I'm in need of running ethernet between nodes in an older brick, steel & mortar building where 802.11* at any power just simply stinks, and no we can't run CAT5 through the walls. Primarily this is to connect several media centers to an internet line.
What is wired in ubiquity though is 75 ohm coax F connector'd.
DLink apparently makes a product: http://www.dlink.com/products/?pid=668
Any other (less pricey) suggestions for running data via 75ohm?
Netgear has one that's US$199.99 for a pair.
Actiontec has a couple of models. Under $150 per pair.
Motorola has this.
Search for "HPNA Ethernet" and "MoCA Ethernet".
You could try to use an Ethernet over Powerline system such the Planet PL501. I have setup it up for a few place where they can't run Ethernet cables and it seems to work reasonably well.