[Hackrf-dev] HackRF Jawbreaker Bugs

[Russell Hande]

I have not seen much discussion about actual hardware bugs, and in
light of the kickstarter, I wanted to post these videos demonstrating
a few issues I have ran into with my beta Jawbreaker, just in case
they are not known, so that they can be addressed before the final
product is created and released.

I have created an unlisted YouTube playlist, so that only those in
this list (and whomever you decide to share them with) can see these.

Don't get me wrong, I love my HackRF and appreciate the opportunity to
be in the beta program, but it is just that, a beta program. As a beta
tester I feel it is important to convey all bugs discovered :)

Here is the YouTube Playlist:
http://www.youtube.com/playlist?list=PL_HDx2US4_VnTErksPGfPaxFXsy2J_1i8


Here are the individual videos:

* Tuning glitch in upper frequencies:

Notice what happens when the center frequency rolls over at the MHz level.
This does not occur at lower frequencies, such as HF, FM, VHF, ect.

http://youtu.be/4v6ughu0pWU

* FM at 1.7ghz:

You don't see many FM stations because I have an FM trap installed,
but the entire 89-108 spectrum appears here. The tuning glitch
described above is also observed in this video.

http://youtu.be/aTucSSaTvuk

* 50mhz Noise:

I've contacted Mr Ossmann directly about this yesterday, but I wanted
to share with the mailing list as well. We know about the noise
induced by the system every 50MHz, but what is odd is if we use a
sampling rate below the specification of the chip (such as 2msps as
demonstrated in the video), the noise is significantly reduced.

http://youtu.be/Oy_yUJAFf04

*Super High Frequency tuning issue:

I don't even know how to describe this. Its like the tuning glitch
mentioned above got worse.

http://youtu.be/liXdkUHC6tk

---

Now, it is possible that the last glitch is caused by the SDRSharp
plugin, but I have modified it to use 64-bit ints rather than 32-bit,
so it should be properly sending 5ghz to the device. The tuning also
stops at 6800mhz, just like it does at 5mhz, so I don't think the
plugin is the problem. Especially when none of these issues (aside
from 50mhz noise obviously) happen in the HF/FM/VHF bands.

I'd just like to re-illiterate I am not complaining, I am reporting
these to try to help improve the final product. I welcome discussion
about these issues.