Ornithologist Arlo Raim from the US was also a radio amateur with a home CallSign: KB9LLF - went silent key on 20th August, 2010.
He was perhaps the best bird tracker in the world. You can read about it at:
In the amateur or ham radio jargon, a deceased ham radio operator is referred to as "Silent Key" - meaning that his telegraph or wireless key has gone quite. The wireless key is a device use to send out Morse codes - a series of dots and dashes over the airwaves.