High-Mu Triode - Beam Power Tube
The 6FM8 Vacuum tube is a duodecar type used in combined vertical-deflection oscillators and amplifiers in
color tv receivers. They require a duodecar 12-contact socket.
Electrical Data:
Heater Voltage ................................ 6.3 V
Heater Current ................................ 1.4 A
Maximum Heater-Cathode Voltage:
Heater Positive with Respect to Cathode
DC Component ............................ 100 V
Total DC and Peak ....................... 200 V
Heater Negative with Respect to Cathode:
DC Component ............................ 100 V
Total DC and Peak ....................... 200 V
Maximum Ratings (Design Center Values)
Pentode:
Plate Voltage ................................. 400 V
Grid No. 2 Voltage ............................ 300 V
Plate Dissipation ............................. 12 W
Grid No. 2 Dissipation ........................ 2.75 W
Grid No. 1 Circuit Resistance
Self Bias .................................. 1M Ω
Bulb Temperature (At Hottest Point) ........... 200 °C
Triode
Plate Voltage ................................. 400 V
Plate Dissipation ............................. 2.5 W
Grid No. 1 Circuit Resistance:
Fixed Bias ................................. 2.2M Ω
Self Bias .................................. 2.2M Ω
Bulb Temperature (At Hottest Point) ........... 200 °C
Characteristics and Typical Operation:
Triode Class A Amplifier
Plate Voltage ................................. 250 V
Grid No. 1 Voltage ............................ -4 V
Amplification Factor .......................... 58
Plate Resistance (approx) ..................... 14K Ω
Transconductance .............................. 4100 µMho
Plate Current ................................. 2.6 mA
Pentode Class A Amplifier
Plate Voltage ................................. 250 V
Grid No. 2 Voltage ............................ 250 V
Grid No. 1 Voltage ............................ -20 V
Plate Resistance (approx) ..................... 5K Ω
Transconductance .............................. 4100 µMho
Plate Current ................................. 50 mA
Grid No. 2 Current ............................ 3.5 mA
Grid No. 1 Voltage for Ib ..................... 100 µa @ -65 V
Vert Defl Amplifier:
DC Plate Supply Voltage ....................... 400 V
Peak Positive-Pulse Plate Voltage ............. 2500 V
DC Grid No. 2 Voltage ......................... 300 V
Average Cathode Current ....................... 75 mA
Peak Cathode Current .......................... 260 mA
Plate Dissipation ............................. 12 W
Grid No. 2 Dissipation ........................ 2.75 W
Substitute
Substitutes ................................... 6LU8