Interesting article, you could probably improve it by researching "75 ohm to 50 ohm impedance matching"
Fascinating article =]
Note that the coaxial cable here acts as the RF medium as a sort of 'ether' if you will. Guess he is lucky that wifi supports csma/cd...
802.11n and faster depends on (Mu-)MIMO to work properly, while coax (even ignoring the impedance mismatch) will only provide you with a single transmission way.
You will get better results repurposing powerline adaptors for this by removing their connection to mains power (using only the signal, WITHOUT its normal, but useless for the data transmission, 110/ 230 volts carrier; WARNING, this requires dangerous electrical changes to the powerline adaptor and understanding of its schematic to rule out that mains power will ever get on the coax wire (but is possible for many brands of powerline adaptors)).
any followup reads on the powerline-coax mod?
If you can lay a coax (or a powerline) cable from site to site, cannot you just lay an ethernet cable?
Well the idea is to re-purpose an already existing coaxial run that was used for TV...
A couple thoughts here:
I second @slh's thoughts about the danger of modifying the powerline adapters. It is dangerous, even if you're sure what you're doing. What's worse is that the next person who comes along won't know what you've done, putting them at risk
If you have coax between the locations, the MOCA adapters that @mbo2o mentions look to work well.
Somewhat OT (not coax-based), but I recently got an internet connection to a cottage 200 feet away using a pair of Ubiquiti NanoStation AC Loco 5GHz airMAX ac CPE (US$47 each at Amazon) with Ubiquiti POE Injectors (US$8 each at Amazon). For less than $150, I got great speed (500mbps+) with complete protection against ground loops/lightning damage/etc.