Well here is a little more info. A quick google search for linksys external antenna gave me PAGES of links to go to where they had external antenna setups and discussions, I'm guessing those weren't what you wanted.
I was told by another wireless LAN radio manufacturer that it was not a good idea to more the two antennas very far apart. Appartently the technology used is a diversity system, where the signal strength from each antenna is compared very rapidly and electronicaly switched to the strongest antenna. It was explained to me that it was not a good idea to use diversity with the antennas separated farther than designed. I've not confirmed this, so I have no idea if it is even an issue. However, it was brought to my attention by the technical people at Cisco.
Now, assuming you want to extend the antenna, lets just review a couple quick things. If you add feedline, you add attenuation, which reduces signal strength. Depending on the type and length of the feedline, this can make a huge difference. Now, the practical way to make up for that loss is to add gain at the antenna. Alternatively you could add an amplifier, but that gets spendy.
So, lets say you just take your existing antenna that comes with the radio, add a 25' piece of RG58 type coax, and relocate it. Assuming good quality feedline such as LMR-195, 25 feet will give you about 4.5dB of attenuation. A 3db attenuation would cut your signal in half, so you can see this is going to reduce your overall signal. Now if we use LMR-400 coax, the attenuation is only about 1.5dB for the 25 feet.
Now for an antenna, if you were to select an antenna with 5db gain or so, you can see that we get some of that loss back, by adding gain. So if you put 25' of LMR-400 with a 4.5db loss, and a 5db gain antenna, you can actually gain .5 db in theory.
Lot's of options for this type of an arrangement, I would make sure that the access point is located as high as possible, and I would experiment with the orientation of the antennas. If, for example, the antenna in your wireless card is at a horizontal orientation and the AP antennas are vertical, you can experience a difference of 20 dB just with the two different polarizations. So, set the latptop up where you use it, monitor the signal strength, and try re-orienting the antennas on the AP for maximum signal strength.
Good Luck! It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
