TV Channel Scanning, Missing Channels & Rescanning

After connecting your TV antenna to the antenna or RF input on your television, use the television's setup menu to perform an Over the Air channel scan.

The exact terminology varies by television manufacturer, but the feature may be called Channel Scan, Auto Scan, Auto Tuning, Channel Search, Auto Program, or something similar.

Before starting the scan, make sure the television's input or tuner mode is set to Antenna, Air, Broadcast, or Over the Air, not Cable. Cable television and Over the Air television use different channel plans and signal formats, so selecting Cable can prevent the television from properly finding local broadcast stations.

During the scan, the television tuner searches the available television RF channels and identifies digital broadcasts that it can successfully decode. The television then stores those stations in its internal channel list.

Once the scan is complete, you should be able to tune to the available local stations using their familiar virtual channel numbers, such as 3.1, 5.1, or 12.1.

Receiving an RF signal at the antenna does not automatically mean the television has that station stored in its channel list.

The television tuner must first detect and successfully decode the station during a channel scan. If the signal was too weak, unstable, or impaired when the previous scan was performed, the tuner may not have added the station.

This can also happen after a broadcaster changes its actual RF channel. The station may continue displaying the same familiar virtual channel number, but your television may need to perform another channel scan to locate the station on its new RF frequency.

If you believe a station should be available, first verify that the antenna system is connected properly and then perform another Over the Air channel scan.

If the station still does not appear, the issue may involve antenna reception, signal strength, interference, antenna direction, or another RF condition rather than the scanning process itself.

You should rescan your television whenever there is reason to believe the available broadcast channel lineup has changed or when your antenna system has been changed.

Common reasons to perform a new channel scan include:

Installing a TV antenna for the first time.

Replacing or repositioning an existing antenna.

Moving the antenna to a different location.

Changing the antenna's aiming direction.

Adding or removing an amplifier or other major system component.

A local television station changing its RF broadcast channel.

A new television station or subchannel beginning service in your area.

A previously available station no longer appearing in the television's channel list.

A rescan allows the television to search the current RF environment and rebuild or update its stored channel information.

It is not normally necessary to rescan simply because reception temporarily becomes weak. If a station is already stored but occasionally pixelates or disappears, the underlying issue is more likely related to reception conditions than the television's channel list.

Yes. This can happen on some televisions.

During a complete automatic channel scan, the tuner searches for signals that are receivable at the time the scan is performed. If a previously stored station happens to be weak, experiencing interference, or temporarily unavailable during the scan, the television may fail to detect it and remove it from the newly created channel list.

For this reason, repeatedly rescanning is not always the best first troubleshooting step for a channel that is already stored but temporarily experiencing reception problems.

If your television offers a manual channel scan, manual tuning, or add channel function, that feature can sometimes be preferable because it may allow you to search for a specific RF channel without deleting the stations already stored.

The availability and operation of manual channel features varies by television manufacturer and model.

It is completely possible for one station to be missing while many other stations work normally.

A TV antenna system does not receive all stations as one combined broadcast. Each station transmits on a particular RF channel, from a particular transmitter location, at a particular power level, and under its own propagation conditions.

A missing station may:

Broadcast from a different tower location.

Use a different RF frequency band.

Arrive at your location with a weaker predicted signal.

Be affected by terrain or obstructions differently.

Experience interference on its particular RF frequency.

Fall outside the strongest reception area of a directional antenna.

Be temporarily operating at reduced power or experiencing a broadcast issue.

The virtual channel number displayed on the television can also be misleading. For example, a station displayed as Channel 5.1 does not necessarily broadcast on RF channel 5.

The Channel Master TV Antenna Map & Technical Information Tool can show the actual RF channel, tower location, direction, distance, and predicted signal strength for stations available at your address.

Comparing the missing station with the stations you receive successfully can often reveal why that particular channel is more difficult to receive.

All three functions involve the television tuner searching for broadcast signals, but they can operate differently.

A channel scan or auto scan generally searches the entire television broadcast spectrum and creates a list of stations the tuner can successfully receive.

A rescan usually refers to performing that automatic scanning process again. Depending on the television, a rescan may replace the previous channel list with a newly detected list.

A manual channel scan allows the user to search a particular RF channel rather than scanning the entire television spectrum. On televisions that support it, this can be especially useful for troubleshooting a missing station or attempting to add a station without disturbing channels that are already stored.

Remember that a manual scan generally requires the station's actual RF channel, not necessarily the virtual channel displayed on the television.

For example, a station displayed as 7.1 might actually transmit on RF channel 22. To manually search for that station, the television may require you to enter RF channel 22.

You can identify the actual RF channels used by stations in your area with the Channel Master TV Antenna Map & Technical Information Tool.