The Rev. Jerry Falwell's controversial Virginia radio station, WRVL-FM, abruptly went off the air early yesterday after someone severed a series of thick steel-encased support cables, toppling the station's 138-foot transmitting tower.

The 24-hour evangelical station, dubbed "the Voice of Liberty" and operated by Falwell's Liberty Baptist College in Lynchburg, has been the object of a bitter dispute since it went on the air last June. Area residents complained to the Federal Communications Commission that the station interfered with their radio and TV reception.

Last January the FCC, which has not yet granted WRVL a permanent license to operate, ordered the 100,000-watt station to reduce power to 5,000 watts. Station officials complied, but petitioned the FCC for a power increase last week.

Yesterday's incident, which is being investigated by the Amherst County Sheriff's Department and the FBI because it involves federally licensed property, occurred at 1:48 a.m. WRVL suddenly lost power during a religious music broadcast, according to station manager Jerry Edwards. When power could not be restored, an engineer drove to remote Tobacco Row Mountain where the tower was located and discovered the damage.

"I haven't the faintest idea who did this," said Falwell, who inspected the damage, estimated it at $100,000 and said it probably is covered by insurance. "Somebody is trying to silence us and is obviously violently against the message I preach. It's very sad there are people who would do this."

Leaders of the Concerned Viewers of Central Virginia, the coalition that has rallied opposition to WRVL, said they had no idea who might have destroyed the tower. "This is quite a surprise to us and I'm afraid it'll make our group look bad," said Sissy Putney who lives near the tower and has long complained about interference.

"It's too bad what happened, but I'll tell you this: Today is the first day since June l7, 1981, that I can listen to the public radio station on the stereo receiver in my living room. It's a nice vacation from WRVL at least," she said.

The tower, at the end of a remote, winding dirt road, had been shot at six months ago, Falwell said, an incident never reported because station officials feared it might encourage more shooting. Station officials said WRVL had received no recent threats.

Falwell said investigators told him that heavy bolt cutters apparently had been used to shear the wires. He said authorities told him they believe more than one person is involved because they took castings of several sets of footprints. Investigators could not be reached for comment yesterday.

Station officials say they expect WRVL will resume broadcasting next week, after the installation of a temporary antenna. Full power could be restored in a month.