Tube-number record
X719 / ECH81
0 archive entries
X719 / ECH81 is a tube type in the TubeDatabase archive (class: Triode-Heptode). Recorded specifications: brand Marconi, year 1958, construction Indirectly heated, socket Noval (B9A), maximum plate voltage 300 V, and maximum plate dissipation 1.7 W. The archive does not yet hold a photographed example of this type.
BrandMarconi
ClassTriode-Heptode
BaseNoval (B9A)
Filament6.3 V @ 300 mA
Construction
Primary TypeIndirectly heated
EnvelopeTubular
SectionsTriode-Heptode
Filament / Heater
Heater NotesIndirectly heated
Absolute Maximum Ratings
Plate Voltage300 V
Typical Operation
| Mode | Plate V | Gm (µmhos) | Rp (Ω) | µ | Plate mA |
|---|---|---|---|---|---|
| Triode Section | 100 V | 3700 | — | 22 | 13.5 mA |
| Heptode Section as r.f. or i.f. Amplifier | 250 V | 2400 | 700000 | — | 6.5 mA |
| Heptode Section as a.m. Frequency Changer | 250 V | 775 | 1000000 | — |
Application Notes
Primarily designed for use as a frequency changer. Rg1-k is 3 megohms.
0 results