Just upgraded from RTL-SDR v3 to the new RTL-SDR v4 and I'm seeing some persistent DC offset issues when using GQRX. The RTL-SDR is recommended for beginners and those on a budget, but this DC spike right at the center frequency is making certain bands unusable. Has anyone found effective workarounds for the RTL2832U DC offset beyond the built-in correction? Running latest GQRX 2.17.5 on Ubuntu 22.04. Wondering if switching to CubicSDR or SDR# might handle this better, or if there's a filter setting I'm missing.

I had the exact same issue with my RTL-SDR v4. CubicSDR continues development and version 0.2.8-test3 works with RTL-SDR v4. Try the latest CubicSDR AppImage - it handles the v4 DC offset much better than GQRX in my experience.

Are you using the "Ignore DC spike" option in GQRX? Also try adjusting the RF gain to around 30-40 dB instead of max - sometimes AGC causes more DC offset issues with the newer dongles.

Consider adding a bias-T and DC blocking capacitor in-line if you're doing serious work. The RTL-SDR v4 is great for the price point but you'll hit these limitations compared to higher-end SDRs like the SDRplay or Airspy units.