EF805S

Name: EF805S
Brand: Telefunken

Small Signal Pentode — Noval — Telefunken

Data: HighHigh quality — base, heater, all universal parameters present, and ≥50% of desirable parameters filled in. Safe to use for design decisions.

↗ Radiomuseum

Known Equivalents & Substitutes

EF85EF8656BY7

Similar Tubes (Not Drop-In Compatible)

19BY7

Brans Vademecum lists as equivalent. Same B9A base and similar characteristics but 19V series-string heater — not a drop-in in 6.3V heater circuits

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Ua max250V

Screen Voltage (max)Ug2 max250V

Anode Dissipation (max)Na2W

Screen Dissipation (max)Ng20.5W

Cathode Current (max)

Notes

Long-life tube: guaranteed 10,000 hours averaged over 100 tubes, provided heater voltage is kept within ±5%
Heater current differs between manufacturers: Telefunken specifies 285 mA, AEG specifies 300 mA
Pin 1 is internally connected to pin 3 (both cathode)
Rg1 max is 3 MΩ for automatic (cathode) bias, reduced to 1.5 MΩ for fixed bias
Free socket contacts must not be used for supporting any circuitry
EF85 is the standard-life equivalent but may differ slightly in heater current and max cathode current ratings

Pin Layout — Noval

1Cathode (connected to pin 3)

2Control Grid

3Cathode (connected to pin 1)

Socket-Compatible Tubes ⚠ Not electrically compatible

6F23 6GK6 AL860 EF183 EF184 EF80 EF800 XF184

References