EF14

EF14 has no equivalent designation confirmed by the archive.

The EF14 is a pentode vacuum tube. The Telefunken datasheet for the EF14 specifies its characteristics and ratings for operation with automatic grid bias generation only.

Characteristics

At a heater voltage of 6.3 V, an anode voltage of 200 V, a screen-grid voltage of 200 V, a suppressor-grid voltage of 0 V, and a grid bias of -3 V, the anode current is 33 mA typical, with minimum and maximum values of 20 mA and 45 mA. At a heater voltage of 5.8 V, the anode current is on average 5 mA lower. Heater current at 6.3 V is 470 mA ± 10%.

At a heater voltage of 6.3 V, an anode voltage of 200 V, a screen-grid voltage of 200 V, a suppressor-grid voltage of 0 V, and an anode current of 12 mA, the transconductance is 5.5 mA/V minimum and 9.5 mA/V maximum. Under the same conditions, the grid bias ranges from -3.5 V minimum to -6.5 V maximum, and the screen-grid current ranges from 1.15 mA minimum to 4 mA maximum.

Input capacitance is 9 to 10 pF, with a mean of 9.5 pF. Output capacitance is 7.6 to 8.8 pF, with a mean of 8.2 pF. Grid-1 to anode capacitance is less than 0.01 pF. The grid voltage at the onset of grid current (with Ia1 ≤ 0.3 μA) is -1.3 V.

Ratings

Maximum operating voltages are 300 V for the anode and suppressor grid, and 200 V for the screen grid. Maximum cold voltages are 550 V for the anode, suppressor grid, and screen grid. Maximum anode dissipation is 5 W, and maximum screen-grid dissipation is 0.7 W. Maximum cathode current is 30 mA, and maximum grid-leak resistance is 0.5 MΩ. Maximum voltage between heater and cathode is 100 V, with an external resistance between heater and cathode of 20 kΩ.

Physical Data

The maximum weight of the EF14 is 40 g.

Original manufacturer datasheets for EF14, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• **TELEFUNKEN**