DZBB-TV traces its history to Metro Manila radio station DZBB, owned by Loreto F. de Hemedes, Inc., later renamed Republic Broadcasting System, Inc. of Robert "Uncle Bob" Stewart. After the success of its radio station, the company ventured into television. On October 29, 1961, RBS Channel 7, the fifth television station in the Philippines, and ABC Channel 5 by the. The television network started its operations with just 25 employees, a surplus transmitter, two old cameras and no lighting equipment and props. The station was always in the red and Stewart was about to give up; when the program "Dancetime with Chito" suddenly became an instant hit and advertising revenues started to pour in. Canned programs from the United States further sustained its success. In 1972, PresidentFerdinand Marcos declared martial law in the Philippines and the station was forced to shut down, though it only lasted for more than 3 months, and returned on the air in late-December of that year; this time, blocktimed by the National Media Production Center with limited three-month permits. In 1974, RBS, including its TV and radio stations, were sold to a triumviratecomposed ofFelipe Gozon, Gilberto Duavit, Sr., and Menardo Jimenez who introduced a programming concept catering to the new audience. The new management acquired new equipment and introduced new programs and a new name, GMA Radio-Television Arts with its new identity, "Where You Belong" in 1979. When democracy in the Philippines was restored in the People Power Revolution in 1986, other television stations began to air, some with their original owners. The political instability of the country also added to the station's burden, when soldiers stormed into its studios for two days in a part of coup attempt to topple then President Corazon Aquino. In July 1987, GMA introduced its new dimension in television broadcasting as the network was transmitted in full stereo, dubbed as GMA StereoVision, and became the first Philippine TV station to broadcast programs in full stereo until 1998 when it switched to the current 100 kilowatt capacity. On November 7, 1988, DZBB officially inaugurated a new 100,000 watt transmitter in Quezon City. Known as the "Tower of Power", the transmitter helped improve the channel's reception in Luzon, and was also the tallest man-made structure in the country at the time.
Digital television
Digital channels
DZBB-TV's digital signal operates on UHF channel 15 and broadcasts on the following subchannels:
In February 2013, GMA Network conduct a digital test broadcast with the ISDB-T standard via its UHF channel 27 frequency. According to a December 2017 press release, the station's upgraded signal transmission covered the areas of Metro Manila, Rizal, Cavite, Laguna, Bulacan and parts of Pampanga, Bataan, Nueva Ecija and Batangas. In 2016, the National Telecommunications Commission, through a memorandum circular, authorized GMA to operate UHF channel 15 as its secondary channel to expand the usage of channels 14-20 for digital TV broadcasts. Following ZOE Broadcasting Network's decision not to renew its joint venture with GMA after June 2019, and a subsequent planned reactivation of DWDB-TV's analog signal for the rest of the GNTV's analog broadcast run, third-party sources reported that the station's digital signal will move to the assigned channel 15 frequency after channel 11's blocktime deal with GMA expires. On May 15, 2019, GMA Network began to transmit its digital test broadcast on UHF Channel 15 as its permanent frequency assigned by National Telecommunications Commission.
