EF860

Small Signal Pentode — Noval

RFT

Known Equivalents & Substitutes

No known equivalents. If you know of any, use the ⚑ Report Issue button above.

Similar Tubes (Not Drop-In Compatible)

EF800

Corresponds to this type per RFT datasheet

Similar low-noise audio pentode on Noval base — different pinout and characteristics

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)250V

Screen Voltage (max)Screen Voltage (max)250V

Anode Dissipation (max)Anode Dissipation (max)2.1W

Screen Dissipation (max)Screen Dissipation (max)0.55W

Cathode Current (max)Cathode Current (max)13mA

Heater-to-Cathode Voltage (max)Heater-Cathode Voltage (max)150V

Typical Operating

Anode Voltage (typical)Anode Voltage210V

Screen Voltage (typical)Screen Voltage210V

Anode CurrentAnode Current10mA

Screen CurrentScreen Current2.6mA

Anode ResistanceInternal Resistance

Capacitances

Grid-to-Plate CapacitanceGrid-to-Anode Capacitance (max)0.012pF

Heater

Heater VoltageHeater Voltage6.3V

Heater CurrentHeater Current0.3A

Notes

Designed for long life in telecommunications preamplifier stages.
Also available as IF860 with 20 V / 95 mA heater for series-string operation.
Life test end point: Ia < 6.7 mA, Ig2 < 1.6 mA, S < 5 mA/V, -Ig1 > 1 uA.
Self-bias only — Rk = 220 ohm (Vg1 approx. -2.75 V).
Screen grid amplification factor mu_g2/g1 = 50.
Tube was noted as being in development ('Rohre befindet sich in der Entwicklung').

Pin Layout — Noval

1Suppressor Grid (g3)

2Cathode

3Suppressor Grid (g3)

References