I got the RPI4 and sold my RPI3 because I now have two SDR radios also running on it. For a little money I upgraded my RPI3 to RPI4 4GB.
Both radios work well in my RPI4 with this power supply.

Yes, I paid $50 for the power supply in order to get a linear power supply which injects much less noise in the SDR as I often listen it remotely on HF bands.

Quote Originally Posted by wiedehopf View Post
Is that power supply really $50? (shakes head in disbelieve)

Anyway get the official power supply for the RPi4, might just solve your problem.
Also if you are using an USB extension, just plug the dongle directly into the RPi.

Have you tried the sd-card in the RPi3?
There is really no need to go to the RPi4.