I am currently serving up WiFi to my grandmother's house across the street. It's about 400 feet away from my router and she averages between 10%-15% signal strength which makes sense considering how far away her house is. The router I'm using is an AC1900. I would like to increase the signal strength so she can have better WiFi access but not really sure the best method to do so.
I thought about replacing one or a few of the standard antennas with high gain antennas but not sure if that would be enough for what I'm trying to do. I am open to any suggestions anyone might have but would like to keep the price down to a reasonable amount.
You could try a Ubiquiti PowerBeam kit. They range in price so it would be up to you on how much you're willing to spend and how much trouble you're willing to go through to set it up.
Had the same idea, but it is a bit pricey. Units start at ~$50:
And you would need two of those, plus an access point which is another ~$80.
You could try with antennas, and it might work, but reliability and signal strength may not still be that good. An alternative that's a bit less expansive than the airMax solution would be to get a second router (I had the Asus AC66U in mind) and set it up in repeater mode. You link the router (AC66U or other) to your home router via 2.4ghz or 5ghz (you'd have to do some testing to see which works better in this specific case, 2.4ghz theoretically has higher range but may or may not be better depending on how congested it is in your area) and then setup the router to give off a different SSID that you connect all your grandmother's stuff too.
I have an AC66U and can confirm that all of this is possible and works with this router, and you can find them on amazon for ~$100:
any way you look at it your going to be roughly $50 into it, exactly how much bandwidth does she need? a cheap $20'ish n150/450 router with removable single antenna and a $15 yagi can act as a link, at 400' the yagi signal pattern would likely cover her entire house, and it's 2.4ghz so obstructions will be less of an issue, or you can look up a wifi pringles can 2.4ghz antenna if your decent with a soldering iron, or you can cheap out and redneck it and place a cheap wok 8" behind your wifi router antenna (will trash any signal behind it)
best advice is eat the coin for a few n150 single removable antenna routers (I used a pair of rosewill rnx-n150rt in similar setup minus the yagi) that can run ddwrt and a cheap ac wifi router (wally world has a $30 one) to allow ac connectivity, set the n150's up with yagi's on each pointed at each other on an unused (use cell app to find clear) channel and run them as a dedicated bridge.
400' is a long way off for wifi without a bridge of some sort, for the use case I would look at a single (no bridge hail mary) or pair of yagi like these
FCC rules for 2.4GHz fixed point-to-point allow for much more than point-to-multipoint, so you can use a much higher EIRP than your router. Someone correct me, but I believe that every 1dB you decrease your radio, you can add 3dB to the antenna gain, so a 24dB radio and a 24dB antenna will give you a very strong starting place to link them up.
the problem is your not actually running point to point, it's still multi point just a very narrow beam width, and the eirp is a total cap value, you can't stack twice and count it once, eirp is literally the total gain of both antenna system and transmitter, also depending on what channel you choose you can get into the ham radio segment of 2.4 band in which case you are a secondary user and subject to any number of rules and regs including greatly reduced legal eirp in that range (avoid the higher channels).
a simple n150 max bandwidth dedicated bridge with a seperate access point added in at grandmas is still the most robust and cost effective option for the distance being covered
Your grandmother probably isnt using much bandwidth to begin with and these are really the best of both worlds. Really good SNR, great antenna for range, its the kali users go to for wireless pentesting. I have the NHA and the NH. The NH is slower but longer range. I can pick up my neighbors wireless at -72dBm in my basement, which in my experience -75dBm is the threshold for packet loss for most wireless receivers, though this depends on the amount of noise on the channels from other wireless around you.
If you arent already you should be using exclusively 2.4Ghz. The higher the freq the shorter the distance it will travel. 5Ghz is not a realistic goal without directional antennae. You'll want your 2.4Ghz to be on channel 1, 6, or 11. Whichever is the least saturated by other networks around you.
You could also pick up a cheaper router that is ddwrt compatible and using it as a repeater in a good reception spot. I do this for my garage with a linksys e1200. You'll need to have a way to do a site survey showing the signal strength in dBm. The values will be negative so the closer to 0 the better the signal strength.
and I've got to get out more, apparently n150 single removable antenna routers are now a unicorn.
It's not overly difficult to add an rp-sma connector onto a cheap router (cheap pigtail from fleabay/banggood/amzon etc, be very carefull picking out as there are multiple type's with the center pin orientation reversed). Probably more involved than your willing to get especially if your not handy with a solder iron and small fine work, still the most cost effective reasonably robust link at your range. past that dealing with ubiquity and line of sight/environmental issue's is next best option, all of the router repeater options may work to varying degree's but your still way out at fringe range dealing with omnidirectional signals and interference from other closer wifi nodes, tree's and the like, a dedicated 2.4 bridge link with yagi's is your best bet.
Preterminated fiber and a pair of media converters will run you about a $100, and will do a gig and is upgradeable to 10G/40G down the road (look at fs.com)
Otherwise, wireless point-to-point link is your best bet.
A pair of Ubiquiti Nanobeam will do about 400 up+down (aggregate), will run you around $160
A pair of Mikrotik disc lite 5 will run you around a $100 and will do 100Mbps in each direction.