he was also into Amateur Radio (ham radio). here is the article from the ARRL website:
One of the best-known names in cinematic as well as Amateur Radio circles, actor Marlon Brando, died in Los Angeles July 1 at age 80. Known to hams worldwide as KE6PZH and FO5GJ, Brando is listed on the FCC database as Martin Brandeaux. He was on the air occasionally through the years with his FO5 call sign from his private island in French Polynesia.
In an interview with Larry King on CNN in 1994, Brando confirmed his continued interest in Amateur Radio. In response to a caller\'s question, he said ham radio provided him with the opportunity to just be himself.
The iconoclastic actor was best known for his roles as Stanley Kowalski in "A Streetcar Named Desire," a dockworker in "On the Waterfront," and Vito Corleone in "The Godfather." He was nominated for eight Academy Awards and won twice.