Used as an input-matching transformer, it connects telephone systems to most public address amplifiers, for telephone paging. In addition it functions as an output-matching transformer to feed program material over a 600-ohm telephone line for "music-on-hold". It is compatible with any amplifier having a 25V output connection.
Hi-Z, 10k-ohm primary impedance
Lo-Z, 600-ohm secondary impedance, balanced with center tap
Matches high-to-low impedance or low-to-high impedance