A helicopter was used to put the final seven parts of the new Multi-Agency Radio Communications System (MARCS) tower in place on Wednesday. The 450-foot, state-owned tower will be the home of Mercer County's radio transmission equipment, which relays emergency radio signals to emergency personnel. That equipment currently is located on a tower along Weitz Road in rural Celina, but soon will be moved to the new tower near Wright State University-Lake Campus and Dibble Road.