EC8010 — Small Signal Triode, Noval | Tubeofile

EC8010

Small Signal Triode — Noval

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Telefunken

↗ r-type.org ↗ TDSL ↗ Radiomuseum

Known Equivalents & Substitutes

8556

Similar Tubes (Not Drop-In Compatible)

6S45P

Soviet frame-grid single triode with very high gm (~45 mA/V) and low ra; similar high-gm low-ra triode concept, higher dissipation (7.8 W vs 4.2 W)

C3g

Siemens/Telefunken frame-grid pentode for Bundespost wideband amplifiers; similar professional-grade construction and tight tolerances, but pentode not triode

D3a

Siemens frame-grid pentode for professional wideband service; similar high-gm design philosophy, different structure

EC8020

Successor Telefunken frame-grid UHF triode with higher gm; same Noval base and design philosophy

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max operating)200V

Anode Dissipation (max)Anode Dissipation (max)4.2W

Cathode Current (max)Cathode Current (max)35mA

Heater-to-Cathode Voltage (max)Heater-Cathode Voltage (max)100V

Notes

Designated 'S.Q. Tube' (Special Quality) by Telefunken — tighter tolerances than standard receiving types.
Frame-grid construction provides exceptionally high transconductance (28 mA/V) for a small-signal triode.
Five grid pins (1, 3, 6, 7, 9) — all must be connected to suppress parasitic UHF oscillation.
Interface-free special cathode: no interface layer builds up even when heated without plate current for extended periods.
No-signal anode supply voltage (Uao) may reach 400 V; operating anode voltage limited to 200 V max.
Grid dissipation limited to 40 mW — grid current must be kept very low.
First published May 1963 (Funkschau #9); Telefunken datasheet dated December 1968 / January 1965.
Radiomuseum lists 8556 as a normally replaceable near-equivalent.
Popular in high-end audio as a low-impedance voltage amplifier and driver stage despite original UHF designation.

Pin Layout — Noval

1Grid

2Cathode

3Grid

Socket-Compatible Tubes ⚠ Not electrically compatible

EC8020

References