Didier Stevens

Sunday 2 August 2020

Videos: Defective USB Cable

Filed under: Hardware,video — Didier Stevens @ 0:00

When I had issues with my portapack, it took me some time to remark that these issues only happened with a particular USB cable.

The SDR would work fine, and then when I would try to record or playback, the screen would turn dark.

You can see this in the following video:

What is happening, is that this particular USB cable is electrically defective: the voltage drop is too large, due to the abnormally high resistance of the cable. The portapack doesn’t receive enough power, and starts to malfunction.

In the following 2 videos, I perform various tests with that defective cable:

Videos on my video blog (with some info on the devices I used):

Saturday 4 April 2020

Video: GNU Radio Companion: Acoustic Beats

Filed under: technology,video — Didier Stevens @ 13:39

In this video, I use GNU Radio Companion (without SDR) to illustrate the acoustic beat phenomenon.

I mention a 400Hz dial tone in this video, but this will vary by country.

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