TUBEOFILE
RE084 — Small Signal Triode, B4 | Tubeofile | Tubeofile
← Browse Medium quality — at least 60% of universal parameters and pins are present, but some key data is missing. Verify specific values against datasheets before critical use.
Known Equivalents & Substitutes
A408 A415 L409 KL70406 LD410
Electrical Specifications
Absolute Maximum
Anode Voltage (max) Max Anode Voltage 150V
Typical Operating
Anode Voltage (typical) Anode Voltage 100V
Anode Current Anode Current 4mA
Anode Resistance Anode Resistance 10,000Ω
Notes
Introduced by Telefunken circa 1927 for battery-powered receivers; filament designed for a 4 V battery supply. Directly heated: the filament doubles as the cathode. Bias the negative filament end to set operating point. Known equivalents: A408 (Valvo), A415 (Philips/RT), L409 (Zenith), KL70406 (Tungsram), LD410 (Tungsram) — all pin-for-pin compatible on the B4 base. RE084k and RE084s are variants with slightly different filament or envelope construction but the same electrical characteristics and B4 base. Pin Layout — B4
1 2 3 4
1 Filament (+)
2 Anode
3 Control Grid
4 Filament (−)
Socket-Compatible Tubes ⚠ Not electrically compatible
Transconductance Transconductance
1.5mA/V
Amplification Factor (μ) Amplification Factor 15—
Heater
Heater Voltage Filament Voltage 4V
Heater Current Filament Current 0.08A