6D6

Small Signal Pentode — UX6

RCA

Known Equivalents & Substitutes

CV1083VT-73

Similar Tubes (Not Drop-In Compatible)

Successor remote-cutoff pentode with similar characteristics but Octal base — not pin-compatible

Later remote-cutoff pentode, Octal base, no top cap — not pin-compatible

78

Same tube with 6.3V heater in identical UX6 base — often listed as direct equivalent but some sources differentiate them

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)300V

Screen Voltage (max)Screen Voltage (max)150V

Anode Dissipation (max)Anode Dissipation (max)2.25W

Typical Operating

Anode Voltage (typical)Anode Voltage (typical)250V

Screen Voltage (typical)

Notes

The 6D6 uses a 6-pin base with the control grid brought out to a top cap. It was introduced in the early 1930s and widely used in pre-war superheterodyne receivers.
Typical operating conditions at Va=250V, Vg2=100V, Vg1=-3V: Ia=8.2mA, Ig2=2.0mA, Rp=800kΩ, Gm=1600 umhos.
Maximum ratings: plate voltage 300V, screen voltage 150V, plate dissipation 2.25W.
The 6D6 was superseded by the 6K7 (Octal base) and later by the 6SK7 (Octal, no top cap), and eventually by the 6BA6 (miniature B7G).

Pin Layout — UX6

1Plate

2Screen Grid (g2)

3Suppressor Grid (g3) / Cathode

4Heater

References