Finding the specific Turn Ratio of a Transformer
You can easily find that the transformer is rated 115 V, 60 Hz for the primary and 28 V secondary. That gives a nominal turns ratio of 115/28 = 4.1:1. The actual ratio used may be slightly different to make the secondary voltage 28 volts at a particular load current and operating temperature. Transformer specifications usually state only the operating specifications, not the design specifications. You probably will not find more than what is easily available.