Who knew, more than 10 years ago, that the UHF spectrum available for use by professional audio wireless products would continue to shrink to where we are today? Some of us did. I’ve been talking about shrinking spectrum since 2006.
In 2012, Geoff Shearing, Henry Cohen, and I began discussing the creation of Radio Active Designs’ UV-1G analog intercom, as we all encountered bandwidth issues with wireless in the 600 MHz band. Large productions demanded increasingly higher channel counts for wireless microphones and in-ear monitors, and we ran out of reliable space. Therefore, we started considering ways to address that problem.
If you recall, the original move from VHF to UHF wireless products started with a demand for higher audio quality and wireless systems with greater range. The original products in the VHF band were limited by square foot coverage, 50 mW of RF power output, and 15 kHz of deviation. The UHF band offered up to 250 mW of output, antennas one-third the size of VHF antennas, which made a big difference for body pack transmitters. Lastly, UHF provided greater range and increased audio quality due to the increase to 75 kHz of deviation.
It wasn’t long before all wireless professional audio products, including intercom systems, operated in the UHF band. Other product areas, including broadcast and cellphones, also started using the UHF band. It was getting crowded.
We knew it wouldn’t improve, so Geoff, Henry, and I started brainstorming ideas for an intercom system that operated in VHF, which was and still is wide open. Many technological advances that digital provided were unnecessary for an intercom system. Yes, an intercom must transmit audio, but the quality doesn’t have to be as pristine as necessary for vocal microphones. Also, the primary objective was spectral efficiency, hence the narrowband amplitude modulation.
That is when we started Radio Active Designs and worked diligently to create the UV-1G. In 2012, I worked as an RF/wireless specialist at Professional Wireless Systems, which I founded in 1994. Henry Cohen was a frequency coordinator and senior RF Systems Design Engineer at CP Communications, while Geoff Shearing served as president at Masque Sound. The goal was to free up RF spectrum by developing a wireless intercom that offered spectral efficiency, accurate broadcast transmission, and simplified setup and antenna deployment. We launched the UV-1G in 2014.
Two years later, the government conducted its second wireless spectrum auction, officially known as Auction 1001, which allocated approximately 100 MHz of the UHF spectrum to television broadcast, essentially eliminating much of its use for audio production purposes.
Some of this was attributable to the government’s 2008 decision mandating that TV stations transition to digital broadcasting to free up radio spectrum for new wireless services (think cell phones). It shouldn’t have been surprising that these television stations would start to require more of the digital spectrum.
As people scrambled to cope with the loss of bandwidth, manufacturers had already been developing products capable of operating in the 700 MHz band, which was more accessible. At that time, we recognized that the UV-1G had already found its niche and decided we had no intention of creating a digital version of the intercom system.
It wasn’t long until the 700 MHz band became so crowded that manufacturers increased production of products that operated in the 1.9 GHz (DECT) Unlicensed Personal Communications band. Fortunately, the UV-1G operates primarily in VHF, so no matter which UHF band becomes overcrowded, the UV-1G is available to provide reliable communications while freeing up UHF bandwidth for use by other wireless products.
The UV-1G streamlines system setup by offering RF channels with a mere 25 kHz occupied bandwidth while using the relatively unused VHF range for all belt-pack portable devices. Enhanced Narrow Band technology makes the transmitter’s occupied bandwidth more predictable and 10 times more spectrally efficient than the current FM technology.
The 1RU unit allows for up to six belt packs per base station and up to six base station links for 36 ISO channels between packs. Base Linking affords matrix-like functionality, providing up to 18 inputs and 24 outputs and comprehensive audio routing to/from packs. Users can roam seamlessly for 600 meters—only one set of antennas required to run a limitless number of belt packs. The Scene Change feature allows each pack to have up to 40 talk paths and the ability to communicate with 20 wired comm channels. Pack parameters – including radio frequencies, assignment, and audio routing – are easily changed via software with an intuitive UI.
The units can coordinate with other users because the UV-1G operates in licensed bands, ensuring error-free production. Radio Active Designs offers several UHF and VHF antennas, combiners, and splitters to facilitate using the UV-1G intercom system.
Since its introduction, the UV-1G has been field-proven in every major live broadcast in the United States and is used in stadiums and arenas worldwide. It is the preferred wireless communication system for industrial power plants and Space Exploration mission control operations.
With the highly crowded 1.9 GHz band, the UV-1G is more relevant than ever for production use. Once again, we’re running out of wireless spectrum – it’s evident everywhere. We cannot fit any more gear into the available RF spectrum. Not only are we seeing this professionally, but the congestion in the DECT PCS band is driving UV-1G sales in the large arena and stadium industries every day.
More than 10 years after the introduction of the UV-1G, the demand for more spectrum persists. Thankfully, the UV-1G analog wireless intercom remains a reliable tool that helps alleviate the issue for live productions and fixed installations worldwide.