Defying storms and the Federal Communications Commission, activists in Berkeley have set up an outlaw radio station in a tree. 

Using a 40-watt transmitter powered by car batteries, ``Tree Radio Berkeley'' is protesting the court-ordered closure of Free Radio Berkeley last June and the 20- year FCC ban on low-powered ``micro radio'' stations nationwide. 

It is the latest and perhaps oddest act of rebellion in the escalating war between the FCC and the large number of tiny, illegal stations across the country. 

``I've never heard of such a thing,'' said David Fiske, a spokesman for the FCC, which says it has shut down unlicensed operations more than 300 times in the past 14 months. 

The tree station has been operating 24 hours a day for eight days from a tall redwood at Willard Park, nicknamed Ho Chi Minh Park in honor of the city's revolutionary heritage. 

The underground operation is perched on three wooden platforms 50 feet above the ground, where federal marshals so far have dared not climb. 

``The weather's been harsh,'' acknowledged ``Birdman,'' one of the two main inhabitants of the arboreal aerie. The tree's thick canopy and a blue tarp afforded some protection for him and his partner, ``Sparrow,'' during the recent heavy rains and strong winds. 

The pair are the most active of a dozen people who have taken turns climbing a rope to the platform to send out commentary about the micro radio movement, tapes by death-row inmate Mumia Abu-Jamal, punk rock by the Dead Kennedys and other programming. 

Supporters say FCC agents last week visited the site, located in a middle-class neighborhood next to Willard Middle School, and warned of arrests and seizure of the equipment if the broadcasts did not cease. Fiske of the FCC said the agency cannot comment on ongoing investigations. 

Berkeley police are deferring to the FCC and not enforcing the city's 10 p.m. park curfew for Tree Radio Berkeley, said police Captain Bobby Miller. 

The FCC insists that radio stations be licensed in order to prevent airwave anarchy and interference with other signals, especially airplane radios. The FCC recently moved swiftly to shut down illegal stations in Sacramento and Napa after complaints that the signals interfered with conversations between pilots and air-traffic control towers. 

The FCC did not react in September when Free Radio Berkeley broadcast in open defiance one night from the front steps of the old City Hall during a Berkeley City Council meeting, but the station's supporters tell of a late-night chase by FCC agents and federal marshals in August through the underbrush in the Berkeley hills. 

The station, which reaches about 10 miles at 104.1 FM, was broadcasting from a secret hillside spot that night, much like it did when Stephen Dunifer began it in 1993. 

When U.S. District Judge Claudia Wilken ordered it shut down on June 16, the station was operating from a building on Alcatraz Avenue in South Berkeley. The judge's action, which forced the station off the air, came in response to a 1994 FCC suit seeking to shut down the broadcast. 

The City Council voted unanimously to express ``moral support'' for the station and ``disappointment'' with the judge's action. 

Dunifer, a leader of the ``free radio'' movement and self-described anarchist, said FCC rules barring licenses to stations with less than 100 watts of power were unconstitutional denials of free speech and that the application process for FCC licenses is prohibitively expensive. 

The FCC is now considering proposals that would allow licenses for stations smaller than 100 watts. 

Dunifer attended a news conference at the tree yesterday but said he is not involved with Tree Radio Berkeley. He estimated that there are about 1,000 small, illegal radio stations nationwide, but Fiske put the number at about 100. 

The tree broadcasters and their supporters on the ground who supply them with burritos and sandwiches risk imprisonment and heavy fines. 

``We're willing to go to jail to defend the few rights we have left,'' said Gerald Smith, whose ``Copwatch Hour'' and ``Slave Revolt Radio'' used to air on Free Radio Berkeley. 

``The average American has no idea how the average person's First Amendment rights are being slowly chipped away,'' Smith said, adding that poor people cannot afford to operate large radio stations or pay the hundreds of dollars often charged by authorities to stage marches and rallies.