By Mike Wireless • June 30, 2009 Mike Wireless, international man of RF mystery So the big day (June 12, formerly February 17, 2009) came and went, and now we have the results of “the change”. For those of you living under a rock for the past 10 years, what has happened is that full-power analog TV broadcasts have ceased in most US markets. At the same time, most of the of spectrum between 698 and 806 MHz, formerly used by TV broadcasts and wireless microphones, now has new owners and is not populated by TV broadcasts any longer. The legal status of wireless microphone systems in the 700 MHz band is not entirely clear, but the FCC’s intentions appear to be that wireless mics will not be allowed here. So let’s look at the spectrum between 500 MHz and 700 MHz, covering most what is now available to DTV broadcasts and Part 74 users, including wireless microphone systems. The first/top image (below) shows this range before the transition, and the second/bottom image (also below) shows the same spectrum after June 12. It is evident that almost all analog sources have disappeared, while only DTV sources remain. What about using wireless microphone systems in the 700 MHz band? First, you may still have systems in the 700 MHz band that will continue to operate, until such time as a new, strong signal comes along and interferes. (click to enlarge) For many, this may be the right approach: use your equipment until it no longer works. However, keep your eyes open for any announcements about the likely FCC ruling rendering such systems actually illegal. . Currently, there are few signals in that range, but there are some, and soon there will be more. For those of us using systems between 470 and 698 MHz, our lives should actually be a bit easier for a while. The spectrum is more open, and we should not see the kinds of rapid changes we have seen over the past couple of years. DTV transmissions are still being optimized, and broadcasters are recommending that people “do a new scan for channels once a month”. I would suggest the same thing for your wireless microphone systems, to insure that you are steering clear of any potential interference. (But you were doing that already, right?) As to what will become of the remaining usable spectrum, it’s too early to tell. But as TVBD (TV Band Devices) begin to appear, we’ll certainly learn more. Signing off for now… Mike Wireless Mike Wireless is the nom de plume of a long-time RF geek devoted to better entertainment wireless system practices the world over. . . More posts on PSW by Mike Wireless: Latest Wireless Series #3: Inside The Lectrosonics D4 Latest Wireless Series #2: Inside The MIPRO ACT Digital Latest Wireless Series #1: Inside The AKG DMS 700 Is The UHF Spectrum Going To Ease Up After June 12? Change The Only Constant In Marketplace For Wireless System Spectrum Also check out: Basic & Essential: What You Need To Know About Wireless Systems (A Primer) Comments Leave a Reply Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website Car Audio says Great article - thanks! You can learn more about car speakers, car amps, and other car audio components, as well as the pros and cons of different manufacturers at http://audiocarplus.com Car Audio says Great article - thanks! You can learn more about car audio and the pros and cons of different manufacturers at http://AudioCarPlus.com Nicholas James says Nice post. really needed it badly for my cisco exams preparation. Keep the good stuff coming up. alton100 says I used to be more than happy to seek out this internet-site.I wanted to thanks in your time for this glorious read!! I positively enjoying each little bit of it and I have you bookmarked to check out new stuff you weblog post hp2-t18 questions // hp2-z07 practice test // hp2-z16 answers // hp questions // ibm practice test // isc answers // jk0-016 tests // jn0-101 questions // Tagged with: AKG Acoustics Analog Concerts Digital Ease Engineer Equipment FCC Interference International Microphones Mike Wireless Mipro New RF Series Signal Spectrum System Systems Television Time Wireless Systems · all topics Subscribe to Live Sound International Live Sound International brings you information on a wide range of pro audio topics. Stay up-to-date, get expert tips, industry news, new products and technologies delivered. Discover how to make smart use of today’s sound technology, Subscribe Today!