6BY7

6BY7 is also designated EF85.

Overview

The 6BY7 is a radio-frequency pentode with variable transconductance, intended for use as a wide-band amplifier. It has a coated unipotential cathode and a small button noval 9-pin base.

Construction and Mounting

The maximum overall length of the 6BY7 is 2 5/8 inches, with a maximum seated height of 2 3/8 inches. The bulb length excluding tip is 2 3/32 inches, and the maximum diameter is 7/8 inch. The 6BY7 can be mounted in any position. Its basing is JETEC basing designation 9 AQ.

Ratings

The 6BY7 heater requires 6.3 volts at 0.3 ampere. Maximum plate voltage is 250 volts, with a maximum plate voltage without current of 550 volts. Maximum plate dissipation is 2.5 watts. Maximum grid No.2 voltage is 250 volts, with a maximum grid No.2 voltage without current of 550 volts and a maximum grid No.2 dissipation of 0.6 watt. Maximum cathode current is 15 mA, and maximum grid No.1 circuit resistance is 3 megohms. Grid No.1 current starts at a grid No.1 voltage of 3 volts.

Capacitances

Grid No.1 to all other elements capacitance is 7.2 μμF, and plate to all other elements capacitance is 3.7 μμF. Plate to grid No.1 capacitance is a maximum of 0.007 μμF, and grid No.1 to heater capacitance is a maximum of 0.15 μμF.

Operating Characteristics

At a supply voltage of 250 volts, plate voltage of 250 volts, grid No.3 voltage of 0 volt, and a grid No.2 series resistor of 60,000 ohms, the operating characteristics include a grid No.1 bias range from -2 to -35 volts, a grid No.2 voltage of 100 volts, a plate current of 10 mA, and a grid No.2 current of 2.5 mA. Transconductance is 6000 micromhos at a grid No.1 bias of -2 volts and 60 micromhos at a grid No.1 bias of -35 volts. Plate resistance is 0.5 megohms at a grid No.1 bias of -2 volts and greater than 5 megohms at a grid No.1 bias of -35 volts. Equivalent noise resistance is 1500 ohms, and input damping at 100 Mc is 2250 ohms.

Applications

The 6BY7 can be used in combination with the 6AJ8 with a common screen grid resistor.

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 6BY7, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• "Miniwatt" 6BY 7
• EF 85 (filed under EF85)

2 further designations appear alongside 6BY7 in the literature but below the evidence threshold used here, so they are not listed as equivalent.