1. In electric blender, blend 1 cup of the cantaloupe chunks, the lemon juice, sugar replacement and salt at high speed until smooth, about 30 seconds.
2. Add remaining cantaloupe chunks; blend at high speed until smooth, about 30 to 45 seconds. Pour into 8 x 8 x 2-inch metal pan; freeze until semi-firm, about 1 hour.
3. Place mixture in large bowl; using electric mixer at high speed, beat until smooth. Return to metal pan; freeze until firm, about 2 hours.