6DQ5

Beam Tetrode — Octal

Known Equivalents & Substitutes

6CD66EX66HD5

Similar Tubes (Not Drop-In Compatible)

Same tube family but 21V/0.6A series heater — not compatible with 6.3V parallel heater circuits

Same tube family but 21V/0.6A series heater — not compatible with 6.3V parallel heater circuits

Same tube but 26.5V/0.45A series heater — not compatible with 6.3V parallel heater circuits

Electrical Specifications

Section 1 — Beam Tetrode

Absolute Maximum

Anode Voltage (max)DC Plate-Supply Voltage (max)990V

Screen Voltage (max)DC Screen Grid Voltage (max)190V

Anode Dissipation (max)Plate Dissipation (max)24W

Screen Dissipation (max)Screen Dissipation (max)3.2W

Cathode Current (max)Cathode Current (max, average)

Notes

The plate (anode) connection is via a top cap (small cap, JEDEC No. C1-1), not a base pin.
Pins 1 and 5 are both Grid No.1; pins 3 and 6 are both Cathode/Suppressor Grid (G3); pins 4 and 8 are both Screen Grid (G2). These dual connections are for low-inductance paths in horizontal-deflection service.
Maximum ratings are specified for horizontal-deflection amplifier service in a 525-line, 30-frame TV system. Peak positive-pulse plate voltage of 6500 V is applicable only when the pulse duration does not exceed 15% of one horizontal scanning cycle (10 µs).
Plate dissipation must be limited in the event of loss of grid signal; a cathode resistor of suitable value should be employed as protective means.
The 26DQ5 is a heater-voltage variant (26.5 V) with identical characteristics otherwise; it is not pin-compatible without a heater supply change.
The DC component of heater-cathode voltage must not exceed 100 V.
Triode-connection data (g2 strapped to anode) is from the RCA manufacturer datasheet. Only µ is stated; gm and ra are not specified for triode mode.

Pin Layout — Octal

1Control Grid (G1)

2Heater

3Cathode

Socket-Compatible Tubes ⚠ Not electrically compatible

References