Hearing audio from across the spectrum

[nzradar]

I'm using an RTL-SDR v3 dongle in Direct Sampling mode and tuned to an HF frequency. I hear the signal of interest but I also get audio from signals across the band I'm tuned to!

[sq2mo]

Try applying a low-pass filter between the rtl-sdr and your antenna - helps for FM signals appearing on HF bands. Reducing the gain could also help, but since you're using direct sampling you probably won't have this option.