2x 6S4S / 6B4G / 6C4C Triodes Black Anode Matched Pair Original Box 1963 NIB NOS

Matched pair of Svetlana output triodes from 1963 with black anodes. Tested on L3-3, 2.8W output power, 500hr service life.

New 6S4S output triode tubes, made on Svetlana factory.

Two tubes in one lot.

Tested on L3-3 tester.

Matched pair.

Each tube was produced in 1963.

Original boxes.

Output triode 6C4C is designed for low frequency power amplification.

The cathode is direct filament oxide.

Works in any position. It is produced in glass design. The greatest weight is 75 g.

Service life is not less than 500 hours.

Octal base with a key.

Nominal electrical data

Filament voltage, V 6.3

Pump current, A 1.0

Anode voltage, V 250

Grid voltage, V -45

Anode current, mA 62

Slope of characteristic, mA/V 5.4

Gain 4.15

Internal resistance, ohm 840

Output power*), W 2.8

Output power at filament voltage 5.7 V*), W 2.25

Cathode emission current, mA 140

Grid reverse current, mA 5.0

Grid insulation resistance, megohm 20

Anode insulation resistance, MOhm 20

Durability, h 500

Durability criteria:

output power*), W 1.6

grid reverse current, µA 7.0

*) At a variable effective grid voltage of 31 V and anode load resistance of 2500 ohms.

Maximum permissible electrical values

Highest filament voltage, V 6.9

Lowest filament voltage, V 5.7

Highest anode voltage, V 360

Highest power dissipated by anode, W 15