High gain 2.4ghz antennas

stevemcol

Hi. Has anyone any experience of high gain SMA wi-fi antennas. I'm thinking the 12dbi ones available on ebay for around a fiver.
Do they effectively improve range / reception or are they a gimmick?

I'm looking to use one to improve reception of my 2.4ghz CCTV but if they work well with wi-fi, it would give me confidence for my application.

Cheers

aerostar

I would say that the gain on these are very optomistic, for good gain one like this http://www.ebay.co.uk/itm/25dBi-2-4GHz-802-11b-g-Wifi-Yagi-Antenna-RP-SMA-WLAN-For-PCI-Card-Router-Modem-/251195952092?pt=UK_Computing_Boosters_Extenders_Antennas&hash=item3a7c720bdc at transmitting and receiver would give you good range and signal strength

Do a search on ebay for 2.4GHz Yagi

stevemcol

I was thinking something a bit more discreet.
http://www.ebay.co.uk/itm/12dbi-WiFi-Magnetic-Base-Omni-Antenna-Aerial-SMA-2-4GHz-/251135073650?pt=UK_Computing_Boosters_Extenders_Antennas&hash=item3a78d11d72

or

http://www.ebay.co.uk/itm/2-4GHz-Router-Network-WLAN-Antenna-Wi-fi-Aerial-RP-SMA-omni-signal-booster-boost-/281068748493?pt=UK_Computing_Boosters_Extenders_Antennas&hash=item417100becd

I already have a reasonable signal. Just trying to clean it up a bit.
Any good?

kwikbreaks

The way any antenna gives gain is by increasing the signal in one direction at the expense of others. A yagi like the one in the link will result in an improved signal where it points but reduced signal off the sides and back. The vertical antennas you see with gains quoted up to maybe 12dB achieve gain by reducing the power sent upwards.

So no it isn't a gimmick but you need to understand the limitations.

I think the quoted 25dB for that yagi is wildly optimistic if it is meant to represent gain over a dipole as are the 12dB values you see quoted for verticals. It will still give a worthwhile boost in the direction it's pointing though.

===

Ah I see you were looking at the verticals. If you use one expect to see the signal reduce on floors above or below where it is located. You can angle them up or down to counteract that a bit. Certainly with the verticals don't expect miracles.

You could always try a homebrew tinfoil reflector if your router is at one end of your property - http://www.freeantennas.com/projects/template2/index.html? - they work similarly to the yagis.

stevemcol

I'll give one of the smaller monopoles a go. I already angle the small vert antenna at 45° to get the best reception so expect these to be similar.
(tx is on the first floor, rx downstairs)

Thanks both.

kwikbreaks

Check the connectors carefully before you buy - especially make sure the router has a detachable one as some don't. Most are RP-SMA but there are the odd exceptions.

GunJack

I use a (stated)10dBi omni purchased from a hong kong seller, cost me all of £1.29 delivered, it just took 2.5 weeks to come. Works like a dream, did exactly what I expected it to do - nice increase of signal for mini-Gun #1's bedroom on top floor (3-storey house). Should be fine with those you're looking at.

mttylad

I have one similar to the one here and it improved things fine.

Certainly better than the little thing the router came with.

IMO getting a yagi inside a house is way over the top.

stevemcol

mttylad wrote: »

I have one similar to the one here and it improved things fine.

Certainly better than the little thing the router came with.

IMO getting a yagi inside a house is way over the top.

ordered! :cool:

stevemcol

Received in the post, up and running and a great improvement, thanks.