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Re: Local Noise on 2.4 GHZ



Sounds like a wireless LAN or possibly pager/Cordless Phone.
Lots of Spread Spectrum and lower power consumer stuff up there!

73

----------
>From: ken durham <kendurham@attbi.com>
>To: amsat bb <amsat-bb@AMSAT.Org>
>Subject: [amsat-bb] Local Noise on 2.4 GHZ
>Date: Mon, Dec 24, 2001, 14:14
>

>Most of the time the AO-40 S downlink is wiped out by
>some kind of noise on the entire 2.4 GHZ  band here. 
>
>I can't seem to locate the direction with the dish. It peaks
>nearly at many different directions and occurs every
>few KHZ across the band, with a VERY strong
>signal at 2402.505. It may actually peak at another 
>freq. outside of the ham band.
>
>There are times when the noise
>stops suddenly for a few minutes or more. It has a 
>buzz like a sawtooth wave at about 120 HZ much like
>power line noise. 
>
>I have tried attenuating the signal to see if the receiver or
>downconverter/pre amp is being overloaded. The noise still
>can't be pinpointed in either plane.
>The peaks are 20db over S9 and the valleys are about S9
>when hunting it with the dish while listening to 2402.505
>with no attenuation.
>
>My dish is 60' from the house and up 30' above ground, so 
>it should be out of the near field of any noise from the computer.
>If it were coming from the computer, I should be able to point
>the dish toward the house to peak the noise. It doesn't appear
>to be coming from the house.
>
>This may be something simple that I've overlooked, but it
>is a problem when trying to work AO-40, causing lost QSO's
>whenever the noise starts up.
>
>I live in Dallas, TX and there are a LOT of RF sources here.
>
>Can anyone tell me what this noise could be or how to pinpoint
>it?
>
>Ken
>
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----
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