6DS8

Triode-Hexode — Noval

Philips

Known Equivalents & Substitutes

Similar Tubes (Not Drop-In Compatible)

6AJ8

Brans lists in same group (Table VIb) — similar triode-heptode converter

ECH81

Same Noval base and pinout — reportedly identical internally to ECH83, only stamped differently

Electrical Specifications

Section 1 — Triode (Oscillator)

Typical Operating

Anode Voltage (typical)Anode Voltage12.6V

Anode CurrentAnode Current0.75mA

TransconductanceTransconductance1.4mA/V

Amplification Factor (μ)Amplification Factor18.3—

Section 2 — Heptode (Mixer)

Typical Operating

Anode Voltage (typical)Anode Voltage12.6V

Screen Voltage (typical)Screen Voltage (g2+g4)12.6V

Anode CurrentAnode Current0.55mA

Anode ResistanceInternal Resistance500,000Ω

TransconductanceConversion Conductance (Sc)

Heater

Heater VoltageHeater Voltage6.3V

Heater CurrentHeater Current0.3A

Notes

Valve Equivalents reference lists as Triode Pentode on B9A base — however radiomuseum and Brans classify correctly as triode-heptode.
Philips interchange confirms 6DS8=ECH83.
Brans Vademecum (Table VIb) lists with 6AJ8, 1B7G, 1C3/DK96, 1L6, and other frequency converters.
Muiderkring Handbook page 163 lists this type.

Pin Layout — Noval

1Heptode Anode

2Heptode Screen Grid (g2+g4)

3Common Cathode

Socket-Compatible Tubes ⚠ Not electrically compatible