[Hackrf-dev] HackRF Oddity @ 1090mhz

[Russell Hande]

After contacting Mr. Ossmann on Twitter, he requested I post this here.

I found this while attempting to port ADSB# to support HackRF. While I
did manage to get it to work a little bit, it is extremely unoptimal
(the same antenna with an RTLSDR will get 100+ frames/sec, whereas
with the HackRF I am lucky to get 5-7)

I decided to investigate this with SDRSharp, and think I found the
reason. The following video pretty much shows it all. Ignore the blip
at 26 seconds, as it is a local FM station (I'm about 1.5 miles from a
3kW broadcast tower broadcasting on 93.5mhz, it happens sometimes
since I have my FM trap off)

This only appears to happen using 2 MSPS, which we know is not within
spec, however, it only happens at this frequency (I can use 2 MSPS
with great success elsewhere in the spectrum, such as HF, or 2m band)

The odd part is towards the end of the video, I adjust the center
frequency by 1kHz, and it stops.

http://youtu.be/szjBRjLleH0 (there is no audio on the video, this is
intentional)