So I'm like a fish out of water when it comes to the hardware side of radios, but hopefully you hardware hacking types can tell me why this won't work (or better yet, tell me that it would work).

I have a router and a computer that have removable antennas that attach with basically a coax connection.  I have a house that isn't too kind to wifi signals but is wired with coax all neatly done inside the walls.  So my crazy thought is why not find some adapters to permit plugging in directly to the coax and using that as the ether for the wifi signals?  I have no idea how well coax would carry 2.4 & 5 Ghz frequencies or if there would be too much signal loss to function.  My bigger concern and the reason I'm hoping for some input before I try it (I have no spare hardware) is what if the signal is too strong?  I seem to recall hearing that wifi chips disable the listening portion when sending the signal so that it doesn't blow it's ears off.  So if the signal is too strong over wires rather than OTA, then would/could it damage the other radios that are plugged in?  Perhaps there's another reason this wouldn't work.  I couldn't find anything on Google and surely I can't be the first person to wonder about this.

TIA.

I think you would be pretty lucky if that works. Problem is first, that the impedance is different, and secondly your coax cable is probably not as good as it needs to be. Best coax cables for 2.4 ghz seem to have a signal loss of 0,5-0,8 db/m, meaning that with a regular transmit power of 18 db you will get 20-35 m. But therefor you would need to replace your coax cables with pretty expensive ones, so you would be better off using good old ethernet.

Good to hear the problem would be not enough signal rather than too much.  If I can find the right pieces I'll give it a shot to see what happens and if it's anything interesting I'll post back here.

Is it a b/g/n WiFi, i.e. 10/100/300 Mbps? If it is a b WiFi, then that will be similar to a 10Mbps ethernet connection through a coax line (1st generation of ethernet). If so, then get two 10Mbps Coaxial/RJ-11 adapters. Connect each coaxial end to the coaxial port of the adapter and the RJ-11 end to the RJ-11 port on your 10/100 Mbps switch as shown below:

Internet -x- 10/100 Mbps switch -x- RJ-11/Coaxial --> Coaxial house wiring <-- Coaxial/RJ-11 -x- 10/100 Mbps switch

That sounds like an excellent idea, Mazilo.  I'm just a little confused: doesn't ethernet (even base10) require 2 pairs of the twisted pair cabling to communicate?  The coax would only carry a single tip/ring pair.  Clearly I'm missing something because now that you've brought it up, I do indeed see RJ-45/BNC converters.  I just don't understand how it works with a single pair.

Back in the old days, a coax cable was sufficient.
http://en.wikipedia.org/wiki/10BASE5
But most likely your tv-cable has an impedance of 75 ohm while ethernet prefers 50 ohm. Just keep it in mind in case it will not work right away.

(Last edited by MBS on 24 Sep 2011, 20:45)

Mux it: http://www.gefen.com/kvm/dproduct.jsp?prod_id=5275

I can attest they work great. A bit pricey, but cheaper than comparable devices.

Not bad. But the cheapest powerline adapters I've seen sell for about 20 bucks each, at similar specs (don't know about maximum distance). Just another attempt to use an existing infrastructure for networking.

This is quite late, but it does work.  You can either case-mod your WiFi router to have an F-connector (solder u.fl cable to an F-connector screwed onto a hole in your box) or you can use an rp-sma to F-connector (a bit obscure, but available commercially for a few dollars a piece) to adapt an antenna port.  If you can't find adapters or your router has internal antennas, you can add in an air-gap on one or both sides.  Over any reasonable length of RG-6/u coax (ie, modern home coax) and a splitter or two the signal levels will be high enough to give full single-stream data-rate at 2.4 or 5 GHz.  Goodput on 802.11ac is over 300Mbps.

It's a totally reasonable thing to do if WiFi over the air isn't working out.  You could also try channeling WiFi through your air-ducting.  I've gotten 500+ Mbps that way over 802.11ac from one end of my house to another.  Air ducting will allow more than one mode to propagate, so you get the benefit of MIMO.

I second jmelzer's answer. You just need some inexpensive converters between 75 Ohms and 50 Ohms, F to SMA or F to RP-SMA. You can use a splitter as well. The Coaxifi kits have all of that. For the average house, the signal loss from splitting the signal and running it over coaxial cable is negligible compared to the standard free space path loss just a few feet from the router, so there can easily be a benefit to using WI-Fi over coax. Worth a shot.

Use Deca units from Amazon by Direct TV.Ethernet to coax---coax to ethernet. About $16 a pair(100Mbps)