A few months ago I sold an excellent keyboard. It was a high-end backlit USB keyboard with good key height. I sold it because it was absolutely unsuitable for a radio amateur - transmitter. During the broadcast, she wrote a few paragraphs of text in a short time and caused the computer to shut down on some bands.
How did I proceed with the "healing" of the keyboard?
– in the first step, I tried grounding the PC case and disconnected all unnecessary peripherals and cables to the computer
– in the second step, I wound the supply cable to the keyboard on a ferrite
– in the third step, I connected the keyboard via a USB hub
– in the fourth step I opened the keyboard and connected 1nF capacitors between the live wires and ground on the PCB
– in the fifth step I sold the keyboard
Only connecting the keyboard via a USB hub had at least a partial effect. During that time I tried about ten keyboards. Keyboards connected via PS/2 appear without any problems. There are no problems with most USB keyboards, but if you hit the "right" model, after broadcasting it is…