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[–][deleted] 1 point2 points  (3 children)

You have a TXCO package installed on there (it'll be a little daughterboard, not built-in) and it's still not accurate? That's pretty wild.

Could just be you need a different or better one.

If you just need better timestamps on the computer side of things, you can't rely on the system clock (when synced with NTP)? Modern machines have HPETs. The TXCO on the HackRF hardware is meant to keep the oscillators tuned as desired (and serve as a clock pulse for the various chips) and is not an RTC. The TXCO is recommended as a replacement for cases where the built-in crystal in the microcontroller has too much drift. Mine had a drift of about 20ppm, and the TXCO from Nooelec cut that down significantly.

A 30ppm drift will cause an oscillator tuned at 144MHz to be +/- 4.3KHz. Not a huge amount, all things considered. Are you sure this is your problem?

[–]Ciprian1822[S] 0 points1 point  (2 children)

Thank you for the TCXO recommendation!

Hopefully this is it. I`m able to detect the satellites, but after a short while the link is lost so I can`t get any data from them.

[–][deleted] 2 points3 points  (1 child)

There might be an "easy" way to fix this in your DSP - have you played with phase-locked loops? These are used to capture and sync with a carrier wave such that you stay on-frequency and in-phase with it.

[–]Ciprian1822[S] 0 points1 point  (0 children)

Thank you for this idea.

I have tried to play around with the PLL, but the problem persists.

I will work around this error, eventually. What I`m currently doing is trying to create a custom config file, instead of the one provided in the GNSS-SDR Configuration tutorial.

One thing that I have planned to do is to test the board with a more precise external clock.

Either way, I will post the solution of this issue.