MASHANTUCKET, CONNECTICUT: The world's largest bingo hall recently installed a Sennheiser RF wireless system worthy of such an establishment, replacing an old system riddled with noise squelches and crossed frequencies. Foxwoods Resort and Casino in Connecticut got its start in 1986 with high-stakes bingo and has since grown to become the largest resort casino in the world, boasting 6,400 slot machines and 350 tables in a gaming space of 315,000 square feet. The resort itself covers 4.7 million square feet and hosts over 40,000 visitors every day, most from within the New York City-Boston-Hartford-Providence parallelogram.
 

Bruce Mosca (Sennheiser RF Technician), James Stoffo (Professional Wireless) and Rick Belt (Sennheiser RF Products Manager)

The size of a football field, the bingo hall employs an elaborate system for calling "bingo!" Each of 36 Foxwoods-employed callers covers an appropriately sized zone of players, listening for any "bingo!" in his or her zone. When a player shouts "bingo!" the nearby caller uses a wireless microphone to relay "bingo!" to the entire hall. It is important that callers acknowledge each "bingo!" If they miss one, the casino has to pay out twice at a loss of thousands of dollars.

James Stoffo of Professional Wireless (Orlando, Florida) first traveled to Foxwoods to force the hall's existing 24-channels of "non-Sennheiser" wireless to behave. The man and company behind the wireless systems at the Super Bowl, the Latin Music Awards and the Wet 'n Wild Water Park, Stoffo and Professional Wireless are widely recognized as the preeminent authorities on wireless installations and one-offs. A third of Foxwoods' existing wireless devices were acting up, with intermodulation crosstalk between transmitters, poor coverage, noise-ups, and squelch bursts into the PA system - not a situation befitting the world's greatest bingo hall!

Stoffo forced the wireless system into submission, installing a Professional Wireless custom Helical Antenna and adjusting frequencies so that sum and difference frequencies on any given transmitter missed all of the receive channels. Precarious but workable, the system would do the job. However, Foxwoods requested 12 more channels of wireless! Cognizant of how he struggled to get 24 channels to work, Stoffo knew that adding 12 more channels from the same wireless manufacturer would be impossible. Their specifications simply wouldn't accommodate it. Instead, Stoffo recommended that Foxwoods start from scratch with 36 channels of Sennheiser wireless.

"Sennheiser is the only company capable of delivering 36 channels in this environment," Stoffo said. "Their transmitters are extremely tight. They only put out one frequency - they don't spur and they don't intermod. The main problem with the old system was that the transmitters created intermod products. Instead of 24 discrete frequencies, there were a couple thousand! They just spewed tons of spurious RF. On the other end, Sennheiser receivers are so selective and sensitive that they're only looking at a discrete portion of the RF band. You don't have to worry about stray signals finding their way in."

On an installation of this size, Stoffo always performs an RF survey before he does anything else. Then he takes all of the potential Sennheiser frequencies and "bangs" them against all of the frequencies for DTV, public safety, analog TV, etc. While the old equipment was all "crystal controlled technology" and necessitated desoldering a crystal in the transmitter and in the receiver, switching crystals, resoldering in the transmitter and in the receiver, and physically tuning the RF sections, the Sennheiser equipment employs the much simpler technology of "switches" and "knobs" to change frequencies. In the case of Foxwoods, Sennheiser even sent Stoffo a custom PROM chip to extend the frequency of the equipment out of "stock" territory.

The lay of the RF land known, Stoffo ordered 36 Sennheiser SK 50 transmitters along with a combination of Sennheiser EM 3032-U dual true-diversity and EM 3532-U computer-controlled, dual true-diversity receivers. He kept the all-important Helical Antenna from the first fix, providing a clean, strong front-end signal for the receivers. He kept the existing headset microphones, which use a momentary switch to allow the callers to call "bingo!" In other words, the RF is always up. The input to the transmitter is what remains silent when the callers aren't calling.

Interestingly, Sennheiser's USA division is just 20 minutes away from Foxwoods in Old Lyme, Connecticut. "It was satisfying to help a neighbor with their RF needs," noted Rick Belt, Sennheiser's RF product manager. "We want to be a good partner to local businesses. And the Sennheiser installation at Foxwoods represents a chance for us to visit a real-world system and learn more about how our technology is really used."