Vacuum Tube - 6SK7, Pentode, Remote Cut-Off, RF
New-Old-Stock (NOS) tube.
Also known by US military identifier VT-117A.
The 6SK7 is a remote-cutoff pentode. It is designed for use as a high-gain radio-frequency or intermediate-frequency amplifier in a radio receiver. Because of its remote-cutoff characteristic, this type will handle large signal voltages without cross-modulation or modulation-distortion and is suitable for use in receivers which employ automatic-volume-control.