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Greven
13-02-2007, 06:10 PM
Does anyone know of any cantenna building instructions that are NZ compatible? All the ones I've found us imperial measurements & talk about something called allthread (Never heard of it before. Is it called something different in NZ?)

My sister needs a little bit more range on her home wireless network (the signal to her computer from the router is very weak) & I thought a cantenna would be a cheap & interesting way to achieve that.)

Murray P
13-02-2007, 06:17 PM
Explain.

What the F is Cantenna?

What are you wishing to do?

You do realise that all building in NZ must comply with the Building Act, the Resource Management Act (if applicable, which it will be at some level) and any local body rules/bylaws (you can probably ignore the latter).

Greven
13-02-2007, 06:19 PM
A cantenna is a cheap wireless antenna made out of a pringles (or similar) can.

Smash King
13-02-2007, 06:39 PM
A friend of mine swears that a tin foil umbrella(not literally), located behind the router, facing the wireless networked pc's does wonders for signal strength.

Rob99
13-02-2007, 06:46 PM
http://www.concentrate.com.au/misc/circular_waveguide_optimise.xls

Link above should help.

I went to a aluminium place and got some pipe 100mm dia, enough for three cantennas for about $20.
I got the same place to weld aluminium caps to one end for next to nothing.

Copper wire I found at the scrap metal yard, asked for 20cm, they snipped off over a metre and gave it to me for free!

Stable connection at over 1km, but have picked it up over 5km away!

Murray P
13-02-2007, 06:48 PM
A cantenna is a cheap wireless antenna made out of a pringles (or similar) can.

Cripes, I walked right into that one with my eyes and ears shut tight, didn't I.
:lol:

Actually, I came across some such plans a while back. Can't for the life of me remember where though. Sorry.

bob_doe_nz
13-02-2007, 07:04 PM
Check you local library for EPE Magazine (http://www.epemag.wimborne.co.uk/) or Elektor (http://www.elektor-electronics.co.uk/) (or similar named) magazine.

One of them did a few articles on that a few years back on making them.

sarel
13-02-2007, 07:06 PM
Greven

Tell me please when you get something? I also need something like that

sarel

Greven
13-02-2007, 07:34 PM
http://www.concentrate.com.au/misc/circular_waveguide_optimise.xls

Link above should help.

I went to a aluminium place and got some pipe 100mm dia, enough for three cantennas for about $20.
I got the same place to weld aluminium caps to one end for next to nothing.

Copper wire I found at the scrap metal yard, asked for 20cm, they snipped off over a metre and gave it to me for free!

Stable connection at over 1km, but have picked it up over 5km away!

Thats brilliant for the measurements, but I still don't know what allthread is, or what I could substitute for it.

Pringles can is obviously no good. I might ask my friend to try and get me some scrap metal from his work. any recommendation's on what I should ask for?


I found another site with a much more simple design than the other ones I looked at - only 4 parts :). A can, an aerial connector, a piece of copper wire & a cable to connect it to your wireless card. http://www.turnpoint.net/wireless/cantennahowto.html

Do DSE sell the connectors and cables I need?

Murray P
13-02-2007, 08:17 PM
I found another site with a much more simple design than the other ones I looked at - only 4 parts :). A can, an aerial connector, a piece of copper wire & a cable to connect it to your wireless card. http://www.turnpoint.net/wireless/cantennahowto.html

Do DSE sell the connectors and cables I need?

Well done, you found the site I mentioned above.

Tricky Dickie's or Jaycar should have everything you need.

Start here, Plugs & Sockets (http://www.jaycar.co.nz/productResults.asp?whichpage=2&pagesize=10&keywords=&CATID=35&SUBCATID=433&form=CAT&SPECIAL=&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=)

Rob99
13-02-2007, 10:26 PM
My first was one like seen on the turnpoint site, worked very well, but rusted out side.

DSE has the bits you need, just make sure you get the correct plug for your access point, linksys uses reverse TNC.
N-connector for the can, get the plug that fits to the end connector.
Cable, I used sky coaxial.

