CHASKA, Minn. — Nestled in the Minnesota River valley, this town is ground zero for a great Internet experiment. And Ben Palmby is a prime test subject.

Palmby signed up for his hometown's high-speed wireless Web service when it was launched two years ago. It was cheap: less than half the cost of high-speed Internet through cable TV or a phone line. But then, the quality of Chaska's service sometimes seemed only half as good. "For the price, you get your money's worth," Palmby said.

Chaska is one of the first U.S. cities to offer almost all of its residents Wi-Fi, short for wireless fidelity. Users plug a city-supplied Wi-Fi receiver into their computers, allowing them to receive Web service through radio signals, thus untethering their machines from telephone cables and making them theoretically mobile.

Wi-Fi systems have been rolled out in close to 60 U.S. cities and counties, according to muni wireless.com, a Web site that tracks municipal Wi-Fi, and are being planned in over 120 more.

Many of those cities are going Wi-Fi for the same reason as Chaska, and they can all learn some lessons from this town of 17,449 at the 2000 census.

Chaska, just like big-city brethren Chicago, Philadelphia and San Francisco, pitched Wi-Fi as a way to bring high-speed wireless to citizens who otherwise might not be able to afford it — or might not want to afford it at around $40 per month.

Chaska's wireless effort has been a success, said Esme Vos, who runs muniwireless.com. "It's considered a very good network."

But Chaska's network has had its share of woes — slow speeds, dead connections — sparking customer angst along the way.

"It took about a year and a half before we felt we really had a good handle on the network," said Bradley Mayer, Chaska's former tech manager whose success there helped land him a job at EarthLink, an Atlanta-based firm that builds Wi-Fi networks.

There's an art to setting up a wireless system, ensuring that radio signals do what they're supposed to do and provide quality Web service.

In Chaska, "There (were) a lot of pre-conceived notions that you could just blast (Wi-Fi signals) through walls and trees and everything," Mayer said.

Instead, Mayer made some unpleasant discoveries. Like that wet, leafy trees absorb radio signals, hampering Wi-Fi coverage. And this one: Wi-Fi signals don't pass through stucco like they do wooden walls, another negative for coverage.

Chaska had to devise ways to remedy problems like that. "You can't change the laws of physics, but you can bend them," Mayer said.

Bigger cities will face even bigger challenges than Chaska, if only because of their size.

"It's an order of magnitude more complex," said Ellen Kirk, marketing vice president at Tropos Networks, a leading Wi-Fi equipment maker. Tropos built Chaska's system.

The idea for a more affordable broadband alternative — one priced less than $20 per month — started with Mayer. He pitched it to Chaska city manager Dave Pokorney, who liked it and brought it to the City Council.

From the outset, Chaska had some advantages to become a Wi-Fi pioneer, including an advanced telecommunications system and a municipal electric utility.

Chaska owns its own light poles, the roosts for radio transceivers in a Wi-Fi system. So, it didn't need to negotiate arrangements to mount the radios.

Wi-Fi systems are made up of a "mesh" of transceivers that bounce signals back and forth from each other. Chaska has 365 of them, covering about 95 percent of the city's households.

Chaska launched the system, dubbed Chaska.net, in June 2004. It offered a four-month free trial to about 1,000 of the city's 8,000 households.

After the trial, the service would cost $16 per month (currently it is $17, while high-speed Internet through phone and cable companies is $25 to $45 per month).

The idea was to essentially use the free trial as a test period to see how Chaska.net worked. "In hindsight, that was a mistake," Pokorney said.

That's because 1,000 households made for too big of a test sample, considering the new network still had bugs. A lot of Chaskans peppered the city with complaints. A smaller sample size would have been easier.

Palmby, a chemical dependency technician, said that at first, Chaska.net was pretty reliable. There were some problems: A lot of his e-mail ended up being read as spam and deleted before he could read it.

But "it was way better than AOL," he said referring to his old dial-up Internet service.

Then, after about six months, Palmby's Chaska.net service began slowing down and sometimes didn't work at all. The problem, he discovered, lay in the city's attempts to improve its overall Wi-Fi coverage by moving some radio transceivers.

Last spring, the city shelled out more money for a new generation of Tropos-made radios.

Network quality and customer satisfaction seem to have improved. This year, "we have seen a significant decrease in the number of people canceling," Pokorney said.