12CX6

RCA 12CX6 sharp-cutoff 7-pin miniature pentode for low-voltage automobile radios operating directly from 12 V storage batteries.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: 7
Nominal heater: 12.6 V / 150 mA

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: 7
Nominal heater voltage: 12.6 V
Nominal heater current: 150 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 40000 Ω
Transconductance: 0.0031 S
Max plate voltage: 33 V
Max screen voltage: 33 V

RCA 1959 low-voltage Class A sharp-cutoff pentode. Typical Va approx 12.6 V (OCR unclear), Vg2 12.6 V, Vg3 0 V, grid supply 0 V with 2.2 MΩ bypassed resistor; Ia 3 mA, Ig2 1.4 mA. Peak heater-cathode +/-30 V. G1-plate <=0.05 pF; input 7.6 pF; output 6.2 pF. Maximum grid circuit resistance 10 MΩ.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

9999 Mixed 2000

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Screen voltage
12.6 V
Typical Class A screen voltage
Plate current
3 mA
Typical Class A plate current
Screen current
1.4 mA
Typical Class A screen current

Characteristic

Plate resistance
40000 Ω
Approximate plate resistance
Transconductance
3100 µS
Typical transconductance