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Wireless Frequency Selection
In accordance with law, the Federal Communications Commission (FCC) auctioned off the frequency range from 614 to 698 MHz (the 600 MHz band) to cell phone companies. They had previously auctioned off the range from 698 to 806 MHz (the 700 MHz band). TV channel 37 (608 to 614 MHz) has never been legal for wireless microphones in the USA. All users of these frequencies including TV stations and wireless microphones must cease using these frequencies. The 700 MHz band became illegal to use on June 12 2010. The 600 MHz band will become illegal to use when the new owners of the frequenecies start using them, or July 13 2020, whichever comes first.
Most wireless mics operate in unused portions of the UHF TV broadcasting spectrum for many good reasons. One of the main reasons these frequencies are excellent for wireless mic use is that the main other users of the frequencies are TV stations and we can determine which frequencies TV stations are operating on in our area and avoid operating our wireless mics on those frequencies. During the transition out of the 600 MHz band, TV stations that had been operating in that band will have to move to lower frequencies mostly in the 470 to 608 MHz UHF TV band. As a result that frequency range will become more crowded and there will be fewer channels not used by TV stations that wireless mics can use. The range from 470 to 608 MHz is still the best available for wireless mics unless you need more channels than you can operate in the free channels in your area.
It is also legal to operate wireless mics in unused portions of the VHF TV band, but there are very few wireless mics currently made that operate on these frequencies.
It is legal to operate wireless mics in the 900 MHz Industrial Scientific and Medical (ISM) band. In many parts of the USA this band is not in heavy use, but the problem is how to determine how much it is used in your area. Since all the users of the 900 MHz band are unlicensed, there is no chart you can consult to determine what frequencies are in use.
Many inexpensive wireless mics operate in the 2.4 GHz band along with most WiFi routers and Bluetooth devices. Unless you are located in a rural area, you may find the other users of this band make it difficult to get reliable wireless mic operation. If you must use this band, keep the receiver as close as practical to the transmitter.
Before purchasing a wireless mic, you should check to see what UHF frequencies will be available for use at your location after July 13 2020. Here are some websites that show what frequencies will be available in major cities in the USA.
FCC Auction TV Repack
Broadcast Spectrum Repack Timeline
If you are not located in one of the cities listed above you can determine the free TV channels by downloading the following Excel file:
Find your latitude and longitude from this website:
Address to Lat-Long Conversion
Enter your Lat and Long into the spreadsheet, then sort the TV stations by distance. You can figure you need to stay off channels that have a TV Station within 80 miles of your location.
The TV channels (36 and lower) without a TV Station on them within 80 miles of your location are what you can run wireless on after July 13, 2020.
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Last Edited 1/15/2018
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