Check the calculator at The distance from the back is 1/4 Lg, which on a 100mm diameter can is 42mm, hence the reason I said 4cm, for a Pringles can. The wider the diametre of the can's aperture, the more the focal point from the back changes.

Simply stick in the diameter of the can into the calculator's D= field, and 2.5 into the f= field and calculate. Then look at the Lg/4 result to find out how far from the back the hole should be. The length of the driven element (the piece of core wire sticking into the can) typically doesn't change. It is 1/4 of the wavelength, and is typically 30mm.

Quote:Then look at the Lg/4 result to find out how far from the back the hole should be. The length of the driven element (the piece of core wire sticking into the can) typically doesn't change. It is 1/4 of the wavelength, and is typically 30mm. Hmm, ja Lg/4 is quite different for a 80mm can. For a 80mm can Lg/4 is 63mm. For a 75mm can its 86mm.

Quote:I think I will strip it. Surely the antenna bit (diapole portion) should be to the right length, so I should be able to slot in the the 'can' at the right height. The antenna bit is probably not a dipole, probably just a pin to connect to the patch. Their lenghts can vary. Just stick to the 30 mm.

Building the Cylinder (Can) Waveguide We chose to build the antenna for 2.442GHz, or channel 7, as this is close to the center of the 13 channels available to us (US designs use channel 6 (2.437Ghz), as they have 11 channels). I have included a key lengths calculator in the form below.

Hi all Rodent when you say that Groenie used the cable from a patch antenna, do you mean he basically took a knife, cut the cable and inserted it into the can at the correct spot. Android installer download. Is it necessary to end the cable off with some kind of receiving dingdang - perhaps even just a bunch of tin foil rolled up in a ball on the end of the wire? I am keen to make one of these cantennas so any advice will help. I have seen your calculator and will be using this to get the correct distance worked out.

I'm now trying to setup my wireless network, and well, my understanding of this, it should be inling with this, as it runs in the 2ghz range. I need another 19m of my connection. And everything works. Would these cantenna's be able to work with these wireless network cards?

I'm currently planning to go to higher ground tomorrow, sticking antenna point through the roof or something. I'm not sure yet.

The objects in my way currently are as follows. I have a about 2 meter wall about 3/2 meters away from the window. Ive put the wireless access point about 2 meters high against the window. About 20-30m away, there is another wall.

It goes as a corner so counts as 2 walls. Wich is about 2-2.5m. Then there are trees.

Thickness is so that visibility is block, but it's no bush. From there it's cleared for the rest of the way, untill about maybe 70m with on wall. And then another 30-40 meters to the other side. (where the usb connection will sit). Currently I get signal at the last wall if I hold up the connection. But I still need that last bit, which is either 20 or 30 or 40meters (I'll measure everything tomorrow).

Would making a cantenna for my access point help? I also see it takes a patch antenna, which would probably be my solution, but it takes a bigger. Socket thingy. I dont know where to buy these. Info and so forth? I would gladly apreciate it. I spent R1400 on the equiptment, and I doubt they gonna take it back.

Oh and this is inside our flat complex So it's legal. The cantenna's are all designs originating from 802.11 kit, so they will definately work.

Check out The Directional Cantenna is probably best suited for your application. Line of sight is best for 802.11, it might be that you cannot get any signal even with the Cantennas, but they may help. Your biggest expense will probably be the pigtails. I'ts also possible to build a passive repeater. You can try mounting a square of galvanized metal in a corner somewhere, to 'bounce' the signal off. There's a lot of info about this kinda stuff on SeattleWireless. Regardless of the repeater, the cantenna's will make your signal more directional, and increase it's strength over range.

Quote:Originally posted by Connection [?]Sorry one more thing. Must the core of the cable be exposed to the metal foil on the inside of the cantenna? Ie should you strip the cable so that the portion inside the can TOUCHES the inner metal lining of the cantenna. Ok now I have thought of a second thing! To make a funnel at the one end I was thinking of just using cardboard coated in foil and attaching this to the can. Once again must the foil on the funnel touch the foil on the inside of the can? Thanks The shielding of the cable has to attach/make contact with the body of the can.