PHILADELPHIA -- LaRonika Thomas got upset when Comcast moved the Sci-Fi channel to its digital service this summer, ensuring she couldn't continue to watch her favorite show, ''Firefly," without paying $20 more a month.
The Chicago resident received The Golf Channel instead on her basic analog cable service.
''I don't watch golf. I would rather have static on than that channel," said the theater director.
''It's an awfully big cost," said Thomas. ''I haven't canceled my service yet, but I may."
Across the country, cable operators have been moving popular channels from analog to digital service, which offers customers better picture and sound but also can handle much larger volume, allowing cable operators to use their networks for more lucrative options such as video on demand and Internet and telephone services.
Markets seeing the change include cities in Massachusetts, Pennsylvania, Connecticut, Illinois, Michigan, California, Louisiana, Nevada, Colorado, and Texas.
''They're trying to reclaim some of the capacity, mostly for HD" or high-definition TV, said Bruce Leichtman, president of the Leichtman Research Group, a research and consulting firm in Durham, N.H.
Digital services let cable operators better compete with satellite TV and soon, phone companies, said Jimmy Schaeffler, an analyst with The Carmel Group, a market research firm in California.
Another reason why digital is alluring to cable: ''It's hugely more profitable," Schaeffler said.
Fees for advanced services can inflate a basic subscriber's bill by 30 percent to 40 percent or more.
But to increase their offering of digital services, cable companies need to free up space on their cable lines -- which means cutting back on analog channels.
''If we ever find a way to take back our analog channels, we in essence triple the capacity of our system," David Fellows, Comcast's chief technology officer, told analysts in May. A digital channel takes one-sixth to one-tenth of space an analog channel occupies.