Posted: Tue Jun 13, 2006 16:08 Post subject: 9dBi Rubber Duck Antenna - Anyone use it?
I've been thinking of upgrading to this instead of using the 2'ish dBi antennas that come with the wrt54gl. We have a linksys high-gain kit here at the office, but if I can save $10+ and also get better gain out of the antenna, I think that these would be the choice. You can find them here
I'm using 2 sets of antennas that look just like these (around Christmas they were free with the purchase of a WRT54G/GS from a local retail electronics store), and they definitely improved my signal strength. (My antennas were in store-branded packaging but I think they're probably the same thing FAB is selling.) As far as getting more gain goes, their '9dbi' rating might be a little exaggerated, so they may not perform much differently than the Linksys kit.
Ok, I'm not too big on wireless, when you say that you don't need a pair, and that I might benefit from one 9dBi and one 2.2dBi, as opposed to two 9dBi antennas, what's benefit of the two seperate antennas? I'm sorry for the noob questions, but this is my first venture into wireless, and I'm sort of curious _________________ WRT54GL
4xConnected wired nodes (2x pc 1x xbox 1x printer)
Joined: 07 Jun 2006 Posts: 88 Location: Reston, VA
Posted: Tue Jun 13, 2006 20:56 Post subject:
JamesCurtis wrote:
Ok, I'm not too big on wireless, when you say that you don't need a pair, and that I might benefit from one 9dBi and one 2.2dBi, as opposed to two 9dBi antennas, what's benefit of the two seperate antennas? I'm sorry for the noob questions, but this is my first venture into wireless, and I'm sort of curious
I suppose you could configure your advanced wireless settings to receive on the 9dBi and transmit on the 2.2dBi. The advantage I would see is that you would only have to purchase one package of two 9dBi antennas for every two routers (as opposed to two packages).
I'm not sure why performance would be better with this configuration...
I thought an antenna's sensitivity had more to do with its ability to receive signals rather than transmit them, but I'd welcome a correction (with explanation) on this thought.
$50 is really no big deal to me, but if I don't "need" to spend an extra $20'ish on one of the antenna's, i'll easily leave it out. Although the router would look funny with 1 large antenna and 1 tiny one ^.^ _________________ WRT54GL
4xConnected wired nodes (2x pc 1x xbox 1x printer)
Well, a lower dbi omni will have better vertical coverage than a high dbi omni which has a larger, flatter radiation pattern. Having different antennas might help in some situations, but I think you'll be looking at possible problems with the antenna diversity switch deciding which antenna to transmit on.
I use a pair of the Linksys 7dBi antennas and they seem to work great. The distance the laptop can travel before getting a degraded signal increased by about 50%. They're about $50 at Walmart for the pair with a nice plastic spacer thingy.
IN THEORY, the diversity chip should be able to utilize the strongest signal from either antenna. having two matched antennas means you probably will have very similar signals on both. having different gain (but both omni) means that it is very likely one will have a higher signal, and it could be the lower db gain antenna even!
that is the theory, but it is fairly well known the diversity chip in the wrt isn't the greatest quality. (hence lots of people outright removing the thing!) YMMV, it is certainly worth a try with the stock and 1 high gain omni.
the biggest problem with different antennas though is if you have multiple clients all generating a fair amount of traffic. the client on the lower db antenna might get the wrt to spend most of the time on that antenna, and not hear the other client in the process.
I have some of those 9 db antennas and they work great. I have a set of them on a wrt54gs and a set of the Linksys Highgain 7db models on a 2nd identical unit. The 9db set gets a better signal than the Linksys set which cost me twice as much.
If you want to know how they compare to the stock antennas the best way is to test for yourself. But, in comparing theoretical strength of the antennas, every 3 db doubles the signal strength, so this set is a little more than 4 times stronger than the stock antennas. _________________ *********************
DD-WRT v23SP2
WRT54GS 2.1 @ 216 Mhz
SD Mod w/ 512 MB Card & Dual Serial Ports
Normally I use 2 7dBi (17010.13xxx) as shown on http://www.wimo.com (no deep link possible). In order to get a higher gain to cover a whole floor I used two 15dBi omnis like:
http://www.fab-corp.com/product.php?productid=489&cat=250&page=1
I got severe package loss when using only one high gain omni and terminating the other antenna socket with and appropriate 50Ohm terminator. In order to reduce the interference of the 2 antennas between each other, one was pointing upwards, while the other was pointing downwards, with about a 20cm overlap (these babies are 96cm long!). This kind of positioning was no problem, because the omnis came with an N-plug and a pigtail adapter was needed anyhow (reducing the effectiveness of the antenna by nearly 2dB). Worked like charm, but had to be replaced by multiple WRTs and sector antennas, when too much metal 'debris' (including the wire mesh in the glas doors!) obstructed the radio waves. I did not kick out the diverity switch, because I do believe in spatial diversity, and it seems to do the trick, even with the sector antennas. Its a steep price to pay though.
Last edited by DrJunge on Thu Aug 10, 2006 10:56; edited 1 time in total
Posted: Fri Jun 16, 2006 15:15 Post subject: Re: 9dBi Rubber Duck Antenna - Anyone use it?
JamesCurtis wrote:
I've been thinking of upgrading to this instead of using the 2'ish dBi antennas that come with the wrt54gl. We have a linksys high-gain kit here at the office, but if I can save $10+ and also get better gain out of the antenna, I think that these would be the choice. You can find them here
I got a set that look and spec just like these for a challenging office environment (old mill building) and they were good for about 2x the area coverage of the stock kit. They were insufficient for other areas and I needed to get the $75 12db omnis for those. Big old WDS star. Much harder than shooting through trees outdoors because they won't let me use my chainsaw. _________________ Formerly participating under a pseudonym to counter an unjust Sveasoft practice.
I've been reading alot about these and everybody talks about long range... what i'd like to know is if anywone knows if this can go through hard stuff at short range ?
I'd like to share my connection with my Building neightbour (100ft. MAX) but the concrete walls makes it hard for the original antennas to reach at 251mW of xmit power.. I've ran outside and my signals gets to like 20 ft. of his router OUTSIDE his building... Do you guys think 9DBi antennas woul'd work through concrete ? And how many would I need ?