Tube-number record
8CN7
0 archive entries
8CN7 is a tube type in the TubeDatabase archive (class: Duplex-Diode High-Mu Triode). Recorded specifications: brand Tung-Sol, year 1956, construction Multi-section, base Small Button (9EN), socket Noval (B9A), maximum plate voltage 400 V, and maximum plate dissipation 1 W. The archive does not yet hold a photographed example of this type.
BrandTung-Sol
ClassDuplex-Diode High-Mu Triode
BaseNoval (B9A)
Filament8.4 V @ 225 mA
Construction
Primary TypeMulti-section
EnvelopeGlass
Base MaterialSmall Button (9EN)
Sections3
Filament / Heater
Warm-up Time11s
Heater NotesSeries or Parallel connection; Heater warm-up time applies to parallel connection only.
Absolute Maximum Ratings
Plate Voltage400 V
Plate Dissipation1 W
Cathode Current5 mA
H-C Voltage200 V
Audio Performance
Key Features
- Coated Unipotential Cathode
- Controlled heater warm-up time
- Separate cathodes for diode and triode sections
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Class A1 Amplifier | 100 V | 1300 | 54000 | 70 | 0.8 mA |
| Class A1 Amplifier | 250 V | 1200 | 58000 | 70 | 1 mA |
Application Notes
Intended for service as a combined horizontal phase detector and reactance tube in television receivers.
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