FC's Fluorescent Magic Eye Tubes

(C) G. Forrest Cook 2008

Introduction

Here is a collection of information on a variety of fluorescent magic eye vacuum tubes that I assembled while designing the hammonator guitar amp project.

Common types: The 6U5-6E5 tube is very common since it was frequently used as a signal strength indicator in 1940s and 1950s consumer radios, it uses an antique 6 pin tube base. Adapters are available for plugging the more modern 1629 type octal tubes into 6U5-6E5 sockets.

Both the EM83 and 6AL7 tubes are dual-bar displays that would be well suited for use as a stereo volume meter. The EM87-6HU6 is a fairly common single channel tube in a miniature 9 pin base, it was originally used as a tuning indicator in radios and as a record level meter in tape recorders. The EM80-6BR5 is in a miniature 9 pin base and it has an unusual fan-shaped display. Russian EM80 tubes from the 1980s are currently available on eBay for reasonable prices.

Some rare types of eye tubes include the miniature 6355, 6977-DM160 and R2164 tubes and special 6U5-6E5 tubes with a red lamp crystal over the center filament.

Many of the photos and schematics shown here were pulled from eBay ads and radiomuseum.org articles, the rest of them are originals.


Eye Tube Types

Type Operating Package Circuit Pinout
6U5-6E5
6AL7
6AF6
EM34
EM71
EM80-6BR5
EM84-6FG6
EM87-6HU6
DM70/DM71
DM160
EAM86

6U5-6E5 Varieties

General Electric RCA Philco Sylvania Zalytron Zenith EZ-6E5D Internal Structure

Fluorescent Tube Types

2E5 top circle, 6 pin, ST bulb
6AB5/6N5 top circle, 6 pin
6AD6 top split circle, octal
6AF6 top split circle, short octal
6AL7 top double rectangle, octal
6U5/6E5 top circle, 6 pin, ST bulb or cylinder
DM70 side exclamation point, wire pins
DM160 side rectangle, wire pins
EAM86/6GX8 side split bar and on/off, 9 pin
EFM11 top circle, octal
EM35 top circle, octal
EM71 top fan, locktal
EM72 top fan, locktal
EM80/6BR5/6E1P side fan, 9 pin
EM83 side double bar, 9 pin
EM84/6FG6/6E3P side split bar, 9 pin
EM87/6HU6 side split bar, 9 pin
EM840 side split bar, 9 pin
ME41 top circle, octal
UM84 side split bar, 9 pin, 12V
JAN-CRC-1629/VT-138 top circle octal
C/EM2 top circle, octal

Links


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