Some Columbus-area customers of Medicom are in for a rude awakening Tuesday if they are fans of the Food Network, Nickelodeon and The History Channel — and don’t have digital adapters.

The cable company on Monday said it will switch off the analog signals of those three popular channels Tuesday and continue pulling the plug on others until the switch away from most of its analog offerings is completed in two weeks.

The move affects those customers with the Family Cable package, which includes channels 23 through 79. Five more channels will be phased out on July 17 before the others disappear on July 24.

Mediacom spokeswoman Phyllis Peters said more than 12,000 digital adapters have been distributed in the Columbus area over the last two months as the company communicated with customers to alleviate any confusion.

“We’ve been promoting this upgrade since early May and most customers are prepared for a smooth transition to a digital lineup,” Phil Skinner, Mediacom area operations director, said in a statement.

Cable subscribers impacted by this move are those with the old, bulky analog sets who don’t already have a standard digital set-top box from the company. Those who have purchased digital-ready televisions in recent years — even without a box — are covered as well.

The digital adapter, which is free for a year and 99 cents monthly after that, will convert the analog signals to digital, thus freeing up space for more digital and high-definition channels and faster Internet, the company said. By July 27, it said, there will be 26 new HD channels and a half-dozen other digital channels offered.

Customers will still be able to view channels 22 and below — which includes the major broadcast networks — without a digital adapter for the foreseeable future, Mediacom has said. But subscribers will not see their monthly bill reduced by not accepting and using an adapter.

To get a digital adapter, stop by the Mediacom office at 6700 Macon Road in Columbus 8 a.m.-5 p.m. Monday-Friday or 9 a.m.-noon Saturdays. Customers also may phone 1-855-230-2225 or 1-800-479-2095 to place an order for up to three free adapter kits per household. To order via the Internet, visit www.mediacomcable.com/order or www.mediacomcable.com/getdigital.