6AQ5

6AQ5 is also designated EL90. Completed sales put the typical price at $9.08 per tube.

The 6AQ5 is a miniature beam-power pentode designed for use in the audiofrequency power output stage of television and radio receivers. It may also be used as a triode-connected vertical deflection amplifier in television receivers. Within its maximum ratings, its performance is equivalent to that of the 6V6-GT.

Construction

The 6AQ5 has a coated unipotential cathode, a T-5 1/2 glass envelope, and an E7-1 miniature button 7-pin base. Its mounting position is any. The heater is rated at 6.3 volts AC or DC at 0.45 ampere, with a warm-up time of 11 seconds. Pin assignments are: pin 1, grid number 1; pin 2, cathode and beam plates; pins 3 and 4, heater; pin 5, plate; pin 6, grid number 2 (screen); pin 7, grid number 1.

Ratings

The maximum bulb temperature at the hottest point is 250 degrees C. The tube has maximum plate and screen dissipation ratings, a maximum DC cathode current of 35 milliamperes, and a maximum peak cathode current of 105 milliamperes. The maximum heater-cathode voltage rating, with the heater positive with respect to the cathode, is 100 volts DC component; the maximum total DC and peak heater-cathode voltage is 200 volts. The maximum grid-number 1 circuit resistance is 0.1 megohm with fixed bias and 2.2 megohms with cathode bias. For operation in a 525-line, 30-frame television system, the maximum peak positive pulse plate voltage is 1100 volts, provided the duty cycle of the voltage pulse does not exceed 15 percent of one scanning cycle. The plate resistance is approximately 58000 ohms. Direct interelectrode capacitance from grid number 1 to plate is approximately 0.4 uuf, and direct interelectrode input capacitance is approximately 8.0 uuf. In stages operating with grid-leak bias, an adequate cathode-bias resistor or other suitable means is required to protect the tube in the absence of excitation.

Related Types

Except for heater ratings, the 5AQ5 is identical to the 6AQ5. The 5AQ5 has a heater rated at 4.7 volts AC or DC at 0.6 ampere and, as a result of its controlled heater warm-up characteristic, is especially suited for use in television receivers which employ series-connected heaters.

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.

Per-tube prices from completed sales, 2026-02-18 to 2026-09-21. Matched pairs and quads are divided out. See the price index for how these move over time.

Original manufacturer datasheets for 6AQ5, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• 6AQ5—5AQ5
• EL90 (filed under EL90)

5 further designations appear alongside 6AQ5 in the literature but below the evidence threshold used here, so they are not listed as equivalent.