The line transformer 00LTD03 is designed for FSK channels with 9.6kBd and to isolate and protect the RTU500 series Modems 23WT24 and 560FSM11 from the telecontrol line. Moreover it can also be connected to other data terminal equipments. It operates at a frequency range from 2 kHz to 50 kHz and is optimized for line impedances of 150 Ohms which applies to above mentioned modems.