VINTAGE TECHNOLOGY ARCHIVE / TUBES / 6Z4

6Z4

6Z4 is also designated 84. Completed sales put the typical price at $6.10 per tube.

Description

The 84/624 is a full wave high vacuum rectifier with a unipotential cathode and a glass bulb, fitted with a small 5 pin base.

Ratings

The heater is rated at 6.3 volts and 0.5 ampere, AC or DC. Maximum ratings include a peak inverse voltage of 1250 volts, a DC heater-to-cathode potential of 450 volts, a steady-state peak plate current per plate of 180 mA, and a DC output current of 60 mA. The maximum AC plate voltage per plate (RMS) is 325 volts, or 450 volts in a choke-input filter application. The minimum total effective plate supply impedance per plate is 65 ohms, and the minimum value of input choke is 10 henrys. Tube voltage drop is 20 volts at 60 mA per plate.

Applications

The Tung-Sol datasheet, dated February 15, 1940, describes the 84/624 as designed for use as a power rectifier in storage battery and AC operated receivers.

Equivalent Types
DesignationEvidenceConfidence
84 141 independent documents strong

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.

What 6Z4 Sells For
MeasurePer tube
Median$6.10
Typical range (25th–75th) $4.24 – $11.98
Most sales (10th–90th) $4.24 – $18.95
Extremes incl. outliers $3.99 – $22.88
Completed sales17
By Condition
ConditionMedianSales
NOS$4.247
used$10.998

Per-tube prices from completed sales, 2026-06-04 to 2026-09-26. Matched pairs and quads are divided out. See the price index for how these move over time.

Datasheets

Original manufacturer datasheets for 6Z4, hosted by Frank Philipse's Electron Tube Data sheets.

ManufacturerDesignationDatasheet
Shuguang 6Z4 PDF (97 KB)
Tung-Sol 84 PDF (101 KB)
Sylvania 84 PDF (77 KB)
RCA 84 PDF (43 KB)
In the Archive

Documents held here and used to write this page.