Anyone here running a cable tv network besides being an ISP? I recently saw some optical to RF converter nodes hanging around in the city. Couldn't take a picture but a quick search leads to me something like this. This seems fascinating and I see videos of cable TV players on YouTube using these optical to RF converters before their set-top box.
Wondering how these work without power (as advertised)? Is there enough power going "outwards" in a regular cable TV set-top box to power the photoreceivers in these adapters? In the case of DTH boxes, they send 30V (and some minor Amps) to dish on the rooftop to power the LNB. Is the case in the cable tv world as well? If not, how can one have electrical RF output without any concept of reverse power?