TUBEOFILE
957 — Sharp Cutoff Pentode, Acorn | Tubeofile | Tubeofile
← Browse Low quality — significant gaps in core data (missing base, heater, universal parameters, or pins). Treat as a research stub; always cross-reference with datasheets.
Known Equivalents & Substitutes
CV2700 VT237
Similar Tubes (Not Drop-In Compatible)
954
Acorn pentode (remote-cutoff) with 6.3V heater — different heater voltage and cutoff characteristic, not interchangeable Electrical Specifications
Absolute Maximum
Anode Voltage (max) Anode Voltage (max) 135V
Typical Operating
Anode Voltage (typical) Anode Voltage 135V
Grid 1 Bias Voltage Grid Voltage -5V
Anode Current Anode Current 4mA
Notes
Acorn-type envelope with radial wire leads — uses special acorn socket (5-pin, JEDEC base 5BD). Battery-type filament: 1.25V at 0.05A — designed for portable/field equipment. GE Essential Characteristics classifies this as 'Medium-Mu Triode (Acorn)' but it is in fact a sharp-cutoff pentode. Sams Substitution Handbook cross-references 01C (and reverse: D1C substitutes 957). TDSL lists CV2700 and VT237 as close or identical substitutes. GE lists typical operating conditions at Va=135V, Vg=-5V, Ia=4.0mA, gm=1600 umhos. Socket-Compatible Tubes ⚠ Not electrically compatible
Transconductance Transconductance
1.6mA/V
Heater
Heater Voltage Filament Voltage 1.25V
Heater Current Filament Current 0.05A