1- Fiber link will give you loss, but the loss will be flat frm 50 to 870 MHz.
2- Cable (coaxial) is different the higher the frequency he higher the loss will be.
3- Bigger cable will also losse less than small cable
4- Most cable size used today are: 500, 625 and 750'
5- Water or moisture getting in the cable will also increase the loss.
So a HFC system can giver you between 3 to 12 dB flat loss with fiber and the coaxial section which is usually between 25 to 32 dB will give for every 1 dB loss at high end 750 MHz, the loss at 50 MHz will generally be 4 time less or 0.25 dB at 50 MHz.
Hope this answer your question.
