19AJ8

Triode-Hexode — Noval

Philips

Known Equivalents & Substitutes

Similar Tubes (Not Drop-In Compatible)

12AJ8

Same structure but 12.6V heater — different series-string voltage

6AJ8

Same structure and Noval pinout but 6.3V heater — Brans lists in same group

6DS8

Brans lists in same group — similar triode-heptode converter

ECH81

Same triode-heptode structure and Noval pinout but 6.3V heater — not interchangeable in series-string circuits

Electrical Specifications

Section 1 — Triode (Oscillator)

Typical Operating

Anode Voltage (typical)Plate Voltage100V

Anode CurrentPlate Current9mA

TransconductanceTransconductance5.5mA/V

Section 2 — Heptode (Mixer)

Absolute Maximum

Anode Voltage (max)Max Plate Voltage

Notes

19V/0.1A heater for series-string operation in AC/DC receivers (no transformer).
Valve Equivalents reference lists as 'Triode Heptode' with Noval (B9A) base.
UCH81 is the European designation for the identical tube with 'U' prefix indicating 100mA series heater.
Brans Vademecum table VIb cross-lists with ECH81, ECH83, and many other converter types.

Pin Layout — Noval

1Heptode Signal Grid (g1h)

2Heptode Plate

3Heptode Grids 2&4 (Screen)