HackRF 2.4GHz

Hi all,

I’ve bought a HackRF and been playing around with it, but I thought
maybe someone could help me out with something. I’m trying to replicate
this ‘hack’, but then with the XN297 transceiver chip:
http://blog.ptsecurity.com/2016/06/phd-vi-how-they-stole-our-drone.html
At 2456MHz I do get a ‘similar’ graph as the one in that blogpost (see
pic 2). However, after demodulating, I get a rather messy output like
the one in pic 3. I use the same GRC setup as in the blogpost. Would
someone happen to know what I could be doing wrong?

Thanks in advance!