Wifi Antenna

[t0bytoo]

Hello. I need to get a better antenna for my Netgear wireless router. The off the shelf jobbie is, I think, 2db.

Any recommendations / places to buy.

Thx

[fiddleabout]

There have been some on eBay in the past.

One thing you need to be sure of is the connector - there are some really weird and wonderful ones out there - not sure about Netgear but my Linksys uses a reverse TNC which are about as common as rocking horse sh1t.

If you want directional gain there are a lot of designs for homebrew stuff on the web. If you need omnidirectional coverage there is more limit on the gain than the claims of manufactures. About the maximum practical vertical aerial would be something called a 7/8 wave. More common would be 5/8 - neither actually offer much gain over what you have assuming that the cheating manufacturer is quoting gain over isotropic instead of gain over dipole.

[mikethebike]

fiddle.....sounds like you know what your talking about...not bad for a dinosour!

[roger rabbit]

Nah mike. Fiddle don't know diddly about radios. I know this because threaded (who tutored Marconi I believe) said that when it comes to radios fiddle is a real ham.

[fiddleabout]

Here's a professionally made one

www.cisco.com/univercd/cc/td/doc/product/wireless/acessory/ant24120.htm#wp34329

It offers good gain but is unlikely to enhance your home (which is why I said anything of any size is impractical) being designed for outdoor freespace mounting it would not be likely to perform to specs if mounted indoors.

I would mention that I used to earn a crust designing telecoms aerials before moving into IT but nobody would believe me

[t0bytoo]

cheers

I ordered a couple of cheapy 5db replacements off ebay. Will see how they work out.

[fiddleabout]

Re: cheers

Good luck.

Are you using 11b or 11g - they both drop speed in chunks as the signal deteriorates but my personal experience found the usable range to be better with 11g (probably because it starts off faster)

I was toying with the idea of a better aerial on my AP/router (which is why I know about ebay and the connector) but at the time I only found stuff which you use to boost PCI card aerials by the simple expedient of putting one on the desk instead of hanging amongst all the cables at the back of the PC - they were all sma connectors so I didn't bother in the end.

[zeitghost]

Re: cheers

I was wondering how they got 12dBi gain and omnidirectional.

It's a colinear.

I remember buying one of those for 458MHz.

It was enormous, about 12 feet long.

And when pressed into service about a year later, didn't work.

Bummer.

[dazza12]

Re: cheers

Where's threaded when you need him?

Might be worth moving this topic into General. I'm sure we'd be very entertained by his wealth of knowledge on the subject.

[fiddleabout]

Re: cheers

The other thing to remember about any high gain omni is that the vertical pattern has to be reduced (the gain has to come from somewhere) so these may not work well in multi-story buildings.

Home-brew is the way to go provided you can get the connector - that way you can experiment with what works best at minimum cost. There are oodles of ham radio designs which can simply be scaled for the frequency you want (provided you select something relatively close). They will be far from perfect if you have no test gear but are unlikely to damage the low power transmitters in WiFi APs.

I'd try simple bodges to start with using a bit of stiff wire. The main problem would be making something that the little lady would allow in the house - most home-brew ain't pretty

You can make a colinear out of a length of coax shoved inside a bit of pipe (possibly lossy) or simply hung from the ceiling.