DC Output Current (max)DC Plate Current (max)155mA
Notes
Tentative data — the 12D4 was introduced by RCA in 1959 for TV damper service.
The 12D4A is a different-rating variant (per TDSL); verify suitability before substitution.
Pin 2 is an internal connection — do not use as a tie point.
Socket terminals 1, 3, and 6 should not be used as tie points.
Base designation 4CG (per GE Essential Characteristics and RCA datasheet).
Heater negative with respect to cathode: 4400V max. Heater positive with respect to cathode: 300V max.
Peak inverse plate voltage rating of 4400V applies when duty cycle of voltage pulse does not exceed 15% of one horizontal scanning cycle (525-line, 30-frame system).
DC component of plate voltage must not exceed 900V. DC component of heater-cathode voltage must not exceed 100V.
Pin Layout — Octal
1Same as Pin 10 (Shell)
2Internal Connection
3Cathode
4
Socket-Compatible Tubes ⚠ Not electrically compatible