In an article in Esquire in 1971, the writer Ron Rosenbaum called Joybubbles the catalyst uniting disparate phreaks. Particularly after news accounts of his suspension from college in 1968 and conviction in 1971 for phone violations, he became a nerve center of the movement.

“Every night he sits like a sightless spider in his little apartment receiving messages from every tendril of its web,” Mr. Rosenbaum wrote.

Josef Carl Engressia Jr. was born May 25, 1949, and moved often because his father was a school-picture photographer. At 4 or 5, he learned to dial by using the hookswitch like a telegraph key. Four years later, he discovered that he could disconnect a call by whistling. He found this out when he imitated a sound in the background on a long-distance call and the line cut off. It turned out that his whistle precisely replicated a crucial phone company signal, a 2,600-cycles-per-second tone.

Joybubbles’s parents had no phone for five years because of their son’s obsession. Later, his mother encouraged it by reading him technical books. His high school yearbook photo showed him in a phone booth.

By the time he was a student at the University of South Florida, Joybubbles was dialing toll-free or nonworking numbers to reach a distant switching point. Unbeknownst to telephone operators, he could use sounds to dial another number, free. He could then jump anywhere in the phone system. He was disconnected from college after being caught making calls for friends at $1 a call. In 1971, he moved to Memphis, where he was convicted of phone fraud. In Millington, Tenn., he was hired to clean phones, a job he hated. In 1975, he moved to Denver to ferret out problems in Mountain Bell’s network.

He tired of that and moved to Minneapolis on June 12, 1982, partly because that date’s numerical representation of 6-12 is the same as the city’s area code. He advertised for people yearning to discuss things telephonic and weaved a web of phone lines to accommodate them. He lived on Social Security disability payments and part-time jobs like letting university agriculture researchers use his superb sense of smell to investigate how to control the odor of hog excrement.

Joybubbles is survived by his mother, Esther Engressia, and his sister, Toni Engressia, both of Homestead, Fla.

His second life as a youngster included becoming a minister in his own Church of Eternal Childhood and collecting tapes of every “Mr. Rogers” episode. When asked why Mr. Rogers mattered, he said: “When you’re playing and you’re just you, powerful things happen.”