6AM5

6AM5 is also designated EL91.

General

The 6AM5 is a power amplifier pentode of miniature construction. It has a T-5-1/2 bulb and a miniature button 7-pin base. Maximum overall length is 2-1/8 inches, maximum seated height is 1-15/16 inches, and maximum diameter is 3/4 inch.

Heater and Pinout

The heater is rated at 6.3 volts a.c. or d.c. and draws 200 mA. Pin 1 is grid No. 1; pin 2 is cathode and grid No. 3; pins 3 and 4 are the heater; pin 5 is the plate; and pin 7 is grid No. 2.

Capacitances

Direct interelectrode capacitance from grid to plate is 0.5 pF maximum. Direct interelectrode input capacitance is 4.2 pF, and output capacitance is 2.2 pF.

Ratings

Maximum plate voltage is 250 volts. Maximum grid No. 2 voltage is 250 volts, and maximum grid No. 2 dissipation is 0.6 watt. Maximum plate dissipation is 4.0 watts. Maximum grid No. 1 voltage is 100 volts, and maximum grid No. 1 current is 3.0 mA. Maximum cathode current is 20 mA. Maximum heater-cathode voltage is 150 volts.

Typical Operation

In pentode connection at 250 volts plate and screen voltage, with a control grid bias of -13.5 volts, plate current is 16 mA, screen grid current is 2.3 mA, transconductance is 2.5 mA/V, and anode resistance is 130 kΩ.

Connections and Applications

The 6AM5 can be operated in triode connection with the screen grid tied to the plate at the socket. In triode connection at 250 volts plate voltage and -13 volts control grid voltage, plate resistance is 3,850 ohms and mutual conductance is 3,000 micromhos. Maximum plate and grid No. 2 voltages in triode connection are each 250 volts. The tube can be used as an r.f. or a.f. amplifier.

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.

Base B7G, viewed from below (the wiring side), pins numbered clockwise from the key. Read from the datasheet's basing table and checked against it automatically — confirm against the original datasheet before wiring.

Original manufacturer datasheets for 6AM5, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• Triode connection (g2 connected to a) (filed under EL91)
• POWER AMPLIFIER PENTODE

4 further designations appear alongside 6AM5 in the literature but below the evidence threshold used here, so they are not listed as equivalent.