By HANS LAETZ
City News Service
Friday's confusing switch by U.S. television broadcasters from analog to digital television is even more confusing in San Diego, where Mexican and low-power TV signals, and channels flitting in from Los Angeles, complicate the matter.
The rest of the nation is set to see its old analog signals retired Friday, part of the nationwide shift in technology that will free up giant chunks of electronic space for new wireless services.
But four of San Diego's six most-popular channels have already made that switch. Only channels 39 and 51 still offer analog feeds broadcast over the air - signals that will cease on Friday.
Several San Diego stations will abandon their longtime electronic homes as they shift to new digital assignments in the UHF band. But to make it easy on viewers, the new digital channels have encoding devices that tell digital TV sets and converter boxes that they are actually watching the old TV channel number.
Adding to the confusion, some digital stations will move their digital signals on Friday to new homes. KUSI-TV, for example, will not only shut off analog channel 51 but will move its programming to digital channel 30, the FCC said.
That means people who use off-air antennas for KUSI, which calls itself Cable Channel 9, will need to use the rescan feature on their TVs or converter boxes to regain its programming after the switch.
And for some people in the back country, canyons or buildings where TV signals have always been a bit dodgy, the switch from analog to digital will mean an end to free, off-air television signals. That's because a few TV stations are slightly moving their antennas, causing a subtle shift in coverage areas.
Other may get better signals. Several California stations are increasing their power now that nearby stations are abandoning their old analog homes.
Tijuana stations are not required to shut off their analog signals, and have no plans to do so. Some Mexico stations with English programming, such as XETV channel 6, do offer digital transmissions from Baja California for their San Diego viewers on a different channel.
If this is confusing, remember that all these actual transmission numbers are quite irrelevant. Every digital-ready TV set, and digital converter box, sold in North America has the built-in ability to scan for available signals, and convert the data into familiar channel names such as channel 8.
And as anyone who has set up a digital off-air receiver knows, digital TV suffers from the
cliff effect,'' where the signal will go from perfect to digital mush without any intermediate steps.
Old analog signals simply gave the TV set a ghost or some static when their signals dipped. But digital TV translates a lousy signal as bad computer data, and starts breaking up and "tiling'' the picture as scenes change.
But most of the viewers in the San Diego television market, who could get acceptable analog pictures up until Friday, will now get digital coverage, the FCC predicts. And that comes with advantages, such as high-definition signals and multicasting.