The reason Brown International (search) got into the business of guarding the president with a sophisticated radar command center is really quite simple, its officers say. Repairing televisions just wasn't paying enough.

While no longer the 12-person repair operation it was in the 1980s, the Huntsville, Ala., company is still a tiny fish in a huge pool of corporations helping the military defend the homeland. But it was Brown's engineers who got a frantic call from an Air Force commander the evening of Sept. 11, 2001.

His message: We want your latest invention, and we want it now.

A C-130 plane was dispatched immediately to pick up the Joint-Based Expeditionary Connectivity Center (search), or JBECC, which the Pentagon had seen a few weeks earlier at a demonstration in Florida.

Such began the homeland security life of the device that has made Brown famous in military circles — a control unit transportable by Humvee (search) vehicle that merges military and civilian radar systems conveniently onto one screen, helping determine quickly whether an approaching aircraft is a friend or foe.

"A military radar will see there is something there but doesn't know what it is," said Brown's president, Terry Beane. "On 9/11, they were having to literally talk on the phone to each other. The problem was they didn't know which planes were OK and which ones weren't because they didn't have all that integrated."

In just over three years, the JBECC technology has developed quite a resume. It has made road trips to guard President Bush at his ranch in Crawford, Texas, and watch over the economic summit in Sea Island, Ga., the Republican National Convention in New York and the winter Olympics in Salt Lake City.

There are at least two JBECC systems, one that travels to major events — particularly those involving the president — and another that is more stationery at an undisclosed location in the Washington area. The Associated Press was granted access to see one of the models.

The operations center itself consists of two monitors inside the cabin of a Humvee. When the truck is parked, a makeshift tent can be expanded to include six even larger screens and a table with various phones and computer terminals. In minutes, the contents can be collapsed into a small compartment in a trailer.

"It has been huge to us, giving us an immediate enhancement to our mission capabilities," said Air Force Lt. Col. Hutch Davis, manager of a Pentagon program aimed at seeking out technology that could aid the military.

Brown International officials say the system had a role — although they won't say how large — in the decision not to shoot down an unrecognized aircraft that entered air space over Washington on June 9, the day of former President Reagan's funeral. The plane, carrying Kentucky Gov. Ernie Fletcher (search), didn't have a functioning transponder to identify itself on radar.

Brown's transition from electronics repair to homeland security didn't happen overnight. Because of the move toward disposable rather than repairable electronics, company founder Mike Lee decided to hire Beane, a former Marine, and others familiar with military operations who could design products helpful to the Pentagon.

One of its first programs, a precursor to the JBECC, was used during the 1991 Gulf War to help Patriot missiles detect enemy missiles. When the Air Force first hired Brown to do some work guarding the homeland, the mission wasn't terrorism, but to develop a system to detect drug-smuggling ships approaching the U.S. coastline.

"We had never envisioned the 9/11 attack," Beane said. "What we were trying to do was get the most information to the commander as absolutely possible."

The company's roots in repairing TVs and VCRs amazes the workers who came on board after it made the leap. Tour the Huntsville office, they say, and you can still see remnants of the old days.

"You can go through the plant and still see test equipment laying in some of the storage closets," said Mike Skelly, program manager for the JBECC. "Then you look and right beside it is a $30,000 soloscope that measures radar."