>>36894
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diy masterrace
biquad is the easiest to build. You can easily get 10dbi with a coat hanger and tinfoil. Up to 15dbi if you build a double biquad and use copper wire.
for the most directional antenna possible, you'll want to build a yagi and put it in a can. All you need for the yagi is copper tape and a sheet of hard plastic. You get the excellent capabilities of a yagi with the can to cut out any noise from behind and the sides. Yagi looks a bit suspicious to bystanders. A good patch or biquad makes it much less obvious that you're pointing a high-gain antenna at a corporate fortress.
Any directional antenna will be greatly aided by an offset-feed reflector dish. The kind you're most likely to find for free will say stuff like "Bell" and "DirectTV" on them and you can usually get them on the side of the road during garbage day. Cantennas and yagis make the best feeds for dishes, but the biquad will still work.
Be aware that some people are deploying WIDS which can triangulate you. Experiment with reflecting your signal off buildings and other surfaces to make it difficult for their security forces to find you.