for forward path fibre optic links in CATV and FTTx networks. The transmitter has an extended frequency range to fulfil DOCSIS 3.1 requirements. HDO921 is installed into HDX installation frame. The product is available on different optical output power classes to fit various optical link requirements. HDO921 has three equal input sections with level and slope adjustments to support broadcast and narrowcast signal distribution. The RF isolation between the input branches is high minimising the leakage of narrowcast signals into unwanted narrowcast node segments. HDO921 power consumption is low but HDO921 still offers the highest level of performance and the widest variety of features, An integrated WDM filter is available as an option for applications where 1310 nm forward path and CWDM return path is transmitted in one fibre. Different optical output power classes are available from +2 dBm up to +12 dBm.