6N21B is a subminiature dual triode, designed for operation as a low-frequency voltage amplifier.
Cathode: indirectly heated, oxide-coated.
Operating position: any.
Envelope: miniature glass.
Service life: at least 2,000 h.
Weight: less than 4.5 g.
General Performance Characteristics for 6N21B:
Nominal Values:
• Heater voltage, V 6.3 ±0.6
• Heater current, mA 395 ±35
• Anode voltage, V 200
• Anode circuit current, mA 3.5 ±1.3
• Mutual conductance, мА/V 3.8 ±1.2
• Cathode circuit resistance, Ohm 330
• Reverse grid current, µA less than 0.2
• Amplification factor 82 ±17
Limiting Values:
• Maximum anode voltage, V 250
• Maximum anode voltage when the tube is cutoff, V 350
• Negative grid voltage, V -50
• Maximum cathode circuit current, mA 10
• Maximum anode dissipation, W 1.0
• Maximum heater-cathode voltage, V 150
•Maximum grid resistance, mOhm 2
