Dead spots in the town’s wireless public safety grid forced Selectmen to add a fourth antenna to a tower owned by Industrial Communications.

The town will license the antennae for $250 a month, which amounts to one-fifth of what the company would charge a private company.

“It’s an improvement to a troubled area in the northeast part of town,” Police Chief Paul Magee said. “We’re looking to install a microwave dish because we are exceeding capacity.”

Magee said the company has been generous to the town in the past. Built in 2003 on Bowen’s Lane, the tower’s original agreement allowed for two antennae at no cost. The tower currently holds three.

“Industrial Communications have been a very good partner with the town and the town’s equipment,” Magee said. “They’ve been very accommodating.”

The terms of the license allow the town or the company to revoke it at any time without cause, said Town Counsel Blair Bailey.

Because of the unexpected cost, Bailey and Magee said it’s likely more money will be requested at Special Town Meeting to fund the change. Magee said he is looking at his budget to make cuts to lessen the cost. He said the money would be well spent.

“It’s absolutely necessary for life safety, not only for the residents, but for officers and members of the Fire Department,” Magee said.