Noval 6.3V/0.6A full-wave rectifier, but JEDEC 9M pinout with single shared cathode — different pin arrangement and no voltage-doubler capability
Electrical Specifications
Absolute Maximum
Anode Voltage (max)AC Plate-Supply Voltage per Plate (max RMS, choke-input)450V
Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)500V
Rectifier
Peak Inverse VoltagePeak Inverse Voltage (absolute max)1,450V
Voltage Drop (typical)Tube Voltage Drop (≈ at 50 mA per plate, read from Average Plate Characteristics curve)
Notes
Generic type 412A — the Bendix 6754 is the industrial/hard-glass (Nonex) equivalent of the Western Electric 412A. Bendix guarantees 10,000 hour life expectancy under conservative operation.
Separate cathodes for each diode section (pins 5 and 6). This is the key architectural difference from conventional full-wave rectifiers like 6X4/EZ80 which share a single cathode — the 6754 can be used as either a full-wave centre-tap rectifier OR a voltage doubler by appropriate external wiring.
JEDEC base code 9ET uses the B9A (Noval) envelope but with a rectifier-specific pinout. NOT pin-compatible with 6203 (9CD) or EZ80 (9M) — each of these Noval rectifiers uses a different pin arrangement.
Hard-glass (Nonex) bulb and tungsten-nonex stem seal permit bulb temperatures up to 300 °C (vs ~175 °C for soft-glass tubes). Nickel pins are gold-plated for low contact resistance.
Heater-cathode voltage rating 500 V (design max); design test condition Ehk ±500 V.
Ratings derate with operation: conservative 85 mA DC output (0-20,000 ft, max life), typical 90 mA (60,000 ft, high life), maximum 100 mA (80,000 ft, medium life).
Peak plate current per plate 300 mA (design centre) / 330 mA (absolute max); peak surge 1.1 A.
Vdrop ≈ 12 V at 50 mA per plate, read from the Average Plate Characteristics curve (page 3 of the Bendix datasheet) — at the typical 100 mA total DC output with choke input (50 mA per plate conducting half-cycle). At 100 mA per plate Vdrop rises to ~19 V.
Cathode heating time 45 seconds — allow warm-up before applying plate voltage.
Each tube undergoes a 45-hour run-in under overload/vibration/shock prior to test to eliminate infant-mortality failures.