strange interference
Submitted by Hughe on Tue, 03/21/2006 - 18:04.
Any Idea what this interference is (around channel 8 )?
I've seen it in two different locations.
Could it be my laptop?
could it be a faulty dongle?
interference
If i switch to battery on my laptop it changes to:
battery
Sometimes it changes to something like this, and then back:
interference 2
I dont have bluetooth on my laptop, and its there with the wifi card and screen backlight turned off too.
It is normal and customary for the CPU board to have a crystal
oscillating at twice the speed of the CPU. They use either the rising
adge or the falling edge to clock the CPU. I was concerned about 900MHz
phones when average CPU speeds passed through that range, but I guess I
should have been doubly paranoid instead.
Yes it does look like interference from my laptop, although i'm not
sure what speed its actualy running at (AMD 3000+ mobile thing).
but more, it seems to be directly linked to what is showing on screen.
Lots of white has lots of wide band interference, lots of black is very
narrow band interference. I'm thinking it could be the
vgachip->flatscreen interfering with the USB (from memory they are
next to eachother on this laptop board)
in the third, i was watching a movie, and then switched back to the wi-spi window.
I'll try on another computer. i'm tempted try a usb extention with
choke filter round each end, but i'm not convinced that will filter
2.4ghz
This looks like real interference. The third image looks a lot like a
microwave, the first two look more like a Wi-Fi signal of some kind.
I have seen a constant signal at 2.400 GHz on a machine that was
running a 1.2 GHz CPU; this signal seemed to be leaking through the USB
connector.
The images above look like real data. One thing you might try is to run
Wi-Spy on another computer in the same location and compare screens to
see if the signal on channel 8 only shows up when Wi-Spy is running on
your laptop.
Ryan