If you recently set up a Wi-Fi network at home, you'll have to ditch that 2.4GHz cordless phone if you don't want to live with interference. Since Wi-Fi networks operate in the 2.4GHz range, your 2.4GHz phone is most likely incompatible. Thankfully, 5.8GHz models are popping up all over the place. Among these high-frequency systems, AT&T's 5840 ($179.95 list price) is up to task.
While it's not quite as slick as Uniden's competing model, the 5885-2, this AT&T unit has enough design embellishments to stand out from the lower-frequency crowd. The phone has blue lights on the earpiece and the base so that you can tell when it's in use or charging, as well as when there's a message waiting. You'll also find a blue-tinted, backlit keypad, lighted caller-ID displays in both the handset and the base, and smooth, silver styling. However, the 5840's nublike antenna doesn't match its sophisticated, high-tech look; we wish it were built into the phone instead. Another design gripe: While the phone feels solid in your hand, it doesn't fit very well nestled between your head and shoulder. For longer chats, you'll probably want to use a headset. By the way, AT&T doesn't include a headset in the box, so you'll have to buy one separately.
In terms of features, this phone's set mirrors that of most cell phones. You can set the time, choose among eight different ringers and a vibrate mode, monitor battery life and range from the LCD, and adjust sound with a side volume-adjustment key. You also get an integrated digital answering machine, which provides three mailboxes and 15 minutes of recording time. However, one area where most AT&T phones fall short is the phone book. This model can store up to 50 names and numbers, whereas most competitors can house 100.
The 5840 supports up to five additional handsets for a total of six (the accessory handset, the 5800 is listed at $79.99); that's more than Uniden's competing model, which can only support two. You can transfer calls between handsets and make intercom calls, but you can't share the phone book among sets or make global tweaks to change the time or share caller-ID info. You'll have to program each handset separately--a big pain. We know of several lower-tech 2.4GHz models that let you make universal changes.
In our Wi-Fi testing environment, the 5840 performed similarly to most 2.4GHz models in terms of distance. It delivered pristine audio--arguably better than the other 5.8GHz models we've tested to date. Callers sounded crisp and clear, even when we used the built-in speakerphones on both the handset and the base. The phone also comes with a cool Sound Select function, which offers four different settings that you can use to adjust the quality of sound during a call. However, frequent use of this feature can drain battery life.
Speaking of battery life, the AT&T 5840's is solid, even if the quoted standby time of five days is a little less than the average among competitors (eight days). In our tests, standby time came up a little short--just less than four days. We also fell two hours short of the rated eight-hour talk time.
All told, we're impressed with the 5840, especially in terms of its audio performance. At $179.95, the 5840 costs a hundred bucks less than the Uniden's arguably slicker-looking--but less flexible--model. But if you want to expand your system, this point is negligible; unlike Uniden, AT&T didn't include an additional handset in the box. With compatible handsets costing $80 a pop, you'll end up eating your savings during the expansion. Still, this AT&T performs exquistely; it's the 5.8GHz phone to get if you need more than two handsets.