Or in other words, "Lets open up a can of worms."

Just like a CB antenna, the size of your antenna depends on the frequency you're going for. When you tune your antenna, all you're doing is making it longer or shorter to match the "size" of your wavelength. On your CB radio the size of your wave is about 36 feet tall, (yes, it's that big.) We can still "see" that signal with an antenna length of 25% of full. That's where the Stainless whips come in. They work well, because they match well to the physical length of that 36 foot tall wave.

Now lets talk about our WiFi. The wavelength of our 2.4GHz signal is only about 4 inches tall. We have to work around this length. We can play around with a quarter of this length, (that's why the little stub in your cantenna is ~1" - same thing as your CB - Right? hehe - he said stub. ). Changing the can size of your cantenna is kind of like changing your antenna length of your CB. Move it a little bit, things change a lot, and not always for the better.

To get more gain, in both Tx and Rx, the easiest way is to point it into a dish - like a satellite dish. The problem with this is, it can give us too much gain. Take something everyone knows - a lazer pointer. Sit in the living room and point the red dot on the wall 10' away and you can hold it on a quarter. Then go outside and hold it on a quarter that's 1 mile away. Even if you could see it, there's no way to hold that point. The cantenna has good gain figures for using it handheld. What we are doing with that tube is changing the signal by pointing it, just like a flashlight. One of the problem I see with the cantenna is they are taking a vertical signal and making it circular, and then trying to talk to a verticle signal. It's like pointing a flashlight into a fogbank. Some of the light gets through, but it's faded. A loose rule of thimb is -3dB, or half your signal is lost. Not the best for data transfer. I'm trying to build something that will improve this. It's kind of tough, because I can't find anyone that's tackled this problem from the way I'm trying.

If you want to improve on the basic cantenna design, don't plug cantenna into Google - plug in the keywords, "waveguide antenna".

 

How about a 32 gallon barrel in a 55 gallon barrel....might be able to microwave someone's turkey on the east coast if we could get an "over the horizon" effect.

-Kerry

 

Watch the Nwst Chapter get blamed for it.

 

I was thinking a C-band satellite (one of the big old ones) dish and a HAM radio signal amplifier.....