[Hackrf-dev] HackRF Jawbreaker Bugs

[Russell Hande]

One more bug that I haven't detailed is the offset, because I haven't
narrowed it down just yet. The offset appears to be variable. By
offset, I mean the tuned frequency's offset from the actual carrier
signal. Down in HF it can be as low as 100hz, up in the 2m band it can
be as much as 500-900hz off. This is variable in the fact that the
offset is different at different frequencies. There is no warm up
time, since it is digital, and not a true crystal oscillator. Thus
this happens if the HackRF is run for 5 seconds or 5 hours.

For example, a local ham repeater tower here is at 147.210mhz, however
to tune where the carrier is directly centered, I have to tune to
147.2109mhz. (+900hz offset)
Shortwave station 15.610mhz is centered on the carrier at 15.6101mhz.
(+100hz offset)

If I had to guess it would be a mathematical problem in the firmware,
since the manufacture of the clockgen chip claims 'precise 0ppm
accuracy' . But this is speculation.

On Sat, Aug 3, 2013 at 3:08 PM, Michael Ossmann <mike at ossmann.com> wrote:

> Thanks for your detailed tests, Russell!  I won't have time to go

> through them all until I'm back home in a few days, but I greatly

> appreciate your efforts to help make HackRF better.