Maine Public Broadcasting Network’s Portland-area radio station went off the air in much of its broadcast area Monday morning after a 30-year-old transmission line became overheated and burned itself out.

The outage left loyal listeners without their favorite station for three days, but repairs were completed around 5:50 p.m. Wednesday, according to Gil Maxwell, chief technology officer for MPBN, and the station was back up and running.

MPBN will shut down its Portland-area radio station for four to five hours Thursday to finish repairs to its transmission system. Carl D. Walsh/Staff Photographer

Maxwell said the station will remain on the air Wednesday evening and into Thursday morning before a temporary shutdown is put into effect to finish “some cleanup work.” Thursday’s shutdown will begin around 9 a.m. and last for four to five hours, Maxwell said.

The episode highlights, in a harsh way, the network’s battle to maintain and replace aging equipment at a time when government funding and grant programs continue to dwindle.

“It’s harder to get the money to maintain this (equipment) so we end up milking them longer,” Maxwell said. “These lines can break any time, but the longer they are out in the harsh elements, the more likely.”

Mark Vogelzang, president and CEO of MPBN, said that cuts in federal grants for equipment create a “dilemma” for the network as it tries to decide which equipment to replace first.

“We’re trying to prioritize (the replacement of equipment) and take care of the most urgent needs,” said Vogelzang. “But sometimes something like this surprises us. We don’t know if a line will last 25 years or 50 years.”

One of the cuts that has hurt MPBN was the elimination a few years ago of a federal grant program which provided public broadcasters with matching funds to replace aging equipment, like transmission lines, Vogelzang said.

WMEA (90.1 FM) went off the air Monday about 1 a.m. because a 30-year-old, 1,600-foot transmission line overheated and burnt itself out, Maxwell said. The line, which runs from a transmitter to the top of a 1,500-foot tower atop Winn Mountain in Sebago, had corroded over time, Maxwell said. But some similar lines last 40 or 50 years, he said.

WMEA’s signal stretches from Augusta to Massachusetts, and it often shows up in radio rating surveys as Portland’s most-listened-to station. A survey by the Nielsen ratings firm in the fall of 2014 estimated WMEA has having the largest weekly audience, more than 140,000 listeners, of stations in southern Maine. Classic rock station WBLM was listed second, with 121,300 weekly listeners and pop/rock station WHOM was estimated to have 120,900 weekly listeners.

Waking up to static on the air at 90.1 FM Monday morning was a disappointment to regular MPBN listeners, who are used to starting their day with a mix of national news, commentary and classical music impossible to replicate on commercial stations.

Living without MPBN for several days was a definite hardship for them.

“I really miss getting the world news overview in the morning, and the local news they have. Now I don’t feel like I know what’s going on when I start my day,” said Camille Smalley of Portland, chief administrator at Gold Frontiers, a precious metals investment firm. “When my fiancée and I are in the car, (MPBN) is the only station we can agree on.”

Rachel Larsen, a biology professor at the University of Southern Maine who lives in South Portland, said she listens to MPBN in the car, either news in the morning or talk shows in the afternoon. When she first couldn’t get WMEA, she blamed her radio. But because she is a donor to MPBN, she has since gotten emails from the network letting her know of the tower problem.

Larsen said the realization that MPBN might be in need of funds to replace aging equipment “makes me even more prone to donate.”

Replacing an entire copper line like the one on the Winn Mountain tower would cost at least $100,000, Maxwell said. Maxwell said the last time he could remember a line burning out in a similar way in Maine was probably 15 years ago.

“It doesn’t happen often, but when it does it’s catastrophic,” he said.

MPBN is a statewide public TV and radio network that maintains transmitters and towers for seven radio stations and five TV stations. The network’s fiscal year 2015 budget lists $11,380,070 in expenses. About 71 percent of the network’s funding comes from members and community support, while 14 percent comes from federal funding and grants, 13 percent from the state, and the remainder from other sources, according to the network.

Bad weather slowed the pace of repairs to the Winn Mountain transmission line. Because of the driving rain Monday, MPBN technicians could not open up the line, which is made of copper, to detect the problem. The problem area, where the burning was, was detected Tuesday, but more rain slowed the repair process.

Maxwell said a tower repair company from Vermont, with specialized equipment needed for the line repair, was on its way to the MPBN tower Wednesday. He said “optimistically” the line could be repaired during the day and the station would be up and running again Wednesday night.

Some Portland-area listeners have been able to get a lower-power, and sometimes scratchy, broadcast on 90.1 FM since Tuesday night. That’s because MPBN is sending its signal out on a low-power antenna on the tower, which is also used by Portland TV station WCSH.

Maxwell did not know the cost of the repairs yet. MPBN also has over-the-air public radio stations in Calais, Camden, Bangor, Waterville, Presque Isle and Fort Kent. The radio programming is also available on line at mpbn.net. MPBN’s Portland-area television station was unaffected; that tower is located in Litchfield.