View WiFi spectrum without switching noise

[aaron_do]

Hi all,


I want to view the spectrum from my Wifi radio card, but I don't want all of the switching noise. i.e. I only want the spectrum during the actual transmit intervals. Can anybody recommend the best possible way to do this, even if it requires expensive equipment? I understand it may require some kind of gating technique in the spectrum analyzer......


thanks,
Aaron

 

[BradtheRad]

There is a 'poor man's spectrum analyzer' on the internet.

Do you have a way to make the wifi transmit continuously for a long time? I think that's what you need to do, to gather data uninterrupted across an entire frequency range.

 

[aaron_do]

I have a spectrum analyzer. The problem is exactly that I can't make the wifi transmit continuously. So how do I view the spectrum? With the Wifi signal turning on/off all the time, the switching can be seen as a modulation to the actual Wifi signal, and it causes the sidebands to look much worse than they actually are.

regards,
Aaron

 

[BradtheRad]

It will keep a wifi active for a long time, if you download a long video. I have obtained hours-long videos (mostly Youtube) via this download site:

en.savefrom.net

1) Copy a desired Youtube link.
2) Paste it where the field says 'Just insert a link'.
3) Click the arrow at the right.
4) The site takes a few seconds to search for the video.
5) If it is successful, then it displays several formats.
6) If 'MP4 720p' is available then I choose that.

The bulk of wifi time is occupied by the router transmitting the file to the computer. From what I understand my computer transmits momentarily after each packet. It sends 'received' or else 'send again'. This takes a tiny percentage of wifi time.

 

[The Electrician]

This will do what you want: https://www.tek.com/datasheet/rsa306b-usb-real-time-spectrum-analyzer

or if you really don't care what it costs: https://www.rohde-schwarz.com/us/product/fsvr-productstartpage_63493-11047.html