6GH8A

6GH8A has no equivalent designation confirmed by the archive.

The 6GH8A is a miniature tube containing a sharp-cutoff pentode and a medium-mu triode, with each section having a separate cathode and being electrically independent. It has a T-6 1/2 glass envelope and an E9-1 small button 9-pin base. The maximum diameter is 0.875 inches, the maximum over-all length is 2.188 inches, and the maximum seated height is 1.938 inches.

Construction

The tube uses heater pins 4 and 5, pentode plate pin 6, pentode cathode/grid number 3/internal shield pin 7, triode cathode pin 8, and triode grid pin 9. The triode plate is pin 1, the pentode grid number 1 is pin 2, and the pentode grid number 2 (screen) is pin 3. Except for being controlled to assure low interelectrode leakage, the 6GH8A is identical to the 6GH8.

Ratings

Design-maximum values include a plate dissipation of 2.5 watts for both sections, a screen dissipation of 0.55 watts, a DC cathode current of 20 milliamperes, and a peak cathode current of 300 milliamperes. The design-maximum heater-cathode voltage with the heater positive with respect to the cathode has a DC component of 100 volts; the total DC and peak heater-cathode voltage is 200 volts with the heater either positive or negative with respect to the cathode. The design-maximum grid-number 1 circuit resistance is 2.2 megohms with either fixed or cathode bias.

Characteristics

At a plate voltage of 125 volts and screen voltage of 125 volts, the pentode section has an average transconductance of 7500 micromhos, an average plate resistance of approximately 200000 ohms, an average plate current of 12 milliamperes, and an average screen current of 4.0 milliamperes. At a plate voltage of 125 volts, the triode section has an average amplification factor of 46, an average plate resistance of 5400 ohms, and an average plate current of 13.5 milliamperes. The grid-number 1 voltage for a plate current of 10 microamperes is approximately -8.0 volts for both sections. The heater voltage for a bogey 6GH8A at a heater current of 0.45 amperes is specified.

Applications

The pentode section is intended primarily for service as an oscillator in the horizontal-deflection system of television receivers.

Original manufacturer datasheets for 6GH8A, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• **6GH8-A**TRIODE-PENTODE