Microphonics

A system sufficiently susceptible to microphonics could experience audio feedback, and make noises if jarred or bumped.

To minimize these effects, some vacuum tubes were made with thicker internal insulating plates and more supports,[4] and tube-socket assemblies were sometimes shock-mounted by means of small rubber grommets placed in the screw holes to isolate them from vibration.

Where tuning was essential, a compromise usually was made between the resistance of the klystron to microphonism and the obtainable performance.

Unwanted microphonics-related audible distortions can often be alleviated by using commercially available vacuum tube mechanical dampers.

Before the introduction of solid-state charge-coupled device (CCD) sensors to produce the image, vacuum tubes performed this task.