Voter records for the period 1934-1982 are held at the University of Pittsburgh Archives Service Center, 7500 Thomas Blvd., Pittsburgh, PA 15260; 412-244-7091. More recent records are held at the Elections Office, 542 Forbes Ave., Rm. 604, Pittsburgh, PA 15219; 412-350-4500. I don't believe there are any existing records prior to 1934.