What Local TV Stations Should I Care About?

When setting up a wireless microphone system, it can be difficult to determine what TV stations have the potential to cause interference, and even harder to know which ones WILL cause interference. The only surefire way to do it is to bring in a real spectrum analyzer, which will cost ten’s of thousands of dollars. However, it is possible to get a pretty good idea of the RF environment with a bit of effort.

To get an idea of what TV stations are in your area, go to TV Fool and use their TV Signal Locater tool. Plug in your venue’s address (or coordinates, if there isn’t a physical address). If you are inside, leave the Antenna Height box blank. If you are outside, enter the height you expect to place your Wireless Mic antennas at. The click “Find Local Channels.”

TV Fool will search its database and tell you what channels you are likely to receive, and how strong they will be. This information is based on topographic information and the FCC’s TV database, and is a pretty good approximation. Scroll down to the table that TV Fool generated.

Each row of this table represents a TV station. The ones at the top are the strongest, and the ones at the bottom are the weakest. Generally speaking, if you are indoors you probably only need to worry about the ones with a light green, yellow, or red background. The green ones are the most likely to cause interference, and the yellow ones may cause interference. The red ones might be a problem, but it’s much less likely.

Make a note of the channel number under the “Real” column of the table for all green and yellow stations, and make a separate list of the red stations. Don’t bother with the gray ones; they won’t be an issue.

Now, you need to convert the TV channel numbers to frequencies. This website has a nice table which you can refer to. Avoid setting your mics to any frequencies within the TV channels you jotted down above.

This should help you get on your way with frequencies which are not occupied by TV stations in your area!

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