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NJ7P Tube Database Search 6550 Power Pentode

Base & Bulb ( RCA RC-29 - 1975)

Application

Glass octal type used in the output stages of high-fidelity audio amplifiers. Requires octal socket.

Mechanical Data

Bulb ...... ST-16 Base ...... Large Wafer Octal 8-Pin Mica with Metal Sleeve Maximum Overall Length ...... 4-3/4 In. Maximum Seated Height ...... 4-3/16 In. Maximum Diameter ...... 2-1/16 In. EIA Base ...... 7S Cathode ...... Coated Unipotential Mounting Position ...... Any

Electrical Data

Heater Voltage ...... 6.3 V Heater Current ...... 1.6 A Direct Interelectrode Capacitances (approx)

Pentode Input ...... 14 pf Output ...... 12 pf Grid to Plate ...... 0.85 pf

Maximum Ratings (Design Center Values)

Pentode Plate Voltage ...... 600 V Grid No. 2 Voltage ...... 400 V Plate Dissipation ...... 35 W

Characteristics and Typical Operation

Class A Amplifier Plate Voltage ...... 400 V Grid No. 2 Voltage ...... 225 V Grid No. 1 Voltage ...... -16.5 V Plate Resistance (approx) ...... 27K Ω Transconductance ...... 9000 µ Plate Current (Zero Signal) ...... 87 mA Plate Current (Maximum Signal) ...... 105 mA Grid No. 2 Current (Zero Signal) ...... 4 mA Grid No. 2 Current (Maximum Signal) ...... 18 mA Grid No. 1 Voltage for Ib ...... 1000 µa @ -35 V Load Resistance ...... 3K Ω Power Output (approx) ...... 20 W Total Harmonic Distortion ...... 13.5 %

Class A Amplifier Plate Voltage ...... 250 V Grid No. 2 Voltage ...... 250 V Grid No. 1 Voltage ...... -14 V Plate Resistance (approx) ...... 12K Ω Transconductance ...... 11000 µ Plate Current (Zero Signal) ...... 140 mA Plate Current (Maximum Signal) ...... 150 mA Grid No. 2 Current (Zero Signal) ...... 12 mA Grid No. 2 Current (Maximum Signal) ...... 28 mA Grid No. 1 Voltage for Ib ...... 1000 µa @ -40 V Load Resistance ...... 1500 Ω Power Output (approx) ...... 12.5 W Total Harmonic Distortion ...... 7 %

Push Pull Class A Amplifier Plate Voltage ...... 400 V Grid No. 2 Voltage ...... 275 V Grid No. 1 Voltage ...... -25 V Plate Current (Zero Signal) ...... 180 mA Plate Current (Maximum Signal) ...... 270 mA Grid No. 2 Current (Zero Signal) ...... 9 mA Grid No. 2 Current (Maximum Signal) ...... 44 mA Load Resistance ...... 3500 Ω Power Output (approx) ...... 55 W

Push Pull Class A Amplifier Plate Voltage ...... 600 V Grid No. 2 Voltage ...... 300 V Grid No. 1 Voltage ...... -33 V Plate Current (Zero Signal) ...... 100 mA Plate Current (Maximum Signal) ...... 280 mA Grid No. 2 Current (Zero Signal) ...... 3 mA Grid No. 2 Current (Maximum Signal) ...... 33 mA Load Resistance ...... 5000 Ω Power Output (approx) ...... 100 W

Push Pull Class A Amplifier Plate Voltage ...... 400 V Grid No. 2 Voltage ...... 300 V Grid No. 1 Voltage Derived from Cathode Bias Resistor ...... 140 Ω Plate Current (Zero Signal) ...... 166 mA Plate Current (Maximum Signal) ...... 190 mA Grid No. 2 Current (Zero Signal) ...... 7.5 mA Grid No. 2 Current (Maximum Signal) ...... 39 mA Load Resistance ...... 4500 Ω Power Output (approx) ...... 41 W

Push Pull Class A Amplifier (Triode Connected) Plate Voltage ...... 450 V Grid No. 2 Voltage ...... 450 V Grid No. 1 Voltage ...... -46 V Plate Current (Zero Signal) ...... 150 mA Plate Current (Maximum Signal) ...... 220 mA Load Resistance ...... 4000 Ω Power Output (approx) ...... 28 W Total Harmonic Distortion ...... 2.5 %

Push Pull Class AB1 Amplifier Plate Voltage ...... 400 V Grid No. 2 Voltage ...... 300 V Grid No. 1 Voltage Derived from Cathode Bias Resistor ...... 140 Ω Peak Grid No. 1 Voltage...... 20 V Plate Current (Zero Signal) ...... 166 mA Plate Current (Maximum Signal) ...... 190 mA Grid No. 2 Current (Zero Signal) ...... 7.5 mA Grid No. 2 Current (Maximum Signal) ...... 39 mA Load Resistance ...... 4500 Ω Power Output (approx) ...... 41 W Total Harmonic Distortion ...... 4 %

Push Pull Class AB1 Amplifier Plate Voltage ...... 400 V Grid No. 2 Voltage ...... 275 V Grid No. 1 Voltage ...... -23 V Peak Grid No. 1 Voltage...... 17 V Plate Current (Zero Signal) ...... 180 mA Plate Current (Maximum Signal) ...... 270 mA Grid No. 2 Current (Zero Signal) ...... 9 mA Grid No. 2 Current (Maximum Signal) ...... 44 mA Load Resistance ...... 3500 Ω Power Output (approx) ...... 55 W Total Harmonic Distortion ...... 3 %

Push Pull Class AB1 Amplifier Plate Voltage ...... 600 V Grid No. 2 Voltage ...... 300 V Grid No. 1 Voltage ...... -16.5 V Peak Grid No. 1 Voltage...... 23 V Plate Current (Zero Signal) ...... 115 mA Plate Current (Maximum Signal) ...... 273 mA Grid No. 2 Current (Zero Signal) ...... 4 mA Grid No. 2 Current (Maximum Signal) ...... 41 mA Load Resistance ...... 5000 Ω Power Output (approx) ...... 100 W Total Harmonic Distortion ...... 2.5 %

Push Pull Class AB1 Amplifier (Ultra-Linear) Plate Voltage ...... 450 V Grid No. 3 Voltage ...... 43% of Primary Winding V Grid No. 2 Voltage ...... 450 V Grid No. 1 Voltage ...... -48 V Peak Grid No. 1 Voltage...... 35.5 V Plate Current ...... 150 mA Load Resistance ...... 3300 Ω Power Output (approx) ...... 70 W Total Harmonic Distortion ...... 2.5 %

Characteristic Curves