@GusW 

The final speed you get will vary due to so many variables. I personally would make the network name different so I know exactly which network I am connecting to, but if you now see signal then you should be seeing the 4220 rather then a weak signal from your router.

Tony wrote

@GusW 

 

The final speed you get will vary due to so many variables. I personally would make the network name different so I know exactly which network I am connecting to, but if you now see signal then you should be seeing the 4220 rather then a weak signal from your router.

@Tony 

I'm definitely seeing the 4220 rather than my router, since when I unplug it and do my WiFi speed test, I get around 3-5 Mbps download. With it plugged in, it increases to around 10-15 Mbps, so a clear difference. Also when it is plugged in, I get WiFi on my patio, whereas, when unplugged I don't. So it's working. I'm just surprised that the signal degrades this much, from over 200 Mbps to down around 10 Mbps, a mere 1/20th of the original. Is this unusual, or just par for the course?

@GusW 

Yes, the quality of the wires, as the signal traverses through the breaker, every bit slows the speed. What you can do is look to get the TL-WPA8630 kit which does a better job sending the powerline signal through your wiring so I would expect better speed (maybe not by much for some improvement). In your case though if the speed you are getting is good enough I would leave it as is.