Tube-number record
4028A
0 archive entries
4028A is a tube type in the TubeDatabase archive (class: High-Mu Triode). Recorded specifications: brand RCA, year 1965, construction Triode, base Ceramic-Metal, socket Planar / disc seal, maximum plate voltage 300 V, and maximum plate dissipation 2.5 W. The archive does not yet hold a photographed example of this type.
BrandRCA
ClassHigh-Mu Triode
BasePlanar / disc seal
Filament6.3 V @ 0.3 mA
Construction
Primary TypeTriode
EnvelopePencil
Base MaterialCeramic-Metal
SectionsSingle
Filament / Heater
Warm-up Time10s
Heater NotesUnipotential Cathode
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| RF Power Amplifier Class C | 250 V | 22500 | — | 70 | 31 mA |
| RF Power Amplifier Class C | 300 V | 22500 | — | 70 | 35 mA |
| Plate Pulsed Oscillator | 1750 V | — | — | — | 2.5 mA |
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