Tube-number record
F-857-B
0 archive entries
F-857-B is a tube type in the TubeDatabase archive (class: Mercury Vapor Half-Wave Rectifier). Recorded specifications: brand Federal Telephone and Radio Corporation, year 1950, construction Rectifier, and maximum plate voltage 22000 V. The archive does not yet hold a photographed example of this type.
BrandFederal Telephone and Radio Corporation
ClassMercury Vapor Half-Wave Rectifier
Construction
Primary TypeRectifier
Rectifier TypeMercury Vapor
EnvelopeGlass
Sections1
Filament / Heater
MaterialMercury Vapor
Warm-up Time60s
Absolute Maximum Ratings
Plate Voltage22000 V
Cathode Current10000 mA
Audio Performance
Key Features
- Mercury vapor
- High-voltage rectifier
- Vertical mounting
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Single Phase - Half Wave (Circuit A) | 15500 V | — | — | — | 10000 mA |
| Single Phase - Full Wave (Circuit B) | 7750 V | — | — | — | 20000 mA |
| Single Phase - Full Wave Parallel (Circuit C) | 7750 V | — | — | — | 40000 mA |
| Single Phase - Full Wave Bridge (Circuit D) | 15500 V | — | — | — | 20000 mA |
| Three Phase - Half Wave (Circuit E) | 9000 V | — | — | — | 30000 mA |
| Double Three Phase - Half Wave (Circuit F) | 9000 V | — | — | — | 60000 mA |
| Three Phase - Full Wave (Circuit G) | 9000 V | — | — | — | 30000 mA |
| Six Phase - Half Wave (Circuit H) | 7750 V | — | — | — | 60000 mA |
Application Notes
For sine wave input and choke input filter to maintain output current substantially constant. Condensed mercury temperature should be measured in the specified zone near the base.
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