6AC6GT

The 6AC6GT is Hytron’s Bantam audio power dual triode in a tubular glass envelope on an octal base. The document describes internal dynamic coupling between input and output triodes, making the systems an amplifier assembly rather than independently accessible sections of an ordinary dual triode. The preserved tentative specifications refer to registration 242, April 30, 1940; sheet 2 carries 4–40. These date the documentation, not independently the first sale.

Heater 6.3 V AC or DC, 1.1 A, distinct from secondary 1.2 A data. The static table gives maximum 180 V for both plates, external bias 0 V, input-plate current 7 mA, output-plate current 45 mA. Listed system parameters are plate resistance 18 kΩ, transconductance 3 mA/V and amplification factor 54. Hytron explains that input-triode bias develops through internal connections and the output triode operates with its grid in the positive region. External zero therefore does not place every grid at its cathode potential.

Single tube with both plate supplies 180 V: load 3500 Ω, input 18 V RMS, output 3.6 W at 9% total harmonic distortion. Input-plate current rises from 7 mA without signal to 13 mA at rated signal; output-plate current from 45 to 47 mA. Stated output-plate dissipation maximum 10 W. Increased drive to the onset of input-grid current can give 4.3 W, but approximately 16% distortion. This higher output does not belong to the 3.6 W, 9% point.

Two-tube push-pull at 180 V: plate-to-plate load 5 kΩ, required input explicitly 46 V RMS grid-to-grid, output 9 W at 10% total distortion. Combined output-plate current rises from 90 mA at idle to 102 mA at rated signal; combined input-plate current from 14 to 25 mA. DC series resistance in the grid return must not exceed 0.5 MΩ. These Hytron GT data must not be replaced with another 6AC6G document’s points simply because the designations resemble each other.

Seven-contact intermediate bakelite octal base, basing 7W-0-0, bulb T-9D. Bottom view: 1 unconnected, 2 heater, 3 output plate, 4 input plate, 5 input grid, 6 omitted, 7 heater, 8 output cathode. Maximum overall height 3 5/16 inches (84.1375 mm), seated height 2 3/4 (69.85 mm), overall diameter 1 5/16 (33.3375 mm). The listed diameter is retained as maximum tube outline, not assigned to glass alone. Documentation: Hytron Corporation, Bantam Type 6AC6GT, Tentative Specifications, two sheets, registration reference 242, April 30, 1940, and 4–40 on sheet 2.