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Dissecting a Buzz Killer cell phone chatter-zapper

We take a case knife to the Buzz Killer Card to see how it reduces that irritating interference your cell phone or smartphone produces around other electronics.

Buzz Killer card and knife
The Buzz Killer Card blocks the chatter-prone GSM smartphone's radio frequency. We conducted some surgery to see what's inside. Victor Dolcourt

We see a lot of unusual tech products of suspect practicality, like a robot that administers sponge baths and a giant touch screen made of ice. You wouldn't initially think that the modest 3.5-inch by 5.5-inch Buzz Killer Card we got in the mail would number among them. Buzz Killers are cardboard thin, and look more like a coaster than a tech accessory--but Buzz Killers hopes you'll use the card as a resting place for your phone.

The card targets the irritating chatter you sometimes hear when you place GSM smartphones next to electronic devices like conference phones, computer speakers, and AM/FM radios (it sounds like whiny, electronic hoofbeats).

The iPhone and other GSM phones broadcast radio frequency when they attempt to connect to the data network. Other electronic devices may turn around and play that outbound "signal," resulting in chatter. (GSM phones are notoriously noisier than CDMA phones due to the TDMA technology that GSM phones use.) Buzz Killers claim to stifle the noise.

Over the weekend, we tested that claim with an iPhone 4 and a notoriously vocal Sony kitchen radio that was plugged in, but not powered on. Sure enough, the radio got busy playing back the iPhone's frequencies as the smartphone downloaded e-mail over 3G. We set it down on a Buzz Killer Card and things got much quieter.

To find out why, we (carefully) split open the card with a case knife to find a thin sheet of iridescent, metalized plastic--like the Mylar skin of a helium-filled balloon--sandwiched between the card's external plastic layers. The "proprietary alloy" works as a shield to minimize the GSM phone's interference, Buzz Killers told us.

Buzz Killer card
Sandwiched between the exterior plastic layers is an iridescent metal alloy skin, akin to the material you'd find on a Mylar balloon or holographic gift wrap. Victor Dolcourt

So does it work? When chatter was low, introducing the Buzz Killer significantly squelched the noise. Other times, the zapper dialed down strong interference to a tolerable hum.

The $7.49 Buzz Killer Cards are certainly handy when needed, but would we carry them with us as a preventative measure, or stock up a conference room? Unlikely. Although failing all else, they do make mighty fine coasters.