6I1P-EV (original box)

The 6I1P-EV (6И1П-ЕВ rus.) triode-heptode of increased durability, reliability and mechanical strength. Designed for frequency conversion with simultaneous automatic gain control in broadcasting receivers.
The 6I1P-EV triode-heptode is used in radio receiving equipment and other radio engineering devices for general and special purposes. Works in any position.

The 6I1P-EV heptode triode is equivalent to the ECH81 and 6AJ8 tubes.

E – characterizing the increased durability of the tube;
V – tube with increased reliability and mechanical strength.

Technical specifications:

• Heating voltage: 6.3V
• Heptode anode voltage: 250V
• Voltage on the second and fourth grids: 100V
• Voltage on the third grid of the heptode: – 9.4V
• Bias voltage on the first grid of the heptode: – 2V
• Bias voltage on the first grid of the triode: – 9.4V
• Triode anode voltage: 100V
• Heating current: 300 ± 25mA
• Current in triode anode circuit: 11 ± 4mA
• Current in the heptode anode circuit: 3.3 ± 1.2mA
• Current in the circuit of the second and fourth grids: 6 ± 2mA
• Current in the circuit of the third heptode grid: 200µA
• Current in the circuit of the first grid of the triode: 200µA
• Heptode conversion steepness: 0.77mA/V
• Heptode internal resistance: 1MOhm
• Triode slope: 3.7mA/V
• Triode Gain 25

Operating time not less than 750 hours.