Bob was well known in the amateur radio community, of course. I owned one or two of his ham microphones. He may have been even better known for his work in con

Bob was well known in the amateur radio community, of course. I owned one or two of his ham microphones. He may have been even better known for his work in concert sound systems for the Grateful Dead, The Who, Joe Walsh, Peter Frampton, and many others. Here is a previous HN discussion with some notes about the term "silent key": https://news.ycombinator.com/item?id=19674170 https://news.ycombinator.com/item?id=19674170