What's the most powerful antenna that supports monitor mode

A railroad tie. That you stole.

You got a good card, what your looking for is a wireless antenna

>>57334035
kek... i used a aluminum bowl with my alfa

File: fa20.jpg (43KB, 364x283px) Image search: [Google]

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Apparently FA-20 is one of the most powerful antenna you can build reaching distance 5 - 8 KM

>>57334035
RF engineer here.

Depends.

I assume you are limiting your scanning to 2.4 GHz.

There is no need to limit yourself to antennas specifically branded for WiFi. It's just a range of frequencies. Nothing special about it.

Passive gain can only do so much, although with a rather large array of elements it can do quite a bit.

In a theoretical sense, a perfect, infinitesimally small, isotropic radiator will have zero gain and will radiate in all directions equally.

In the reverse, you can narrow down your search field to get higher and higher gain. E.g. instead of a sphere you could have a hemisphere and gain 3 dB. A quartersphere for 6 dB, etc.

You will, of course, now be limiting your range to a certain direction or shape, but some directions aren't relevant, like straight up or straight down (sometimes; if you live in an apartment complex it could matter).

Also, front to back ratios and side lobes and what not make these decisions imperfect.

Lots of other factors.

Anyway, antennas really aren't magic, and if you wanted, you could just build your own. A couple classmates of mine made an rather long range/high-gain helical antenna for a few bucks with shit from home depot and a couple bucks spent on coaxial cable and a RP-SMA termination from digi-key.

That, combined with active amplification (which I assume is what that thing does) could make for some serious range. Way more effective than shitty aluminum can hacks.

>>57334482
Just wondering, what if you spinned focused antenna on a circular moment using any fast motor or something... would the antenna still effective???

File: IMG_20161101_084940.jpg (4MB, 4224x3168px) Image search: [Google]

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>>57334482
I already own this for TV. I assume I could get 2.4GHz with it? If so, would I just have to wire it up?

http://www.wifi-highpower.com/128-kit-yagi-17-dbi-24-ghz-et-trepied.html
test yagi

File: TL-ANT2415D.jpg (9KB, 590x443px) Image search: [Google]

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>>57334035
TL-ANT2415D (in an urban environment). You can use it indoors too