Vacuum Tube - 6L7, Heptode
New-Old-Stock (NOS) tube.
Also known by US military identifier VT-87.
The 6L7 is a mixer tube designed for service with a separate oscillator as the first detector in superheterodyne receivers. The control grid is of the remote cut-off type which allows the use of AVC and minimizes cross-modulation. The control grid is of the sharp cut-off type. The tube may be used as a volume expander or as a doubly controlled general purpose amplifier.