Electrically identical but Octal (IO) base instead of P8A side-contact — not pin-compatible
EL5G
Glass envelope variant with different bulb shape — check base compatibility
Electrical Specifications
Absolute Maximum
Anode Dissipation (max)Anode Dissipation (max)18W
Typical Operating
Anode Voltage (typical)Anode Voltage250V
Screen Voltage (typical)Screen Voltage250V
Grid 1 Bias VoltageGrid 1 Bias Voltage-16V
Notes
Heater power is only 8.4 W for 18 W anode dissipation — exceptionally favorable ratio for the era.
Transconductance (7 mA/V) is notably higher than contemporary 9 W pentodes like the EL2 (2.8 mA/V), requiring only 0.5 Veff input for 50 mW output sensitivity.
Anode and screen voltage are both 250 V — no separate high-voltage supply needed, simplifying power supply design.
Heater current of 1.35 A (later reduced in successor EL3N to 0.9 A) makes this tube unsuitable for series-heater strings.
Anode connection is via top cap. The P8A side-contact base carries heater, cathode, grids, and metallization.
For 5 W output at slightly above 5% THD, or 7.7 W at 10% THD in Class A single-ended operation.
Pin Layout — P8A
1Control Grid
2Cathode
3Heater
4
Socket-Compatible Tubes ⚠ Not electrically compatible