"People will come up to me and tell me they are fans of my show," Castellanos said. "When they ask me what they can do to support me, I say, 'Hey, just [continue to] watch.' "
The show "serves as a touchstone for its audience," said Lydia Hernandez-Velez, a former board member of the Pennsylvania chapter of the national Latino youth-advocacy group Aspira. She's been a guest on the show.
"You watch it so you know what's going on in the [Latino] community. The combination of Diego's genius and commitment to the show makes it easy to watch, even if you don't agree with him."
Though the show has a Latino theme and audience, it is broadcast in English, which is one of its draws, said another frequent guest, Nilda Ruiz, president and CEO of the Asociacion Puertorriquenos en Marcha, a local, Latino-based human-services and economic-development group. APM, also marking its 40th birthday recently, gave Castellanos the Adelante (Moving Forward) Award, celebrating the show's four decades on the air.
"A lot of times, when people try to reach out to our community, if the show is in Spanish, it will reach the first generation, but it's not likely to reach the second and third generations," Ruiz said. "He's a visionary."
Castellanos has been honored numerous times, not only for his television persona but also for his volunteer work.
"I tell youngsters the ticket to getting into hard-to-get jobs, obviously, first, is a good education and, second, is volunteer, volunteer, volunteer," said Castellanos, who has worked in radio and print as well as TV journalism. "I have had a lot of experience with journalism. But working within the community and reaching out to the people through my [volunteer] jobs was how I recruited people to be on my show."
Castellanos started in broadcasting in 1954, hosting a Spanish-language show on WCAM (1310-AM) in Camden, according to a profile on the Broadcast Pioneers of Philadelphia website. He was inducted into the Pioneers' hall of fame in 2002.
Born in Puerto Rico, Castellanos has spent most of his adult life in the Delaware Valley. He graduated from Marquette University with a degree in journalism, got a master's degree from Montclair State University and earned a doctorate in education from Fairleigh Dickinson University.
Besides his TV career, he has worked for the New Jersey State Department of Education, directing the office that enforced affirmative action, equal access, gender equity and bilingual education. He also has taught at four universities.
"The most important thing about Diego, besides his persistence about getting people on the show, is that he has always been active in the community," said Johnny Irizarry, director of La Casa Latina, the University of Pennsylvania's Center for Hispanic Excellence. Irizarry met Castellanos at local culture and arts organization Taller Puertorriqueno.
"I began working at Taller in 1986," said Irizarry. "I met Diego right around the time I started. He's been very supportive by frequently participating in our events, plugging new programs, and is always present during the Puerto Rican Parade and all the events related to Latino Heritage Month. He probably doesn't even realize how large of a role he plays."
When Castellanos is not taping or volunteering, the Lansdale resident most likely can be found at Isla Verde, a restaurant and lounge on American Street near Lehigh Avenue.
"I live alone and don't know how to cook," Castellanos admitted. Castellanos has been married twice and has children from both marriages, but said that he is estranged from his family.
Castellanos said that he is often recognized in restaurants, but joked that this is "probably because I am always eating out."
Appreciative fans have sometimes picked up the check or bought him a drink. However, sometimes the opposite happens. "Customers have had their waitress bring me their checks to pay for their dinner or their drinks," Castellanos said. "I guess they heard I was on TV and can afford it."
In 40 years, he's done more than 2,000 shows, which made it hard for him to choose his favorites.
"Having a one-on-one conversation with a celebrity I have admired is nothing short of awesome," Castellanos said. "But the one show that has stayed on my mind and brings tears to my eyes every time I think about it is one we aired at the end of January last year, on which we pleaded for bone-marrow donors for two young people with terminal illnesses that could only be saved by timely and matching bone-marrow donations."
One of the patients, 20-year-old Manny, appeared on the show.
"[Manny] looked straight into the camera and said - unabashed - 'Please help me. I will die soon if a donor is not willing or able to share the gift of life,' " Castellanos recalled. "This broke my heart to pieces. . . . This is the one interview that has stayed on my mind and in my heart."
Manny eventually did find a match, but later died, Castellanos added.
Bernie Prazenica, 6ABC president and general manager, praised Castellanos' show for broadening understanding of the Latino community in the Delaware Valley. "We have to give much of the credit to the endless commitment of Diego Castellanos, who has worked tirelessly to cover issues that are important not only to the Hispanic community but often to the region at large."
Castellanos put it more simply: "I try to understand the needs of the community I am serving through my program. It can be hard at times, but I love my job and wouldn't ask for anything else."