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Wireless UHF & VHF Microphones & TV interference

TV interference with wireless UHF & VHF microphones affected by new ruling

TV Broadcasting Switches From Analog to DigitalRobert L. asks:

I’m shopping for a wireless microphone. I live in an area with several strong signal TV stations.  Will this affect my microphone?  And if so, should I consider a UHF or VHF microphone?

AudioMan explains his non-interference policy when it comes to optimizing the operation of wireless microphones in an area with strong TV signals…

I detect in your question about wireless microphones and strong signal interference some underlying concern about the upcoming switchover to digital TV (currently scheduled for June 12, 2009). 

This broader issue is addressed in an article on government reallocation of the radio spectrum by the FCC which I wrote a few months back.

But to answer your immediate question, your safest bet is to opt for either a VHF wireless microphone or a UHF wireless microphone that operates outside the soon to be proscribed 698-806 mHz bandwidth

The problem is not the TV broadcast stations.

But, as part of the reorganization of the electromagnetic spectrum, the FCC auctioned the 700 band to the highest bidders (including Qualcomm and AT&T) to facilitate the development of wireless broadband Internet service throughout the United States (and to make some money for the US government - more than $19 billion). While some UHF frequencies are fine, if your UHF wireless microphone operates in the 698-806 mHz bandwidth you may be subject to severe interference and possibly be in violation of the law.

Ironically some of the TV stations which currently broadcast in the lower VHF range (channels 2 - 6) will be vacating that bandwidth. That means that the much maligned VHF microphones utilizing those frequencies will see somewhat improved performance.

If you go for a VHF wireless mic, you should have fewer problems with cross-channel interference even if you have a large number of digital TV stations broadcasting in your area.

Again, let me clarify that the digital TV switchover will affect some, but by no means all, UHF wireless mics currently in use.  The UHF mics being made and sold now are not in the bandwidth that will be affected come June.  And in fact many makers of UHF mics are offering trade-ins on older wireless microphones for new wireless microphones that comply with the new FCC regulations

Wireless mics that operate on the UHF bandwidth generally provide somewhat better sound and clearer transmission – at a higher price – than VHF mics.  If you’re using your microphone for spoken word applications or even for karaoke, the sonic difference won’t really matter.  If you’re a musician using your mics in a studio or onstage, however, the new UHF mics may be advisable.

For more info about specific wireless microphones check out our huge selection of wireless microphones by AKG, Nady, Sennheiser and Shure

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