UL2

Power Pentode — P8A

Valvo

Known Equivalents & Substitutes

No known equivalents. If you know of any, use the ⚑ Report Issue button above.

Similar Tubes (Not Drop-In Compatible)

Electrically identical to EL8 but uses Y8A steel base — different base from both EL8 and UL2

Successor type on Rimlock base — different base, not pin-compatible

Identical electricals but 6.3 V parallel heater — not a drop-in in series-string heater circuits

Electrical Specifications

Typical Operating

Anode Voltage (typical)Anode Voltage250V

Screen Voltage (typical)Screen Voltage250V

Grid 1 Bias VoltageGrid 1 Bias Voltage-7.5V

Anode CurrentAnode Current20mA

TransconductanceTransconductance

Heater

Heater VoltageHeater Voltage35V

Heater CurrentHeater Current0.1A

Notes

Series-heater (100 mA) version of the EL8/EL2. Electrically identical sections — only the heater voltage/current differs (35 V at 100 mA vs 6.3 V at 500 mA).
The suppressor 'grid' consists of only two rods and the plate is elliptical — a minimal suppressor structure typical of beam power designs.
Part of the Philips/Valvo transitional series for AC/DC receivers with series-string heaters.
Pin functions inferred from EL8/EL13 pinout — verify against original documentation before wiring.
A rare and poorly documented type. Maximum ratings carried over from EL8 data where available.

Pin Layout — P8A

1Screen Grid (inferred from EL13 Y8A pinout — verify before use)

2Control Grid (inferred from EL13 Y8A pinout — verify before use)

3Cathode + Suppressor Grid (inferred from EL13 Y8A pinout — verify before use)

Socket-Compatible Tubes ⚠ Not electrically compatible

References

5.5mA/V

4No Connection (inferred from EL13 Y8A pinout — verify before use)

5Heater (inferred from EL13 Y8A pinout — verify before use)

6Heater (inferred from EL13 Y8A pinout — verify before use)

7No Connection (inferred from EL13 Y8A pinout — verify before use)

8Anode (inferred from EL13 Y8A pinout — verify before use)