[Today's post is by theater maven and FMC Operations Coordinator Nicole Duffey]

Do you own a wireless microphone?

If so, take a moment to check out its specs — chances are it uses a part of the 700 MHz band of the electromagnetic spectrum to do its thing. If so, you’ll have to stop using your wireless mic this June. If you don’t, you could be putting someone’s life in danger.

Per the FCC:

OPERATION OF WIRELESS MICROPHONES IN THE 700 MHZ BAND

IS PROHIBITED AFTER JUNE 12, 2010

Let’s start at the beginning of this story. The VERY beginning.

By the mid 1800s, scientists had begun to catch on to the existence of the electromagnetic spectrum. This spectrum includes everything from microwaves, infrared, visible light, ultraviolet light, X-Rays, gamma rays and good old-fashioned radio waves. Think about the spectrum as a road with many lanes. The electromagnetic highway is a special road where only one car (signal) can be in a lane (frequency) at given time. If multiple signals try to cram into one lane all the cars all crash. That crash on the electromagnetic spectrum is called interference.

Electromagnetic communications began to take off in the early 1900s with what we now call AM radio. Ships at sea could communicate with each other and with folks on land like never before. When interference from amateur radio users started to become a problem for ships, the US Government began passing laws to regulate the use of spectrum “as the public convenience, interest, or necessity” required. Since no one can “own” the airwaves, the spectrum is the property of the American people and held in trust by the government to (theoretically) be used to serve the public interest. A regulatory body called the Federal Radio Commission was set up, which later became the Federal Communications Commission (FCC) that we know today.

When television began broadcasting in the 1930s, the FCC licensed portions of the spectrum in the 700 MHz band for the TV stations to use. Because TV broadcasts were still a developing technology, they had to give each station an empty lane on each side to prevent other stations from interfering with their signal. (Think back to the car metaphor from earlier.) These empty lanes were called “white spaces.”

When wireless microphone technology was came along in the 1950s, they used those same white spaces as their lanes to transmit signal. Since the mics were only broadcasting in very small areas, and because TV technology was improving, there wasn’t really any interference from their use of the blank space between the TV stations. Sort of like parking your car in an unused lane for while running into the post office for a few minutes. No harm, no foul.

But as years passed and technology improved, more and more wireless mics parked on more and more spectrum. Improvements were also made to TV broadcast signals until they didn’t need those “buffer lanes” anymore. Eventually, with the advent of digital broadcasting, TV no longer required the 700 MHz portion of the spectrum at all. To put it another way: TV got flying cars, so the FCC wanted to put their old lanes to better use.

If your grandparents traded in the rabbit ears on their TV for a little black box in early 2009, you know about this already. This digital transition was our government taking back the 700mh portion of the spectrum from over-the-air broadcast television.

Now, it’s important to note that the 700 MHz lanes isn’t just any old electromagnetic blacktop — it’s more like the HOV lane. Frequencies in this band are capable of carrying a lot more data than many other portions of the spectrum, making them super valuable to wireless providers and potentially members of the public.

The first thing that happened when the government began the process of reclaiming this spectrum was to auction off pieces of it in an anonymous auction process that raised $19.6 billion for the federal government. The big buyers were Verizon and AT&T, who will have to abide by some openness standards to ensure that any compatible device will be able to work. Could new networks built on this spectrum bring quality internet connectivity to more Americans via wireless technology? It’s certainly a possibility. For musicians it could mean a new way to connect with fans, and vice versa.

In addition to the part going to new wireless use, another portion of the 700 MHz portion is going to first responders, so the next time you see an ambulance or a fire truck speed past, they may very well be in communication with their home base via improved wireless communications using that fertile spectrum.

And that’s why you need to trade in your wireless mic for something that uses a different portion of the spectrum. It’s been squatting on a little piece of air that it was never officially licensed for — and if it does still work after June 12, 2010 — there is a real chance that it could cause interference for any emergency rescue worker nearby.

The really sucky part is that you’ll probably have to pay to replace or upgrade your equipment. In a rough economy, this is unwelcome news for countless wireless mic users. Many musicians don’t have mic replacement in the budget this year. And that goes for a lot of churches, venues, sports and conference facilities — the list goes on.

As the staffer who typically answers the phone at the FMC offices, I’ve spoken to a handful of people trying to understand this situation. Some folks are understandably steamed. Personally, I think that blame is really tricky here, because when wireless mics were first developed, no one watching “I Love Lucy” could’ve predicted gadgets like iPhone, to say nothing of “smart spectrum sensing devices.”

On the other hand, since nothing in government happens particularly quickly, it seems like the microphone companies should’ve seen this coming.

Last week, I spoke with Michael, a wireless mic user in Wisconsin who bought his equipment in 2007 and was angry enough about having to pay $200 (plus freight) for a replacement that he got the local media involved. Michael told me that, after the news station called the company that made Mike’s mic, the manufacturer sent him a very nice email offering to replace his equipment free of charge.

In my interwebs sleuthing, I also found a public statement from one company who actually had an ad about their wireless mic rebates. “When Avlex began marketing Mipro wireless microphones in 1999,” it states, “we made a conscious decision to not sell products operating in the soon to be prohibited 698-806 MHz range.” Meaning, Mipro customers who purchased microphones more than a decade ago will need to replace, but those customers from the past ten years are golden.

We encourage you to take the time to look closely at your wireless microphone and replace it if need be. The FCC site has a great FAQ to help you along.

Further Reading:

WIRED article about the 2008 Spectrum Auction

Alvex and the Mipro rebate program

Freaky Pictures of Old Televisions

The Electromagnetic Spectrum

US Spectrum Allocation Chart