6GV8

The 6GV8, also identified as ECL85 in the RCA manual, combines a high-gain triode section and a power-pentode section in one envelope. RCA presents it for sync-amplifier and video-output stages in television receivers; other sources describe uses in vertical-deflection generation and output. The two sections have their own connections and limits, so pentode data must not be read as triode data.

The 6GV8/ECL85 heater requires 6.3 V and 0.9 A according to the RCA table. The adjacent types 9GV8/XCL85, 10GV8/LCL85 and 18GV8/PCL85 have different heater ratings, although the same manual says they are otherwise identical. The base is a miniature nine-contact type with bottom-view basing 9LY: 4 and 5 are the heater; 1, 2 and 3 serve the triode plate, grid and cathode respectively; 6, 7, 8 and 9 are the pentode plate, screen grid, cathode with suppressor and control grid. The pinout is essential for distinguishing the two systems in one envelope.

In RCA's absolute-maximum table for a class A1 amplifier, both sections have a 550 V plate-supply limit and a 250 V DC plate-voltage limit. The triode has a maximum average cathode current of 15 mA and maximum plate dissipation of 0.5 W. The pentode has a maximum average cathode current of 75 mA and maximum plate dissipation of 7 W; for its screen grid RCA gives a 550 V supply limit, 250 V DC limit and 2 W maximum input. Supply and DC values are separate entries in the table, not peak voltages.

For a triode operating point at 100 V plate voltage and −0.8 V grid voltage, RCA gives an amplification factor of 50, plate resistance about 7,600 ohms and transconductance 6,500 µmhos. For the pentode, a characterisation point at 170 V on plate and screen with the control grid at −15 V gives 41 mA plate current. These are measurement conditions, not universal values for an apparatus.