What is the RCA-6146b vacuum tube?

The RCA-6146b (RCA 6146B) is a tetrode vacuum tube designed for transmitting applications. HF transmitting beam..

What is a RCA-6146b substitute or equivalent?

Direct equivalents to the RCA-6146b include 8298A. These share the same pinout and operating envelope, so they can usually be swapped without circuit changes — though batch-to-batch variations between manufacturers (NOS vs current production) may shift the sonic character noticeably.

What are the key specifications of the RCA-6146b?

Amplification factor μ ≈ 4, transconductance gm ≈ 7 mA/V, max plate voltage 750 V, max plate dissipation 35 W, heater 6.3 V / 1.125 A.

Is the RCA-6146b still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the RCA-6146b as Common availability. NOS (new-old-stock) examples from RCA, Mullard, Tung-Sol, GE, Sylvania and Telefunken trade among collectors; modern production where it exists comes mostly from JJ Electronic, Electro-Harmonix, Tung-Sol (New Sensor), Genalex, and a handful of small-batch makers.

What does the RCA-6146b sound like?

HF transmitting beam.. Sonic character also depends heavily on the circuit operating point, the surrounding tubes in the stage, and the output transformer when present — use the interactive loadline calculator on this page to explore the trade-offs.

By Jean-Michel Falligan Devergne · Reviewed May 29, 2026

←RCA-6146b

← QQE03-12 RE604 →Compare → 8298A

RCA-6146b RCA 6146B Tetrode Vacuum Tube

Tetrode6.3V / 1.125AOctalSPICE

Sourcefrostburg/worldtube 6146B (beam tetrode)Reviewed2026-05-29StatusDataModelCalcModelKoren pentodePDF

Beam power tetrode rated at 35W for high-power output stages

Datasheet ↗SPICE

RCA 6146B — RCA — tetrode vacuum tube — (1952)

7.0mA/V

13.0pF

0.2pF

8.50pF

GAIN4%

POWER88%

DRIVE50%

LINEARITY95%

SPECIFICATIONS

Heater6.3 V · 1.125 A

Max Plate Voltage750 V

Pa max35 W

Gain Factor4

gm7 mA/V

rp—

Inter-electrode capacitances

Cgk13 pF

Cgp0.22 pF

Cpk8.5 pF

PinoutOctal

Era1952

RarityCommon

HEATER6.3V / 1.125A

MAX PLATE750V / 35W

BASEoctal

Source datasheets

3 manufacturer datasheets cross-checked for RCA 6146B

3 verified

EXECUTIVE SUMMARY

The RCA-6146b is a indirectly-heated beam tetrode from RCA, introduced around 1952. Commonly used in transmitting applications. HF transmitting beam.

APPLICATIONS

High-power output

Generic tetrode transmitting stage

• PA/public address

VS 8298A

Pd 0%Full comparison →

HISTORY

Introduced1952ManufacturerRCA

Golden Age

RCA-6146b Datasheet

Local mirror · PDF

↗

METRIX TESTER

Test this tube on a Metrix

SIMILAR TETRODES

View all →

12E1Power 1614Power (PP)1625Transmitting / Power 4Y100ROutput Power 4Y75ROutput Power 5881Power (PP)5AQ5Power 5V6Power