On June 12, 2009, KCET shut off the UHF analog television signal it had been running since 1964, and completed its transition into high-definition digital broadcasting.
The television medium has always been dependent on advances in technology, from the black and white broadcast era, to the introduction of the Ultra High Frequency (UHF) signals - which KCET broadcasted on for many years on UHF channel 28 - to cable, stereo sound, and high-definition screen technologies.
Starting in 1996, Congress mandated a 10-year timetable for all high-power television stations to transition to a digital signal, which was extended several times to June, 2009. KCET prepared for this starting in 1998 when it purchased its first digital transmitter. On June 9, 2000, KCET initiated its first digital television signal, broadcasting a PBS test loop on digital channel 59.1.
According to Jeremy Howard, KCET's RF & Transmission Supervisor, digital channel 59.1 was always intended as a temporary home to test the station's digital signal, and would later migrate to the more familiar 28.1 during the actual transition. KCET was the 18th PBS station in the country to broadcast an HD digital TV signal.
In 2003, KCET experienced a number of advances in its digital broadcasting. PBS launched a new satellite specifically for HD programming, which allowed stations to down-convert HD programs to air on the analog signal. KCET upgraded its digital signal to high-definition capability and became the first PBS station in the country to air an HD signal 24 hours a day, seven days a week. By 2004, enough technical upgrades were performed so that KCET was finally able to simulcast the same programming on both its digital and analog channels.
The final transition to digital began in 2008 when the initial tests were conducted for the new digital transmitter. KCET was ready for the intended February 2009 transition date, but delayed its plans after Congress voted to postpone the transition date to June 12.
On 11:45 a.m. on June 12, 2009, KCET shut off its 155 kilowatt UHF analog transmitter, located at the top of Mount Wilson in the San Gabriel Mountains, and began broadcasting digitally on its new HD digital channel, 28.1.
"We practiced everything to do the job within 40 minutes, which involved shutting off the old transmitter, putting in a new piece of pipe (large coaxial wire), and warming up the new transmitter. It took half an hour and three people to do the work," said Howard. "It was all kind of theoretical up to that point, we crossed our fingers, and off we went."
It cost $2.5 million to upgrade the station to digital broadcast technology, which included a new Harris digital transmitter, and upgrades to electrical systems and infrastructure, primarily at the Mt Wilson transmitting center.
In addition to its main HD signal on channel 28.1, KCET also broadcasts over the air three other standard-definition sub-channels to 11 counties across Southern and Central California: KCETLink (28.2), which airs a combination of KCET and LinkTV programs; V-Me (28.3)*, a Spanish-language public TV channel; and NHK World (28.4), showing news and lifestyle programming from Asia.
*This article makes reference to Vme. As of Mar. 30, 2017, Vme is no longer distributed by KCET. Click here for more information.