849

Power Triode — DHT — Jumbo3

RCA

Known Equivalents & Substitutes

CV2669

Similar Tubes (Not Drop-In Compatible)

Smaller transmitting triode (75W Pa_max vs 300W); same general application class but much lower power capability

Smaller transmitting triode (100W Pa_max vs 300W); same UX4 pinout family but different base and much lower power rating

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Plate Voltage (max)3,000V

Anode Dissipation (max)Plate Dissipation (max)300W

Cathode Current (max)Plate Current (max)350mA

Typical Operating

Anode Voltage (typical)Plate Voltage (typical, Class A)3,000V

Grid 1 Bias VoltageGrid Voltage (Class A)-132V

Anode CurrentPlate Current (Class A)100mA

Anode ResistancePlate Resistance3,250Ω

TransconductanceTransconductance

Output

Output PowerOutput Power (Class A)100W

Load ImpedanceLoad Resistance (Class A)18,000Ω

Heater

Heater VoltageFilament Voltage11V

Heater CurrentFilament Current5A

Notes

DHT tube: the thoriated tungsten filament serves as the cathode; there is no heater-cathode isolation.
Maximum plate current is 350 mA.
The plate (anode) connection is made via a top cap; the base carries only filament and grid connections.
Class A amplifier at Va=3000V: Vg=-132V, Ia=100mA, mu=19, gm=5.8 mA/V, ra=3250 Ohm, rl=18000 Ohm, Po=100W.
Designed primarily for broadcast transmitter service; also used in high-power SE audio amplifiers.
Pa_max is 300W (CCS). The tube requires forced-air cooling in most installations at full ratings.
Filament may be operated on AC or DC. Grid bias voltage is referenced to filament midpoint.

Pin Layout — Jumbo3

1Filament

2Grid

3Filament

TCTop Cap —Plate (Top Cap)

Socket-Compatible Tubes ⚠ Not electrically compatible

References