Vacuum Tube - 6Q7, Dual Diode, Triode
New-Old-Stock (NOS) tube.
Also known by US military identifier VT-92.
The 6Q7 combines two diodes and a high-mu triode in a single envelope, using a common cathode. It is designed for service as a diode detector, AVC rectifier, and as a high gain resistance coupled amplifier in AC, storage battery, and AC - DC operated receivers.