In an older house, the wire mesh in walls surrounding the furnace behave like a Faraday cage and block wifi signals. It is also difficult to lay new cable, however there is television cable to multiple locations due to there once having been a roof-installed, television antenna.

It would be relatively trivial to install the wifi router at the center distribution point, then have the antenna broadcasting/receiving the signal plugged in at each of the old television outlets.

I assume that it would not be too difficult to find an adapter for SMA <-> F-type connectors. The cable is actually RG-59 rather than RG-6, but I assume that it still has relatively good RF isolation along its length, which is no more than a couple hundred feet in any direction.

Does anyone know a problem with the idea? Will a router get confused if there is /too little/ interference between the two antenna? Is that length of cable (~100ft) too long for the signal a router broadcasts?

I have seen that it is also possible to use old ~$30/each FiOS cable modems available on eBay to extend a network over television cable. However, that seems like a less elegant solution, and might interfere with upnp and dlna services I'd like to have work on a single network.

Thanks if anyone has answers or suggestions before I try this project!