6C5

6C5 is also designated 6C5GT. Completed sales put the typical price at $15.96 per tube.

General Description

The 6C5 is a general-purpose triode designed for service as an oscillator, detector, or amplifier. The Tung-Sol datasheet covers three versions: the 6C5 with a metal shell and a 6-pin octal base, the 6C5G, and the 6C5GT. The Hytron datasheet for the 6C5GT describes it as a cathode-type triode with an internal shield connected to the No. 1 base pin, a small octul base, and a T-9D bulb.

Ratings

According to the Tung-Sol datasheet, the heater is rated at 6.3 volts and 0.3 ampere AC or DC. Maximum plate voltage is listed as 300 volts, maximum plate dissipation as 2.5 watts, and minimum grid voltage as 0 volts.

Characteristics

The Tung-Sol datasheet gives characteristics at a plate voltage of 250 volts, grid voltage of -8 volts, plate current of 8 mA, plate resistance of 10,000 ohms, transconductance of 2000 micromhos, and amplification factor of 20. The Hytron datasheet gives transformer-coupled characteristics with a maximum plate voltage of 250 volts, grid voltage of -8 volts, plate current of 8.0 milliamperes, plate resistance of 10,000 ohms, mutual conductance of 2000 micromhos, and amplification factor of 20. The Hytron datasheet also provides resistance-coupled characteristics with a plate supply voltage of 250 volts, grid voltage of approximately -5 volts, plate current of approximately 1.5 milliamperes, load resistance of 50,000 to 100,000 ohms, voltage amplification of 14, and output voltage (at 5% second harmonic) of 42 volts. For grid-leak detector service, the Hytron datasheet lists a maximum plate voltage of 250 volts, grid voltage of approximately -17 volts, and a plate current adjusted to 0.2 milliampere at zero signal, with a grid leak of 0.1 to 1.0 megohm and a grid condenser of 50 to 500 μμF.

Capacitances

The Tung-Sol datasheet gives direct interelectrode capacitances for the 6C5 as: grid to cathode 3.0 μμF, plate to cathode 11 μμF, grid to plate 2.0 μμF. For the 6C5G, the values are: grid to cathode 4.4 μμF, plate to cathode 12 μμF, grid to plate 2.2 μμF. For the 6C5GT, the Tung-Sol datasheet lists: grid to cathode 3.6 μμF, plate to cathode 11 μμF, grid to plate 1.6 μμF. The Hytron datasheet for the 6C5GT gives interelectrode capacitances of grid No. 1 to plate 1.6 μμF, grid No. 1 to cathode 3.6 μμF, and plate to cathode 11.0 μμF.

Operating Notes

The Tung-Sol datasheet notes that the DC resistance in the grid circuit should not exceed 1.0 megohm. The Hytron datasheet similarly states that grid circuit resistance should not exceed 1.0 megohm. The Hytron datasheet also advises that voltage between heater and cathode should be kept to a minimum if direct connection is not possible. For characteristic curves, the Hytron datasheet refers the user to type 6C5G.

Equivalence is asserted only where the archive's own literature states it directly, in at least 40 separate documents. Tubes that merely substitute in some circuits are not listed here.

Per-tube prices from completed sales, 2026-07-23 to 2026-09-20. Matched pairs and quads are divided out. See the price index for how these move over time.

Original manufacturer datasheets for 6C5, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• RMA Release # 190 (filed under 6C5GT)
• PRINTED IN U.