The Model 425 FM Isolation Transformer is finished with tuning and test, and it’s way to shipping. This type of transformer allows the transmission line feeding an FM antenna to pass the transmitter power across the base insulator of a series fed AM tower. The Model 425 is rated to handle up to 25 kW of FM power and up to 40 kV Peak AM Voltage while adding very little additional AM Shunt Capacitance.