Watertown’s Police and Fire departments will be getting new portable radios as part of upgrades to the first responder radio system that has become unreliable. On Tuesday night, the Town Council approved borrowing $1.77 million to fund the first of two phases in the $4 million plan to upgrade the Townwide radio infrastructure. The second phase is planned to be completed next year. The system is used by the Police, Fire and Department of Public Works to communicate. The system also links Watertown’s first responders with police and fire departments in nearby communities, as well as regional fire and police organizations.