Viewers in the 15 percent of households that receive free, over-the-air television via antenna will have to rescan their TV tuner periodically over the next two years, according to WKAR-TV.

WKAR will be the first area station to move to new frequencies assigned by the FCC on or before May 9, followed by other local stations, including WSYM and WLAJ.

The frequency reassignments are part of a project by the FCC to make room in the broadcast spectrum for wireless broadband services and new digital TV technologies. By law, nearly 1,000 TV stations nationwide must change broadcast frequencies by the spring of 2020.

No new devices, equipment or services will be needed to continue receiving the local stations. Antenna TV viewers must simply go into their tuner channel settings and rescan to locate stations after each makes their assigned change.

To make the move, WKAR is replacing the main broadcast antenna that sits atop the station’s 1000-foot tower, the 20-year-old transmitter, the transmission line to the antenna and an auxiliary antenna.

It will be a $2 million project for WKAR, paid for almost entirely by the proceeds of the recent FCC spectrum auction.

Beginning April 20 through completion of the project in May, WKAR-TV and 90.5 FM and 105.1 FM will be broadcasting at substantially reduced power as crews work on the transmitter. This may result in poor or no reception for some viewers and listeners. FM broadcasts are affected by the work because the TV and FM broadcast antennas are on the same tower.

There will also be short periods when the stations are off the air entirely for crew safety when working on the antenna.

Comcast and AT&T U-verse services will not be affected by the work; however, other pay TV service providers receive the WKAR signal over the air, and they will be adversely impacted.

When WKAR completes the work and returns to the air at full power, WKAR-TV will continue to appear at channels 23.1, 23.2, 23.3A and 23.4 after a rescan for channels.

For more information about changes, visit the National Association of Broadcasters website. Updates and more info about the WKAR-TV project are at wkar.org.