Relatedly, in the United States, the Federal Communication Commission (FCC) regulates radio frequency bands; VHF bands run from 30 MHz to 300 MHz and UHF bands run from 300 MHz and 3 GHz. The FCC also oversees which frequecies can be used for particular purposes — and as such, auctioneer wireless sound systems are restricted to only certain VHF or UHF bands.
Generally VHF [Very High Frequency] has a lower amplitude (height of wave) and wider (less frequent) wavelength. UHF [Ultra High Frequency] on the other hand has a higher amplitude and narrower wavelength comparatively.
Despite commonly found lore, VHF isn’t necessarily better than UHF and UHF isn’t necessarily better than VHF. They are just different. In other words, a “higher frequency” doesn’t mean a “better frequency.”
The VHF band is used for television, radio, emergency communication, etc, and thus interference on the VHF band is a material issue. However, the FCC has setup a special VHF band of 169 – 172 MHz which is reserved for traveling professional applications. As such, a system set at 169.505, for example, would only interfere with another like system on that same frequency.
The UHF band is as well used for television and other applications and such interference is a potential issue. However, there are far more UHF frequencies available and many auctioneer systems contain multiple user-selectable frequencies which can alleviate interference.
Otherwise, due to VHF’s lower amplitude and lower wavelength, auctioneer systems usually require an more notable antenna than for a UHF system. On the other hand the VHF frequency is much longer which can greatly extend the possible distance from the transmitter to the receiver — as such UHF systems require more power to match a similar VHF range.
Historically UHF systems have cost more than VHF systems but that cost differential is becoming smaller. Commensurate with power requirements, still today most UHF systems are heavier with multiple batteries and associated components.
As most in the auction industry know, we are sound system dealers. We sell and service both VHF and UHF equipment. It has been our experience for over 15 years that the VHF systems are more dependable and less expensive as compared to UHF systems which are typically less dependable and more expensive.
What we’re suggesting isn’t that a VHF system is always better but rather that a UHF system isn’t always better either. Wouldn’t a “higher wattage ultra high frequency” system have to be better than a “lower powered lower frequency” system? As we’ve discussed here, there are merits to both very-high and ultra-high frequencies. And more wattage isn’t a feature, but more often a unfortunate necessity.
Mike Brandly, Auctioneer, CAI, AARE has been an auctioneer and certified appraiser for over 30 years. His company’s auctions are located at: Mike Brandly, Auctioneer, Keller Williams Auctions and Goodwill Columbus Car Auction. He serves as Adjunct Faculty at Hondros College of Business, Executive Director of The Ohio Auction School and Faculty at the Certified Auctioneers Institute held at Indiana University.