Topic of interest

[Mosaic]

Hi All:
This taught  me something new:
https://youtu.be/BnR_DLd1PDI

Now for modern preamps etc, such as found in video cams....a cellular phone on silent mode (in your pocket or from a bystander)appears to emit an interfering EM squawk when it recvs a msg. This signal can get sneak into the audio recording without you knowing it  . A live feed picks up the interference.

I was wondering if an exercise to test this might be interesting: enclose the caps in a preamp with foil that is grounded and see if the interference is diminished. One wonders whether there are modern caps with 3 pins...one for a body ground shield/can.