9AK8

9AK8 is also designated PABC80.

The 9AK8 is a triple diode triode, incorporating a coated unipotential cathode, designed for video and audio signal detection in television receivers. It has a small button 9-pin noval base with a JETEC basing designation of 9E.

Construction

The 9AK8 has a maximum overall length of 2 5/8 inches, a maximum seated height of 2 3/8 inches, and a bulb length excluding tip of 2 ± 3/32 inches. Its maximum diameter is 7/8 inch. The mounting position is any. Pin 1 connects to diode plate No. 3, pin 2 to diode plate No. 2, pin 3 to diode cathode No. 2, pins 4 and 5 to the heater, pin 6 to diode plate No. 1, pin 7 to the cathode of the triode and diodes No. 1 and 3 plus the internal shield, pin 8 to the triode grid, and pin 9 to the triode plate.

Ratings

The heater requires 9.5 volts at 0.3 ampere. For the diode sections, the peak inverse voltage rating is 350 volts for each diode. Diode No. 1 has an average current rating of 1 mamp and a peak current rating of 6 mamps, while diodes No. 2 and No. 3 each have an average current rating of 10 mamps and a peak current rating of 75 mamps. The voltage between diode cathode No. 2 and the heater is rated at 150 volts, and the external resistance between heater and cathode is 20,000 ohms. The voltage between heater and cathode is 150 volts.

For the triode section, the plate voltage rating is 250 volts, the plate voltage without current rating is 550 volts, and the plate dissipation rating is 1 watt. The grid circuit resistance rating is 3 megohms, and the grid current starting point is -1.3 volts.

Characteristics

The triode section has an amplification factor of 70. Its plate resistance is 54,000 ohms at plate voltages of 100 and 170 volts, 56,000 ohms at 200 volts, and 58,000 ohms at 250 volts. Transconductance is 1300 micromhos at plate voltages of 100 and 170 volts, 1250 micromhos at 200 volts, and 1200 micromhos at 250 volts. Diode No. 1 has a plate resistance of 5000 ohms at a plate voltage of +10 volts, while diodes No. 2 and No. 3 each have a plate resistance of 200 ohms at a plate voltage of +5 volts. The ratio of plate resistances of diode No. 2 to diode No. 3, or vice versa, is maximum 1.5.

Capacitance values include: diode plate No. 1 to all other elements, 0.9 μμF; diode plate No. 2 to all other elements, 4.5 μμF; diode plate No. 3 to all other elements, 4.5 μμF; diode cathode No. 2 to all other elements except diode plate No. 2, 4.5 μμF; diode plate No. 1 to heater, max. 0.25 μμF; diode plate No. 3 to heater, max. 0.2 μμF; diode cathode No. 2 to heater, 2.7 μμF; triode grid to all other elements, 1.9 μμF; triode plate to all other elements, 1.2 μμF; triode plate to grid, 2.1 μμF; triode grid to heater, max. 0.04 μμF; between the diode and triode sections, 0.1 μμF; grid to diode plate No. 1, max. 0.07 μμF; grid to diode cathode No. 2, max. 0.005 μμF; grid to diode plate No. 3, max. 0.02 μμF; triode plate to diode plate No. 1, max. 0.1 μμF; triode plate to diode cathode No. 2, max. 0.01 μμF; triode plate to diode plate No. 3, max. 0.1 μμF.

Applications

The datasheet states that the triode section can be used without special precautions against microphonic effect when the A.C. input voltage is higher than 10 millivolts for an output of 50 milliwatts at frequencies of 800 c/s and higher. The datasheet was issued on 4.4.1954.

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.

Original manufacturer datasheets for 9AK8, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• PABC80 (filed under PABC80)
• 9AK8