EF80

Name: EF80
Brand: Philips

Small Signal Pentode — Noval — Philips

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

↗ r-type.org ↗ TDSL ↗ Radiomuseum

Known Equivalents & Substitutes

6BX6Z719CV1376

Similar Tubes (Not Drop-In Compatible)

EF800

Special quality version of EF80 with tighter tolerances — electrically equivalent, drop-in compatible, but selected for professional use

Electrical Specifications

Section 1 — Pentode

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)300V

Screen Voltage (max)Screen Voltage (max)300V

Anode Dissipation (max)Anode Dissipation (max)2.5W

Screen Dissipation (max)Screen Dissipation (max)0.7W

Notes

Cathode is brought out to two pins (pins 1 and 3) to reduce input impedance degradation at high frequencies. For input impedance measurements and optimal RF performance, both cathode pins must be connected to the input return; output circuit should connect to the other cathode pin.
Fixed bias is not recommended by Tesla datasheet. When using grid leak resistor of 0.2 MΩ, it is insufficient to develop the required negative bias — cathode bias resistor is needed.
Suppressor grid (g3) is brought out to a separate pin (pin 9) and is internally connected in the standard Noval base arrangement. Must be connected to cathode externally.
When used as video amplifier, gain between control grid input and cathode ray tube input should not exceed 25 to prevent microphonic effects.
Rg_max depends on bias method: 0.5 MΩ for fixed bias, 1 MΩ for cathode (self) bias.
Triode-strapped data sourced from Tom Schlangen 'Pentodes Strapped as Triodes' (2009 measured data table), not from the manufacturer datasheet.

Pin Layout — Noval

1Cathode

2Control Grid (g1)

3Cathode

Socket-Compatible Tubes ⚠ Not electrically compatible

6F23 6GK6 AL860 EF183 EF184 EF800 EF805S XF184

References