The Telefunken EAM86 is a magic eye tuning indicator vacuum tube that also contains a triode system. It was primarily designed for use in vintage tape recorders as a level indicator and in radios as a tuning indicator.
Function: The EAM86 is a dual-function tube, incorporating both a triode amplifier and a "magic eye" indicator system in a single glass envelope.
Application: It is commonly found in vintage audio equipment, specifically as a visual indicator for recording levels in tape recorders or for signal strength (tuning) in AM/FM radios.
Design: The indicating system has a fluorescent display with two horizontal rectangular bars (or "magic bars") which converge or separate based on the applied signal voltage, indicating the correct level or tuning point.
Base: It uses a miniature 9-pin Noval (B9A) base.
Equivalents: The EAM86 is also known by the alternative US designation 6GX8.