Keyboard RFI - WTF?

Having recently sorted out some LCD screen RFI by replacing a new model with an infinitely quieter, older one, the RFI problem has become a headache again!

You know the feeling: RFI and you really, really want to sort it out.  After ages of getting nowhere, I started using a simple battery-powered AM radio to detect what was making noise.

This proved a very powerful system!  Almost immediately, I could detect very strong RFI coming from a cheap HiPoint keyboard that I'd moved from my Raspberry Pi for use at the rig.

The HiPoint Model KBHM-660 keyboard (often sold with a mouse), which produces truly monumental RFI levels.

The sheer level of RFI this small keyboard produced, despite having a metal base that might have made it well earthed, was incredible!

Replacing the keyboard with a standard curvy Microsoft unit instantly resolved the problem, and restored radio-quietness to the station!  There is now no materially significant RFI from the recent changes to an external microphone and external screen and keyboard.

So, next time you are desperate for an RFI solution - use an AM radio to first figure out where your efforts should be concentrated!