NetStumbler.org Forums - View Single Post - how do i find out how much db my antenna is

lincomatic · 07-25-2002

if you're getting interference, it will probably show up as a higher noise figure. try changing channels from 1 to 6 to 11 (these are the only 3 non-overlapping channels) and see if the noise level goes down with any of them. hopefully, it's not wideband noise that would pollute all of the channels.

also, when measuring the gain of an antenna make sure you don't do it inside...the reflections from the walls will skew your readings quite a bit. the ideal setup is to have both the AP and card outside in an open area w/ less reflections, but if not, at least take the client machine outdoors.

which brings to mind yet another question for anyone who knows... what is a better indication of gain, increased SNR or increased signal. i've noticed that when i use a good antenna sometimes the SNR goes up more than the signal because the noise also goes down.

07-25-2002	#4 (permalink)
lincomatic Squaaawk! WiFi! WiFi! Join Date: Apr 2002 Location: Tinsel Town Posts: 1,682	if you're getting interference, it will probably show up as a higher noise figure. try changing channels from 1 to 6 to 11 (these are the only 3 non-overlapping channels) and see if the noise level goes down with any of them. hopefully, it's not wideband noise that would pollute all of the channels. also, when measuring the gain of an antenna make sure you don't do it inside...the reflections from the walls will skew your readings quite a bit. the ideal setup is to have both the AP and card outside in an open area w/ less reflections, but if not, at least take the client machine outdoors. which brings to mind yet another question for anyone who knows... what is a better indication of gain, increased SNR or increased signal. i've noticed that when i use a good antenna sometimes the SNR goes up more than the signal because the noise also goes down. __________________ ~lincomatic Last edited by lincomatic : 07-25-2002 at 11:39 PM.