Yet another source of radio interference

[Reece]

For some time my ordinary solid state bedside clock radio has had a strong buzz on the AM band. I don't use that radio much but the other day had occasion to have it on and decided to try to track down the source. Imagine my surprise when I found it immediately. I have one of those blood pressure cuffs in a small white clamshell plastic case (which I also don't use much), and it was sitting on top of the radio. Moving it away stopped the noise. Even when off it emits hash. It uses AAA cells and is like so many items these days: there is not a dedicated on/off switch that truly disconnects all power, but has a "sleeping and ready" circuit waiting for you to push the tactile button.