14E6 — Duplex-Diode High-Mu Triode

The 14E6 is an indirectly heated multi-unit vacuum tube containing a triode section and two diode units within a single envelope. It is classified as a duplex-diode high-mu triode and is designed for receiving-tube applications, including Class A voltage amplification.

Heater and Physical Specifications

The 14E6 is equipped with an indirectly heated cathode. The heater is designed for operation with the following nominal ratings:

• Heater Voltage: 12.6 V

• Heater Current: 0.15 A

Physically, the tube is constructed according to the 9-30 outline drawing. It features an 8W base connection configuration, which utilizes an eight-pin base layout with a central indexing key to ensure correct orientation in its socket.

Electrical Characteristics and Class A Operating Point

The triode section of the 14E6 is rated for a maximum plate voltage of 250 V. Under typical Class A amplifier operating conditions, the triode section exhibits the following electrical characteristics:

• Plate Voltage: 250 V

• Negative Grid Voltage: 9.0 V

• Plate Current: 9.5 mA

• Plate Resistance ($r_p$): 8,500 ̩

• Transconductance ($g_m$): 1,900 µmhos

• Amplification Factor ($μ$): 16

At this operating point, the tube provides a moderate amplification factor of 16. The relationship between the triode's parameters can be verified mathematically: multiplying the transconductance by the plate resistance ($0.0019 \text{ S} \times 8,500 \ \Omega$) yields a calculated value of approximately 16.15, which closely aligns with the published amplification factor of 16.

The duplex-diode portion of the tube consists of two independent diode anodes sharing the common cathode structure, suitable for detection or automatic volume control functions, though specific operating parameters for the diode elements are not tabulated.

Technical Summary

The 14E6 is a duplex-diode high-mu triode vacuum tube featuring a 12.6 V, 0.15 A heater, an 8W base, and a 9-30 physical outline. It is designed to operate at a maximum plate voltage of 250 V. In typical Class A amplifier service, the triode section operates with a 9.0 V negative grid bias, drawing 9.5 mA of plate current, and provides an amplification factor of 16 with a plate resistance of 8,500 ̩ and a transconductance of 1,900 µmhos.