76 — Small Signal Triode, UX5 | Tubeofile

76

Small Signal Triode — UX5

RCA

Known Equivalents & Substitutes

CV615VT-76

Similar Tubes (Not Drop-In Compatible)

Same UX5 base and 6.3V/0.3A heater, but lower mu (9.2 vs 13.8) and different plate resistance (8400 vs 9500 ohms)

Electrically identical but 2.5V/1.0A heater on UX5 base — 76 uses 6.3V/0.3A

Similar medium-mu triode successor on Octal base — not pin-compatible with UX5

6P5G

Electrically identical but Octal base — not pin-compatible with UX5

6P5GT

Electrically identical but Octal base — not pin-compatible with UX5

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Plate Voltage (max)250V

Anode Dissipation (max)Plate Dissipation (max)1.4W

Heater-to-Cathode Voltage (max)Peak Heater-Cathode Voltage (max)90V

Max Grid ResistorMax Grid Resistor1MΩ

Typical Operating

Notes

Electrically identical to the type 56, differing only in heater voltage (6.3V vs 2.5V) and heater current (0.3A vs 1.0A). Introduced in March 1933 as the 6.3V heater replacement for the 56.
Succeeded by the 6P5GT, 6C5G, 6P5G, and 6P5M on Octal bases. The 76 uses the pre-war UX5 (Small-Shell Small 5-Pin) base with basing designation 5A.
The Sams Tube Substitution Handbook lists the 37, 37A, 56A*, 56AS*, 67*, and 67A* as substitutes for the 76 (* = may not work in all circuits). The 37/37A share the same base and heater but have different electrical characteristics (lower mu).
Maximum grid-circuit resistance is 1.0 megohm. The cathode should preferably be connected to a mid-tap on the heater supply winding or to a center-tapped resistor across the heater winding. Heater-to-cathode voltage must not exceed 90V.
One of the classic pre-war American triodes, documented in over 2,000 radio receiver models from 1933 to 1953. Widely used in AC-powered superheterodyne receivers of the 1930s as detector and first audio stage.

Pin Layout — UX5

1Heater

2Anode (Plate)

3Control Grid

4Cathode

Socket-Compatible Tubes ⚠ Not electrically compatible

References