Vacuum Tube - 7B8, Heptode
New-Old-Stock (NOS) tube.
Also known by US military identifier VT-208.
The 7B8 is a pentagrid converter designed to perform the combined functions of the oscillator and mixer in superheterodyne receivers. Except for interelectrode capacitances, the electrical characteristics of the 7B8 are identical to those of the 6A8.