PL38 — Power Pentode, Octal | TubeofileKnown Equivalents & Substitutes
No known equivalents. If you know of any, use the ⚑ Report Issue button above.
Similar Tubes (Not Drop-In Compatible)
6CN6
American designation for EL38 — same electrical characteristics but 6.3V heaterSame electrical characteristics but 6.3V/1.4A parallel heater — not a drop-in in 300mA series-string circuits Electrical Specifications
Section 1 — Pentode
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)800V
Screen Voltage (max)Screen Voltage (max)400V
Anode Dissipation (max)Anode Dissipation (max)25W
Screen Dissipation (max)Screen Dissipation (max)8W
Cathode Current (max)Cathode Current (max)200mA
Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)100V
Max Grid ResistorMax Grid Resistor (Pa < 25 W)0.5MΩ
Typical Operating
Anode Voltage (typical)Anode Voltage275V
Screen Voltage (typical)Screen Voltage275V
Grid 1 Bias VoltageGrid 1 Bias Voltage-9V
Anode CurrentAnode Current91mA
Screen CurrentScreen Current
Capacitances
Grid-to-Plate CapacitanceGrid-to-Plate Capacitance1.2pF
Input CapacitanceInput Capacitance18pF
Output CapacitanceOutput Capacitance8pF
Section 2 — Triode Strapped
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)400V
Anode Dissipation (max)Anode Dissipation (max)25W
Cathode Current (max)Cathode Current (max)200mA
Typical Operating
Anode Voltage (typical)Anode Voltage300V
Heater
Heater VoltageHeater Voltage30V
Heater CurrentHeater Current0.3A
Notes
- 300mA series-string heater (30V/0.3A) for AC/DC TV receivers. The 'P' prefix in Mullard/Philips nomenclature denotes a 300mA heater string design.
- Valve Equivalents database confirms I/O base (Octal with top cap), 30V heater.
- Philips interchange lists PL38 with no cross-reference — no known American equivalent designation.
- Electrically identical to EL38 in all electrode characteristics; only the heater differs.
- Not interchangeable with EL38/6CN6 without heater circuit modification.
Pin Layout — Octal
1Suppressor Grid
2Heater
3No Connection
4
Socket-Compatible Tubes ⚠ Not electrically compatible
11mA
Anode ResistanceAnode Resistance20Ω
TransconductanceTransconductance14mA/V
Amplification Factor (μ)Amplification Factor (g1-g2)16.5—
Cathode Resistor (self-bias)Cathode Resistor (self-bias)120Ω
Anode CurrentAnode Current
60mA
Anode ResistanceAnode Resistance1,000Ω
TransconductanceTransconductance12mA/V
Amplification Factor (μ)Amplification Factor (μ)12—
Output
Output PowerOutput Power3.6W
Load ImpedanceLoad Impedance3,100Ω
Screen Grid
TCTop Cap —Anode (Top Cap)