Dr. Stewart was the trustee of the University of Pittsburgh Amateur Radio Club W3YI. During my undergraduate years at Pitt in the mid 1980's he was extremely supportive of the club and instrumental in helping us acquire equipment and antenna space.
http://www.post-gazette.com/pg/10098/1048808-122.stm
Dr. Stewart will be sorely missed by everyone who knew him. I had the honor of interacting with him while I was Business Manager and later President of PARC around 2000 ~ 2003. He was a great ally of the club; he was also the most interesting, engaging person I've ever met. I'm proud to have considered Doc a friend.