6AM6

6AM6 is also designated EF91.

The 6AM6 is a miniature, indirectly heated, high-slope RF pentode intended for use as an RF or IF amplifier.

Construction

The tube is mounted in a standard T5 bulb and fitted with a B7G base. The cathode is indirectly heated. The heater is intended for operation in parallel with other valves in AC-operated equipment and requires 6.3 volts at a nominal 0.3 ampere. The maximum DC heater-cathode potential is 150 volts. The maximum overall length is 2-1/8 inches, the maximum diameter is 3/4 inch, and the maximum seated height, excluding tip, is 1-19/32 inches.

Electrode Arrangement

Pin 1 is the control grid (g1), pin 2 is the cathode, pins 3 and 4 are the heater connections, pin 5 is the anode, pin 6 is the suppressor grid (g3) and shield, and pin 7 is the screen grid (g2). The Brimar datasheet states that the suppressor grid should be connected to the cathode and under no circumstances to the anode.

Ratings

The maximum anode voltage is 300 volts at an anode current of 10 mA and 550 volts at zero anode current; the maximum screen voltage is 300 volts at 10 mA anode current and 450 volts at zero anode current. In some operating conditions, the maximum anode voltage is 250 volts. Maximum anode dissipation is 3.0 watts, with a figure of 3.3 watts given for some operating conditions; maximum screen dissipation is 0.9 watt. Maximum cathode current is 30 mA, and maximum DC control grid current is 1 mA. The maximum grid 1 circuit resistance is 100,000 ohms with fixed bias and 500,000 ohms with auto bias.

Characteristics

The mutual conductance is of the order of 7.5 mA/V. Capacitance values vary with measurement configuration: input capacitance is given as 7.5 pF, 5.1 pF, or 8.6 pF; output capacitance as 3.2 pF, 5.3 pF, or 3.1 pF; and grid-to-anode capacitance as 0.005 pF or 2.7 pF. Cathode-to-anode capacitance is 0.2 pF.

Applications

The tube is designed for use as an RF or IF amplifier and is efficient as an IF amplifier at intermediate frequencies around 10 Mc/s. It is suitable for use as an FM limiter or television sync separator, and can be used as an oscillator due to its high slope. It can also serve as a frequency changer at frequencies up to about 150 Mc/s or as a grounded-grid amplifier at frequencies of the order of 100 Mc/s.

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 6AM6, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• BRIMAR
• EF91 (filed under EF91)

5 further designations appear alongside 6AM6 in the literature but below the evidence threshold used here, so they are not listed as equivalent.