1LH4

Tube amp rating 50mA filament current; base lock-in (loctal) 8-pin glass envelope layout; high-mu vacuum tube diode-triode engineered to handle low-frequency signal detection and first-stage audio voltage amplification; voltage 1.4 Volts filament / 110 Volts plate maximum. Equivalents: Sylvania 1LH4, Philco 1LH4. Real-Life Examples: Vintage multi-band personal portable radios, mobile emergency radio base layouts, and historical laboratory test equipment panels.