Oct 1, 2005 12:00 PM, By George Petersen

PUSHING BANDWIDTH BOUNDARIES

When you consider wireless technology, these are the good old days. Unlike other segments of audio, where the word “vintage” is spoken with reverence, new wireless systems offer better performance with greater reliability and more freedom from interference and dropouts than units that are even a few years old. Besides, that “classic” VHF system taking up room in your closet isn't of much use: Since the FCC re-allocated those frequencies, all you'll get out of that guitar rig is static.

Finding a great system today is no big deal. However, with wireless systems that are increasingly easier to use and more affordable, one main concern is finding some clear sky in the crowded frequency spectrum in which to operate. With that in mind, Shure developed UHF-R^™, the company's new flagship wireless system for live performance.

Making its AES debut this month, UHF-R offers fast, automated setup; real-time system tweaking over network control; and 2,400 selectable frequencies over a wide 60MHz bandwidth, providing up to 40 simultaneous compatible systems per band. “One of the challenges faced by our engineering team was to meet or exceed the performance of our high-end wireless products, but also stretch the tuning range of the product,” says UHF-R project manager Michael Carnahan.

UHF-R's extended bandwidth comes as a result of Track Tuning, a filtering system similar to the one used to create the almost-1,000MHz bandwidth employed by VHF and UHF television signals to increase signal isolation from intermodulation distortion. UHF-R operates by using a narrow, moveable filter within its 60MHz bandwidth. As the user selects different frequencies within the band, the filter shifts to attenuate any possible interference that may be created by frequency intermodulation outside the filter range.

“That's one of the main advantages of our Track Tuning filtering technology,” Carnahan says. “With Track Tuning, when you center on a particular frequency, you're less likely to pick up interference.”

UHF-R is designed to work within three UHF 60MHz-wide frequency ranges: H4 (518 to 578 MHz), J5 (578 to 638 MHz) and L3 (638 to 698 MHz), with the ability to operate up to 40 systems in each band or up to 108 systems using all three bands. (In Europe, where wireless allocations are different, UHF-R operates in bands up to 75MHz wide.)

“We built in some scanning features to sort a set of usable frequencies in a given band,” Carnahan says. “Users get an optimum curve telling what channels are usable based on other wireless devices in the area, TV channels, et cetera. We're trying to take the setup process and make it as efficient as possible.”

Among UHF-R's standard features are Flash memory for storing six 60-channel custom groups; automated infrared transmitter setup with custom group upload; Audio Reference Companding; built-in USB and Ethernet connectivity; AMX/Crestron compatibility; bit-mapped LCD on all transmitters; and eight hours of operation on two AA cells. The compact UR1 bodypack transmitter can be used with any Shure headworn or lavalier mic (or optional instrument cable), and the UR2 handheld can be ordered with a choice of SM58/86/87 or Beta 58/87A/87C interchangeable capsules. Options include antenna splitters, antenna/power distribution, an in-line antenna amplifier and various passive and active antennas.

With UHF-R, Shure has updated its Wireless Workbench^™ software (which can be downloaded at www.shure.com). Now at Version 4, this Windows-based application simplifies management of networked wireless systems, with access to all system parameters — either globally or to individual units — in the system. New functions in V. 4 include full remote monitoring and control of network, the creation of custom groups, infrared sync setup, and Frequency-Compatibility Calculator and Auto-Frequency-Selection Wizards. The latter scans the RF environment, accessing the networked hardware to recommend usable frequencies. The Wireless Workbench's frequency-compatible wizards consider various makes and models of hardware (including PSM monitors) and create a blend of optimal frequencies to use, “allowing customers to address frequency coordination issues by themselves,” says Carnahan.

“In basic terms, UHF-R allows us to stretch the available bandwidth and maintain solid RF performance,” concludes Carnahan. “I'm excited to see how the tools we've built into it really take the guesswork out of wireless setup and coordination.”

For more information, contact Shure at 847/800-2000 or visit www.shure.com.