6X4

6X4 has no equivalent designation confirmed by the archive. Completed sales put the typical price at $15.95 per tube.

The 6X4 is a miniature heater-cathode type twin diode designed for full-wave rectifier operation in compact power supplies. It has a coated unipotential cathode and is intended for service in automobile and a-c radio receivers.

Construction

The 6X4 uses a T-5½ glass envelope and an E7-1 miniature button 7-pin base. It may be mounted in any position. The pinout is: Pin 1 – Plate Number 2, Pin 2 – No Connection, Pin 3 – Heater, Pin 4 – Heater, Pin 5 – No Connection, Pin 6 – Plate Number 1, Pin 7 – Cathode.

Ratings

In automotive service from a 6-volt battery source, the permissible range in heater voltage is from 5.0 to 8.0 volts. The maximum AC plate-supply voltage per plate (RMS) is 450 volts with a choke-input filter and 325 volts with a capacitor-input filter. The maximum DC output current is 70 milliamperes. The full-wave rectifier maximum DC output voltage at the filter input is 350 volts with a choke-input filter and 365 volts with a capacitor-input filter at a DC output current of 35 milliamperes; at 70 milliamperes, it is 340 volts with a choke-input filter and 310 volts with a capacitor-input filter. The tube voltage drop at 70 milliamperes DC per plate is 22 volts.

Per-tube prices from completed sales, 2026-06-14 to 2026-09-26. Matched pairs and quads are divided out. See the price index for how these move over time.

Original manufacturer datasheets for 6X4, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• **6X4**

3 further designations appear alongside 6X4 in the literature but below the evidence threshold used here, so they are not listed as equivalent.