Tube-number record
21FMP4
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BrandGeneral Electric
ClassCathode Ray Tube
BaseCRT base (B7 family)
Filament6.3 V @ 600 mA
Construction
Primary TypeDisplay / CRT
EnvelopeRectangular
Sections1
Filament / Heater
Warm-up Time11s
Heater NotesWarm-up time 11 seconds
Absolute Maximum Ratings
Plate Voltage22000 V
Grid 2 Voltage100 V
Grid 1 Voltage-140 V
H-C Voltage180 V
Audio Performance
Key Features
- Electrostatic focus
- Magnetic deflection
- Aluminized screen
- Non ion-trap gun
- External conductive coating
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Cathode Drive Service | 18000 V | — | — | — | — |
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