If you go to a scrap metal yard they may have the copper wire you need, I got mine for free.

The trick is to have the access point as close to the antenna as possible, to avoid signal loss over the coaxial cable. You may need to run an extension cord, or give POE(power over ethernet) a go.

Graham L
14-02-2007, 04:38 PM
It's easy to build an antenna. It's easiest to build one which will be less efficient than a commercially made one. :D If you can reliably work to within a tenth of a mm, go ahead. If you are good at fitting RF connectors, go ahead. N type connectors are expensive; SMA (R) are more commonly used for WiFi I would have throught.

I'd try a simple reflector first. That uses an existing antenna, which will work. Stan Swan did some experiments in Wellington a few years ago and wrote them up for Silicon Chip magazine. "stan swan wifi" to Google (google.co.nz) will give lots of links.

Greven
14-02-2007, 05:49 PM
It's easy to build an antenna. It's easiest to build one which will be less efficient than a commercially made one. :D If you can reliably work to within a tenth of a mm, go ahead. If you are good at fitting RF connectors, go ahead. N type connectors are expensive; SMA (R) are more commonly used for WiFi I would have throught.

I'd try a simple reflector first. That uses an existing antenna, which will work. Stan Swan did some experiments in Wellington a few years ago and wrote them up for Silicon Chip magazine. "stan swan wifi" to Google (google.co.nz) will give lots of links.

The aerial is just to get a reliable signal through a couple of walls in her house. Would the USB wok be the best (or easiest) option? She has a USB adaptor in the computer closest to the router & a PCI wifi card in the other one.

Graham L
15-02-2007, 11:15 AM
I think it's easiest and cheapest (and most likely to be successful) to try a reflector before anything else.

If both computers are on the same side of the router, a simple sheet of cardboard covered with aluminium foil "behind" the router antenna(e) will double the field strength in "front" of it. The curious ways that very high frequencies propagate in non-freespace environments might even let this work even if they are on opposite sides of the router. Try different orientations.

Stan's wire strainer paraboloc reflectors worked across the Wellington harbour; you don't need anything like that amount of signal strength enhancement.

Rob99
15-02-2007, 11:25 AM
What is the access point, you can do a boost with a firmware update on certain models.

Greven
15-02-2007, 05:35 PM
It is a belkin router - she got the belkin wireless starter kit with a wireless router & USB wifi adaptor. The computers are on opposite sides of the router.

Graham L
18-02-2007, 01:37 PM
If the router has two antennae,you could try a reflector placed between them. :D That would give two beams ... each a bit stronger than the omni radiation normally produced. If there'sonly one antenna (or anyway) I'd try a reflector, and experiment to find the orientation which gives the best results.This direction is unlikely to be exactly towards either of the computers. ;)

Greven
18-02-2007, 01:50 PM
After using the wireless for a while with both computers in the same room as the wireless router, she has decided it isn't fast enough. Not a big loss though - wireless routers aren't much more expensive than ones without wireless & now she has a USB wifi adaptor that visitors can plug into their laptops & get on the network without much messing around.

I expected 802.11g to provide more than enough speed to stream videos (movies & music videos) to the computer by the TV, but they lag when going through the wireless & they don't lag when going though the cat5.

godfather
18-02-2007, 03:48 PM
"Allthread" is lengths of threaded rod, available from any Mitre 10, Bunnings etc. It is exactly what it says, a rod of "all thread". Not sure how you could misinterpret the name really.

Its not a bolt, its long lengths of threaded plated steel in various diameters, you buy the nuts and washers to suit. Not expensive either.

I use it when I cannot get the right lentgth of bolt, just cut it to suit and put a nut and washer at each end.

Graham L
19-02-2007, 04:08 PM
I've always known that product as "screwed rod", because that's what it is. Great for making U-bolts. :cool: "Allthread" looks as if it might be a tradename.

godfather
19-02-2007, 08:51 PM
I know a man that goes by that very name.
I prefer allthread...