Input CapacitanceInput Capacitance (g1 to all except anode)14pF
Output CapacitanceOutput Capacitance (anode to all except g1)6pF
Section 2 — Triode Strapped
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)250V
Anode Dissipation (max)Anode Dissipation (max)8W
Cathode Current (max)Cathode Current (max)180mA
Typical Operating
Anode Voltage (typical)Anode Voltage250V
Heater
Heater VoltageHeater Voltage6.3V
Heater CurrentHeater Current1.05A
Notes
PL81 is the 300 mA series-heater equivalent (different heater specification, not a direct drop-in for 6.3 V parallel heater circuits).
Anode and screen dissipation limits are jointly defined by a combined Wa + Wg2 graph; TDSL lists Pa_max = 8 W and Ps_max = 4.5 W as individual limits.
Pins 6, 7, and 8 are internal connections (ic) per the Philips datasheet pinout diagram and must not be externally wired.
Va_max of 250 V applies to continuous operation as an A.F. amplifier; in line output (deflection) service, Va up to 550 V and Vs up to 550 V are permitted with appropriate pulse duty-cycle limits (max 22% of cycle, max 18 µs).
Triode-strapped data sourced from diyAudio forum discussion citing Philips EL81 datasheet (https://www.diyaudio.com/community/threads/is-the-6888-tube-worth-messing-with.356750/page-2), not directly visible in the fetched datasheet pages.