The transmit port (output) of 2048kHz digital clock should meet the following specifications. The signal is measured at the line side of the transmit transformer, at the near end of the cable, with a 75 ohm or 120 ohm resistive load in place of the cable. From implementation viewpoint, the output signal is a configuration mode of the E1 output port that is designated as a timing source and will have similar electrical and connector characteristics. The 2048kHz digital clock output signal accuracy and jitter characteristics will be directly related to the 2048kHz system clock used to generate the synchronization signal together with the transmitter characteristics. The system clock signal will be the same clock signal that is used to define the HDB3 (pulse) signal timing for the same port in E1 mode. Note that the pulse rate of an E1 signal is 2048k pulses per second, whereas its fundamental frequency is 1024kHz, therefore the transmission of a 2048kHz system clock in place of an E1 signal can be considered a doubling of the frequency of the transmitted data signal. Refer to application note AN-857 for more details. For other questions not addressed by the Knowledge Base, please submit a technical support request.