Proper Cantenna Calculator

This calculator reports 86mm for the pringles hole. Now on Rodents FAQ and other places, people speak of a 4cm hole. Which is it?
 
There might be confusion between the Pringles cantenna and a Yagi type cantenna which is more complicated.

With regards to the placing of the hole it also depends on what parameters you give the calculator. The frequency Sentech uses is around 2.51 GHz, not 2.4 GHz. Also, if your can's diameter is 10 cm versus 8 cm you are also going to get different answers. If you are using just the empty can, this calculator is correct. I compared the results to what I found in an antenna book of mine.

Ajax
 
It looks like Cantenna is now the answer. I bought the patch antenna from Fast Comm, and my signal strength went from 1-5% to 1-6%:)
Actually not funny.
 
Does anyone know if I am able to use the Patch antenna provided by Fast Comm and insert it in a can. Maybe discard the plastic surrounding the core components, as it is coming apart anyway.
 
You can basically re-use the cable, and use it inside your cantenne. Groenie has done this to make his own cantenna which worked much better than the patch. The components inside the patch are basically not useful.

You say that it's popping out of it's casing? Is the thing then made shoddily? I'd like to hear more about this, since everyone I've talked to about patch antennae have said that they basically do nothing.

<center><h5><font color="red">Oo. MyWireless <s>Hacks</s> Tweaks & Tech Info.oO </font id="red"></h5><h6>Have you checked the fawking FAQ?</h6></center>
 
It's stuck together with double sided tape and after about 5 minutes of trying to adjst it came apart. If it worked, I would have used some plastic glue to stick it together, but it doesn't work, so why bother.

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.

Or maybe look for a dish to put behind it
 
Yes its made of molded plastic, which does not stay together, but it works well, you just need a little glue to fix it now and again.

Keep Surfing
 
Check the calculator at http://www.saunalahti.fi/elepal/antenna2calc.php

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.


<center><h5><font color="red">Oo. MyWireless <s>Hacks</s> Tweaks & Tech Info.oO </font id="red"></h5><h6>Have you checked the fawking FAQ?</h6></center>
 
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="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.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

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.

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="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.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
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.

Ajax
 
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. 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.

Thanks[8)]
 
[?]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
 
Eya ppl. 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 ? d-link 120+.

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).

Any idea's ? 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 ... erm .. socket thingy. I dont know where to buy these.

Any ideas? 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 http://www.seattlewireless.net/index.cgi/DirectionalAntenna

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.

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<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Connection</i>
<br />[?]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
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

The shielding of the cable has to attach/make contact with the body of the can. The CORE of the cable, must not, it must just stick 30mm into the can.

For a funnel you can use heavy foil and cardboard. As long as the surface is smooth after your wrapped the foil around it.

<center><h5><font color="red">Oo. MyWireless <s>Hacks</s> Tweaks & Tech Info.oO </font id="red"></h5><h6>Have you checked the fawking FAQ?</h6></center>
 
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