical)Anode Voltage (typical)250V

Screen Voltage (typical)Screen Voltage (typical)250V

Grid 1 Bias VoltageGrid 1 Bias Voltage-6V

Anode CurrentAnode Current36mA

Screen CurrentScreen Current4mA

Anode ResistanceAnode Resistance50,000Ω

TransconductanceTransconductance9mA/V

Cathode Resistor (self-bias)Cathode Resistor (self-bias)150Ω

Output

Output PowerOutput Power4.5W

Load ImpedanceLoad Impedance7,000Ω

Heater

Heater VoltageHeater Voltage6.3V

Heater CurrentHeater Current0.9A

Heater

5Screen Grid

6Metallization (external shield)

7Suppressor Grid (internally connected to cathode)

8No Connection

TCTop Cap —Anode (top cap)