ECH 81
0 Tubes in archive
BrandPhilips
ClassTriode-Heptode
BaseNoval
Filament6.3V @ 300mA
Construction
Primary TypeTriode-Heptode
EnvelopeGlass
SectionsDouble
Filament / Heater
Heater NotesIndirect heating; A.C. or D.C.; series or parallel supply
Absolute Maximum Ratings
Plate Voltage300 V
Plate Dissipation1.7 W
Grid 2 Voltage125 V
Grid 1 Voltage-1.3 V
Cathode Current12.5 mA
H-C Voltage150 V
Audio Performance
Power Output0.05 W
Key Features
- Indirectly heated
- Low microphonic effect
- Multi-purpose AM/FM mixer
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Heptode as Mixer | 250V | 750 | 1000000 | - | 3mA |
| Heptode as RF/IF Amplifier | 250V | 2400 | 700000 | - | 6.5mA |
| Triode section (Typical) | 100V | 3700 | - | 22 | 13.5mA |
Application Notes
Heptode section can be used without special precautions against microphonic effect in circuits where input voltage is >= 50mV for 50mW output.
Datasheet Viewer
Loading datasheet...
Sort by
Showing 1 to 0 of 0 results