Tube-number record
920
0 archive entries
920 is a tube type in the TubeDatabase archive (class: Twin Phototube). Recorded specifications: brand RCA, year 1938, construction Other / special, base Small-Shell Small 4-Pin (A4-5), socket 4-pin, and maximum plate voltage 90 V. The archive does not yet hold a photographed example of this type.
BrandRCA
ClassTwin Phototube
Base4-pin
Construction
Primary TypeOther / special
EnvelopeT-9
Base MaterialSmall-Shell Small 4-Pin (A4-5)
SectionsTwin
Filament / Heater
Absolute Maximum Ratings
Plate Voltage90 V
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Gas Amplification Test | 90 V | — | 2500000 | 9 | 0.002 mA |
Application Notes
Intended for sound-on-film reproduction using either transformer or resistance coupling. Load resistance should be at least 2.5 Megohms for supply voltages of 90V and currents above 1 uA.
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